Department of Chemistry, University at Buffalo, State University of New York, Buffalo, NY 14260-3000, USA.
Chemistry. 2011 Jan 3;17(1):161-73. doi: 10.1002/chem.201001343. Epub 2010 Nov 12.
Ab initio molecular dynamics (MD) and relativistic density functional NMR methods were applied to calculate the one-bond Hg-C NMR indirect nuclear spin-spin coupling constants (J) of [Hg(CN)(2) ] and [CH(3) HgCl] in solution. The MD averages were obtained as J((199) Hg-(13) C)=3200 and 1575 Hz, respectively. The experimental Hg-C spin-spin coupling constants of [Hg(CN)(2) ] in methanol and [CH(3) HgCl] in DMSO are 3143 and 1674 Hz, respectively. To deal with solvent effects in the calculations, finite "droplet" models of the two systems were set up. Solvent effects in both systems lead to a strong increase of the Hg-C coupling constant. From a relativistic natural localized molecular orbital (NLMO) analysis, it was found that the degree of delocalization of the Hg 5d(σ) nonbonding orbital and of the HgC bonding orbital between the two coupled atoms, the nature of the trans Hg-C/Cl bonding orbital, and the s character of these orbitals, exhibit trends upon solvation of the complexes that, when combined, lead to the strong increase of J(Hg-C).
从头算分子动力学（MD）和相对论密度泛函 NMR 方法被应用于计算 [Hg(CN)₂] 和 [CH₃HgCl] 在溶液中的 Hg-C ¹¹⁹ NMR 间接核自旋-自旋耦合常数（J）。MD 平均值分别为 3200 和 1575 Hz。[Hg(CN)₂] 在甲醇和 [CH₃HgCl] 在 DMSO 中的实验 Hg-C 自旋-自旋耦合常数分别为 3143 和 1674 Hz。为了在计算中处理溶剂效应，建立了这两个体系的有限“液滴”模型。两个体系中的溶剂效应对 Hg-C 耦合常数有很强的增强作用。从相对论自然局域分子轨道（NLMO）分析中发现，Hg 5d(σ)非键轨道和两个耦合原子之间的 Hg-C 成键轨道的离域程度、反式 Hg-C/Cl 成键轨道的性质以及这些轨道的 s 特征，在配合物的溶剂化过程中表现出一定的趋势，这些趋势共同导致了 J(Hg-C)的强烈增加。
