Hetero-bimetallic alkali titanosilicates [MOTi{OSi(O t Bu) 3 } 3 ] 2 (M = Li-Cs) with terminal Ti-O - groups.

The molecular titanosilicate [( t BuO 3 ) 3 SiO] 3 TiNEt 2 (1) was obtained from the reaction between silanol ( t BuO 3 ) 3 SiOH and titanium amide Ti(NEt 2 ) 4 . The reaction of 1 with alkali metal hydroxides MOH (M = Li, Na, K, Rb, Cs) offers a straightforward route to the alkaline salts of titanosilicates [MOTi{OSi(O t Bu) 3 } 3 ] 2 with a terminal Ti-O - moiety. All compounds were characterised by single-crystal X-ray diffraction studies. Hirshfeld atom refinement and QTAIM analysis of the electron density in 1 and in the Rb salt 5 revealed the D-A nature of the Ti-O and Ti-N bonds and the presence of agostic C-H⋯Rb interactions.