Electrochemical Generation of Cyano Ligated Molybdenum Sulphur Tetramer Cubane Core: Synthesis and Characterization

Abstract

For the first time the conversion of trimeric {M3S4} 4+ to tetrameric (M4S4} 4+ core has been made for molybdenum complex. The complex, K5[Mo3S4(CN)9] (1) on using with strong reducing agent transformed into K8[Mo4S4(CN)12] (2) in near quantitative yield. The diamagnetic complex (1) containing {Mo3} 6 core can accommodate two electrons in its non bonding molecular orbital 2a1 under reducing environment to give a complex ion [Mo3S4(CN)9] 7with [Mo3] 8 electronic configuration. This reduced species undergoes re-oxidation by atmospheric air to give back the original compound with [Mo3] 6 core via a partially oxidized an intermediate species [Mo3S4(CN)9] 6with [Mo3] 7 core shows a characteristic EPR signal. However, under drastic reducing condition, the two electrons reduced species [Mo3S4(CN)9] 7with [Mo3] 8 core accommodate the next coming electron to its antibonding 2e orbital and thus achieve an unstable tri-nuclear [Mo3(III)] 9 core, where each metal centre has been reduced by one electron. The highly unstable and super reduced species [Mo3S4(CN)9] 8with [Mo3(III)] 9 configuration undergoes core transformation from cuboidal trinuclear [Mo3(IV)S4] 4+ to the cubane type tetranuclear core [Mo4(III)S4] 4+ of [Mo4S4(CN)12] 8complex ion. The corresponding tungsten-analogue though responses this reduction, but quickly oxidizes back to the starting material during work-up procedure.

Comparative Study of Physico- chemical Parameters of Ground water of Residential and Industrial area of Sirgitti in Bilaspur District

“…High chloride ion concentration indicates organic pollution in the water bodies. In water Samples when combine with calcium and magnesium may increase the corrosiveness of water 18 . Chlorides are generally found present in municipal sewage, human feces, urinary discharges etc.…”