Isolation and single crystal study of [Nb-2(mu-OMe)(2)((OPr)-Pr-i)(8)]. Can alcohol interchange provide the homoleptic niobium isopropoxide?

Sammanfattning

Niobium isopropoxide, Nb((OPr)-Pr-i)(5), is an attractive precursor of simple and complex niobium oxides in sol-gel technology. This compound cannot, unfortunately, be obtained by alcohol interchange starting from linear chain homologues such as Nb(OMe)(5) or Nb(OEt)(5). The equilibrium in the latter reaction favours formation of mixed-ligand complexes, [Nb-2(OR)(2)((OPr)-Pr-i)(8)], R = Me, Et. In particular, [Nb-2(OMe)(2)(OPri)(8)] (1) has been isolated in high yield from repeated treatment of Nb-2(OMe)(10) with excess of isopropanol. The X-ray single crystal study reveals a dinuclear structure containing a pair of edge-sharing octahedra with methoxide ligands in the bridging position. Infrared (IR) and mass spectroscopy (MS) studies confirmed the incomplete ligand substitution. The H-1-NMR spectra suggest equilibrium between different molecular forms in solution. Solvothermal interaction of 1 with La chips in toluene/isopropanol media results in formation of a mixture of LaNb2((OPr)-Pr-i)(13) and La2Nb4(mu(4)-O)(4)(OH)(2)(mu-(OPr)-Pr-i)(8)((OPr)-Pr-i)(8) (2)

Nyckelord

Niobium alkoxides; Alcohol interchange; Sol–Gel; Precursors; Lanthanum; Solvothermal synthesis

Publicerad i

Journal of Sol-Gel Science and Technology
2007, Volym: 43, nummer: 1, sidor: 105-109 Utgivare: SPRINGER

SLU författare

• Seisenbaeva, Gulaim

  • Institutionen för molekylära vetenskaper, Sveriges lantbruksuniversitet
    

• Kessler, Vadim

  • Institutionen för molekylära vetenskaper, Sveriges lantbruksuniversitet
    

Publikationens identifierare

DOI: https://doi.org/10.1007/s10971-007-1568-0

Permanent länk till denna sida (URI)

https://res.slu.se/id/publ/14594