Borylene complexes (BH)L2 and nitrogen cation complexes (N+)L2: isoelectronic homologues of carbones CL2.

Quantum chemical calculations using DFT (BP86, M05-2X) and ab initio methods (CCSD(T), SCS-MP2) have been carried out on the borylene complexes (BH)L(2) and nitrogen cation complexes (N(+))L(2) with the ligands L=CO, N(2), PPh(3), NHC(Me), CAAC, and CAAC(model). The results are compared with those obtained for the isoelectronic carbones CL(2). The geometries and bond dissociation energies of the ligands, the proton affinities, and adducts with the Lewis acids BH(3) and AuCl were calculated. The nature of the bonding has been analyzed with charge and energy partitioning methods. The calculated borylene complexes (BH)L(2) have trigonal planar coordinated boron atoms which possess rather short B-L bonds. The calculated bond dissociation energies (BDEs) of the ligands for complexes where L is a carbene (NHC or CAAC) are very large (D(e) =141.6-177.3 kcal mol(-1)) which suggest that such species might become isolated in a condensed phase. The borylene complexes (BH)(PPh(3))(2) and (BH)(CO)(2) have intermediate bond strengths (D(e) =90.1 and 92.6 kcal mol(-1)). Substituted homologues with bulky groups at boron which protect the boron atom from electrophilic attack might also be stable enough to become isolated. The BDE of (BH)(N(2))(2) is much smaller (D(e) =31.9 kcal mol(-1)), but could become observable in a low-temperature matrix. The proton affinities of the borylene complexes are very large, particularly for the bulky adducts with L=PPh(3), NHC(Me), CAAC(model) and CAAC and thus, they are superbases. All (BH)L(2) molecules bind strongly AuCl either η(1) (L=N(2), PPh(3), NHC(Me), CAAC) or η(2) (L=CO, CAAC(model)). The BDEs of H(3)B-(BH)L(2) adducts which possess a hitherto unknown boron→boron donor-acceptor bond are smaller than for the AuCl complexes. The strongest bonded BH(3) adduct that might be isolable is (BH)(PPh(3))(2)-BH(3) (D(e) =36.2 kcal mol(-1)). The analysis of the bonding situation reveals that (BH)-L(2) bonding comes mainly from the orbital interactions which has three major contributions, that is, the donation from the symmetric (σ) and antisymmetric (π(||)) combination of the ligand lone-pair orbitals into the vacant MOs of BH L→(BH)←L and the L←(BH)→L π backdonation from the boron lone-pair orbital. The nitrogen cation complexes (N(+))L(2) have strongly bent L-N-L geometries, in which the calculated bending angle varies between 113.9° (L=N(2)) and 146.9° (L=CAAC). The BDEs for (N(+))L(2) are much larger than those of the borylene complexes. The carbene ligands NHC and CAAC but also the phosphane ligands PPh(3) bind very strongly between D(e) =358.4 kcal mol(-1) (L=PPh(3)) and D(e) =412.5 kcal mol(-1) (L=CAAC(model)). The proton affinities (PA) of (N(+))L(2) are much smaller and they bind AuCl and BH(3) less strongly compared with (BH)L(2). However, the PAs (N(+))L(2) for complexes with bulky ligands L are still between 139.9 kcal mol(-1) (L=CAAC(model)) and 168.5 kcal mol(-1) (L=CAAC). The analysis of the (N(+))-L(2) bonding situation reveals that the binding interactions come mainly from the L→(N(+))←L donation while L←(N(+) )→L π backdonation is rather weak.

[1]  Ralf Tonner,et al.  Carbodicarbenes—divalent carbon(0) compounds exhibiting carbon–carbon donor–acceptor bonds , 2011 .

[2]  W. Thiel,et al.  Synthesis, structure, and reactivity of a dihydrido borenium cation. , 2011, Angewandte Chemie.

