X-ray crystal structures and solution dynamics of sodium organofluorotitanates [Na{Ti2(C5Me5)2F7}] and [NaTi6(C5Me5)5F20(H2O)]·(THF)

[Na{Ti2(C5Me5)2F7}] (1) was prepared from sodium fluoride and [{Ti(C5Me5)F3}2] [H.W. Roesky, et al., Angew. Chem. Int. Ed. Engl. 31 (1992) 864–866]. The solid-state 1 consists of a polymeric chain of two rows of dititanate anions [Ti2(C5Me5)2F7]− connected by sodium ions in the middle of the chain. Each sodium ion is coordinated by five fluorine atoms from three [Ti2(C5Me5)2F7]− anions. The variable-temperature 19F NMR of CD3CN solution of 1 revealed interconversions of monomeric species [Na(CD3CN)n{Ti2(C5Me5)2F7}] (1solv) with different number of CD3CN ligands on the sodium ion. The addition of HMPA to the CD3CN solution of 1 allows 19F NMR observation of 1·HMPA (1a) and 1·HMPA·CD3CN (1b) in the slow exchange. The solid-state structure of [NaTi6(C5Me5)5F20(H2O)]·(THF) (2·THF) reveals the sodium ion coordinated by four fluorine atoms from the anion [Ti2(C5Me5)2F7]− and by three fluorine atoms from the cluster [Ti4(C5Me5)3F13(H2O)].