@article { ISI:000260803700002, title = {Lacunary Keggin type polyoxotungstates in conjunction with a phase transfer catalyst: an effective catalyst system for epoxidation of alkenes with aqueous H2O2}, journal = {Journal of Molecular Catalysis A-Chemical}, volume = {294}, number = {1-2}, year = {2008}, month = {OCT}, pages = {8-13}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Na-9[SbW9O33] in conjunction with a phase transfer catalyst (methyl tricapryl ammonium chloride) is a highly efficient catalytic system for the selective epoxidation of alkenes with aqueous H2O2 as the oxidant. Importantly, the reactions can be carried out in the absence of any organic solvents. The alkene epoxidation reactions with both, a transition metal ion substituted polyoxotungstate as well as a transition metal ion free polyoxotungstate precursor indicates that the tungstate group is the active center for the oxidation reaction. It was also observed that the transition metal ion does not play any significant role in the reaction. IR studies support the formation of tungsten-peroxo species and also show that the catalyst is stable in the presence of phase transfer catalyst when aqueous H2O2 is used as an oxidant. (C) 2008 Elsevier B.V. All rights reserved.

}, keywords = {alkenes, Aqueous H2O2, epoxidation, Na-9[SbW9O33], Phase transfer catalyst, polyoxometalates}, issn = {1381-1169}, doi = {10.1016/j.molcata.2008.07.003}, author = {Ingle, Rohit H. and Raj, N. K. Kala} } @article { ISI:000316624600020, title = {POM-catalyzed in situ ligand synthesis for the construction of metal complexes and their use in the formation of coordination polymers}, journal = {Chemphyschem}, volume = {14}, number = {5}, year = {2013}, month = {APR}, pages = {1009-1015}, publisher = {WILEY-V C H VERLAG GMBH}, address = {BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY}, abstract = {

Six organicinorganic hybrid materials were synthesized by the in situ oxidation of neocuproine by using MoO3/Na2MoO4 as the catalyst in the presence of Cu(NO3)2. The crystal structures of Mo8-Cu4-PHEN and Mo8-Cu2-5(2PIC) are composed of [Mo8O26]4 polyoxometalate (POM) units, whereas the crystal structure of Mo6-Cu-COPHEN is composed of a [Mo6O19]2 POM unit; both POM units could be considered as the active form of the catalyst. Reaction of the hybrid materials with 1,3,5-benzenetricarboxylic acid (BTC) resulted in the formation of two different coordination polymers (CPs) under different reaction conditions. These CPs, depending on their structural attributes, exhibit distinct differences in the adsorption of H2, CO2, and water. The use of 2-methylpyridine instead of neocuproine does not give any oxidation products under the same reaction conditions due to the incorrect positioning of the methyl group with respect to the CuII center.

}, keywords = {coordination polymers, Copper, N ligands, organicinorganic hybrid composites, polyoxometalates}, issn = {1439-4235}, doi = {10.1002/cphc.201201019}, author = {Dey, Chandan and Banerjee, Rahul} } @article {47586, title = {Polyoxometalate clusters: inorganic ligands for functional materials}, journal = {Journal of Cluster Science}, volume = {33}, year = {2022}, month = {SEP}, type = {Review}, abstract = {

Research in polyoxometalates (POMs) is a diverse growing field with variations in application. POMs are consisting of metal ion and oxide. Peripheral oxides of POM can share spare electron pairs to behave as ligands. This property of POM was utilized for constructing coordination polymers (CPs), synthesizing transitional metal substituted POM for catalysis, synthesizing and stabilizing nano-particles, etc. POM connected structures have provided an opportunity of heterogenization of some homogeneous POM catalyst. Furthermore, diamagnetic POM ligands have been suitable for stabilizing and isolating magnetic ions inside clusters. The scope of this review is to summarize the role of POMs as ligands to prepare POM based CPs, synthesize and stabilize metal nano-particles and isolate magnetic ion or unit.

}, keywords = {Coordination polymer, Inorganic ligand, materials science, polyoxometalates, synthesis design}, issn = {1040-7278}, doi = {10.1007/s10876-021-02110-8}, author = {Dey, Chandan} }