Nuclear spin relaxation study of the solution reorientation of 3,5-dichlorophenyl- and phenylethynyl-mercury cyanide molecules and shielding tensors of nuclei forming the –HgCN and –CCHgCN groups: estimation of the heavy atom effect of mercury

✍ Scribed by Sergey Molchanov; Adam Gryff-Keller

• Publisher: John Wiley and Sons
• Year: 2003
• Tongue: English
• Weight: 120 KB
• Volume: 41
• Category: Article
• ISSN: 0749-1581
• DOI: 10.1002/mrc.1261

✦ Synopsis

Abstract

3,5‐Dichlorophenylmercury cyanide (1) and phenylethynylmercury cyanide (2) dissolved in DMSO‐d~6~ have been investigated using ^13^C, ^15^N and ^199^Hg NMR and density functional theory (DFT) calculations. The longitudinal relaxation times of ^13^C and ^199^Hg nuclei of compounds 1 and 2 and of the ^15^N nucleus of 1 have been measured at two magnetic fields. On the basis of these data the rotational diffusion constants describing the reorientation rates of the investigated molecules in solution and the shielding anisotropy parameters for nuclei of atoms forming the –HgCN group have been determined. The available NMR characteristics of several other cyanomercury compounds and those containing the ethynylmercury fragment have also been collected. The experimental values of carbon and nitrogen shielding parameters for the cyanomercury and ethynylmercury groups have been compared with those calculated theoretically using the DFT GIAO method. This comparison has allowed an estimation of the size of the deshielding heavy atom effect experienced by the sp‐hybridized mercury‐bonded carbons atoms. Copyright © 2003 John Wiley & Sons, Ltd.