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Mixed‐Ligand Copper Complexes with 8‐Methylthioquinoline and Triphenylphosphane or the o ‐Semiquinone/Catecholate Redox System
Author(s) -
Ye Shengfa,
Sarkar Biprajit,
Niemeyer Mark,
Kaim Wolfgang
Publication year - 2005
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.200500567
Subject(s) - chemistry , semiquinone , copper , crystallography , thioether , electron paramagnetic resonance , ligand (biochemistry) , tautomer , phosphine , valence (chemistry) , stereochemistry , photochemistry , redox , inorganic chemistry , nuclear magnetic resonance , organic chemistry , biochemistry , physics , catalysis , receptor
The complex [Cu(MTQ)(PPh 3 ) 2 ](BF 4 ), MTQ = 8‐methylthioquinoline, exhibits distorted tetrahedral coordination at thecopper( I ) center. One of two crystallographically independent molecules found in the unit cell exhibits a more pronounced inclination towards a (3+1) coordination arrangement. In comparison to the analogous complex with the related imine/thioether chelate ligand 1‐methyl‐2‐(methylthiomethyl)‐ 1H ‐benzimidazole, the cation [Cu(MTQ)(PPh 3 ) 2 ] + shows stronger bonding of Cu I to S and weaker interaction with N. With 3,5‐di‐ tert ‐butyl‐ o ‐semiquinone as co‐ligand instead of two PPh 3 ligands a valence‐tautomer equilibrium situation involving the copper( II )‐catecholate state can be observed by EPR spectroscopy, showing an unusually large isotropic 63,65 Cu hyperfine coupling of 2.1 mT and an untypically small isotropic g value of 1.975. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)