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Dinuclear Macrocyclic Quinoline Bridged Mercury and Silver Bis( N ‐heterocyclic Carbene) Complexes: Synthesis, Structure, and Spectroscopic Studies
Author(s) -
Lin CaiXia,
Kong XiaoFei,
Xu FengBo,
Zhang ZhengZhi,
Yuan YaoFeng
Publication year - 2013
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.201300067
Subject(s) - quinoline , carbene , chemistry , acetonitrile , medicinal chemistry , stereochemistry , crystallography , polymer chemistry , organic chemistry , catalysis
Quinoline bridged imidazolium precursors 5,8‐bis( N ‐ R ‐imidazolylidenylmethylene)quinoline PF 6 – salts [H 2 L](PF 6 ) 2 [ R = Me ( 1a ), R = naphthylmethyl ( 1b )] were prepared by quaternization of N ‐methylimidazole and N ‐naphthylmethylimidazole with 5,8‐bis(bromomethyl)quinoline, respectively. Reaction of the imidazolium ligands 1a and 1b with Hg(OAc) 2 and Ag 2 O in acetonitrile gave the macrocyclic transition metal carbene complexes [Hg 2 L 2 ](PF 6 ) 4 ( 2a and 2b ) and [Ag 2 L 2 ](PF 6 ) 2 ( 3a and 3b ), respectively. All the N‐heterocyclic carbene complexes were characterized in detail by NMR, ESI‐MS, and elemental analysis. Structures of complexes 2a and 3a were determined by X‐ray diffraction studies. Structural studies revealed that the coordination arrangement of the central mercury atom in complex 2a displays a tricoordinate mode and the molecular conformation results in a“closed” form with the bridging quinoline functionality in the macrocycle, whereas the silver complex 3a does not show an coordiantion between the bridging quinoline and the Ag I ion, which results in an “open” conformation of the macrocycle. The Hg II and Ag I NHC complexes showed similar UV absorption and luminescence in acetonitrile solutions.