Dichlorosilanes with bulky substituents R(Me3C)SiCl2 react with liquid ammonia to give geminal silyldiamines [R(Me3C)Si(NH2)2, 1: R = CH2 Me, 2: R = CHMe2]. In the reaction of the monolithium derivatives of these compounds with halosilanes 1-amino-1.3-disilazanes are obtained [(NH2)(Me3C)RSi-NH-SiR1R2R3; 3: R = CMe3, R1 = R2 = R3 = Me; 4: R = R1 = CMe3, R2 = R3 = Me; 5: R = R1 = R2 = CMe3, R3 = H; 6: R = R1 = CMe3, R2 = Me, R3 = F; 7: R = CHMe2, R1 = R2 = R3 = Me]. If monolithiated diamines are treated with trifluorosilanes cyclisation occurs to give (NH-Si(CMe3)2-NH-SiFR)cyclodisilazanes [R = N(SiMe3)(CMe3) (8); R = N(SiMe2CMe3)2 (9)]. 50% of the educts are recovered. The spirocyclic compound 10 is isolated from the reaction of the dilithiated 1-amino-1.3-disilazane 3 with F3SiN(SiMe2CMe3)2. NH-SiF-Functional cyclodisilazanes can be obtained in the reaction of the dilithium derivative of compound 4 with trifluorosilanes [(N(SiMe2CMe3)-Si(CMe3)2-NH-SiFR), R = Ph (11); R = CMe3 (12)]. The lithium derivative of 12 crystallises with TMEDA as adduct 13. In the reaction of the lithiated compound 12 with Me3SiCl, LiCl elimination and substitution of the N-atom is observed (14). The treatment of 13 with PhCHO leads to a 1.3-diaza-5-oxa-2.4-disila-cyclohexane (15 a, b). Starting from lithiated 12 the methoxysubstituted cyclodisiloxane 16 is accessible in the reaction with MeOH. As result of its reactivity towards Me2SiF2 the fluorosilyl-substituted cyclodisilazane 17 is obtained. Crystal structures of 9-11 and 13 have been determined.
Reactions of ThX4 (X = F, Cl, Br, I) with Liquid Ammonia – Crystal Structures and a Theoretical Study of Ammine Thorium(IV) Halide Ammoniates
