Molybdenum(VI) complexes of a 2,2'-biphenyl-bridged bis(amidophenoxide): competition between metal-ligand and metal-amidophenoxide π bonding.

The 2,2'-biphenyl-bridged bis(2-aminophenol) ligand 4,4'-di-tert-butyl-N,N'-bis(3,5-di-tert-butyl-2-hydroxyphenyl)-2,2'-diaminobiphenyl ((t)BuClipH(4)) reacts with MoO(2)(acac)(2) to form ((t)BuClipH(2))MoO(2), where the diarylamines remain protonated and bind trans to the terminal oxo groups. This complex readily loses water on treatment with pyridine or 3,5-lutidine to form mono-oxo complexes ((t)BuClip)MoO(L), which exhibit predominantly a cis-β geometry with an aryloxide trans to the oxo group. Exchange of the pyridine ligands is rapid and takes place by a dissociative mechanism, which occurs with retention of stereochemistry at molybdenum. Oxo-free alkoxide complexes ((t)BuClip)Mo(OR)(2) are formed from ((t)BuClipH(2))MoO(2) and ROH. Treatment of NMo(O(t)Bu)(3) with (t)BuClipH(4) results in complete deprotonation of the bis(aminophenol) and formation of a dimolybdenum complex ((t)BuClip)Mo(μ-N)(μ-NH(2))Mo((t)BuClip) containing both a bridging nitride (Mo-N = 1.848 Å, Mo-N-Mo = 109.49°) and a bridging amide group. The strong π bonding of this bis(amidophenoxide) ligand allows the molybdenum center to interconvert readily among species forming three, two, one, or zero π bonds from multiply bonded ligands.

[1]  Seth N. Brown.  Metrical oxidation states of 2-amidophenoxide and catecholate ligands: structural signatures of metal-ligand π bonding in potentially noninnocent ligands. , 2012, Inorganic chemistry.

[2]  Seth N. Brown,et al.  Gauging electronic dissymmetry in bis-chelates of titanium(IV) using sterically and electronically variable 2,2′-biphenoxides , 2011 .

[3]  Seth N. Brown,et al.  Optically active bis(β-diketonate) complexes of titanium. , 2010, Dalton transactions.

[4]  Seth N. Brown,et al.  Redox-active tripodal aminetris(aryloxide) complexes of titanium(IV). , 2010, Inorganic chemistry.

[5]  J. Klinowski,et al.  Crystal and supramolecular structures of dioxomolybdenum(VI) and dioxotungsten(VI) complexes of dihydroxybenzoic acids , 2010 .

[6]  Seth N. Brown,et al.  Intermetallic communication in titanium(IV) ferrocenyldiketonates. , 2009, Inorganic chemistry.

[7]  G. Coates,et al.  New facets of an old ligand: titanium and zirconium complexes of phenylenediamine bis(phenolate) in lactide polymerisation catalysis. , 2009, Chemical communications.

[8]  T. Weyhermüller,et al.  Targeted oxidase reactivity with a new redox-active ligand incorporating N2O2 donor atoms. Complexes of Cu(II), Ni(II), Pd(II), Fe(III), and V(V). , 2008, Inorganic chemistry.

[9]  A. F. Heyduk,et al.  Isolation and characterization of a neutral imino-semiquinone radical. , 2008, Journal of the American Chemical Society.

[10]  Brad C. Bailey,et al.  A tungstenVI nitride having a W2(mu-N)2 core. , 2008, Inorganic chemistry.

[11]  G. Sheldrick.  A short history of SHELX. , 2008, Acta crystallographica. Section A, Foundations of crystallography.

[12]  Seth N. Brown,et al.  Mononucleating Bis(β-diketonate) Ligands and Their Titanium(IV) Complexes , 2006 .

[13]  R. Fröhlich,et al.  Dicatechol cis-dioxomolybdenum(VI): a building block for a lithium cation templated monomer-dimer equilibrium. , 2006, Dalton transactions.

[14]  Seth N. Brown,et al.  Six-coordinate titanium complexes of a tripodal aminetris(phenoxide) ligand: synthesis, structure, and dynamics. , 2005, Inorganic chemistry.

