Articles written in Journal of Chemical Sciences
Volume 104 Issue 3 June 1992 pp 431-436 Physical and Theoretical
Correlation of ground and excited state dissociation constants of
R Murugesan B Rajasekar T Lekshmana Thanulingam A Shunmugasundaram
The ground and excited state dissociation constants of
Volume 107 Issue 1 February 1995 pp 1-10 Inorganic and Analytical
Spectral and voltammetric studies on titanium substituted Keggin-type heteropolyanions
R Murugesan P Sami T Jeyabalan A Shunmugasundaram
Bonding and redox properties of mono- and dititanium substituted 12-heteropolytungsto-phosphates and their complexes with bivalent Mn, Co, Ni and Cu are studied by UV-Vis, ESR and cyclicvoltammetric techniques. The heteropoly blue analogue [TiIIITiIVW10PO40]8− is unstable and its presence in solution is proved by optical and ESR spectroscopy. ESR results reveal that the odd electron is trapped on the titanium atom at 77 K. The optical electronegativity of Ti(III) in this heteropoly blue is estimated to be 2.4 from the intervalence charge transfer (IVCT) bands. X-ray powder diffraction results show that the complexes K5MII[Ti2W10PO40].xH2O(MII = Cu or Mn) are isomorphous with K7[Ti2W10PO40].6H2O. Electronic spectroscopy indicates very high symmetry around the bivalent metal ion M in the K5MII[Ti2W10PO40].xH2O complexes. This high symmetry is confirmed in K5Cu[Ti2W10PO40] by the observation of dynamic Jahn-Teller (JT) distortion at 300 K and static JT distortion at 77 K.
Volume 114 Issue 1 February 2002 pp 75-82 Physical and Theoretical
EPR investigations of electron transfer in one-electron reduced α-1,4 K5[PV2W10O40].3H2O
C M Varghese A Shunmugasundaram R Murugesan T Jey Abalan
Heteropoly blues of α-1,2 and α-1,4 isomers of [PV2W10O40]5−have been prepared by using the electrochemical technique. EPR spectra, measured as a function of temperature over a wide range (20-300 K), are explicable in terms of electron-hopping processes in heteropoly blues. Temperature dependence of A∥of the isomers suggest that the activation energy for electron hopping is greater for the α-1,4 isomer than the α-1,2 isomer. Other parameters like stability of the blues and intra-molecular electron transfer rate constants are also evaluated using EPR as the tool.
Volume 135, 2023
Continuous Article Publishing mode
Click here for Editorial Note on CAP Mode