New Fluorinated Stannic Compounds as Precursors of F-Doped SnO2 Materials Prepared by the Sol−Gel Route

• Published in: Inorganic chemistry Vol. 38; no. 21; pp. 4671 - 4679
• Main Authors: Gamard, A, Jousseaume, B, Toupance, T, Campet, G
• Format: Journal Article
• Language: English
• Published: American Chemical Society 18.10.1999
• ISSN: 0020-1669; 1520-510X
• DOI: 10.1021/ic990163s

Dialkoxydi(β-diketonate)tin(IV) compounds react either with difluorodi(β-diketonate)tin(IV) or with butanoyl fluoride to yield novel tin complexes Sn(OR1)F(R2COCHCOR2)2 1 (R1 = tert-amyl, isopropyl, ethyl; R2 = methyl, tert-butyl). Multinuclear 1H, 13C, 19F, and 119Sn NMR spectroscopic characterization showed that complexes 1 are octahedral in solution with a cis configuration for the fluorine and the alkoxide group. Kinetics of configurational rearrangements were studied by variable-temperature 13C NMR spectroscopy. The hydrolytic behavior of 1 was determined for different hydrolysis ratios h = [H2O]/[1]. For R1 = tert-amyl, a dimeric fluorinated species was mainly obtained for h = 0.5, and addition of 2 mol equiv of water led to a fluorinated stannic oxopolymer soluble in CH3CN. In the latter case, the powder obtained after solvent elimination and treatment in air at 550 °C consisted of crystalline SnO2 cassiterite particles containing the required amount (3 mol %) of doping fluorine and exhibiting electronic conductivity comparable to that of Sn-doped In2O3. Complexes 1 are the first precursors of F-doped SnO2 materials prepared by the sol−gel route.