[15]  Elky Almaraz,et al.  Six-coordinate monooxo molybdenum(VI) complexes with N-4-diethylaminosalicylidene-N′-4-nitrobenzoyl hydrazine and catechol ligands: preparation and spectroscopic properties , 2004 .

[16]  R. Shoemaker,et al.  Coordination complexes of molybdenum with 3,6-di-tert-butylcatechol. Addition products of DMSO, pyridine N-oxide, and triphenylarsine oxide to the putative [MoVIO(3,6-DBCat)2] monomer and self-assembly of the chiral [(MoVIO(3,6-DBCat)2)4] square. , 2004, Inorganic chemistry.

[17]  P. Scott,et al.  Chiral-at-metal organolanthanides: enantioselective aminoalkene hydroamination/cyclisation with non-cyclopentadienyls , 2003 .

[18]  K. Wieghardt,et al.  o-Iminobenzosemiquinonato complexes of Mn(III) and Mn(IV). Synthesis and characterization of [Mn(III)(L(ISQ))(2)(L(AP))] (S(t) = 1) and [Mn(IV)(L(ISQ))(2)(L(AP)-H)] (S(t) = 1/2). , 2002, Inorganic chemistry.

[19]  R. Scopelliti,et al.  Photochemical Activation of the N≡N Bond in a Dimolybdenum-Dinitrogen Complex: Formation of a Molybdenum Nitride. , 2001, Angewandte Chemie.

[20]  F. A. Schultz,et al.  Monooxo molybdenum(VI) complexes with catecholate and 2,2′-thiobis(phenolate) ligands: preparation and electrochemical and spectroscopic properties , 2001 .

[21]  A. Carinci,et al.  The synthesis and conformation of sterically congested seven-membered rings containing tetracoordinate germanium(IV): determination of the DeltaG* for ring inversion. , 2001, Inorganic chemistry.

[22]  F. A. Schultz,et al.  Six-coordinate monooxo molybdenum(VI) complexes with catecholate and salicylaldehyde thiosemicarbazone ligands , 2000 .

[23]  J. Strähle,et al.  Synthese und Kristallstruktur der Molybdännitrido‐Komplexe [MoNCl3(MeCN)]4 und [MoNCl2(bipy)]4 , 2000 .

[24]  T. Agapie,et al.  In pursuit of the molybdenum(III) tris(thiolate) fragment: unusual structure of a dimolybdenum mu-nitrido complex. , 2000, Inorganic chemistry.

[25]  Christopher C. Cummins,et al.  A Cyclometalated Resting State for a Reactive Molybdenum Amide: Favorable Consequences of β-Hydrogen Elimination Including Reductive Cleavage, Coupling, and Complexation , 1999 .

[26]  K. Dehnicke,et al.  MONCL3(THF)4 : EIN NITRIDO-KOMPLEX MIT GEFALTETEM MO4N4-ACHTRING , 1999 .

[27]  P. Hitchcock,et al.  Non-planar co-ordination of C2-symmetric biaryl-bridged Schiff-base ligands: well expressed chiral ligand environments for zirconium† , 1999 .

[28]  D. Hughes,et al.  Diastereoselective Self-Assembly and Crystal Structure of the Chiral, Anionic Molybdenum-Based [2+2] Molecular Square [{MoO2(C21H20O4)}2]4- , 1998 .

[29]  W. M. Davis,et al.  Atom‐Bridged Intermediates in N‐ and P‐Atom Transfer Reactions , 1997 .

[30]  Leo Radom,et al.  Harmonic Vibrational Frequencies: An Evaluation of Hartree−Fock, Møller−Plesset, Quadratic Configuration Interaction, Density Functional Theory, and Semiempirical Scale Factors , 1996 .

[31]  Neil G. Connelly,et al.  Chemical Redox Agents for Organometallic Chemistry. , 1996, Chemical reviews.

[32]  S. Geib,et al.  Molecular structure of [W(N)(O-2,6-C6H3iPr2)3]2: a metal-nitrido compound with a cyclic diyne structure , 1996 .

