18-Crown-6 and Titanium Tetrafluoride − Preparation of the TiIV Fluoride Crown Ether Complexes (TiF4)2(18-Crown-6) and the Stabilization of cis-TiF4(H2O)2 in [{cis-TiF4(H2O)2}2(18-Crown-6)]

✍ Scribed by T. Stanley Cameron; Andreas Decken; Evgeny G. Ilyin; Grigori B. Nikiforov; Jack Passmore

• Publisher: John Wiley and Sons
• Year: 2004
• Tongue: English
• Weight: 181 KB
• Volume: 2004
• Category: Article
• ISSN: 1434-1948
• DOI: 10.1002/ejic.200400310

✦ Synopsis

Abstract

Reaction of TiF~4~ and 18‐crown‐6 in MeCN affords the molecular complex [(__cis‐__TiF~4~)~2~(18‐crown‐6)] (1) only. Water and THF displace the 18‐crown‐6 in the tetrafluoro complex 1, with the formation of __cis‐__TiF~4~L~2~. The complex __cis‐__TiF~4~(H~2~O)~2~ and 18‐crown‐6 form [{__cis‐__TiF~4~(H~2~O)~2~}~2~(18‐crown‐6)] (2), in which __cis‐__TiF~4~(H~2~O)~2~ and 18‐crown‐6 are connected by hydrogen bonding through the protons of coordinated H~2~O in TiF~4~(H~2~O)~2~ and the oxygen atoms of the crown ether. Complexes 1 and 2 were characterized by X‐ray single crystal analysis, elemental analysis, IR, NMR and Mass spectroscopy. The relative basicities of the 18‐crown‐6 and the molecular donor ligands MeCN, THF, H~2~O toward Ti^IV^ fluoride were established by NMR spectroscopic investigations of the substitution reactions. 18‐crown‐6 is slightly more basic than MeCN, similar to that of Et~2~O, and less basic than THF and H~2~O. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)