[3]  W. Thiel,et al.  Synthese, Struktur und Reaktivität eines Dihydridoboreniumkations† , 2011 .

[4]  G. Frenking,et al.  Synthesis and Characterization of a Neutral Tricoordinate Organoboron Isoelectronic with Amines , 2011, Science.

[5]  Dhilon S. Patel,et al.  Divalent N(I) compounds with two lone pairs on nitrogen. , 2011, The journal of physical chemistry. A.

[6]  Philipp Bissinger,et al.  Selektive Generierung und Abfangreaktion eines NHC-stabilisierten B-H-Borylens† , 2011 .

[7]  T. Kupfer,et al.  Trapping the elusive parent borylene. , 2011, Angewandte Chemie.

[8]  G. Frenking,et al.  Divalent Pb(0) compounds , 2011 .

[9]  Mohand Melaimi,et al.  Stabile cyclische Carbene und verwandte Spezies jenseits der Diaminocarbene , 2010 .

[10]  G. Bertrand,et al.  Stable cyclic carbenes and related species beyond diaminocarbenes. , 2010, Angewandte Chemie.

[11]  G. Frenking,et al.  Carbodicarbenes and related divalent carbon(0) compounds. , 2010, Chemistry.

[12]  W. Thiel,et al.  Synthese und Koordinationseigenschaften von Stickstoff(I)‐ Liganden , 2010 .

[13]  W. Thiel,et al.  Synthesis and coordination properties of nitrogen(I)-based ligands. , 2010, Angewandte Chemie.

[14]  I. Císařová,et al.  New lipophilic 2-amino-N,N'-dialkyl-4,5-dimethylimidazolium cations: synthesis, structure, properties, and outstanding thermal stability in alkaline media. , 2009, Chemistry.

[15]  Gernot Frenking,et al.  Divalent E(0) compounds (E = Si-Sn). , 2009, Chemistry.

[16]  G. Frenking,et al.  Exocyclic delocalization at the expense of aromaticity in 3,5-bis(pi-donor) substituted pyrazolium ions and corresponding cyclic bent allenes. , 2009, Journal of the American Chemical Society.

[17]  G. Bertrand,et al.  Synthesis of a simplified version of stable bulky and rigid cyclic (alkyl)(amino)carbenes, and catalytic activity of the ensuing gold(I) complex in the three-component preparation of 1,2-dihydroquinoline derivatives. , 2009, Journal of the American Chemical Society.

[18]  G. Frenking,et al.  Synthesis and ligand properties of a persistent, all-carbon four-membered-ring allene. , 2009, Angewandte Chemie.

[19]  Gernot Frenking,et al.  Divalent silicon(0) compounds. , 2009, Chemistry.

[20]  Artur Michalak,et al.  A Combined Charge and Energy Decomposition Scheme for Bond Analysis. , 2009, Journal of chemical theory and computation.

[21]  Dhilon S. Patel,et al.  Novel (+)N(<--L)2 species with two lone pairs on nitrogen: systems isoelectronic to carbodicarbenes. , 2009, Chemical communications.

[22]  Ralf Tonner,et al.  Divalent carbon(0) compounds , 2009 .

[23]  M. Straka,et al.  Theoretical mapping of new L-(N+)-L family of species with donor-acceptor bonding between N+ and ligand L , 2008 .

[24]  G. Frenking,et al.  First and second proton affinities of carbon bases. , 2008, Chemphyschem : a European journal of chemical physics and physical chemistry.

[25]  G. Bertrand,et al.  Synthesis and ligand properties of stable five-membered-ring allenes containing only second-row elements. , 2008, Angewandte Chemie.

[26]  G. Bertrand,et al.  Synthesis of an extremely bent acyclic allene (a "carbodicarbene"): a strong donor ligand. , 2008, Angewandte Chemie.

[27]  A. Fürstner,et al.  Coordination chemistry of ene-1,1-diamines and a prototype "carbodicarbene". , 2008, Angewandte Chemie.