[33]  J. Fettinger,et al.  Aggregation of Nitrido–Metal Complexes: The Example of [(η5‐C5Me5)Mo(N)Cl2] , 1995 .

[34]  M. Albrecht,et al.  Macrobicyclic Tris(catecholate ligand) complexes: Spectroscopy, Electrochemistry, and the Structure of K2[(H2-bicappedTRENCAM)MoO2] , 1994 .

[35]  P. Legzdins,et al.  Nitrosyl N-O bond cleavage induced by reducing agents. Synthesis and characterization of novel nitrido-bridged bimetallic complexes of molybdenum and tungsten , 1994 .

[36]  A. Rheingold,et al.  Dealkylation of an organoimido ligand leading to a binuclear (µ-nitrido) complex of molybdenum(IV): structure of the [Cl3(py)2MoNMo(py)2Cl3]– anion , 1994 .

[37]  D. Darensbourg,et al.  Crystal structure of tetraethylammonium bis(catecholato)-dioxo-molybdenum(VI), C28H48MoN2O6 , 1994 .

[38]  R. H. Holm,et al.  A Thermodynamic Scale for Oxygen Atom Transfer Reactions , 1993 .

[39]  M. Chaudhury,et al.  Chemistry of molybdenum. Part 7. Reactivity of terminal oxo-ligands in cis-[MoO2(acda)2](Hacda = 2-aminocyclopent-1-ene-1-carbodithioic acid) toward proton- and electron-donor reagents. Synthesis, redox chemistry and spectroscopic characterisation of neutral seven-co-ordinate catecholato and aryldia , 1991 .

[40]  P. Fanwick,et al.  Synthesis, structure, and spectroscopic properties of germanium and tin compounds containing aryloxide ligation: comparison of aryloxide bonding to group 4 and group 14 metal centers , 1990 .

[41]  C. Pickett,et al.  Synthesis, reactivity, and electrochemistry of some new nitrides of molybdenum and tungsten: crystal structure of trinuclear [{µ-MoN(N3)2}{NMo(N3)(Et2PCH2CH2PEt2)2}2] , 1990 .

[42]  U. Müller,et al.  Nitridokomplexe von Molybdän(V); Synthesen, IR- und EPR-Spektren. Die Kristallstruktur von [Na(15-Krone-5)Na(THF)]2[MoNCl3 ·THF]4·2THF / Nitrido Complexes of Molybdenum(V); Syntheses, IR, and EPR Spectra. Crystal Structure of [Na(15-Crown-5)Na(THF)]2[MoNCl3·THF]4·2THF , 1989 .

[43]  W. Clegg,et al.  Facile conversion of a cationic MoIV phosphinimato complex into an anionic nitrido-bridged dimer with a bis(trimethylphosphine)iminium counterion , 1989 .

[44]  C. Dekock,et al.  Synthesis and molecular structure of di-and tetra-nuclear nitrido(oxo)molybdenum(VI) compounds containing trimethylsiloxy and n-base ligands , 1989 .

[45]  J. Mayer,et al.  Metal-oxygen multiple bond lengths: a statistical study , 1988 .

[46]  F. A. Schultz,et al.  Synthesis, electrochemistry, and spectroscopic properties of six-coordinate monooxomolybdenum(VI) complexes containing tridentate Schiff base and bidentate catecholate ligands. Crystal and molecular structure of (N-salicylidene-2-aminophenolato)(naphthalene-2,3-diolato)oxomolybdenum(VI) , 1988 .

[47]  W. Newton,et al.  Correlation of redox and spectroscopic properties in seven-coordinate oxomolybdenum(VI) hydroxylamido catecholato complexes , 1988 .

[48]  J. Zubieta,et al.  Coordination complexes of polyoxomolybdate anions. Characterization of a tetranuclear core from reactions in methanol: syntheses and structures of two polyoxomolybdate alcoholates, (MePPh3)2[Mo4O10(OCH3)6] and (n-Bu4N)2[Mo4O10(OCH3)2(OC6H4O)2], and their relationship to a general class of tetranucle , 1987 .

