Five dirhenium(III) compounds, Re2(3,5-(CH3)2ap)4Cl2 (1), Re2(ap)4Cl2 (2), Re2(3-MeOap)4Cl2 (3), Re2(3-Clap)4Cl2 (4), and Re2(3,5-Cl2ap)4Cl2 (5), were synthesized and characterized, where 3,5-(CH3)2ap, ap, 3-MeOap, 3-Clap and 3,5-Cl2ap are 2-(3,5-dimethylanilino)pyridinate, 2-anilinopyridinate, 2-(3-methoxyanilino)pyridinate, 2-(3-chloroanilino)pyridinate and 2-(3,5-dichloroanilino)pyridinate, respectively. Structural studies revealed the Re–Re bond lengths ranging from 2.2214(4) to 2.2262(11) Å, signifying that the dirhenium core maintains its quadruple bond. The asymmetric nature of 2-anilinopyridinate ligands resulted in several possible regioisomers: compounds 1 and 4 adopt a cis-(2,2) arrangement, while compounds 2 and 5 assume trans-(2,2) and (3,1) arrangements, respectively. All five compounds display three (quasi)reversible one electron couples, two oxidations and one reduction, and their electrode potentials correlate linearly with the Hammett constant of the aniline substituent.
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This work was supported in part by the Office of Naval Research (Contract Number N00014-03-1-0531), the National Science Foundation (CHE0242623) and the University of Miami (CCD-diffractometer fund). We thank Dr. G.-L. Xu for advice on the synthesis of HXap ligands, Mr. R. McGuire for examining the emission properties of compounds 1–5.
F. A. Cotton, C. A. Murillo, and R. A. Walton (eds.), Multiple Bonds between Metal Atoms, 3rd edn. (Springer Science and Business Media, Inc., New York, 2005)Google Scholar
Cotton F. A., Gu J., Murillo C. A., Timmons D. J. (1999) J. Chem. Soc. Dalton Trans. 21:3741CrossRefGoogle Scholar
Kadish K.M., Wang L.-L., Thuriere A., Van Caemelbecke E., Bear J.L. (2003) Inorg. Chem. 42:834CrossRefGoogle Scholar
Hisano T., Matsuoka T., Tsutsumi K., Muraoka K., Ichikawa M. (1981) Chem. Pharm. Bull. 29:3706Google Scholar
SAINT V 6.035 Software for the CCD Detector System (Bruker-AXS Inc., 1999)Google Scholar
(a) SHELXTL 5.03 (WINDOW-NT Version), Program Library for Structure Solution and Molecular Graphics (Bruker-AXS Inc., 1998); (b) G. M. Sheldrick, SHELXS-90, Program for the Solution of Crystal Structures (University of Göttigen, Germany, 1990); (c) G. M. Sheldrick, SHELXL-93, Program for the Refinement of Crystal Structures (University of Göttigen, Germany, 1993)Google Scholar