[28]  G. Frenking,et al.  Divalent carbon(0) chemistry, part 1: Parent compounds. , 2008, Chemistry.

[29]  Ralf Tonner,et al.  Divalent carbon(0) chemistry, part 2: Protonation and complexes with main group and transition metal Lewis acids. , 2008, Chemistry.

[30]  Artur Michalak,et al.  Applications of natural orbitals for chemical valence in a description of bonding in conjugated molecules , 2008, Journal of molecular modeling.

[31]  Artur Michalak,et al.  Bond orbitals from chemical valence theory. , 2008, The journal of physical chemistry. A.

[32]  G. Frenking,et al.  C(NHC)2: zweibindige Kohlenstoff(0)‐Verbindungen mit N‐heterocyclischen Carbenliganden – theoretische Belege für eine Molekülklasse mit vielversprechenden Eigenschaften , 2007 .

[33]  G. Frenking,et al.  C(NHC)2: divalent carbon(0) compounds with N-heterocyclic carbene ligands-theoretical evidence for a class of molecules with promising chemical properties. , 2007, Angewandte Chemie.

[34]  Artur Michalak,et al.  Donor–Acceptor Properties of Ligands from the Natural Orbitals for Chemical Valence , 2007 .

[35]  Rian D. Dewhurst,et al.  Intramolecular "hydroiminiumation" of alkenes: application to the synthesis of conjugate acids of cyclic alkyl amino carbenes (CAACs). , 2007, Angewandte Chemie.

[36]  Jiří Čížek,et al.  On the Use of the Cluster Expansion and the Technique of Diagrams in Calculations of Correlation Effects in Atoms and Molecules , 2007 .

[37]  Artur Michalak,et al.  Natural orbitals for chemical valence as descriptors of chemical bonding in transition metal complexes , 2007, Journal of molecular modeling.

[38]  E. Baerends,et al.  Kohn-Sham Density Functional Theory: Predicting and Understanding Chemistry , 2007 .

[39]  G. Frenking,et al.  Orbital overlap and chemical bonding. , 2006, Chemistry.

[40]  Ralf Tonner,et al.  Carbodiphosphoranes: the chemistry of divalent carbon(0). , 2006, Angewandte Chemie.

[41]  G. Frenking,et al.  Carbodiphosphorane: die Chemie von zweibindigem Kohlenstoff(0) , 2006 .

[42]  G. Frenking,et al.  Direct estimate of the strength of conjugation and hyperconjugation by the energy decomposition analysis method. , 2006, Chemistry.

[43]  F. Weigend.  Accurate Coulomb-fitting basis sets for H to Rn. , 2006, Physical chemistry chemical physics : PCCP.

[44]  Donald G Truhlar,et al.  Design of Density Functionals by Combining the Method of Constraint Satisfaction with Parametrization for Thermochemistry, Thermochemical Kinetics, and Noncovalent Interactions. , 2006, Journal of chemical theory and computation.

[45]  G. Bertrand,et al.  Stable cyclic (alkyl)(amino)carbenes as rigid or flexible, bulky, electron-rich ligands for transition-metal catalysts: a quaternary carbon atom makes the difference. , 2005, Angewandte Chemie.

[46]  F. Weigend,et al.  Balanced basis sets of split valence, triple zeta valence and quadruple zeta valence quality for H to Rn: Design and assessment of accuracy. , 2005, Physical chemistry chemical physics : PCCP.

[47]  S. Grimme.  Accurate calculation of the heats of formation for large main group compounds with spin-component scaled MP2 methods. , 2005, The journal of physical chemistry. A.

[48]  G. Frenking,et al.  The nature of the chemical bond revisited: an energy-partitioning analysis of nonpolar bonds. , 2005, Chemistry.

[49]  Erik Van Lenthe,et al.  Optimized Slater‐type basis sets for the elements 1–118 , 2003, J. Comput. Chem..

