The Tautomerism of Heterocycles: Five-membered Rings with Two or More Heteroatoms

[1]  Y. Terui,et al.  Thiol-disulfide exchange reactions of bis(methyl-1H-tetrazol-5-yl) disulfide studied by proton nuclear magnetic resonance spectroscopy , 1985 .

[2]  V. Kepe,et al.  Migration of an acyl group in the pyrazole system: synthesis of 1-acyl-3-hydroxy-1H-pyrazoles and related derivatives. A new preparation of N,N′-diacylhydrazines , 1998 .

[3]  R. N. Butler,et al.  A dipole moment study of annular tautomerism in 5-p-tolyltetrazole , 1980 .

[4]  V. Minkin.  Design of low-energy barrier intramolecular rearrangements by fitting stereoelectronic requirements of reaction paths , 1989 .

[5]  R. C. Mehrotra,et al.  Metal β-diketonates and allied derivatives , 1978 .

[6]  A. Katritzky,et al.  The chemistry of N-substituted benzotriazoles. Part 7. The isomeric composition and mechanism of interconversion of some N-(aminomethyl)benzotriazole derivatives , 1987 .

[7]  V. Pochinok,et al.  The Azidoazomethine–Tetrazole Tautomerism , 1975 .

[8]  J. Elguero,et al.  STRUCTURE OF 3-NITROPYRAZOLE IN SOLUTION AND IN THE SOLID STATE , 1997 .

[9]  J. Elguero,et al.  Systèmes aromatiques à 10 électrons π derivés de l'aza-3a pentalène. XVII. Tautomérie azido/tétrazole dans la série du pyrazole , 1974 .

[10]  J. Elguero,et al.  PACKING MODES IN EIGHT 3-ETHOXYCARBONYLPYRAZOLE DERIVATIVES. INFLUENCE OF THE SUBSTITUENTS ON THE CRYSTAL STRUCTURE AND ANNULAR TAUTOMERISM , 1999 .

[11]  T. W. Whaley,et al.  The pH dependence of nitrogen-15 NMR shifts and coupling constants in aqueous imidazole and 1-methylimidazole. Comments on estimation of tautomeric equilibrium constants for aqueous histidine , 1980 .

[12]  J. Simpson,et al.  Bromination of imidazole complexes of pentaammine-cobalt(III). Synthesis, structure and reactivity , 1991 .

[13]  J. Catalán,et al.  Importance of aromaticity on the relative stabilities of indazole annular tautomers: an ab initio study , 1996 .

[14]  J. Muir,et al.  Structure of (2-benzoxazolethiolato)(triphenylphosphine)gold(I). , 1989, Acta crystallographica. Section C, Crystal structure communications.

[15]  E. Kleinpeter,et al.  Substituent effects on azido-tetrazolo equilibria — s-Triazolo/4,3-c/tetrazolo/1,5-a/pyrimidines , 1978 .

[16]  E. Pedersen,et al.  Heterocyclic studies. 2. 5‐Chloro‐1H‐1,2,3‐triazole‐4‐carboxaldehydes, preparation and rearrangement reactions , 1984 .

[17]  R. Flammang,et al.  CID experiments on C-aminotriazole , 1976 .

[18]  S. Misra,et al.  Synthesis, Characterization and Biological Activity of Co(II), Ni(II), Cu(II) and Zn(II) Complexes with Mercapto Thiadiazole , 1991 .

[19]  J. Elguero,et al.  THE STRUCTURE OF THE COMPOUNDS RESULTING FROM THE REACTION OF ARYLHYDRAZINES WITH DEHYDROACETIC ACID : AN NMR AND CRYSTALLOGRAPHIC STUDY , 1995 .

[20]  L. Taliani,et al.  Action des réartif's électrophiles sur les hydroxy‐3 thiadiazoles‐1,2,4 , 1979 .

[21]  D. H. O'brien,et al.  The Rearrangement of the trimethylsilyl group in (trimethylsilyl)pyrazoles , 1971 .

[22]  Tadashi. Sasaki,et al.  Tetrazolo-azido isomerization in heteroaromatics-III , 1971 .

[23]  M. Meyer.  Computational study of imidazole and methyl imidazoles , 1994 .

[24]  Geoffrey I. Webb,et al.  Applications of 15N NMR to a study of tautomerism in some monocyclic azoles , 1985 .

[25]  I. S. Kashparov,et al.  Heterocyclic pleiadiene analogs , 1971 .

[26]  A. Terzis,et al.  Cu(I) Complexes with heterocyclic thiones and triphenylphosphine as ligands. The crystal structure of [Cu(tzdtH)2 (PPh3)2]NO3 , 1989 .

[27]  J. Pommier,et al.  I. Synthese et structure , 1977 .

[28]  D. V. D. Helm,et al.  Structure of 6-azidotetrazolo[5,1-a]phthalazine, C8H4N8, isolated from the toxic dinoflaggelate Gymnodinium breve , 1985 .

[29]  J. Elguero,et al.  Solid state structure of NH-pyrazoles not easily amenable to crystal structure determinations: The case of 3(5)-phenyl-5(3)-methylpyrazole and 3,5-diphenyl-4-methylpyrazole , 1995 .

[30]  V. Enchev,et al.  A semiempirical and ab initio MO study of the tautomers ofN-unsubstituted pyrazolones [hydroxy pyrazoles] , 1992 .

[31]  G. Wilkinson,et al.  Cyclopentadienyl-triethylphosphine-copper(I) and bis-cyclopentadienylmercury(II) , 1956 .

[32]  R. Weiss,et al.  Synthesis, X-ray crystal structure, and magnetic and spectroscopic properties of a novel copper(I)–copper(II) cluster , 1980 .

[33]  A. D. Garnovskii,et al.  COMPETITIVE COORDINATION : AMBIDENT LIGANDS IN THE MODERN CHEMISTRY OF METAL COMPLEXES , 1997 .

[34]  J. Elguero,et al.  1,2-Proton shifts in pyrazole and related systems: a computational study of [1,5]-sigmatropic migrations of hydrogen and related phenomena† , 1998 .

[35]  R. Becker.  Theory and interpretation of fluorescence and phosphorescence , 1969 .

[36]  T. Sawada,et al.  Alkyl-substituted benzo[1,2-d :3,4-d' ]diimidazoles. Preparation and annular tautomerism , 1998 .

[37]  K. Bhattacharyya,et al.  Excited-State Intramolecular Proton Transfer of 2-(2'-Hydroxyphenyl)benzimidazole in Micelles , 1995 .

[38]  J. Vilarrasa,et al.  MNDO semiempirical and 4-31G ab initio SCF-MO calculations of heteroaromatic compounds , 1985 .

[39]  R. Faure,et al.  Systèmes aromatiques à 10 électrons π dérivés de l'aza‐3a pentalène. IX—etude par RMN de l'équilibre azide/tetrazole dans le cas du tetrazolo [5,1‐b] benzothiazole , 1974 .

[40]  F. Peral,et al.  Self-association of imidazole and its methyl derivatives in aqueous solution. A study by ultraviolet spectroscopy , 1997 .

[41]  J. Siegel.  Mills—Nixon Effect: Wherefore Art Thou? , 1994 .

[42]  S. Kozima,et al.  Formation of organotin-nitrogen bonds , 1977 .

[43]  R. Osman,et al.  Molecular orbital studies of tautomerism in tetrazole , 1985 .

[44]  J. Elguero,et al.  Etude dans la serie des organogallylazoles I. Synthese et structure , 1981 .

[45]  J. Elguero,et al.  Substituent effects on the 15N NMR Parameters of Azoles , 1997 .

[46]  G. Pappalardo,et al.  A theoretical and experimental dipole moment study of annular tautomerism in tetrazole , 1982 .

[47]  A. Katritzky,et al.  Reactions of 1-(.alpha.-alkoxyalkyl)- and 1-(.alpha.-(aryloxy)alkyl)benzotriazoles with the Grignard reagents. A new and versatile method for the preparation of ethers , 1989 .

[48]  M. Voronkov,et al.  X-ray diffraction examination of the molecular structure of guanazole (3,5-diamino-1h-1,2,4-triazole) , 1979 .

[49]  Z. Smedarchina,et al.  Golden rule study of excited-state proton transfer in 2-(2-hydroxyphenyl)benzoxazole and 2-(2-hydroxy-4-methylphenyl)benzoxazole , 1993 .

