Synthesis of novel tri-podal mesogenic alkenes and side-chain polysiloxanes

Tridentate Lewis Acids: Boron‐, Silicon‐ and Gallium‐Functionalised Tris(dimethylsilyl)methanes

“…Piers' borane was synthesised according to a reported protocol. [38][39][40] The syntheses of tris(dimethylsilyl)methane (1), [27] tris-(bromodimethylsilyl)methane (2) [27] and tris(dimethylvinylsilyl)-methane (6) [28] have been described elsewhere. NMR measurements were performed at 298 K with Bruker Avance III 500, Bruker Avance III 300 and Bruker DRX 500 spectrometers.…”

“…For this reason a further backbone equipped with vinyl groups was synthesised. Starting with chloro(dimethyl)vinylsilane and bromoform, following the literature protocol of Ganicz and Stańczyk, [28] tris(vinyldimethylsilyl)methane (6) was synthesised (Scheme 2). Subsequent reaction with methyllithium and then trimethylsilyl chloride afforded tris(vinyldimethylsilyl)(trimethylsilyl)methane (7; Scheme 2).…”

Novel oligocarbosilazanes bearing promesogenic end groups

“…In contrast, judging from DSC and microscopic studies, oligomers containing mesogen A (compounds A1, A2 and A3, Table 2) did not exhibit any mesomorphic properties. Although both starting mesogens exhibit LC properties in a free form [8,9], it was previously found that mesogen A, when attached as a side chain to polymers with relatively low molar ratio of functional units, produced materials with poor or even no LC properties [5,7,8]. Therefore, during the course of our research, we directed our attention to mesogen B which was reported to be more effective in systems with a low degree of functionalization [7,9].…”

“…All substrates were used as received from suppliers. The syntheses of SiH-containing mesogens were performed as reported elsewhere [5].…”

“…Two promesogenic compounds (A, B, Figure 3) containing one reactive SiH group were obtained by hydrosilylation of the corresponding alkene-terminated analogues with a large excess of commercially available tetramethyldisiloxane (HSiMe 2 OSiMe 2 H), as described previously [5].…”