[50]  S. Grimme.  Improved second-order Møller–Plesset perturbation theory by separate scaling of parallel- and antiparallel-spin pair correlation energies , 2003 .

[51]  G. Frenking,et al.  Towards a rigorously defined quantum chemical analysis of the chemical bond in donor–acceptor complexes☆ , 2003 .

[52]  T. Iwamoto,et al.  A stable silicon-based allene analogue with a formally sp-hybridized silicon atom , 2003, Nature.

[53]  G. Frenking,et al.  Nature of the Metal−Ligand Bond in M(CO)5PX3 Complexes (M = Cr, Mo, W; X = H, Me, F, Cl): Synthesis, Molecular Structure, and Quantum-Chemical Calculations , 2002 .

[54]  Ioannis S. K. Kerkines,et al.  On the Bonding Nature of the N5+(=N(N2)2+) Cation and Related Species N(CO)x+, N(NH3)x+, and NRx+, x = 1, 2 and R = He, Ne, Ar, Kr. Do We Really Need the Resonance Concept? , 2002 .

[55]  G. Frenking,et al.  The Dewar-chatt-Duncanson bonding model of transition metal-olefin complexes examined by modern quantum chemical methods , 2002 .

[56]  Gernot Frenking,et al.  Understanding the nature of the bonding in transition metal complexes: from Dewar's molecular orbital model to an energy partitioning analysis of the metal–ligand bond ☆ , 2001 .

[57]  F. Matthias Bickelhaupt,et al.  Chemistry with ADF , 2001, J. Comput. Chem..

[58]  R. Ponec,et al.  On the nature of bonding in N 5 + ion , 2001 .

[59]  B. Roos,et al.  A theoretical study of the nitrogen clusters formed from the ions N3 - , N5 + , and N5 - , 2001 .

[60]  R. Bartlett,et al.  Possible Products of the End-On Addition of N3- to N5+ and Their Stability , 2001 .

[61]  K. Christe,et al.  Polynitrogen chemistry. Synthesis, characterization, and crystal structure of surprisingly stable fluoroantimonate salts of N5+. , 2001, Journal of the American Chemical Society.

[62]  M. Nguyen,et al.  Decomposition mechanism of the polynitrogen N5 and N6 clusters and their ions , 2001 .

[63]  Li Jie Wang,et al.  A Quantum Chemical Theoretical Study of Decomposition Pathways of N9 (C2v) and N9+ (C2v) Clusters , 2001 .

[64]  S. Chien,et al.  An isomeric study of N5+, N5, and N5−: a Gaussian-3 investigation , 2000 .

[65]  J. Koput.  An ab initio study on the equilibrium structure and CCC bending energy levels of carbon suboxide , 2000 .

[66]  M. Nguyen,et al.  Theoretical study of the pentanitrogen cation (N5 , 2000 .

[67]  Wenguo Xu,et al.  Ab initio and density functional theory study of the mechanism of synthesis of the N5+ cation , 1999 .

[68]  Bernhardi,et al.  Isolation and Structure of the OCNCO(+) Ion. , 1999, Angewandte Chemie.

[69]  K. O. Christe,et al.  N5+: ein neuartiges homoleptisches Polystickstoff‐Ion als Substanz mit hoher Energiedichte , 1999 .

[70]  Holger Patzelt,et al.  RI-MP2: optimized auxiliary basis sets and demonstration of efficiency , 1998 .

[71]  G. Frenking,et al.  Transition Metal Coordinated Al(X)L2 and Ga(X)L2 Fragments , 1998 .

[72]  F. Weigend,et al.  RI-MP2: first derivatives and global consistency , 1997 .

[73]  Gernot Frenking,et al.  The bonding of acetylene and ethylene in high-valent and low-valent transition metal compounds , 1996 .

[74]  M. Frisch,et al.  Using redundant internal coordinates to optimize equilibrium geometries and transition states , 1996, J. Comput. Chem..

