Adducts of tin(IV) tetrahalides with neutral lewis bases. I. Vibrational study of the cis-trans isomerism in solution

✍ Scribed by S.J. Ruzicka; A.E. Merbach

• Publisher: Elsevier Science
• Year: 1976
• Tongue: English
• Weight: 783 KB
• Volume: 20
• Category: Article
• ISSN: 0020-1693
• DOI: 10.1016/s0020-1693(00)94120-3

✦ Synopsis

A large number of SnX4*2L and SnX4*L-L tin-(IV) tctrahalide adducts were synthesized and analyzed (X = Cl, Br; L = MezO, EtzO, THF, Me& Et2S, THT, Me$e, MeCN, Me3CCN, Me&O, HMPA, TMPA; L-L = (MeOCH2-)2). Their cis or trans geometry was determined by infrared and Raman spectroscopy. For the SnC14 -2THT adduct, both isomers could be isolated by changing the solvent polarity. 771~ existence of a cis-tram equilibrium in solution has been demonstrated for the majority of the adducts by Raman measurements. This equilibrium strongly depends upon the solvent polarity, the cis isomer being favoured in a highly polar medium. Using a simplified model for Wilson S F-G matrices, the Sn-X force constants were determined and the following sequences deduced fk the strength of the tin-ligand bond in SnX4.2L: MezSe > Me# -THT -Et,S > Me20 -THF -Et20 and HMPA > TMPA.