[49]  D. Fenske,et al.  Synthese und Kristallstruktur von (PPh4)2[Mo2NCl9]2, einem μ-Nitridokomplex mit Molybdän(V), und -(VI) , 1987 .

[50]  M. Chisholm,et al.  Trialkoxynitridomolybdenum compounds: (RO)3Mo.ident.N. Preparation, structures (R = tert-Bu and iso-Pr), and comparisons with a tungsten analog (R = tert-Bu) , 1986 .

[51]  F. A. Schultz,et al.  Synthesis and properties of seven-coordinate (catecholato)bis(dithiocarbamato)oxomolybdenum(VI) complexes exhibiting metal- and ligand-centered electrochemistry , 1986 .

[52]  C. Pierpont,et al.  Synthesis of Tris(3,5-di-tert-butylcatecholato)molybdenum(VI) and its reaction with molecular oxygen , 1986 .

[53]  G. Morris,et al.  Structural, spectroscopic and electrochemical studies on a new Mo(VI) catecholate complex , 1986 .

[54]  G. Morris,et al.  SYNTHESIS OF (1,2-BENZENEDIOLATO(2-)-0,0')OXOBIS(1-PIPERIDINOLATO(1-)-0,N)MOLYBDENUM( VI), [MOO(C5H10NO)2(C6H4O2)], AND STRUCTURE DETERMINATION BY CORRELATED H-1-C-13 TWO-DIMENSIONAL NMR-SPECTROSCOPY AND X-RAY CRYSTALLOGRAPHY , 1985 .

[55]  U. Müller,et al.  Molybdännitridtrichlorid-di-n-butylether, [MoNCl3 · O(C4H9)2]4; Darstellung, IR-Spektrum und Kristallstruktur , 1982 .

[56]  M. Noble,et al.  TETRANUCLEAR DIALKYLDITHIOPHOSPHATE COMPLEXES OF MOLYBDENUM(V) WITH NITRIDE LIGANDS , 1982 .

[57]  R. F. Fenske,et al.  Theoretical study of o-quinone complexes of chromium and vanadium , 1982 .

[58]  D. T. Sawyer,et al.  Formation and characterization of bis(tetramethylammonium) [bis(3,5-di-tert-butylcatecholato)oxoperoxomolybdate(VI)] , 1982 .

[59]  T. Yamato,et al.  Studies on selective preparation of aromatic compounds. 20. Selective preparation of 2-mono- and 2,2'-disubstituted biphenyl using the tert-butyl group as a positional protective group , 1979 .

[60]  C. Pierpont,et al.  Synthesis, structure, and properties of the oxygen-deficient bis(3,5-di-tert-butylcatecholato)oxomolybdenum(VI) dimer, [MoO(O2C6H2(t-Bu)2)2]2 , 1979 .

[61]  D. T. Sawyer,et al.  Formation of bis[bis(3,5-di-tert-butylcatecholato)oxomolybdenum(VI)] and related stable molybdenum-catechol complexes , 1979 .

[62]  J. Strähle,et al.  Darstellung, Kristallstruktur und Infrarotspektrum von [MoNCl3 · POCl3]4/Preparation, Crystal Structure and Infrared Spectrum of [MoNCl3 · POCl3]4 , 1978 .

[63]  J. Dilworth,et al.  Preparation and X-ray crystal structure analysis of a novel, trinuclear nitrido complex [{Et2NCS2)3MoN}2Mo(S2CNEt2)3]3+[PF6–]3 , 1976 .

[64]  C. Pierpont,et al.  Distorted trigonal prismatic coordination in tris(9,10-phenanthrenequinone)molybdenum , 1975 .

[65]  C. Pierpont,et al.  Bridging and terminal o-benzoquinone coordination. Crystal and molecular structure of hexakis(tetrachloro-1,2-benzoquinone)dimolybdenum , 1975 .

[66]  R. Wentworth.  Trigonal prismatic vs. octahedral stereochemistry in complexes derived from innocent ligands , 1972 .

[67]  Joachim Strhle.  Die Kristallstruktur von Molybdännitridchlorid, MoNCI3 , 1970 .