[50]  D. Beke.  Heterocyclic Pseudo Bases , 1963 .

[51]  L. Párkányi,et al.  SYNTHESIS AND STRUCTURAL STUDY OF AZIDONAPHTHO-AS-TRIAZINES. “ANNELATION EFFECT” IN AZIDE-TETRAZOLE EQUILIBRIA , 1985 .

[52]  G. M. Kheifets,et al.  Study of Tautomerism by Nuclear Magnetic Resonance Spectroscopy , 1972 .

[53]  P. K. Walsh,et al.  Picosecond kinetic and vibrationally resolved spectroscopic studies of intramolecular excited-state hydrogen atom transfer , 1989 .

[54]  A. Heller,et al.  Intramolecular proton transfer reactions in excited fluorescent compounds , 1970 .

[55]  K. Pihlaja,et al.  Direct NMR spectroscopic proof for the ring-chain tautomerism in the thiazolidine system , 1988 .

[56]  V. N. Babin,et al.  1H and 13C NMR study of tautomerism in azoles—I : Proton transfer in the absence of solvation , 1975 .

[57]  K. Lempert,et al.  The annular desmotropy of S-methyl-5,5-diphenyl-2-thiohydantoin , 1973 .

[58]  J. Bravo,et al.  Tautomerism in coordinated 1-phenyl-5-thione-1,2,3,4-tetrazole (HL) Synthesis and crystal structure of [SnMe2(phen)L2] (phen = 1,10-phenanthroline) , 1996 .

[59]  P. Steel,et al.  Heterocyclic tautomerism. VI. A redetermination and reassignment of the structure of 2‐aminothiazol‐4(5H)‐one (pseudothiohydantoin) , 1994 .

[60]  D. White,et al.  Oxidation of Triarylimidazoles. Structures of the Photochromic and Piezochromic Dimers of Triarylimidazyl Radicals1 , 1966 .

[61]  A. V. Kessenikh,et al.  15N NMR spectroscopy of 5-(2-heteroaryl)formazans and their zinc and cadmium chelates , 1995 .

[62]  R. Shunmugam,et al.  Vibrational spectra of imidazoline-2-thione and imidazoline-2-one , 1987 .

[63]  J. Elguero,et al.  Molecular structure and dynamics of C-1-adamantyl substitutedN-unsubstituted pyrazoles studied by solid state NMRspectroscopy and X-ray crystallography , 1997 .

[64]  Thomas Elsaesser,et al.  FEMTOSECOND STUDIES OF VIBRATIONALLY HOT MOLECULES PRODUCED BY INTRAMOLECULAR PROTON TRANSFER IN THE EXCITED STATE , 1995 .

[65]  Alan R. Katritzky,et al.  Ring-Chain Tautomerism , 1985 .

[66]  V. Stefani,et al.  COMPUTATIONAL STUDY OF THE EXCITED STATES OF 2,5-BIS(BENZOXAZOL-2'-YL)-HYDROQUINONE AND ITS MONOMETHOXY DERIVATIVE , 1997 .

[67]  Alan R. Katritzky,et al.  Isomerizations of N-(α-aminoalkyl)-1,2,4-triazoles and N-(α-aminoalkyl)tetrazoles , 1990 .

[68]  B. Y. Simkin,et al.  The concept of aromaticity in heterocyclic chemistry , 1993 .

[69]  N. Shimba,et al.  Determination of Protonation and Deprotonation Forms and Tautomeric States of Histidine Residues in Large Proteins Using Nitrogen−Carbon J Couplings in Imidazole Ring , 1998 .

[70]  F. Fülöp,et al.  Recent Developments in Ring-Chain Tautomerism II. Intramolecular Reversible Addition Reactions to the C=N, C=N, C=C, and C=C Groups , 1996 .

[71]  S. Kennedy,et al.  The electronic structure of heteroaromatic molecules; ab initio calculations and photoelectron spectra for the aza derivatives of benzo[c] furan, benzo [c] thiophen, N-methyl isoindole and related compounds , 1978 .

[72]  G. Webb,et al.  A 15N NMR Study of the Tautomeric Equilibria of Some 5-Substituted Tetrazoles , 1986 .

[73]  Donald G. Truhlar,et al.  Correlation and solvation effects on heterocyclic equilibria in aqueous solution , 1993 .

[74]  W. Freyer.  Pyrazolonderivate. IV [9]. Zur Tautomerie und Stereochemie von 4‐Aminomethylen‐Δ2‐pyrazolinonen‐(5) , 1978 .

[75]  E. Alcalde,et al.  Imidazo[1,2-a]tetrazole and tetrazolo[1,5-a]benzimidazole , 1975 .

[76]  D. M. Forkey,et al.  Mass spectrometry of methyltetrazoles , 1969 .

[77]  A. Maquestiau,et al.  Fragmentation de Triazoles sous l'Impact Electronique–III Benzotriazole et Derives Alkyles , 1973 .

[78]  Robert N. Muller,et al.  Equilibre prototropique de 4-acylisoxazolin- et pyrazolin-5-ones , 1975 .

[79]  P. Camps,et al.  Effect of N‐substituents on the 13C NMR parameters of azoles , 1988 .

[80]  H. Reimlinger.  1.5-Dipolare Cyclisierungen, I. Begriffsbestimmung und Beiträge zur Imidazid/Tetrazol-Tautomerie , 1970 .

[81]  J. Elguero,et al.  13C NMR chemical shifts of N-unsubstituted- and N-methyl-pyrazole derivatives , 1984 .

[82]  J. G. Haasnoot,et al.  Synthesis and characterization of orthometalated rhodium(III) complexes containing substituted triazoles , 1991 .

[83]  W. Holzer,et al.  4-Acyl-5-methyl-2-phenylpyrazolones: NMR and X-Ray Structure Investigations , 1999 .

[84]  D. Kocjan,et al.  Ab initio calculations on the hydration of dimethylpyrazole and indazole. Solvent effects on tautomeric energies. , 1988 .

[85]  V. N. Babin,et al.  Proton-transfer reactions in azoles , 1977 .

[86]  J. Elguero,et al.  AN EXPERIMENTAL APPROACH TO THE MILLS-NIXON EFFECT : TAUTOMERISM OF 3(5),4-POLYMETHYLENEPYRAZOLES , 1994 .

[87]  J. Catalán,et al.  New ultraviolet stabilizers: 3- and 5-(2'-hydroxyphenyl)pyrazoles , 1992 .

[88]  G. Webb,et al.  An investigation of the tautomeric equilibria of some 3‐hydroxyindazole derivatives by 15N NMR spectroscopy , 1985 .

[89]  R. N. Butler.  Recent Advances in Tetrazole Chemistry , 1977 .

[90]  N. Ernsting,et al.  Singlet excited-state intramolecular proton tranfer in 2-(2t'-hydroxyphenyl) benzoxazole: Spectroscopy at low temperatures, femtosecond transient absorption, and MNDO calculations. , 1992 .

[91]  P. D. Maria,et al.  Tautomerism of aminothiazoles. pKBH+ Values of 2-aminothiazoles and of some model imines , 1982 .

[92]  Vladimir I. Minkin,et al.  Ligand environment and the structure of schiff base adducts and tetracoordinated metal-chelates , 1993 .

[93]  C. Párkányi,et al.  AN HMO STUDY OF THE AZO-HYDRAZONE TAUTOMERISM IN DIAZONIUM COUPLING PRODUCTS OF 5-ISOXAZOLONES , 1980 .

[94]  K. Davarski,et al.  Structure of bis(2‐aminothiazole)dichlorozinc(II) , 1993 .

[95]  J. Catalán,et al.  Influence of lone pair repulsion vs resonance energy on the relative stabilities of molecular structures : a theoretical approach to the equilibrium between 1H- and 2H-benzotriazole tautomers , 1994 .

[96]  R. Taft,et al.  Electrostatic proximity effects in the relative basicities and acidities of pyrazole, imidazole, pyridazine, and pyrimidine , 1986 .

[97]  C. Wentrup.  Hetarylnitrenes—II : Azido/tetrazoloazine tautomerisation, and evidence for nitrene formation in the gas-phase , 1970 .

[98]  S. M. Ramsh,et al.  NMR spectral study of the structure of 2-amino-4-thiazolinones , 1986 .

