Resistivity studies of metal complexes of lignocaine hydrochloride

The temperature dependence of resistivities of the complexes lignocainehydrochloride-chromium (CRE), monochlorotrinitro copper(II) lignocaine (CUNL) and lignocainehydrochloride-manganese (MNL) has been studied. All the compounds exhibit semiconducting behaviour which cars be accounted for by the stacking of the donor and acceptor molecules in the crystal structure. The degree of fall of resistivity of the compounds decreases in the order MNL, CRL, CUNL, The complex CUNL shows appreciable conductivity in the temperature range 234-279 K, as well as in the range 388-468 K. This behaviour might be attributed to the phase transition (if it exists) of the complex at a lower temperature

Optical studies of two smectic liquid crystals

The temperature variations of refractive index, density and order parameter of the compounds 2-4(4'-cyanophenyl)-5-n-heptyl-1,3-dioxane (PDX) and 4-n'-pentylcyclohexyl-(4-n-pentylcyclohexane)-1-carboxylate (OS) are reported in the smectic and isotropic phases. The principal molecular polarizabilities (alpha(e), alpha(o)) and the order parameters S have been evaluated using the anisotropic internal field model (Neugebauer's approach). The theoretical estimates of the mean and principal molecular polarizabilities using the modified Lippincott-delta-function potential model are in close agreement with the values evaluated from the experimental results

Crystal structure of mesogenic material – 2-(4′-Undecoxy phenyl)-5-N-hexyl pyrimidine

The title compound, C27H42N2O, exhibits a highly ordered smectic phase in the range 43-61.5-degrees-C while heating and 61.5-37.5-degrees-C while cooling. It crystallizes in the monoclinic system, space group P n, with two antiparallel molecules comprising the asymmetric unit. The unit cell parameters are a = 7.195(3) angstrom, b = 8.976(3) angstrom, c = 39.861(11) angstrom, beta = 86.349(5), Z = 4; D(c) = 1.062 Mg . m-3; Cu Kalpha radiation; mu = 0.46 mm-1. The structure was solved by direct methods (MULTAN80) using 3229 observed reflections I > 2.5 sigma(I)] and refined by block-diagonal and full-matrix least-squares method to Rf = 0.076 (Rw = 0.075). The molecules with extended chains show layered packing

Crystal structure of lignocaine hydrochloride – platinum complex

The title compound, PtC28N4O2H44Cl6, crystallises in the monoclinic space group C2(1)/c with a = 25.484(2) angstrom, b = 11.137(3) angstrom, c = 26.701(2) angstrom, beta = 106.66(2)-degrees having eight molecules per unit cell. D(c) = 1.604 Mg.m-3. D(m) = 1.598 Mg.M-3. The structure was solved by MULTAN using 5074 observed reflections I> 2.5sigma(I)]. It was refined by block diagonal least squares method to a final R(f) = 0.036 (Rw = 0.032)

Electrical resistivities and activation energies of diphenyl pyraline hydrochloride complexes

The resistivity measurements of a series of complexes of diphenyl pyraline hydrochloride with cobalt acetate (COAD), copper chloride (CUD), copper acetate (CUAD) and cobalt thiocyanate(COCND) as a function of temperature were undertaken. All the materials studied show semiconducting behaviour. This behaviour can be accounted for by the alternate stacking of the donor and acceptors in the crystal structured. The activation energy of the complexes range between 0.36 and 1.40 eV

Crystal Structure of Lignocaine Hydrochloride–Zinc Chloride Complex

Crystal and molecular structure of lignocaine hydrochloride-zinc chloride complex, ZnCl4C28N4O2H44, is reported. The sample cyrstallizes in the monoclinic space group P2(1) with a = 9.128(2) angstrom, b = 19.196(5) angstrom, c = 19.696(5) angstrom, beta = 95.81(1)degrees, V = 3433.43(1) angstrom3, Z = 4. The structure of the title compound was solved using 3527 counter intensities with I > 2.5sigma(I) using CuK(alpha) radiation and refined to an R value of 0.071. Each metal group is associated with a pair of ligands. The planes of the phenyl groups of one of the pair are nearly perpendicular to the planes of the phenyl groups of the other

Crystal structure of mesogenic material–4′-n-pentyl cyclohexyl-(4-n-pentyl cyclohexane)-1-carboxylate

The compound C23O2H42 crystallizes in the triclinic space group P1 with a = 5.5478(2) angstrom, b = 9.7768(3) angstrom, c = 10.6846(2) angstrom, alpha = 96.428(3)degrees, beta = 94.161(4)degrees, tau = 103.807(3)degrees and one molecule per unit cell. D(calc) = 1.047 Mg . m-3. The structure was solved by direct methods (SOLVER-NRCVAX1) using 1611 observed reflections I > 2sigma(I)]. It was refined by block-diagonal and full-matrix least-squares method to a final R of 0.078. The molecule is almost stretched and linear. The angle between the mean planes of the cyclohexane rings is 3.87(2)degrees. The packing of the molecules exhibits a strong layering as required for a smectic liquid crystalline phase - the cyclohexane groups forming one line with the extended alkyl chains penetrating into the neighbouring layers

Crystal structure of mesogenic material–2-(4′-cyano phenyl)-5-n-heptyl-l, 3 dioxane

The crystalline form of 2-(4'-cyano phenyl)-5-n heptyl-1,3 dioxane C18NO2H25 is orthorhombic and is assigned to space group P2(1)2(1)2(1) with four molecules per unit cell. The cell parameters are a = 5.5450(2) angstrom, b = 7.7334(3) angstrom, c = 41.0765(2) angstrom. D(calc) = 1.082 Mg . m-3. The structure was refined to an R = 0.07 for 840 counter intensities. The molecule is linear. The packing of the molecules shows a strong layered arrangement. This mesogenic compound exhibits a smectic phase in the range 53-55-degrees-C during heating and 55-42-degrees-C during cooling

Crystal-Structure of Monochloro Trinitro Cu(Ii) Lignocaine Complex

The crystal structure of monochloro trinitro copper (II) lignocaine complex, CuC28H44O11N7Cl, has been determined by X-ray diffraction using CuK(alpha) radiation. The compound crystallizes in the monoclinic space group P 2(1)/n with unit cell parameters a=10.554(2) angstrom, b = 24.402(7)angstrom, c = 14.124(3) angstrom, beta = 100.025(20)-degrees with Z = 4, D(c) = 1398 Mg m-3, D(m) = 1.391 Mg m-3, mu = 2.08 mm-1. The structure was solved using 5242 reflections I > 2.5sigma (I)] out of 6764 reflections using MULTAN. The final residuals are R(f) = 0.120 (R(w) = 0.109). The copper coordination is seven in.the complex. The plane of one of the nitrate groups almost bisects the molecule