title: Resonance Character of Copper/Silver/Gold Bonding in Small Molecule⋅⋅⋅M-X (X=F, Cl, Br, CH3, CF3) Complexes.
abstract: The resonance character of Cu/Ag/Au bonding is investigated in B⋅⋅⋅M-X (M=Cu, Ag, Au; X=F, Cl, Br, CH3, CF3; B=CO, H2O, H2S, C2H2, C2H4) complexes. The natural bond orbital/natural resonance theory results strongly support the general resonance-type three-center/four-electron (3c/4e) picture of Cu/Ag/Au bonding, B:M-X↔B(+) -M:X(-) , which mainly arises from hyperconjugation interactions. On the basis of such resonance-type bonding mechanisms, the ligand effects in the more strongly bound OC⋅⋅⋅M-X series are analyzed, and distinct competition between CO and the axial ligand X is observed. This competitive bonding picture directly explains why CO in OC⋅⋅⋅Au-CF3 can be readily replaced by a number of other ligands. Additionally, conservation of the bond order indicates that the idealized relationship bB⋅⋅⋅M +bMX =1 should be suitably generalized for intermolecular bonding, especially if there is additional partial multiple bonding at one end of the 3c/4e hyperbonded triad.
authors.affiliation: College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging, Key Laboratory of Molecular and Nano, Probes, Ministry of Education, Shandong Normal University, Jinan 250014 (P.R. China). gqzhang@sdnu.edu.cn.
authors.forename: Guiqiu
authors.initials: G
authors.lastname: Zhang
authors.affiliation: College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging, Key Laboratory of Molecular and Nano, Probes, Ministry of Education, Shandong Normal University, Jinan 250014 (P.R. China).
authors.forename: Huanjing
authors.initials: H
authors.lastname: Yue
authors.affiliation: Department of Chemistry, University of Wisconsin, Madison, WI 53706 (USA).
authors.forename: Frank
authors.initials: F
authors.lastname: Weinhold
authors.affiliation: College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging, Key Laboratory of Molecular and Nano, Probes, Ministry of Education, Shandong Normal University, Jinan 250014 (P.R. China).
authors.forename: Hui
authors.initials: H
authors.lastname: Wang
authors.affiliation: College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging, Key Laboratory of Molecular and Nano, Probes, Ministry of Education, Shandong Normal University, Jinan 250014 (P.R. China).
authors.forename: Hong
authors.initials: H
authors.lastname: Li
authors.affiliation: College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging, Key Laboratory of Molecular and Nano, Probes, Ministry of Education, Shandong Normal University, Jinan 250014 (P.R. China).
authors.forename: Dezhan
authors.initials: D
authors.lastname: Chen
mesh_terms: D056831:Coordination Complexes / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D006219:Halogens / Q000737:chemistry*; D008024:Ligands; D008958:Models, Molecular; D012834:Silver / Q000737:chemistry*
chemical_list: D056831:Coordination Complexes; D006219:Halogens; D008024:Ligands; D012834:Silver; D006046:Gold; D003300:Copper
keywords: bond theory; ligand effects; resonance structures; structure elucidation; transition metals