학술논문
Synthesis and Structural Characterization of N-Heterocyclic Carbene Complexes of Silver(I) and Rhodium(I) from Caffeine
Document Type
Article
Source
Organometallics; April 2004, Vol. 23 Issue: 8 p1928-1931, 4p
Subject
Language
ISSN
02767333; 15206041
Abstract
The imidazolium cation 1,3,7,9-tetramethylxanthinium methyl sulfate (1a ) is obtained by the reaction of caffeine with dimethyl sulfate. The anion exchange of 1a gives 1,3,7,9-tetramethylxanthinium hexafluorophosphate (1b ). Ligand 1a reacts with Ag2 O in water to yield an N-heterocyclic carbene (NHC) silver(I) complex (2a ). Similarly, ligand 1b reacts with Ag2 O in DMSO to yield NHC silver(I) complex 2b in high yield. A carbene transfer reaction of 2b with [Rh(COD)Cl]2 gives NHC Rh(I) complex 3 . All compounds were characterized by 1H NMR, 13C NMR, and mass spectrometry. The solid-state structures of 1b , 2b , and 3 were determined by X-ray crystallography.