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Silver(I) Complexes of 1,3‐Dialkyl‐4,5‐dimethylimidazol‐2‐ylidenes and their Use as Precursors for the Synthesis of Rhenium(V) NHC Complexes
Author(s) -
Oehlke Elisabeth,
Kückmann Theresa,
Abram Ulrich
Publication year - 2007
Publication title -
zeitschrift für anorganische und allgemeine chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.354
H-Index - 66
eISSN - 1521-3749
pISSN - 0044-2313
DOI - 10.1002/zaac.200700021
Subject(s) - rhenium , transmetalation , carbene , reactivity (psychology) , chemistry , medicinal chemistry , derivative (finance) , stereochemistry , polymer chemistry , organic chemistry , catalysis , medicine , alternative medicine , pathology , financial economics , economics
Ag(BF 4 ) reacts with N‐heterocyclic carbenes (NHC) of the type 1,3‐dialkyl‐4,5‐dimethylimidazol‐2‐ylidene (L R , R = Me, Et, i‐Pr) under formation of [Ag(L R ) 2 ] + complexes. [Ag(L Et ) 2 ](BF 4 ) and [Ag(L i‐Pr ) 2 ](BF 4 ) can be isolated from such procedures as air‐stable solids, while the methyl derivative decomposes rapidly in the reaction mixture. The Ag–carbene bond lengths in [Ag(L i‐Pr ) 2 ](BF 4 ) are 2.08(1) Å. This is in accordance with the bonding situation in other Ag NHC complexes and does on its own not allow conclusions to be drawn concerning the bonding order or the reactivity of the compound. Reactions of [Ag(L Et ) 2 ](BF 4 ) with common rhenium(V) starting materials such as [ReOCl 3 (PPh 3 ) 2 ] or (NBu 4 )[ReOCl 4 ] give the known Re V NHC complex [ReO 2 (L Et ) 4 ] + . This transmetallation reaction represents a new approach to rhenium or technetium NHC complexes which possess potential for applications in nuclear medicine.