Silicagel support mediated nonphotolytic cleavage of the rhenium–rhenium bond of [{NC5H4N=NC6H4(R)}(CO)3Re0]2.Synthesis of the monomeric species ReI{NC5H4N=NC6H4(R)}(CO)3Cl, crystal structure, spectroscopic and electron-transfer properties
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Title |
Silicagel support mediated nonphotolytic cleavage of the rhenium–rhenium bond of [{NC5H4N=NC6H4(R)}(CO)3Re0]2.Synthesis of the monomeric species ReI{NC5H4N=NC6H4(R)}(CO)3Cl, crystal structure, spectroscopic and electron-transfer properties
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Creator |
SAMANTA, RAMAPATI
MUNSHI, PRADIP SANTRA, BIDYUT KUMAR LOKANATH, NK SRIDHAR, MA PRASAD, JS LAHIRI, GOUTAM KUMAR |
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Subject |
rhenium
cleavage of rhenium electron transfer |
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Description |
The reaction of Re2(CO)10 with the 2-arylazopyridine ligand, L [L=NC5H4–N=N–C6H4(R), R=H, o-Me/Cl, m-Me/Cl] in dry THF under a dinitrogen atmosphere afforded a metal–metal bonded product of the type (L)(CO)3Re0–Re0 (CO)3(L) 1. On a silica gel column and in the presence of chlorinated solvents (CHCl3 or CH2Cl2) the complex 1 transformed into a mononuclear complex of composition ReI(L)(CO)3Cl 2, where the cleavage of Re–Re bond of 1 and the oxidative addition of chlorine to the rhenium center have taken place consecutively. The molecular structure of the complex 2a (R=H) has been determined by single crystal X-ray diffraction. The crystal lattice consists of two crystallographically independent Re(L1)(CO)3Cl molecules which are non-superimposable mirror images; d and l enantiomers, exist in a 1:1 ratio. The complexes 2 display irreversible ReI→ReII oxidation processes near 1.5 V versus SCE and two quasi-reversible azo (N=N) reductions in the ranges −0.28 to −0.48 V and −0.83 to −1.06 V versus SCE. The complexes of the type 1 exhibit only four successive azo reductions in the range 0 to −2 V versus SCE. Both the complexes (1 and 2) display dπ(Re)→π*L metal-to-ligand charge-transfer transitions near 500 nm and intraligand n–π* and π–π* transitions near 400 and 300 nm, respectively. The complexes 2 are susceptible to a spontaneous chloride exchange reaction.
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Publisher |
Elsevier
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Date |
2009-03-23T09:44:54Z
2011-11-25T20:18:28Z 2011-12-26T13:08:07Z 2011-12-27T05:56:07Z 2009-03-23T09:44:54Z 2011-11-25T20:18:28Z 2011-12-26T13:08:07Z 2011-12-27T05:56:07Z 1999 |
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Type |
Article
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Identifier |
Journal of Organometallic Chemistry 579(1-2), 311-320
0022-328X http://dx.doi.org/10.1016/S0022-328X(99)00016-9 http://hdl.handle.net/10054/1084 http://dspace.library.iitb.ac.in/xmlui/handle/10054/1084 |
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Language |
en
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