Journal
POLYHEDRON
Volume 51, Issue -, Pages 27-40Publisher
PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/j.poly.2012.11.050
Keywords
Cu(l)- and Ag(I)-coumarin Schiff base complexes; X-ray structure; Fluorescence; Coulometric oxidation; DFT computation
Categories
Funding
- CSIR
- UGC
- PURSE New Delhi
Ask authors/readers for more resources
Mixed ligand complexes of Cu(I) and Ag(I) with bis(diphenylphosphino)methane (dppm)/1,2-bis(diphenylphosphino)ethane (dppe) and N-{(2-pyridyl) methyliden}-6-coumarin (L) have been synthesized and characterized by elemental analyses, conductivity, H-1 NMR, UVVis and fluorescence spectral data. The coordination of dppm to M(I) forms a binuclear metallacycle, [(L)M(mu-dppm)(2)M(L)](X)(2) (X = NO3 or ClO4), and one of the complexes has been characterized by single crystal X-ray structure analysis. The dppe ligand is a bidentate chelator, which is supported by the X-ray structure of [Cu(dppe)(L)]ClO4. In the Ag(I) complex, dppe is serving as a bridging agent to form the binuclear complex [(L)Ag(mu-dppe)Ag(L)](NO3)(2), and NO3- asymmetrically chelates Ag(I), which exhibits solvent polarity dependent coordination. In a coordinating polar solvent, like MeCN, the nitrate group dissociates and shows conductivity, while in nitrobenzene the complex is non-conducting and supports no dissociation. The complexes are more fluorescent than free L. Cyclic voltammetry shows a Cu(II)/Cu(I) quasireversible couple, while the Ag(I) complexes exhibit deposition of Ag(0) on the electrode surface. The coulometric and Cl-2 oxidation of the Cu(I) complexes have isolated Cu(II) complexes that are established by spectroscopic and magnetic data. The electronic configuration of the complexes is assessed by DFT computation, and the spectral and redox properties are explained. (C) 2013 Elsevier Ltd. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available