[99]  L. Forlani.  Tautomerism of some amino aza-containing heterocycles , 1992 .

[100]  David M. Miller,et al.  Tautomeric Equilibria of 3-Hydroxypyrazole in the Gas Phase and in Solution: A Theoretical Study Combining ab Initio Quantum Mechanics and Monte Carlo Simulation Methods , 1994 .

[101]  B. Alcaide,et al.  Reaction of .alpha.-diketones with 2-amino alcohols. Intramolecular competitive 6-exo-trig vs 5-endo-trig processes. A systematic and kinetic study , 1992 .

[102]  F. Zerbetto,et al.  Microwave spectrum and ab initio calculations of indazole , 1992 .

[103]  A. Terzis,et al.  Synthetic and structural chemistry of nickel(II)/1-methylbenzotriazole complexes , 1994 .

[104]  A. Tkachev,et al.  New pyrazole-, isoxazole- and N-acylpyrazoline derivatives with a pinane carbon frame , 1996 .

[105]  V. V. Alekseev,et al.  Ring-chain isomerism (tautomerism) of functionally substituted hydrazones (review) , 1988 .

[106]  J. C. Martin,et al.  Silane inversion catalyzed by weak nucleophiles: pseudorotation of 10-Si-5 intermediates , 1985 .

[107]  R. Boese,et al.  The First Monomeric Diorgano(pyrazolyl)borane: A Nonclassical Boronium Ion in Solution? , 1990 .

[108]  A. Whittaker,et al.  Molecular Cocrystals of Carboxylic Acids. XIV* The Crystal Structures of the Adducts of Pyrazine-2,3-dicarboxylic Acid with 4-Aminobenzoic Acid, 3-Hydroxypyridine and 3-Amino-1,2,4-triazole , 1994 .

[109]  M. Palmer,et al.  The electronic structure of aromatic molecules: ab inito molecular orbital studies and photoelectron spectra for the aza-derivatives of indole, benzofuran and benzothiophen , 1978 .

[110]  T. Ueda,et al.  Spectroscopic proof for intermolecular or intramolecular hydrogen bonds in ketoenol tautomers of 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone , 1994 .

[111]  J. Elguero,et al.  Structure and Dynamics of 3,5-Di-tert-butylpyrazole Probed by Combined X-ray Crystallography and 15N Solid State NMR , 1995 .

[112]  L. Gagliardi,et al.  Microwave spectra of benzotriazole and pyrimidinotriazole , 1993 .

[113]  S. Zaidi,et al.  The nature of the complexes of 2,5-dimercapto 1,3,4-thiadiazole (bismuthiol)I)) with copper(I) and copper(II) , 1975 .

[114]  M. Kajitani,et al.  Keto and Enol Tautomers of 4-Benzoyl-3-methyl-1-phenyl-5(2H)-pyrazolone , 1995 .

[115]  A. Terzis,et al.  Synthesis and characterization of copper(I) halide complexes with heterocyclic thiones and triphenylphosphine as ligands. The X-ray crystal structure of copper(I) 1-methyl-1,3-imidazoline-2-thione bis(triphenylphosphine)bromide, [Cu(PPh3)2(meimtH)Br] , 1990 .

[116]  J. Elguero,et al.  Theoretical study of the azido-tetrazole isomerization , 1976 .

[117]  John D. Roberts,et al.  A nitrogen-15 nuclear magnetic resonance study of the acid-base and tautomeric equilibriums of 4-substituted imidazoles and its relevance to the catalytic mechanism of .alpha.-lytic protease , 1982 .

[118]  J. Bats.  The crystal structure of 2,5-dimercaptothiadiazole , 1976 .

[119]  C. Pettinari,et al.  Synthesis and characterization of some tin(II) and tin(IV) derivatives of 4-acyl-5-pyrazolones. Crystal structure of bis(1-phenyl-3-methyl-4-acetyl-pyrazolon-5-ato)tin(II) , 1994 .

[120]  U. Casellato,et al.  Preparation, characterization and crystal structure of tetrakis[1-methyl-2(3H)-imidazolinethione] dimethyltin(IV) nitrate , 1992 .

[121]  F. Cotton.  Fluxionality in organometallics and metal carbonyls , 1975 .

[122]  B. Jursic,et al.  WHY IS TETRAZOLE NOT PRACTICAL AS A DIENE IN DIELS-ALDER REACTIONS? AN AB INITIO THEORETICAL STUDY , 1995 .

[123]  T. C. Downie,et al.  The crystal and molecular structure of 5-amino-2-thiol-l,3,4-thiadiazole , 1972 .

[124]  Geoffrey I. Webb,et al.  15N NMR studies of the tautomeric equilibrium of some 1‐hydroxybenzotriazoles , 1985 .

[125]  G. Goetz-Grandmont,et al.  MOLECULAR MODELLING AND SPECTROSCOPIC STUDIES OF THE INTERACTIONS BETWEEN CHELATING AND ELECTRON-DONOR METAL EXTRACTANTS: THE SYSTEM TRI-N-OCTYLPHOSPHINE OXIDE - 3-PHENYL-4-BENZOYL-ISOXAZOL-5-ONE ( ‘HPBI‘ ) IN WET TOLUENE AND CHLOROFORM. , 1996 .

[126]  S. M. Ramsh,et al.  Structure and dual reactivity of 2-phenylpemoline , 1989 .

[127]  M. Nguyen,et al.  Theoretical study of the vinyl azide-.upsilon.-triazole isomerization , 1978 .

[128]  J. Vilarrasa,et al.  Diazo-, azo, and azidoazoles. 8. Effect of substituents on the 3-azidobenzo-as-triazine/tetrazolo[5,1-c]benzo-as-triazine/tetrazolo[1,5-b]benzo-as-triazine equilibrium , 1982 .

[129]  J. Elguero,et al.  Theoretical study of the structure and tautomerism of N 1 -unsubstituted pyrazoles in the solid state , 1997 .

[130]  A. Katritzky,et al.  The Chemistry of N-Substituted Benzotriazoles. Part 18. A Study of the Influence of Structure on the 1- to 2-(N,N-Dialkylaminoalkyl)benzotriazole Equilibrium , 1989 .

[131]  C. Silvestru,et al.  New organotin(IV) derivatives of 1-phenyl-1H-tetrazole-5-thiol. Crystal and molecular structure of 1∞[Bz3SnSCN4Ph], a polymer built through secondary intermolecular Sn⋯N bonds , 1994 .

[132]  W. L. Purcell,et al.  Solvent Effects on the Linkage Isomerization of the N1-Bonded Pentaamminecobalt(III) Complex of 5-Methyltetrazole , 1991 .

[133]  M. Amici,et al.  Nitrile oxides in medicinal chemistry-2. synthesis of the two enantiomers of dihydromuscimol , 1990 .

[134]  E. Shtefan,et al.  THE TAUTOMERISM OF HETEROCYCLIC THIOLS. FIVE-MEMBERED HETEROCYCLES , 1996 .

[135]  J. T. Edward,et al.  Thiohydantoins. IX. Tautomerism of some Methylation Products , 1972 .

[136]  W. Camp,et al.  The crystal and molecular structure of 3‐methyl‐3‐pyrazolin‐5‐one , 1971 .

[137]  Tatsuya Kawamoto,et al.  Carbon-Carbon Bond Formation in Helical Nickel(II) Complex, cis-Bis[2-N-(phenylmethylideneamine)benzenethiolato]nickel(II) , 1992 .

[138]  J. Elguero,et al.  Freezing of equilibrium of 1,2,3-triazole and 3(5)-methylpyrazole by complex formation with 1,1-bis(2,4-dimethylphenyl)but-2-yn-1-ol, and X-ray crystal structure of the complexes , 1988 .

[139]  A. Grabowska,et al.  Picosecond transient-absorption and gain spectra of the excited internally hydrogen bonded benzoxazole derivatives: experimental proof of the thermal activation of the intramolecular proton transfer , 1991 .

[140]  G. Jung,et al.  Benzotriazole 1‐oxide and 1‐hydroxybenzotriazole, C6H5N3O: structures of both tautomeric forms , 1983 .

[141]  J. Galigné,et al.  Structure cristalline et moléculaire du benzotriazole , 1974 .

