Abstract

The structure of the N,N-dimethylthioformamide (DMTF)solvated gallium(III)ion has been determined in solution by means of extended X-ray absorption fine structure (EXAFS)spectroscopy. The gallium(III) ion is four-coordinate in tetrahedral fashion with a mean Ga-S bond distance of 2.233(2)angstrom in DMTF solution. At the dissolution of indium(III)perchlorate or trifluoromethanesulfonate in DMTF coordinated solvent molecules are partly reduced to sulfide ions, and a tetrameric complex with the composition [In4S4(SHN(CH3)(2))(12)](4+) is formed. The structure of the solid tetrameric complex in the perchlorate salt was solved with single crystal X-ray diffraction. Four indium(III)ions and four sulfide ions form a highly symmetric heterocubane structure where each indium binds three bridging sulfide ions and each sulfide ion binds three indium(III)ions with a mean In-S bond distance of 2.584(1)angstrom, and S-In-S angles of 90.3(1)degrees. Each indium(III)additionally binds three DMTF molecules at significantly longer mean In-S bond distance, 2.703(1)angstrom; the S-In-S angles are in the range 80.3-90.4 degrees. Large angle X-ray scattering data on a DMTF solution of indium(III)trifluoromethanesulfonate show that the same tetrameric species characterized in the solid state is also present in solution, whereas the EXAFS measurements only give information about the In-S bond distances due to the short core hole lifetime. (C) 2010 Elsevier B. V. All rights reserved.

Keywords

Gallium(III); Indium(III); N,N-dimethylthioformamide (DMTF); EXAFS

Published in

Inorganica Chimica Acta
2011, volume: 365, number: 1, pages: 220-224
Publisher: Elsevier

Authors' information