Spirocyclic tin salicyl alcoholates - a combined experimental and theoretical study on their structures, Sn NMR chemical shifts and reactivity in thermally induced twin polymerization

• Published in: Dalton transactions : an international journal of inorganic chemistry 2019, Vol.48 (1), p.22-23
• Main Authors: Kitschke, Philipp, Preda, Ana-Maria, Auer, Alexander A, Scholz, Sebastian, Rüffer, Tobias, Lang, Heinrich, Mehring, Michael
• Format: Article
• Language: English
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/c8dt03695k

The spirocyclic tin salicyl alcoholate, 4 H ,4′ H -2,2′-spirobi[benzo[ d ][1,3,2]dioxastannine] ( 1 ), and its 6,6′-dimethoxy ( 2 ) and 8,8′-di- tert -butyl-6,6′-dimethyl derivative ( 3 ) were synthesized and thermally induced twin polymerization of precursor 2 was performed to give a SnO 2 -containing hybrid material. Studies on the molecular structures of 1-3 were carried out using 119 Sn{ 1 H} CP MAS NMR spectroscopy and DFT calculations. Crystallization of compound 3 from dimethyl sulfoxide solution provided the Lewis acid-base adduct 3 (dmso) 2 exhibiting a hexacoordinated tin atom in the solid state, in agreement with the results of the spectroscopic and DFT calculation data. 119 Sn NMR spectroscopy of the compounds 1-3 and 3 (dmso) 2 revealed equilibria among the diverse oligomers in solution phase pointing at hexacoordinated tin atoms. Studies on a series of spirocyclic tin salicyl alcoholates regarding their molecular structures and their reactivity in twin polymerization are presented.