The title lead(II) derivative was obtained as dark blue crystals by treatment of PbCl2 with (TMEDA = N,N,N‘,N‘-tetramethylethylenediamine) in tetrahydrofuran and its structure determined by X-ray diffraction. The compound is in effect the first dialkylead(II) species to be structurally characterized. The C−Pb−C angle is 117.1(2)°. Analogous treatment of SnCl2 yielded a yellow solid, which was judged from spectroscopic data to be the TMEDA complex of the analogous stannacycloalkane.

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This review focuses on recent developments in the chemistry of side chain liquid crystal polymers. It concentrates on current trends in synthetic methods and novel, well defined structures, supramolecular arrangements, properties, and applications. The review covers literature published in this century, apart from some areas, such as dendritic and elastomeric systems, which have been recently reviewed.

A series of novel side chain polymers-silylated polyethylenes were prepared containing 4′-methoxyphenyl-4-(ω-alkenyloxy)benzoate mesogenic groups of the general formula {-CH2-CH[SiMe2-(CH2)mOC6H4C(O)OC6H4OMe]}n-, where m ) 4, 5, 8, 11. The ones having five and eight carbon atoms in the alkane moiety of a flexible spacer proved to be liquid crystalline, independent of molecular weight (DP ) 75, 230). Alternative synthetic pathways have been described starting with anionic polymerization of Me3SiVi or Me2PhSiVi in the presence of BuLi, followed by functionalization of side silyl group to give reactive Si-H bonds and hydrosilylation of terminal, mesogenic alkenes. The properties of liquid crystal polyethylenes were compared with those of side chain polycarbosilanes of similar structure. The advantage of polyethylenes, while preserving all important features of polycarbosilanes, is shown by their broad temperature range of mesophase formation and the economically attractive synthesis.

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Side chain polysiloxane with 5-(pentyloxy)-3-methyloxy-9,10,16,17,23,24-hexakis(octenyloxy)phthalocyanine moieties is synthesized by hydrosilylation reaction. The phase behavior and thermooptical properties of the polysiloxane and starting 2-(pent-4-enyloxy)-3-methyloxy-9,10,16,17,23,24-hexakis(octenyloxy)phthalocyanine is examined by POM (Polarizing optical microscopy), TOA (thermooptical analysis), DSC (differential scanning calorimetry), AFM (atomic force microscopy) and SAXS (small angle X-ray scattering) studies. The effect of the attachment of phthalocyanine to polysiloxane chains over phase transitions and phase morphology is discussed in details

6 ) 2 , 7. The structures of 7 and 8 have been confirmed by X-ray studies which indicate that both compounds show K‚‚‚Me contacts in the range 3.3-3.5 Å. The ether-free reagent 7 reacted with YbI 2 in benzene to give the cyclic Yb(II) derivative CH 2 SiMe 2 C(SiMe 3 ) 2 -YbC(SiMe 3 ) 2 SiMe 2 CH 2 , which was found to be somewhat more stable toward Et 2 O than the previously studied Yb{C(SiMe 3 ) 3 } 2 . Reaction of the lithate [Li(TMEDA) 2 ][CH 2 SiMe 2 C(SiMe 3 ) 2 -LiC(SiMe 3 ) 2 SiMe 2 CH 2 ] (2a) with ZnCl 2 in THF gave a cyclic compound CH 2 SiMe 2 C(SiMe 3 ) 2 -

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