Effect of lateral substituent and chain length on mesomorphic properties of novel alkoxy benzyloxy benzoates of cyanophenyl rod-shaped compounds

Three novel homologous series of rod-shaped cyanophenyl alkoxy benzoate liquid crystalline compounds with lateral polar fluorine and chlorine substituent were prepared, and chemical structures of novel materials have been characterized by standard spectral technique and elemental analysis. The mesophase characterization was carried out using the combination of polarized optical microscopy and differential scanning calorimetry. All the compounds exhibit wide thermal range of enantiotropic SmA phase.

Diphenylantimony(V) oxo/chloro carboxylates and phosphinates: crystal structures of {SbPh2Cl[O2P(C6H11)2]}2O and [SbPh2(O2CPh)2]2O

Reaction of SbPh(2)Cl(3) (1 mol) with the silver salt of dicyclohexylphosphinic acid (2 mol) afforded {SbPh(2)Cl[O2P(C6H11)(2)]}O-2 1, a similar reaction with AgO2P(C8H15)(2) gave a product formulated as {SbPh(2)Cl[O2P(C8H15)(2)]}O-2 2. Similar reactions with silver carboxylates (1:3 stoichiometry) led to the crystalline derivatives [SbPh(2)(O(2)CR)(2)]O-2 (R = Ph 3, CHPh(2) 4, 2,4,6-Me(3)C(6)H(2) 5, 2-MeC(6)H(4) 6 or 4-MeC(6)H(4) 7), whereas the 1:2 reaction afforded crystalline SbPh(2)Cl(O(2)CR)(2) (R = Ph 8, 2-MeC(6)H(4) 9 or 4-MeC(6)H(4) 10). Interconversion of the previously known compounds [SbPh(2)(O(2)CMe)(2)]O and Sb(4)Ph(8)O(6) . 3MeCO(2)H was achieved and established by H-1 NMR spectroscopy. Compounds 1 and 3 were further characterized by X-ray diffraction; the antimony in 1 is six-co-ordinated with bridging phosphinates whereas in 3 it is seven-co-ordinated with chelating benzoates. Short Sb-O (oxo) distances (1.923 Angstrom) and near linearity at the bridging ox