Preparation of Thiocarboxylate, Thiocarbamate and Xanthate Complexes of Pentacoordinate Nickel(II): Insertion of Heterocumulenes Into Nickel(II) Hydroxido Complexes

The hydroxido complexes [Ni(N 3 ‐mc)(μ‐OH)] 2 [PF 6 ] 2 [N 3 ‐mc = 2,4,4‐trimethyl‐1,5,9‐triazacyclododec‐1‐ene (N 3 ‐mc1) or 2,4,4,9‐tetramethyl‐1,5,9‐triazacyclododec‐1‐ene (N 3 ‐mc2)] react in the presence of alcohols with CS 2 or PhNCS to yield xanthate [(N 3 ‐mc)Ni{S 2 C(OR′)}][PF 6 ] or O ‐alkyl N ‐phenylthiocarbamate [(N 3 ‐mc)Ni{PhNC(OR′)S}][PF 6 ] complexes; these compounds represent the first examples of N,S‐chelating thiocarbamates bound to nickel(II). The reactions of [Ni(N 3 ‐mc)(μ‐OH)] 2 [PF 6 ] 2 with thiocarboxylic acids yield the corresponding thiocarboxylate derivatives [(N 3 ‐mc)Ni{SC(O)R′}][PF 6 ]. These paramagnetic nickel(II) complexes were characterized by both one‐ and two‐dimensional (COSY) 1 H NMR spectroscopic techniques. The crystal structures of [(N 3 ‐mc2)Ni(S 2 COCH 3 )][PF 6 ] ( 2 ), [(N 3 mc2)Ni{PhNC(OCH 2 CH 3 )S}][PF 6 ] ( 8 ), [(N 3 ‐mc2)Ni{SC(O)CH 3 }][PF 6 ] ( 10 ) and [(N 3 ‐mc1)Ni{SC(O)Ph}][PF 6 ] ( 11 ) were determined. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)