EPR and electronic spectroscopic studies of Keggin type undecatungstophosphocuprate(II) and undecatungstophosphocuprate(II)

• Type: Article in International Scientific Journal
• Date: 1999

Authors

Gamelas, JA (Author) Other; Santos, ICMS (Author) Other; Freire, C (Author) FCUP; de Castro, B (Author) FCUP; Cavaleiro, AMV (Author) Other

Journal

Title: Polyhedron

Vol. 18

Pages: 1163-1169

ISSN: 0277-5387

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 10 Citations

Scopus - 10 Citations

Scientific classification

FOS: Natural sciences > Chemical sciences

Other information

Authenticus ID: P-001-652

DOI: 10.1016/s0277-5387(98)00410-0

Abstract (EN): The coordination of Cu(II) to the Keggin type anions alpha-undecatungstophosphocuprate(II) and alpha-undecatungstoborocuprate(II) was investigated in different environments by EPR and electronic spectroscopy. This study has shown that the coordination geometry around Cu(II) in the tetrabutylammonium (TBA) salts, (TBA)(4)H-x[XW11CuO39], with X = P or B, is square pyramidal, with copper bound to the five oxygen donor atoms of the polyoxometalate, whereas for the [XW11Cu(H2O)O-39](n-) anion, on the corresponding potassium salt, a tetragonally elongated pseudo-octahedral geometry was found. For the potassium salts, in aqueous solution, six-coordinated copper is, the only form found. For the TEA salts, in nonaqueous solvents, we can observe either the presence of only one form (the six-coordinated Cu(II) species, with a solvent molecule bound to copper), or of two forms: the solvent coordinated copper anions and the five-coordinated copper [XW11CuO39](n-) anions.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 7