13C and 199Hg nuclear magnetic resonance study of alkynyl mercury(II) compounds

✍ Scribed by Angelika Sebald; Bernd Wrackmeyer

• Publisher: Elsevier Science
• Year: 1982
• Tongue: English
• Weight: 912 KB
• Volume: 38
• Category: Article
• ISSN: 1386-1425
• DOI: 10.1016/0584-8539(82)80192-x

✦ Synopsis

Alkynyl mercury compounds of the type Hg(C=C-R)r (I), R'-Hg-C=C-R (II) and R'-Hg-GC-Hg-R' (III) have been studied by 'H, 13C and lPHg NMR. Chemical shifts (6'H, S"C, SIWHg) and coupling constants J(lWHg'H), J('99Hg'3C), J(13C'H) and J('3C5'3C) (in natural abundance) are reported. The changes in magnitude of the coupling constants 'J('99Hg'3C=) and 'J('3Ca'3C) cannot be fully explained in terms of changes in the "s-character" of the Hg-C= bond and the CzC bond, respectively. The shielding of the alkynyl carbon linked to mercury in II is decreased by cc. 23 ppm as compared to the analogous carbon in I. This indicates a greatly different degree of polarization for the Hg-Cz bonds in I and II in agreement with the behaviour of 'J('99Hg'3C=) and 'J('3C='3C). The solvent and temperature dependence of the lWHg chemical shift of I (R = C6HJ, C4Hg") and II (R = H, R' = CH3) has been studied. The results indicate covalent interactions of I with amines, pyridine, dimethylsulnhide and Br-, while the interaction with acetonitrile and oxygen donors (DMSO, DMF, dioxane, acetone) is of a different nature. R'=CR(a) CzH4b) Cd-b"(c) WWX&(d) WW3CI-W CHKHQ) GH&) R=C.,H9" R' = CH,(b) &H,(l) R' = CsH5 R' = Cl(k) C=C-C,H,"(l) CHAm) GHh) R'-Hg-C=C-Hg-R R'=%.(a) CzHAU CdMc) GJ-Ud)