CRYSTAL STRUCTURE AND ELECTRONIC SPECTRUM OF A VANADYL ALPHA-HYDROXYCARBOXYLATE COMPLEX . SODIUM TETRAETHYLAMMONIUM BIS(BENZILATO)OXOVANADIUM(4) DI-2-PROPANOLATE

This paper presents the crystal structure of monomeric sodium tetraethylammonium bis(benzilato)oxovanadmm(IV) di-2- propanolate, Nal[C2H5)4N] VO[(C6H5COCO3]22C3H7OH, as determined by three-dimensional Fourier methods with the positional and isotropic thermal parameters refined by least-squares methods to a conventional R factor of 0.12 based on 2435 nonzero reflections. The data were collected on multiple films by the equiinclination Weissenberg technique. The purple platelike crystals are monoclinic, space group P21/c, with a = 10.86 ± 0.02, b = 24.32 ± 0.04, c = 16.30 ± 0.02 Å, and β = 98° 57′ ± 9′. The density, as measured by flotation, is 1.23 ± 0.01 g/cm3,in agreement with 1.238 g/cm3 calculated assuming four molecules in the unit cell. The vanadium atom is in a 5-coordinate, distorted square-pyramidal environment with the vanadyl oxygen at the apex, and the two bidentate ligands arranged trans to oneanother. The solution, single-crystal, and polycrystalline optical spectraexhibit four bands similar to those of the trans-vanadyl(IV) d-tartrate system. Correlation of the structure ofthe vanadyl(IV) α-hydroxycarboxylates with their optical spectra suggests two possible orderings of the crystal field levels. © 1969, American Chemical Society. All rights reserved.