Inorg. Chem. 1987,electrons and formation of nonregular TCNQ chains, probably tetramerized. Such tetramerization can be the result of a specific interaction between TCNQ and dipole moments of cations. In this situation a systematic temperature change in the activation energy, E,, can occur. ConclusionsT C N Q complex salts with metallocene ions represent an interesting class of semiconducting organometallic compounds. Their transport and spectral properties are determined by the appearance of TCNQ chains. At high temperature the chains are nearly uniform, with delocalized electrons. This delocalization is seen from both spectral and transport properties. At low temperature the salts are characterized by nonregular charge dis-26, 1331-1338 1331 tribution along the chains. This is shown not only by the appearance of the energy gap at about 0.3 eV (and as a consequence the thermally activated electrical conductivity and strongly T dependent thermoelectric power) but also directly by the presence of the new absorption bands characteristic of TCNQ" with 0.3 < 6 < 0.6.The physical properties of TCNQ salts with metallocene ions are not unusual for organic low-dimensional conductors. The large, three-dimensional ions do not cause significant changes in the properties of the salts. This points to a secondary role for the counterions in TCNQ salts. However, in order to achieve a definitive interpretation of the properties of the salts, it appears necessary to include studies of other phenomena, especially spin ordering, for which ESR measurements will soon be carried out. [Cr(bpy),](PF,), and [Rh(bpy),](PF6), both crystallize in the trigonal space group R32, with site symmetry D, for the metal ions. Absorption and Zeeman spectra of neat [cr(bpy),](PF6), and dilute [Rh(bpy),](PF6),:Cr'+ in the region of ligand field transitions as well as emission spectra and EPR of the latter have been studied. Ground-state (4A2) and first-excited-state (2E) zero-field splittings and gvalues for Cr3+ and assignments of bands at higher energy to 4A2 -ZTI electronic origins are reported. The fine structure in the region of the 4A2 -4T2 and *T2 transitions is ascribed to vibrational sidebands of the former.

Abstract:The aim of the present study was to isolate and study about the antioxidant and antibacterial activity of carotenoid pigment. Sporobolomyces sp. isolated from the phyllosphere surface of rice plant has found to produce carotenoid pigment. The present investigation was carried out for antioxidant assays viz., DPPH, iron reducing and metal chelating activity. A steady increase in the antioxidant activities was observed in the carotenoid pigment with raising the pigment concentration. In the present study, the maximum antioxidation characteristics of carotenoid by DPPH, iron reducing and metal chelating assays (75.04 %, 1.88 % and 59.32 %) were achieved by pigmentation of Sporobolomyces sp. at the concentration of 100 µg ml -1 . The antibacterial activity was studied on several organisms like Enterococcus sp., Staphylococcus aureus, Streptococcus faecalis, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa. Among the six pathogens, the pigment was found to be more effective against E. coli (2.9 cm) and S. aureus (2.6 cm). This study revealed that yeast carotenoid pigment was a potential source for its use in food and pharmaceutical applications.

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