[142]  C. Cogrossi.  Infrared spectra of some 1,3-dihetero-2-thio-4-carbonyl rings: 2-thio-4-keto-oxazolidines, 2-thio-hydantoins, rhodanines, 2-thio-4-keto-selenazolines , 1972 .

[143]  Dominique Bourgeon,et al.  Spectrométrie de Masse D'Hétérocycles Azotés. VI—Tautomérie en Phase Gazeuse d'Isoxazolones‐5 , 1977 .

[144]  J. Elguero,et al.  FLUOROPYRAZOLES : AN AB INITIO STUDY , 1999 .

[145]  J. Montgomery,et al.  STUDIES ON THE AZIDOAZOMETHINE-TETRAZOLE EQUILIBRIUM. I. 2-AZIDOPYRIMIDINES. , 1965, The Journal of organic chemistry.

[146]  A. D. Garnovskii,et al.  Novel Thiosalicylhydrazonates of Nickel(II) , 1991 .

[147]  Vladimir I. Minkin,et al.  Stereodynamics and degenerate ligand exchange in solutions of tetracoordinate chelate complexes of nontransition metals , 1994 .

[148]  V. P. Mamaev,et al.  1H and 13C NMR study of azido-tetrazole tautomerism of 2-azido-4-methylpyrimidine , 1990 .

[149]  C. Dardonville,et al.  An experimental (flash vacuum pyrolysis) and theoretical study of the tautomerism of pyrazolinones at high temperatures , 1999 .

[150]  W. Bachovchin,et al.  Direct observation of the tautomeric forms of histidine in nitrogen-15 NMR spectra at low temperatures. Comments on intramolecular hydrogen bonding and on tautomeric equilibrium constants , 1993 .

[151]  V. P. Mamaev,et al.  Use of 13C1H coupling constants for the investigation of azide—tetrazole tautomerism in aromatic nitrogen heterocycles. Detection of ditetrazolo [1,5‐a: 1′,5′‐c:] pyrimidine , 1988 .

[152]  R. M. Minyaev,et al.  Double proton shifts in associates of formic acid with hydrides of third period elements , 1996 .

[153]  K. S. Siddiqi,et al.  Spectral and magnetic studies on the complexes of 2,5-dimercapto-1,3,4-thiadiazole (bismuthiol I) with Co(II), Ni(II), Zn(II), Cd(II) and Hg(II) , 1977 .

[154]  E. S. Raper.  Complexes of heterocyclic thione donors , 1985 .

[155]  J. Elguero,et al.  Molecular structure and tautomerism of 3,5-bis(4-methylpyrazol-1-yl)-4-methylpyrazole , 1993 .

[156]  G. Valle,et al.  Organotin complexes with 1-methyl-2(3H)-imidazolinethione. The crystal structure of dichloro[1-methyl-2(3H)-imidazolinethione]dimethyltin(IV) , 1993 .

[157]  P. Wegner,et al.  1.3‐Cycloadditionen mit Trimethylsilyl‐azid; über isomere N‐Acetyl‐1.2.3‐triazole , 1966 .

[158]  A. Nesmeyanov.  Metallotropy and dual reactivity , 1975 .

[159]  F. J. Luque,et al.  Azidoazomethine−Tetrazole Isomerism in Solution: A Thermochemical Study , 1998 .

[160]  S. Trofimenko.  Polypyrazolylborates, a new class of ligands , 1971 .

[161]  G. Franchini,et al.  Tin (IV) tetrahalide complexes of 2,5-disubstituted 1,3,4-thiadiazoles , 1980 .

[162]  Robin K. Harris,et al.  NMR study of desmotropy in Irbesartan, a tetrazole-containing pharmaceutical compound , 1998 .

[163]  A. Katritzky,et al.  S,S'‐ and S,N‐disubstituted derivatives of 1,3,4‐thiadiazoledithiones , 1990 .

[164]  D. Goodgame,et al.  Synthesis and X-ray characterisation of some heterometallic Hg–M complexes with 2-oxazolidone , 1993 .

[165]  R. Leung-Toung,et al.  Tautomeric equilibrium and hydrogen shifts of tetrazole in the gas phase and in solution , 1993 .

[166]  A. Tempczyk,et al.  Application of mass spectrometry to the study of prototropic equilibria in 5-substituted tetrazoles in the gas phase; experimental evidence and theoretical considerations , 1983 .

[167]  A. Katritzky,et al.  Substituent effects in the bis(benzotriazolylmethylation) of aromatic amines , 1990 .

[168]  K. Akiyama,et al.  Excited triplet state generated from excited state intramolecular proton transfer in 2-(2′-hydroxyphenyl)benzothiazole , 1992 .

[169]  C. Dardonville,et al.  Tautomerism of 1-(2′,4′-dinitrophenyl)-3-methyl-2-pyrazolin-5-one: theoretical calculations, solid and solution NMR studies and X-ray crystallography , 1998 .

[170]  T. C. Downie,et al.  The crystal and molecular structure of 2‐mercaptobenzimidazole , 1976 .

[171]  M. Ríos,et al.  AB INITIO STUDY OF GROUND AND EXCITED STATE PROTON TRANSFER IN 2-(2'-HYDROXYPHENYL)BENZOXAZOLE , 1995 .

[172]  D. G. O'sullivan.  657. Vibrational frequency correlations in heterocyclic molecules. Part VI. Spectral features of a range of compounds possessing a benzene ring fused to a five-membered ring , 1960 .

[173]  F. Cotton,et al.  Stereochemically Nonrigid Organometallic Molecules, XXXII. The Rearrangement of Trimethylgermyl-N-Pyrazolides and N-Imidazolides , 1972 .

[174]  Tatsuya Kawamoto,et al.  Valence Isomerization. Synthesis and Characterization of Cobalt and Nickel Complexes with Non-Innocent N2S2 Ligand , 1997 .

[175]  T. Elsaesser,et al.  Excited-state proton transfer in 2-(2'-hydroxyphenyl)benzothiazole transient electronic absorption measured on the picosecond time scale , 1988 .

[176]  V. A. Zagorevskii,et al.  Tautomerism of 1-phenyl-3-methyl-4-benzyl-5-pyrazolone , 1991 .

[177]  D. Grant,et al.  Carbon-13 magnetic resonance study of solvent stabilized tautomerism in pyrazoles , 1977 .

[178]  P. T. Kaye,et al.  Tautomerism in 2-trichloro- and 2-trifluoro-acetamidothiazoles , 1982 .

[179]  S. Eaton,et al.  Inter- and intramolecular ligand exchange reactions of ruthenium(II) carbonyl porphine complexes with nitrogen bases , 1972 .

[180]  L. Brady.  Electron impact‐induced fragmentation of 5‐aminotetrazole , 1970 .

[181]  B. S. Garg,et al.  Synthesis and Spectral Characterization of Complexes of Sodium 2-[4-Amino-5-Mercapto-3-(1,2,4-Triazolylazo)] Naphthol-4-Sulphonate (Amtn-4S) with Cobalt(II), Nickel(II) and Copper(II) , 1988 .

[182]  J. Elguero,et al.  High resolution 13C nuclear magnetic resonance spectra of solid pyrazoles. Application to annular tautomerism , 1988 .

[183]  M. Yáñez,et al.  THE STRUCTURE OF AMINOAZOLES AND ITS RELATIONSHIP WITH AROMATICITY. CRYSTAL AND MOLECULAR STRUCTURE OF TWO POLYMORPHIC FORMS OF 4-AMINOPYRAZOLE , 1998 .

[184]  F. J. Luque,et al.  Theoretical Study of Azido−Tetrazole Isomerism: Effect of Solvent and Substituents and Mechanism of Isomerization , 1998 .

[185]  J. Tomasi,et al.  Electrostatic interaction of a solute with a continuum. A direct utilizaion of AB initio molecular potentials for the prevision of solvent effects , 1981 .

[186]  W. Reynolds,et al.  13C NMR investigation of tautomeric and acid-base equilibria of pyrazolone T and three analogs , 1991 .

[187]  J. Wiench,et al.  NMR study of some sydnones, isosydnones, and isothiosydnones , 1996 .

[188]  C. A. Ramsden,et al.  Preparation, structure and addition reactions of 4- and 5-aminoimidazoles , 1992 .

[189]  T. Dziembowska,et al.  Spectral investigations of the tautomeric equilibria of thioacyl derivatives of 2-aminothiazole and 2-aminobenzothiazole , 1988 .

