pi-donor/acceptor effect on lindqvist type polyoxomolibdates because of various multiple-bonded nitrogenous ligands
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Date
2007
Journal Title
Journal ISSN
Volume Title
Publisher
AMER CHEMICAL SOC
Abstract
The electronic structures of Lindqvist type functionalized polyoxometalates (POM) ([Mo6O18R](n-) R = O, NO, NAr, NNAr, NNAr2; n = 2, 3) have been investigated using density functional methods. We discuss the role of the replacement of terminal oxo ligands by pi-donor/acceptor multiple-bonded nitrogenous ligands on the basis of geometrical parameters, charge analyses, reactivity indexes, and vibrational spectra. The calculated reactivity indexes (chemical potential, electronegativity, hardness, and electrophilicity) indicate that the most reactive functionalized POMs are those substituted by pi-acceptor ligands. These pi-acceptor ligands induce a decrease in the hardness and an increase in the chemical potential and electrophilicity, thus increasing the reactivity. Our calculations are in reasonable agreement with reported experimental data.
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Keywords
OXO-NITROSYL COMPLEXES, DENSITY-FUNCTIONAL THEORY, CYCLOPHOSPHAZENE COMPLEX, ORGANOIMIDO DERIVATIVES, ELECTRONIC-STRUCTURE, RELATIVE BASICITIES, MOLECULAR-STRUCTURE, 2ND DERIVATIVES, MO, POLYOXOMETALATE