Department of Chemistry and Centre for Research in Mass Spectrometry, York University, 4700 Keele Street, Toronto, Ontario, Canada M3J 1P3.
J Phys Chem A. 2010 Jul 8;114(26):6964-71. doi: 10.1021/jp102470x.
Using competitive threshold collision-induced dissociation (TCID) measurements, experimental bond dissociation energies have been evaluated for the water, methanol, and acetonitrile adducts of silver(I)-amide complexes. The influence of the solvent molecules on the binding energy of silver(I) to acetamide, N-methylacetamide, and N,N-dimethylacetamide was investigated. Experimental results show that solvents decrease the amide binding energy by 4-6 kcal mol(-1). Using density functional theory (DFT), binding energies were evaluated using nine functionals, after full geometry optimizations with the ECP28MWB basis set for silver and the 6-311++G(2df,2pd) basis set for the other atomic constituents of the ligands. In addition, calculations employing the DZVP basis set for Ag and DZVP2 for C, H, N, and O atoms at the B3LYP and MP2 levels of theory were used to investigate the influence of the basis set on the theoretical bond energies. A comparison of the experimental and theoretical silver(I)-ligand bond dissociation energies enables an assessment of the limitations in the basis sets and functionals in describing the energetics of the metal-solvent interaction and the metal-amide interaction. No single functional/basis set combination was found capable of predicting binding energies with a sufficiently high level of accuracy for the silver(I)-amide solvent complexes.
使用竞争的阈能碰撞诱导解离(TCID)测量,评估了银(I)-酰胺配合物的水、甲醇和乙腈加合物的实验键离解能。研究了溶剂分子对银(I)与乙酰胺、N-甲基乙酰胺和 N,N-二甲基乙酰胺结合能的影响。实验结果表明,溶剂使酰胺的结合能降低了 4-6 kcal/mol。使用密度泛函理论(DFT),在 ECP28MWB 基组对银进行全几何优化,并在 6-311++G(2df,2pd)基组对配体的其他原子组成部分进行优化后,使用 9 种泛函评估了结合能。此外,还使用 DZVP 基组对 Ag 和 DZVP2 基组对 C、H、N 和 O 原子进行了 B3LYP 和 MP2 理论水平的计算,以研究基组对理论键能的影响。将实验和理论的银(I)-配体键离解能进行比较,可以评估基组和泛函在描述金属-溶剂相互作用和金属-酰胺相互作用的能量学方面的局限性。没有发现单一的泛函/基组组合能够以足够高的准确度预测银(I)-酰胺溶剂配合物的结合能。