Structural, Spectral, Biological and Electrochemical Studies Of Some ...

2.6.5. NMR spectra
IH and 13C NMR spectra were recorded on a Broker DPX 300 in CDCl3 /DMSO-d 6
(CHe!), 0 = 7.26 and 13CDC13, 0 = 77) with TMS as internal reference at RRL,
Thiruvananthapuram. COSY homonuclear and HMQC heteronuclear spectra were
recorded with AMX 400 at I. I. Se. Bangalore.
2.6.6 EPR spectra
The EPR spectra were recorded on Varian E-112 X-band spectrometer operating with
100 KHz modulation frequency using TCNE (g=2.00277) as field marker at RSIC,
lIT, Bombay.
2.6.7 Mtsssbauer spectra
The Mossbauer spectra were recorded with a constant velocity Mossbauer
spectrometer with a multi channel analyzer CMCA-IOOOA supplied by Mls Wiessel
Germany. [Source 57CO (Rh)] at I.I.C, I.I.T, Roorkee.
2.6.8 Cyclic voltammetry
Cyclic voltammetry is the electrochemical equivalent of spectroscopy. It is a useful
tool for studying electrochemical reversibility and the effects of follow up chemical
reactions. It is the single most powerful tool for examining the electrochemical
properties of a chemical substance or material. Both thermodynamic and kinetic
information are available in a single experiment. The properties ofboth reactants and
products can frequently be discerned from a single voltammogram or from a series of
voltammograms obtained as a function of scan rate, concentration, pH, solvent type
temperature and so forth [8].
The cyclic voltammetric measurements were performed on a Cypress system
model CS-I090/ model CS -1087 computer controlled electro analytical system at
RRL Thiruvananthapuram. Measurements were made on the degassed (N2 bubbling
for 10 min) solutions in dimethylfonnamide (10. 3 M) containing 0.1 M tetrabutyl
anunonium fluroborate as the supporting electrolyte. The three electrode system
consisted of glassy carbon (working) platinum wire (counter) and Ag/AgCI
(reference) electrode or SCE.
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