[190]  D. Lesieur,et al.  Regioselective Acylation of Benzoselenazolinone , 1993 .

[191]  G. L'abbé,et al.  Synthesis of 1,4-disubstituted tetrazoline-5-thiones , 1976 .

[192]  José Elguero,et al.  Acidity and Basicity of Indazole and its N-Methyl Derivatives in the Ground and in the Excited State , 1994 .

[193]  M. Palmer,et al.  Assignment of the UV photoelectron spectra of the azoles by Ab initio multi-reference configuration interaction calculations , 1987 .

[194]  J. Metzger.  Thiazole and its derivatives , 1979 .

[195]  G. Adembri,et al.  Synthesis and properties of 5‐isoxazolethiols , 1967 .

[196]  K. Leander,et al.  Crystal Structure of Some Benzoxazoline Derivatives. , 1973 .

[197]  M. Mcpartlin,et al.  LIGAND REARRANGEMENT REACTIONS. AN UNUSUAL HYDROGEN TRANSFER REACTION PROMOTED BY ZINC(II) SALTS , 1977 .

[198]  K. Zeller,et al.  Photolyse von Naphth[2,3‐d]‐1,2,3‐oxadiazol — Ein Beitrag zum Oxiren‐Problem , 1994 .

[199]  A. Virovets,et al.  SYNTHESIS AND X-RAY CRYSTAL STRUCTURE OF NEW COMPLEX TRANS-DINITRODIAQUA-BIS(1-PHENYLTETRAZOLE) COPPER(II) , 1994 .

[200]  A. Katritzky,et al.  Synthesis, reaction, theoretical calculation, NMR study and X-ray crystal structure of 1-substituted and 1-unsubstituted 1H-pyrazol-5(2H)-ones , 1997 .

[201]  Y. Takeda,et al.  Structure elucidation of longikaurin A and longikaurin B, new biologically active diterpenoids from Rabdosia longituba and chemical conversion of oridonin into dihydrolongikaurin A , 1988 .

[202]  S. M. Ramsh,et al.  Structure of 2-amino-4-thiazolinone and its 2-aryl derivatives in the crystalline state , 1985 .

[203]  C. Dobson,et al.  Acid-base and tautomeric equilibriums in the solid state: nitrogen-15 NMR spectroscopy of histidine and imidazole , 1982 .

[204]  J. Elguero,et al.  The Unusual Properties of 5‐Methyl‐4,5,6,7‐Tetrahydro‐1H‐Indazole in the Solid State , 1997 .

[205]  M. Itoh,et al.  Photochemistry of transient tautomer of 7-azaindole hydrogen-bonded dimer studied by two-step laser excitation fluorescence measurements , 1987 .

[206]  N. Ernsting,et al.  State-selectivity of excited-state intramolecular proton transfer in a double benzoxazole: jet spectroscopy and semiempirical calculations. , 1992 .

[207]  M. Itoh,et al.  Transient absorption and two-step laser excitation fluorescence studies of photoisomerization in 2-(2-hydroxyphenyl)benzoxazole and 2-(2-hydroxyphenyl)benzothiazole , 1985 .

[208]  A. A. Konstantinchenko,et al.  Heterocyclic analogs of pleiadiene. 55. 2-Azidoperimidines: Stability of the tetrazole form , 1981 .

[209]  A. Neves,et al.  NMR and semi‐empirical study of the tautomerism of­2,2′‐bisbenzimidazolyl , 1998 .

[210]  J. Catalán,et al.  Structure of benzotriazole in the gas phase : a UV experimental study , 1993 .

[211]  J. Elguero,et al.  Tautomerism of NH-pyrazolinones in the solid state: the case of 3(5)-ethoxycarbonyl-5(3)-hydroxypyrazole , 1998 .

[212]  W. D. Krugh,et al.  The microwave spectrum of tetrazole , 1974 .

[213]  J. Elguero,et al.  Study of 1-hydroxybenzotriazole/benzotriazole N-oxide tautomerism in the gas phase by photoelectron spectroscopy , 1995 .

[214]  A. Schweig,et al.  IR and UV matrix photochemistry and solvent effects: the isomerization of diazocyclohexadienones (ortho quinone diazides) — detection of molecules with the 1,2,3-benzoxadjazole structure. A UV/Vis and IR absorption and UV photoelectron spectroscopic investigation , 1991 .

[215]  R. Hosmane.  An efficient, one-step synthesis of 2-imidazolin-4(5)-one , 1984 .

[216]  W. V. Philipsborn,et al.  15N‐NMR Spectra of Azoles with Two Heteroatoms , 1983 .

[217]  J. Elguero,et al.  Tautomerism and the Mills-Nixon-like effect in pyrazoles , 1997 .

[218]  M. Kuehne.  The Total Synthesis of Vincamine , 1964 .

[219]  J. Elguero,et al.  Observation of a series of degenerate cyclic double, triple, and quadrupole proton transfers in solic pyrazoles , 1992 .

[220]  R. Uggla,et al.  Benzotriazole Complexes. I. The Crystal Structure of Di-mu-chloro-bis[bis(benzotriazole)chlorocopper(II)] Monohydrate. , 1981 .

[221]  V. Kalcheva,et al.  2-Aminooxazoles and their derivatives (review) , 1981 .

[222]  John D. Roberts,et al.  Carbon-13 Magnetic Resonance Studies of Azoles. Tautomerism, Shift Reagent Effects, and Solvent Effects , 1974 .

[223]  N. M. Sergeyev.  Nuclear magnetic resonance spectroscopy of cyclopentadienyl compounds , 1973 .

[224]  J. Abboud,et al.  Basicity of C-substituted pyrazoles in the gas phase : an experimental (ICR) and theoretical study , 1992 .

[225]  R. Faure,et al.  Etude de l'équilibre azido ⇌ tétrazole dans la séric du thiazolo[2,3-e]-tétrazole. III. Effects des substituants† , 1977 .

[226]  J. Elguero,et al.  Host-guest chemistry. The structure and proton disorder of the three-component crystal formed by 3(5)-methyl-4-nitropyrazole, (R, R)-(−)-trans-4,5-bis (hydroxydiphenylmethyl)-2,2-dimethyl-1,3-dioxolane and toluene , 1996 .

[227]  P. Steel,et al.  Heterocyclic Tautomerism. II. 4-Acylpyrazolones. X-Ray Crystal Structures of 4-Benzoyl-5-methyl-2-phenylpyrazol-3(2H)-one and 4-Acetoacetyl-3-methyl-1-phenylpyrazol-5-ol , 1985 .

[228]  The Mills-Nixon effect on enol-enol tautomerism in β-dicarbonyl compounds and on annular tautomerism in NH-pyrazoles: A semi-empirical study , 1997 .

[229]  P. J. Taylor,et al.  The Prediction of Tautomer Equilibria in Hydrated 3-Hydroxypyrazole: A Challenge to Theory , 1993 .

[230]  P. Schleyer,et al.  On the Nature of Pyrazolylborane. An Ab Initio/IGLO/NMR Study , 1990 .

[231]  R. Valters.  Ring-Chain Isomeric Transformations of Hydroxy-, Amino-, and Mercapto-Derivatives of Carbonyl Compounds and Their Heteroanalogues , 1974 .

[232]  Kenneth B. Wiberg,et al.  Solvent effects. 1. The mediation of electrostatic effects by solvents , 1991 .

[233]  P. J. Taylor,et al.  The tautomerism of indazolinone in aqueous solution. A note on the ‘principle of vinylogy’ , 1996 .

[234]  S. Ham,et al.  Pericyclic and Pseudopericyclic Thermal Cheletropic Decarbonylations: When Can a Pericyclic Reaction Have a Planar, Pseudopericyclic Transition State?1 , 1997 .

[235]  J. Elguero,et al.  A 13C NMR spectroscopy study of the structure of N-H pyrazoles and indazoles , 1993 .

[236]  F. Isaia,et al.  2-S-Methyl-5,5-dimethylimidazolin-4-one: chemical behaviour and crystal structure of its Δ1 tautomer , 1991 .

[237]  M. Ōki.  Applications of dynamic NMR spectroscopy to the dissociation of chemical bonds in organic, organometallic, and coordination compounds , 1989 .

[238]  M. Orozco,et al.  Solvent effects on tautomerism equilibria in heterocycles , 1997 .

