An oxorhenium(V) Schiff-base complex: Synthesis, characterisation, structure, spectroscopic and electrochemical aspects

作者：Majumder Smita; Bhattacharya Arnab; Naskar Jnan Prakash; Mitra Partha; Chowdhury Shubhamoy^*

来源：Inorganica Chimica Acta, 2013, 399: 166-171.

DOI：10.1016/j.ica.2013.01.018

• Oxorhenium(V) complex
• Schiff-base ligand
• Fluorescence
• Electrochemistry
• DFT calculation

Reaction of equimolar proportion of trans-ReOCl3(PPh3)(2) with HL, a 1:1 Schiff-base condensate of salicylaldehyde and allylamine, in chloroform gives rise to ReO(L)(PPh3)Cl-2 1a in optimal yield. 1a has been characterized by C, H and N microanalyses, ESI-MS, FT-IR, UV-Vis spectra, molar conductivity measurements. The X-ray crystal structure of 1a reveals that it is an octahedral cis-Cl,Cl oxorhenium(V) complex. The rhenium center is in 'NO2Cl2P' coordination sphere. 1a crystallizes in the orthorhombic space group Pna2(1) with a = 17.3541(11), b = 10.2737(6), c = 15.2113(10) angstrom, V = 2712.0(3) angstrom(3) and Z = 4. The photophysical and electrochemical aspects of 1a have been studied. Electrochemical studies in dichloromethane show Re(V) to Re(VI) oxidation at 1.437 V along with a reduction of Re(V) to Re(IV) at -0.705 V versus Ag/AgCl. Excitation of 1a in chloroform at 460 nm leads to a fluorescent emission at 525 nm with a quantum yield (Phi) of 0.17. Geometry optimization of the cis-Cl,Cl complex 1a vis-a-vis its trans analogue, trans-Cl,Cl complex 1b, have been performed at the level of the density functional theory (DFT). It is revealed that 1b is more stable than 1a by 4 kcal per mole of energy in gas phase.

• 出版日期2013-4-1