Chelated bis(NHC) complexes of saturated (imidazolin-2-ylidene) NHC ligands: structural authentication and facile
Michael G Gardiner1, David S McGuinness1, Catriona R Vanston1
1School of Physical Sciences (Chemistry), Private Bag 75, University of Tasmania, Hobart, Tasmania 7001, Australia. Michael.Gardiner@utas.edu.au.
Abstract:
The CH2-linked bis(NHC) complexes [{(SMesIm)2CH2}PdBr2] and [{(SMesIm)2CH2}Pd(NCMe)2][PF6]2 are reported. These represent the first structurally characterized chelated, saturated bis(NHC) complexes. The complexes are subject to facile ligand fragmentation during their synthesis. Longer (CH2)n-linkers in the imidazolin-2-ylidene-based series of ligands afforded the pendant imidazolinium mono(NHC) complexes [{(SMesImH)(SMesIm)(CH2)n}PdBr3] by reaction of the diimidazolinium salts (n = 2, 3) with palladium acetate. These did not react to give the bis(NHC) complexes, as was the case for [{(SMesImH)(SMesIm)CH2}PdX3] (X = Br, I). Disilver(i) complexes [{(SMesIm)2(CH2)n}2Ag2][PF6]2n = 1 and 3, were also prepared.
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