[239]  J. R. Bartels-Keith,et al.  Carbon-13 nuclear magnetic resonance studies of heterocycles bearing carbon-sulfur and carbon-selenium bonds: 1,3,4-thiadiazole, 1,3,4-selenadiazole, and tetrazole derivatives , 1977 .

[240]  A. Katritzky,et al.  A Novel Synthesis of tert‐ Alkyl Sulfides , 1991 .

[241]  S. Trofimenko.  The coordination chemistry of pyrazole-derived ligands , 1972 .

[242]  M. Mahon,et al.  Organotin(IV) derivatives of acylpyrazol-5-ones , 1996 .

[243]  A. F. Janzen,et al.  Hydrolysis and intermolecular silyl exchange in N-(trimethylsilyl)imidazole and N-(trimethylsilyl)-2-methylimidazole , 1976 .

[244]  K. Pihlaja,et al.  Ring-chain tautomerism in 1,3-thiazolidines , 1990 .

[245]  C. Pettinari,et al.  Tin(IV) and organotin(IV) derivatives of anionic 4-acyl-5-pyrazolonato ligands: synthesis, spectroscopic characterization (IR, far-IR, 119Sn mössbauer, 1H, 13C and 119Sn NMR) and behavior in solution crystal and molecular structure of trans-diphenylbis[1-phenyl-3-methyl-4-(4-bromobenzoyl) -pyrazolon , 1996 .

[246]  P. Cozzini,et al.  STRUCTURE OF 3-AMINO-4,5-DIHYDROPYRAZOLES IN ACID MEDIA : X-RAY STRUCTURE OF 3-AMINO-1-PHENYL-4,5-DIHYDROPYRAZOL-2-IUM PICRATE AND THE ORIGIN OF BROAD SIGNALS IN 1H NMR SPECTROSCOPY , 1995 .

[247]  W. Freyer.  Pyrazolonderivate. V [1]. UV-spektroskopisches und photochemisches Verhalten von N-mono- und N,N-disubstituierten 4-Aminomethylen-Δ2-pyrazolinonen-(5) , 1978 .

[248]  Richard Goddard,et al.  Pyrrole and a Co-crystal of 1H- and 2H-1,2,3-Triazole , 1997 .

[249]  J. Elguero,et al.  Freezing of equilibrium of 1,2,4-triazole by complex formation with 1,1-di(2,4-dimethylphenyl)but-2-yn-1-ol, and X-ray crystal structure of the complex , 1987 .

[250]  J. Abboud,et al.  Tautomerism and aromaticity in 1,2,3-triazoles: the case of benzotriazole , 1989 .

[251]  V. A. Shlyapochnikov,et al.  Investigation of the protolytic equilibria of nitraminotetrazoles in aqueous media , 1984 .

[252]  E. Jalviste,et al.  Spectroscopy of jet-cooled benzimidazole and benzotriazole , 1993 .

[253]  V. Zoete,et al.  Design, synthesis and antioxidant properties of ovothiol-derived 4-mercaptoimidazoles , 1997 .

[254]  A. Katritzky,et al.  Ab initio and semiempirical calculations on the tautomeric equilibria of N-unsubstituted and N-substituted benzotriazoles , 1990 .

[255]  E. Giorgini,et al.  Reactions of (tertiary phosphine)gold(I) substituted imidazoles or pyrazolones with acidic reagents: protonation, zole displacement, and adduct formation. Crystal structure determination of the adduct 1-methyl-2-(cyclohexylphosphinegoldthiolato)imidazole · 2benzimidazole , 1988 .

[256]  P. A. Harris,et al.  Propotropic tautomerism of heteroaromatic compounds , 1991 .

[257]  A. W. Baker,et al.  Intramolecular Hydrogen Bonding. II. The Determination of Hammett Sigma Constants by Intramolecular Hydrogen Bonding in Schiff's Bases , 1959 .

[258]  M. Vincent,et al.  Tautomerism of 1,2,3- and 1,2,4-triazole in the gas phase and in aqueous solution : a combined ab initio quantum mechanics and free energy perturbation study , 1990 .

[259]  A. Sousa,et al.  Electrosynthesis and studies of adducts of 2-amino-1-methylbenzimidazole with metal chelates based on 2-tosylamino-N-salicylideneaniline , 1996 .

[260]  R. Faure,et al.  Les benzazoles (indazole, benzimidazole, benzotriazole) structure moleculaire et proprietes fondamentales , 1974 .

[261]  Mark S. Gordon,et al.  Effect of Hydration and Dimerization of the Formamidine Rearrangement , 1991 .

[262]  W. Stadlbauer,et al.  REGIOSELECTIVE AZIDATION OF 2,4-DICHLOROQUINOLINES , 1994 .

[263]  M. Chanon,et al.  Electronic structure of sulphur compounds—VII photoelectron spectra of thiocarbonyl heterocycles , 1974 .

[264]  Donald L. Thompson,et al.  Crystal Packing and Molecular Dynamics Studies of the 5-Nitro-2,4-dihydro-3H-1,2,4-triazol-3-one Crystal , 1997 .

[265]  A. D. Garnovskii,et al.  Direct Evidence for Bidentate Character of Potentially Tridentate N,S-Ligands. Molecular Structures of Bis[N-(2-pyridyl)thiosalicylidene-κS-amino-κN]nickel(II) and Bis{1-isopropyl-3-methyl-4-[N-(2-pyridyl)imino-κN-methyl]pyrazole-5-thiolato-κS}copper(II) , 1992 .

[266]  J. Elguero,et al.  Azido/tetrazole equilibrium in the thiazoloacridinone series , 1996 .

[267]  P. Luger,et al.  Experimental electron density study of 1,2,4-triazole at 15 k. A comparison with ab initio-calculations , 1997 .

[268]  E. Giralt,et al.  Determination of the preferred tautomeric form of 4-nitrohistidine , 1986 .

[269]  R. Radeglia,et al.  Pyrazolonderivate, VI: Eine13C-NMR Studie an Merocyaninen vom 2-Pyrazolin-5-on-Typ , 1978 .

[270]  J. Montgomery,et al.  Studies on the Azidoazomethine-Tetrazole Equilibrium , 1964 .

[271]  W. Meutermans,et al.  The influence of the nitro group on the solid-state structure of 4-nitropyrazoles : the cases of pyrazole, 3,5-dimethylpyrazole, 3,5-di-tert-butylpyrazole and 3,5-diphenylpyrazole. I: Static aspects (crystallography and thermodynamics) , 1994 .

[272]  P. Barbara,et al.  Michael Kasha - Editorial, Biographical Sketch, Summary of Research Contributions, Research Associates, and Publications list , 1991 .

[273]  D. Dumanović,et al.  Basicity of nitropyrazoles and their simultaneous spectrophotometric determination. , 1975, Talanta: The International Journal of Pure and Applied Analytical Chemistry.

[274]  R. Sessoli,et al.  Synthesis, crystal and molecular structure, and magnetic properties of bis[(.mu.-3,5-diamino-1,2,4-triazole-N1,N2-bis(.mu.-3,5-diamino-1,2,4-triazolato-N1,N2)triaquacobalt(II))]cobalt(III) trichloride nonahydrate , 1991 .

[275]  A. Mckillop,et al.  4- and 5-nitroimidazoles: 13C NMR assignment of structure , 1983 .

[276]  A. H. Zewail,et al.  Femtosecond molecular dynamics of tautomerization in model base pairs , 1995, Nature.

[277]  V. V. Alekseyev,et al.  Ring-chain tautomerism of thiocarbohydrazones , 1990 .

[278]  A. Peregudov,et al.  Metallotropic Tautomeric Transformations of the σ,σ-Type in Organometallic and Complex Compounds , 1981 .

[279]  J. Atwood,et al.  Crystal and molecular structures of tetrafluoroborate salts of the cis-chlorobis(triethylphosphine)(3-(trifluoromethyl)-5-methylpyrazole)platinum(II) and cis-chlorobis(triethylphosphine)(indazole)platinum(II) cations , 1983 .

[280]  A. Maquestiau,et al.  Fragmentation de Triazoles Sous L'Impact Electronique—II 1,2,3‐Triazole , 1973 .

[281]  K. Hass,et al.  Novel Structural Modifications Associated with the Highly Efficient Internal Conversion of 2-(2‘-Hydroxyphenyl)benzotriazole Ultraviolet Stabilizers , 1997 .

