The Local Structure of Liquid TiCl4 Analyzed by X-Ray Diffraction and Raman Spectroscopy

Abstract

Structural analyses were performed to determine the local structure of liquid TiCl 4 using laboratory-scale X-ray diffraction and Raman spectroscopy from which the existence of tetrahedral TiCl 4 molecules in the liquid was definitely confirmed. Conventionally, in molten salts, the valence increase of the central metal ion, for example in the range from 1 to 3, leads to more complicated liquid structures, yet a further increase in valence is usually accompanied by an enhanced covalency, forming stable tetrahedral molecules like e. g. CCl 4 . We discuss the intermolecular structure of TiCl 4 liquid as well as the intramolecular one.

Structure of Neat Liquids Consisting of (Perfect and Nearly) Tetrahedral Molecules

“…Although the first studies (in the mid-1970s) were performed on single materials (SiCl 4 , refs and ), later comparative investigations on more than one member of the family have become customary (see, e.g., X-ray diffraction on GeCl 4 and SnCl 4 , ref ; SiCl 4 and GeCl 4 , ref ; neutron diffraction on CCl 4 , SiCl 4 , TiCl 4 , and SnCl 4 , ref ; on each tetrachloride in the series, refs and ). As an extension to these investigations concerning neat liquids, mixtures of these tetrachlorides have also been measured. ,, Interestingly, a rather wide range of neutron data are available, whereas unfortunately, no comprehensive synchrotron X-ray diffraction investigation is available at present (even though the technique is perfectly fit for such studies, as exemplified by liquid TiCl 4 ). The published data are in reasonable agreement for a given material (although some problems have been reported, see ref concerning liquid SnCl 4 ), and a database of experimental total scattering structure factors provides a solid foundation for subsequent simulation/modeling studies.…”

“…As an extension to these investigations concerning neat liquids, mixtures of these tetrachlorides have also been measured. 144,145,260 Interestingly, a rather wide range of neutron data are available, whereas unfortunately, no comprehensive synchrotron X-ray diffraction investigation is available at present (even though the technique is perfectly fit for such studies, as exemplified by liquid TiCl 4 150 ). The published data are in reasonable agreement for a given material (although some problems have been reported, see ref 147 concerning liquid SnCl 4 ), and a database of experimental total scattering structure factors provides a solid foundation for subsequent simulation/modeling studies.…”

Improving Ti Incorporation into the BEA Framework by Employing Ethoxylated Chlorotitanate as Ti Precursor: Postsynthesis, Characterization, and Incorporation Mechanism

“…The spectra of EtOH, DCM, TiCl 4 , and TEOT were obtained for reference and are shown in Figure A, and the Ti precursor liquids were analyzed and are shown in Figure B. The peaks at 382 and 486 cm –1 (Figure A, c) are assigned to TiCl 4 , , and the peaks at 606, 922, and 1072 cm –1 (Figure A, d) are assigned to TEOT . When TiCl 4 (or TEOT) was dissolved in DCM (Figure B, a and f), an obvious decrease in the peak intensity (compared to Figure A, b and d) and blue shift of approximately 2–5 cm –1 in the characteristic absorption bands (280 and 699 cm –1 for Figure A, b and 322, 390, 606, 922, 1072, and 1169 cm –1 for Figure A, d) are observed, which suggest interaction between solvent and Ti-containing compounds.…”