1018074-86-6Relevant articles and documents
'Pincer' pyridine dicarbene complexes of nickel and their derivatives. Unusual ring opening of a coordinated imidazol-2-ylidene
Pugh, David,Boyle, Aimee,Danopoulos, Andreas A.
, p. 1087 - 1094 (2008)
The reaction of NiBr2(DME), DME = 1,2-dimethoxyethane, with the 'pincer' pyridine dicarbene ligands (C-N-C) (2) and (C-NMe-C) (2 Me), (C-N-C = 2,6-bis-[(DiPP)imidazol-2-ylidene]pyridine, C-N Me-C = 2,6-bis-[(DiPP)imidazol-2-ylidene]-3,5-dimethylpyridine, DiPP = 2,6-diisopropylphenyl) gave the square planar complexes [Ni(C-N (Me)-C)Br]Br, 3?(Br)- and 3Me?(Br) - respectively. Transmetallation from [(C-NMe-C) 2Ag2](Ag6I8), 6Me? (Ag6I8)2- to NiBr2(DME) gave [Ni(C-NMe-C)Br](AgI2), 3Me?(AgI 2)-. Reaction of 3?(Br)- with KPF 6 resulted only in exchange of the ionic bromide, however the reaction of 3?(Br)- with AgBF4 in MeCN or AgOTf in THF resulted in the exchange of both coordinated and ionic bromides, giving rise to the square planar 4?(BF4)-2 and octahedral 5, respectively. In contrast, the reaction of 3Me? (AgI2)-, with excess AgOTf resulted in an unusual 'reverse transmetallation' leading to 6Me?(OTf)-. The substitution of tmeda in Ni(CH3)2(tmeda), tmeda = N,N,N′,N′-tetramethylethylenediamine, by 2 produced the complex 7, in which ring opening of the heterocyclic imidazole ring of one of the NHC functional groups has taken place. The Royal Society of Chemistry.