[282]  J. Elguero,et al.  STRUCTURE OF 4-UNDECYLPYRAZOLE IN THE SOLID STATE: A 13C AND 15N CPMAS NMR SPECTROSCOPY STUDY , 1995 .

[283]  I. Polyakova,et al.  Structure of 1(5)-aryl-3-phenyl-5(1)-(2-benzothiazolyl)formazanes , 1991 .

[284]  J. Elguero,et al.  Proton transfer in solid heterocycles: An X-ray and CPMAS NMR study , 1994 .

[285]  R. Taft,et al.  Electrostatic proximity effects in gas-phase acidities and basicities: a comparison of theoretical methods (INDO, MNDO, AM1 and ab initio) , 1990 .

[286]  A. P. Budhkar,et al.  Synthesis and Spectral Studies on Metal Complexes of 2-Alkylthio-5-Mercapto-1,3,4-Thiadiazoles , 1986 .

[287]  Fun Hoong-Kun,et al.  A complex salt formed in reactions of nBuSnCl3 with 1-(2-methyl-2,3-dihydrobenzothiazol-2-yl)-2-ketones , 1993 .

[288]  E. Okafor.  A 1H and 13C-NMR spectral study of some 4-acyl-3-methyl-1-phenylpyrazol-5-ones in chloroform , 1984 .

[289]  R. Cooks,et al.  An investigation into the mechanism of gas-phase tautomerism using mass specrometry , 1971 .

[290]  J. Elguero,et al.  Synthesis, Spectroscopy and Tautomeric Study of Thiazoles substituted in positions 2 and 4 by hydroxy, mercapto and amino groups , 1985 .

[291]  H. Limbach,et al.  Combined X-ray Diffraction and 15N CPMAS NMR Study of Molecular Structure and Proton Order/Disorder Phenomena in Cyclic N,N‘-Bisarylformamidine Dimers , 1997 .

[292]  P. Jones.  Ring-Chain Tautomerism. , 1963 .

[293]  R. Taft,et al.  A theoretical and experimental study of the intrinsic basicities of methyldiazoles , 1990 .

[294]  B. V. Trzhtsinskaya,et al.  Structure and properties of imidazole-2-thiones (review) , 1988 .

[295]  José Elguero,et al.  A computational approach to intermolecular proton transfer in the solid state: assistance by proton acceptor molecules , 1998 .

[296]  J. Trotter,et al.  The crystal and molecular structure of a dideuterio(pyrazol-1-yl)gallane dimer , 1973 .

[297]  A. S. Vinogradov,et al.  The synthesis of stable perfluoroazidoazomethines and their rearrangement to perfluorodialkylcarbodiimides , 1985 .

[298]  Mercedes González,et al.  Ground- and Excited-State Tautomerism in 2-(3'-Hydroxy-2'-pyridyl)benzimidazole , 1994 .

[299]  L. I. Kuznetsova,et al.  Synthesis of transition metal complexes with heteroazomethinic ligands: a comparison of traditional and electrochemical methods , 1998 .

[300]  A. Vaisburg,et al.  Chemistry of hydroxy, mercapto, and selenolo aldimines of the heteroaromatic series (review) , 1992 .

[301]  S. Trofimenko.  Boron-pyrazzole chemistry. I. Prrazaboles , 1967 .

[302]  K. Neuvonen,et al.  Investigation of the applicability of cis-urocanic acid as a model for the catalytic Asp–His dyad in the active site of serine proteases based on 1H NMR hydrogen bonding studies and spectroscopic pKa measurements , 1998 .

[303]  G. Sørensen,et al.  The Molecular Structure and Tautomer Equilibrium of Gaseous 1,2,3-Triazole Studied by Microwave Spectroscopy, Electron Diffraction and Ab Initio Calculations , 1988 .

[304]  A. Millefiori,et al.  An ab initio study of the tautomeric equilibria and structure of 2,5-dimercapto-1,3,4-thiadiazole , 1987 .

[305]  J. Wiench,et al.  A multinuclear NMR investigation of some benzotriazoles in solution and the solid state , 1994 .

[306]  H. Limbach,et al.  Dynamic NMR Study of the Tautomerism of Bicyclic Oxalamidines: Kinetic HH/HD/DD Isotope and Solvent Effects , 1994 .

[307]  O. Jiménez-Sandoval,et al.  Crystal and molecular structure of 1-phenyl-1H-tetrazole-5-thiolato-trimethyltin(IV), Me3SnSCN4Ph, exhibiting unusual trimeric associations through intermolecular N → Sn bonds. , 1994 .

[308]  D. D. Nekrasov.  Synthesis, chemical properties, and biological activity of 2-Amino-4-oxazolinones and their tautomeric 2-Amino-4-oxazolidones (Review) , 1996 .

[309]  F. Baglin,et al.  Amino-Imino Interconversion in Crystalline 5-Aminotetrazole-Monohydrate , 1972 .

[310]  A. Mangia,et al.  The crystal and molecular structure of 7-chloro-1,2-benzoisothiazolin-3-one , 1969 .

[311]  Eric S. Raper,et al.  Complexes of heterocyclic thionates. Part 1. Complexes of monodentate and chelating ligands , 1996 .

[312]  M. Bruce,et al.  Rhodium complexes of pyrazole and derived ligands: Another case of metal-shuttling? , 1974 .

[313]  L. I. Kuznetsova,et al.  Advances in the Coordination Chemistry of Azoles , 1973 .

[314]  F. J. Luque,et al.  Theoretical Evaluation of Solvent Effects on the Conformational and Tautomeric Equilibria of 2-(2'-Hydroxyphenyl)benzimidazole and on Its Absorption and Fluorescence Spectra , 1999 .

[315]  J. Elguero,et al.  Annular tautomerism in the solid state: a high resolution n.m.r. study , 1981 .

[316]  J. Zukerman-Schpector,et al.  Crystal structure of triphenyl(5-mercapto-1-phenyl-1,2,3,4-tetrazolato)tin(IV) , 1994 .

[317]  V. Minkin,et al.  Molecular Design of Tautomeric Compounds , 1987 .

[318]  J. Lang,et al.  Synthesis and crystal structure of a binuclear copper(I) bromide complex of benz-1,3-thiazolidine-2-thione and triphenylphosphine, [Cu(bztzdtH)(PPh3)Br]2 , 1996 .

[319]  J. Elguero,et al.  13C NMR of indazoles , 1995 .

[320]  D. Simov,et al.  Stretching vibrations of the azomethine group of 2-aminobenzoxazole derivatives , 1979 .

[321]  G. Abowitz,et al.  Refinement of the crystal and molecular structure of 1,2,4‐triazole (C2H3N3) at low temperature , 1969 .

[322]  Alan R. Katritzky,et al.  Handbook of heterocyclic chemistry , 1985 .

[323]  R. N. Butler,et al.  A study of annular tautomerism, interannular conjugation, and methylation reactions of ortho-substituted-5-aryltetrazoles using carbon-13 and hydrogen-1 n.m.r. Spectroscopy , 1981 .

[324]  C. Pettinari,et al.  Tin(IV) and organotin(IV) complexes containing the anion of some substituted-3-methyl-4-acyl-5-pyrazolones. Crystal structure of dimethylbis(1-phenyl-3-methyl-4-benzoyl pyrazolon-5-ato)tin(IV) , 1993 .

[325]  R. Taft,et al.  The tautomerism of 1,2,3‐triazole, 3(5)‐methylpyrazole and their cations , 1989 .

[326]  M. Tiŝler,et al.  Some Aspects of Azido-Tetrazolo Isomerization , 1973 .

[327]  C. Pettinari,et al.  Synthesis, characterization and spectroscopic investigations of tin(IV) and organotin(IV) derivatives of 4-aroyl-5-pyrazolones. Crystal structure of trans-dimethylbis[1-phenyl-3-methyl-4-(4-bromobenzoyl)- pyrazolon-5-ato]tin(IV) , 1994 .

[328]  J. Vilarrasa,et al.  A 200‐MHZ PROTON NMR STUDY OF THE NAPHTHO(2,1‐E)TETRAZOLO(5,1‐C)‐AS‐TRIAZINE/3‐AZIDONAPHTHO(2,1‐E)‐AS‐TRIAZINE/NAPHTHO(2,1‐E)TETRAZOLO(1,5‐B)‐AS‐TRIAZINE EQUILIBRIUM , 1983 .

