Synthesis, characterization and X-ray structure of one-dimensional polymeric complexes with triangular molybdenum clusters as building blocks: Na 2Ga 2[Mo 3O 4(O 2CEt) 8] 2 and Na 2AlGa[Mo 3O 4(O 2CEt) 8] 2

Abstract

The heterometallic polymeric cluster complexes Na 2Ga 2[Mo 3O 4(O 2CEt) 8] 2 ( 1) and Na 2AlGa[Mo 3O 4(O 2CEt) 8] 2 ( 2) have been prepared by reaction of Mo(CO) 6, NaMoO 4·2H 2O with GaCl 3 and a mixture of AlCl 3 and GaCl 3 (1:1 molar ratio), respectively, in heated propionic anhydride and characterized by X-ray crystallography. The structures are isostructural and each consists of two triangular propionate cluster units [Mo 3O 4(O 2CEt) 8] 4−, which act as polydentate ligands to link trivalent heterometal and sodium ions forming one-dimensional chain structures. Both clusters decompose in 2 M HCl at room temperature to produce discrete [Mo 3O 4] 4+ cluster units. Thermal analysis of 1 reveals that the complex is air stable up to 250°C. IR spectra show the characteristic bands of [Mo 3O 4] 4+ cores at 745–812 cm −1.