[75]  Gernot Frenking,et al.  Theoretical Studies of Organometallic Compounds. XIX. Complexes of Transition Metals in High and Low Oxidation States with Side-On-Bonded .pi.-Ligands , 1995 .

[76]  Marco Häser,et al.  Auxiliary basis sets to approximate Coulomb potentials (Chem. Phys. Letters 240 (1995) 283-290) , 1995 .

[77]  G. Frenking,et al.  Comparative Theoretical Study of Lewis Acid-Base Complexes of BH3, BF3, BCl3, AlCl3, and SO2 , 1994 .

[78]  J. Gal,et al.  Superbases in the gas phase: Amidine and guanidine derivatives with proton affinities larger than 1000 kj mol−1 , 1993 .

[79]  Hans W. Horn,et al.  Fully optimized contracted Gaussian basis sets for atoms Li to Kr , 1992 .

[80]  Hans W. Horn,et al.  ELECTRONIC STRUCTURE CALCULATIONS ON WORKSTATION COMPUTERS: THE PROGRAM SYSTEM TURBOMOLE , 1989 .

[81]  M. Head‐Gordon,et al.  A fifth-order perturbation comparison of electron correlation theories , 1989 .

[82]  A. Becke,et al.  Density-functional exchange-energy approximation with correct asymptotic behavior. , 1988, Physical review. A, General physics.

[83]  L. Curtiss,et al.  Intermolecular interactions from a natural bond orbital, donor-acceptor viewpoint , 1988 .

[84]  J. Sotiropoulos,et al.  Synthesis and reactivity of diazomethylenephosphoranes (P=C=N2). New phosphacumulene ylides and first stable pseudo-unsaturated diazo derivatives , 1987 .

[85]  R. Bartlett,et al.  The full CCSDT model for molecular electronic structure , 1987 .

[86]  P. Jensen,et al.  The infrared spectrum of carbon suboxide in the ν6 fundamental region: Experimental observation and semirigid bender analysis , 1986 .

[87]  J. Perdew,et al.  Density-functional approximation for the correlation energy of the inhomogeneous electron gas. , 1986, Physical review. B, Condensed matter.

[88]  R. Bartlett,et al.  A full coupled‐cluster singles and doubles model: The inclusion of disconnected triples , 1982 .

[89]  J. Zink,et al.  Structure and triboluminescence of polymorphs of hexaphenylcarbodiphosphorane , 1978 .

[90]  Rodney J. Bartlett,et al.  Many‐body perturbation theory, coupled‐pair many‐electron theory, and the importance of quadruple excitations for the correlation problem , 1978 .

[91]  J. S. Binkley,et al.  Electron correlation theories and their application to the study of simple reaction potential surfaces , 1978 .

[92]  J. Pople,et al.  Møller–Plesset theory for atomic ground state energies , 1975 .

[93]  Keiji Morokuma,et al.  Molecular Orbital Studies of Hydrogen Bonds. III. C=O···H–O Hydrogen Bond in H2CO···H2O and H2CO···2H2O , 1971 .

[94]  J. Cizek.  On the Correlation Problem in Atomic and Molecular Systems. Calculation of Wavefunction Components in Ursell-Type Expansion Using Quantum-Field Theoretical Methods , 1966 .

[95]  M. Plesset,et al.  Note on an Approximation Treatment for Many-Electron Systems , 1934 .

[96]  Pekka Pyykkö,et al.  Molecular single-bond covalent radii for elements 1-118. , 2009, Chemistry.

[97]  Takeaki Iwamoto,et al.  Trigermaallene and 1,3-Digermasilaallene , 2005 .

[98]  G. Frenking,et al.  The nature of the chemical bond in the light of an energy decomposition analysis , 2005 .

[99]  A. Ellern,et al.  The Structure of Carbon Suboxide, C3O2, in the Solid State , 2001 .

[100]  P. J. Wheatley,et al.  Structure of triphenylphosphoranylideneketen , 1966 .