[329]  T. V. Domareva-Mandel'shtam,et al.  REVERSIBLE VALENCE ISOMERISATION , 1966 .

[330]  W. Jackson,et al.  .pi.-Bonded Intermediates in Linkage Isomerization Reactions of a Tetrazole Coordinated to Pentaamminecobalt(III): An 15N NMR Study , 1994 .

[331]  W. L. Purcell,et al.  Nitrogen-15 NMR studies of tetrazole complexes of pentaamminecobalt(III). Implications concerning the transition state for linkage isomerization , 1993 .

[332]  J. Elguero,et al.  Structure of 3(5)-methyl-4-nitropyrazole in the solid state: tautomerism, crystallography and the problem of desmotropy , 1994 .

[333]  J. Elguero,et al.  Azido–tetrazole tautomerism in the azole series , 1974 .

[334]  W. Meutermans,et al.  (4S,7R)-7,8,8-Trimethyl-4,5,6,7-tetrahydro-4,7-methano-1H(2H)-indazole (campho[2,3-c]pyrazole): comparison between the X-ray structure and carbon-13 NMR data in the solid state , 1993 .

[335]  J. Elguero,et al.  STRUCTURE AND TAUTOMERISM OF 3(5)-AMINO-5(3)-ARYLPYRAZOLES IN THE SOLID STATE AND IN SOLUTION : AN X-RAY AND NMR STUDY , 1997 .

[336]  John D. Roberts,et al.  Nitrogen-15 nuclear magnetic resonance spectroscopy. The state of histidine in the catalytic triad of .alpha.-lytic protease. Implications for the charge-relay mechanism of peptide-bond cleavage by serine proteases , 1978 .

[337]  H. Hofmann,et al.  Semiempirical and ab initio Calculations on the Tautomerism of Pyrazolin-5-ones in the Gas Phase and in Solution , 1982 .

[338]  R. Sessoli,et al.  catena-μ-(3,5-Diamino-1,2,4-triazole-N2,N4)-bis(thiocyanato-N)manganese(II). Synthesis, crystal structure, infrared and magnetic characterization , 1993 .

[339]  V. N. Babin,et al.  NMR studies of tautomerism of benzotriazole , 1969 .

[340]  M. Haugg,et al.  SYNTHESES AND STRUCTURE DETERMINATIONS OF TWO COPPER(II)-THIONE COMPLEXES , 1996 .

[341]  Infantes,et al.  3(5),4-Dimethyl- and 3,4,5-trimethylpyrazole at 200 K. X-ray crystallography and quantum-chemical analysis. , 1999, Acta crystallographica. Section B, Structural science.

[342]  W. Hull,et al.  15N‐NMR Spectroscopic Detection of the Tetrazolo[1,5‐a]pyrimidine/2‐Azidopyrimidine Equilibrium , 1980 .

[343]  R. Faure,et al.  Etude en Résonance Magnétique Nucléaire du Carbone‐13 de Quelques Aminopyrazoles. Sur le Problème de la Détermination des Constantes d'Equilibre Tautomère , 1979 .

[344]  P. K. Bharadwaj,et al.  Synthesis and studies of Cu(II)-thiolato complexes: bioinorganic perspectives , 1997 .

[345]  L. Deady,et al.  The chemistry of 2,1-benzisothiazoles. VIII. Tautomerism of 2,1-Benzisothiazolin-3-one and the preparation of N- and O-alkylated derivatives , 1975 .

[346]  S. Patai.  The chemistry of azido group , 1971 .

[347]  R. Faure,et al.  Etude de l'équilibre dans les oxazolo[2,3-e], thiazolo[2,3-e] et isoxazolo[2,3-d]tétrazoles. II. Etude de l'effet de la température par dipolemetrie et résonance magnétique nucléaire , 1977 .

[348]  S. Toppet,et al.  1H and 13C NMR study of the prototropic tautomerism of 4(5)-vinyl-1,2,3-triazole in dimethylformamide as solvent , 1978 .

[349]  C. Mcauliffe,et al.  Electrochemical synthesis of benzothiazole-2-thionato complexes of nickel(II), Zinc(II) and cadmium(II): the crystal structure of 2,2′-bipyridine bis(benzothiazole-2-thionato)zinc(II) , 1993 .

[350]  V. N. Chernenko,et al.  5-Amino-3-trifluoromethyl-1H-1,2,4-triazole , 1998 .

[351]  Ernst Anders,et al.  A MO theoretical study on the rearrangements of 1-hyroxy- and 1-(acyloxy)-1,2,3-triazoles and their benzotriazole analogues : comparison of ab initio and semiempirical calculations , 1992 .

[352]  O. A. Osipov,et al.  Direct evidence of coordination on the endocyclic nitrogen atom in the adducts of 2-aminoazoles and 2-aminoazines with copper(II) acetate , 1989 .

[353]  A. Bacchi,et al.  Investigations on the Amidine System in Amidinobenzisothiazole Derivatives , 1995 .

[354]  V. N. Babin,et al.  NMR study of polycrystalline azoles , 1991 .

[355]  S. Druzhinin,et al.  Excited state proton transfer dye lasers , 1998 .

[356]  V. Enchev,et al.  Tautomerism of N-unsubstituted pyrazolones (hydroxypyrazoles): MNDO and MNDO + CI study of C-substituted tautomers , 1992 .

[357]  R. Valter,et al.  Ring–Chain Isomeric Conversions of Aldehydo-carboxylic and Keto-carboxylic Acids and Their Derivatives , 1973 .

[358]  S. Olivella,et al.  Diazo-, azo-, and azidoazoles. V. MNDO calculations on the 2-azidoimidazole/imidazo[1, 2-d]tetrazole equilibrium , 1979 .

[359]  J. Elguero,et al.  Intermolecular Triple Proton and Deuteron Transfer in Crystalline 3,5-Dimethylpyrazole Studied by NMR, NQR, and X-ray Methods , 1989 .

[360]  C. Guérin,et al.  Nucleophilic displacement at silicon sterochemistry and mechanistic implications , 1980 .

[361]  W. L. Purcell,et al.  Linkage isomers of 5-methyl- and 5-phenyltetrazolato(1-) complexes of pentaamminecobalt(III) and their isomerization reactions , 1982 .

[362]  A. D. Garnovskii,et al.  Five-and Six-Membered Heteroaromatic Compounds as σ and π Ligands , 1998 .

[363]  D. Hibbs,et al.  Studies in nitrosopyrazoles. Part 2.1 Solution and solid-state NMR studies of 3,5-disubstituted and 1,3,5-trisubstituted-4-nitrosopyrazoles. Crystal structures of 1,3,5-trimethyl-4-nitrosopyrazole and 3,5-di-tert-butyl-4-nitrosopyrazole , 1997 .

[364]  W. Schindler,et al.  MO-Berechnungen zur photographischen Farbentwicklung. IX. Experimentelle und quantenchemische Untersuchungen zur Acidität von Pyrazolonen-(5)† , 1976 .

[365]  H. Mukai,et al.  Steric effects of polymethylene chain length on the liquid-liquid extraction of copper(II) with bis(4-acylpyrazol-5-one) derivatives , 1989 .

[366]  S. Trofimenko.  Boron-Pyrazole Chemistry , 1966 .

[367]  B. Jursic.  Ab Initio and Density Functional Theory Study of the Ethylene Cycloaddition Reaction to 4H-Pyrazole , 1995 .

[368]  R. Valters.  Recent Developments in Ring–Chain Tautomerism I. Intramolecular Reversible Addition Reactions to the C = O Group* , 1995 .

[369]  V. N. Babin,et al.  13C-NMR study of the role of tunnelling in the tautomerism of pyrazole , 1976 .

[370]  W. V. Philipsborn,et al.  15N‐NMR‐Spektroskopie — neue Methoden und ihre Anwendung , 1986 .

[371]  G. L'abbé,et al.  Mechanism of the thermal decomposition of vinyl azides , 1974 .

[372]  C. Pettinari,et al.  Organotin derivatives of 4-acyl-5-pyrazolones. Crystal structure of trans-di(t-butyl)bis(1-phenyl-3-methyl-4-benzoyl-pyrazolon-5-ato)tin(IV) , 1991 .