Polymorphism of righthanded octyloxycyanobiphenyl

Thermal and relaxational properties of glass-forming material, 3,3-dimethyl-1-butanol

“…For example, in the case of p-methoxybenzylidene-p 0 -butylaniline (MBBA) the stable and the metastable crystalline phases melt at T = 295.3 K and T = 294.0 K, respectively [22], and in the case of 2,3,6,7,10,11-hexa-octanoyloxy-triphenylene three crystal polymorphs exhibit their melting temperatures at 348 K, 359.7 K, and 362.6 K [23]. Such examples are also reported for chiral cyanobiphenyls like isopentylcyanobiphenyl [14] and 4-methylheptyloxy-4 0 -cyanbiphenyl [17].…”

“…The Polish authors of the present paper have developed adiabatic calorimetry, neutron inelastic scattering and dielectric relaxation studies for 3,3-dimethyl-1-butanol as a part of the large project for glass-formers having various values of fragility [14][15][16][17]. The substance has been chosen as a suitable candidate for our investigations because we expected it will exhibit a low fragility as the isomer of 2,3-dimethyl-2-butanol [18].…”

Neutron-scattering study of low-energy excitations in some organic glass formers

“…97%. On cooling down from room temperature (relatively slowly, with cooling rate e.g.-0.5 K/min) both substances formed glass states-glass of cholesteric phase of 5*CB [11] and glass of isotropic liquid of 8*OCB [14,15]. For each substance crystallization occurred not on cooling but on heating the sample from a glass and a metastable crystal was formed.…”

“…Moreover, the purpose of this paper is to show the details of density of states in solid phases of 5*CB and 8*OCB and to compare the BP observed in a glass of liquid crystalline phase and in a glass of isotropic liquid. Isopentyl cyanobiphenyl (5*CB) is a liquid crystalline (cholesteric) glass former [9][10][11][12][13] and isooctyloxy cyanobiphenyl (8*OCB) is a substance forming glass of isotropic liquid [14][15][16]. Both substances studied in our group earlier by various experimental techniques have chiral molecules and reveal polymorphism of solid state.…”

Quasi-elastic neutron scattering of cyanobiphenyl compounds with different terminal chains

“…The motions of 5*CB and 8*OCB molecules around short axes studied by dielectric relaxation method [1,[8][9][10] revealed that the antiparallel correlations in molecular arrangements, growing with decreasing temperature, are significantly smaller for 5*CB (8*OCB) than for 5CB (8OCB) [11,12]. This result can explain the absence of nematic and smectic phases for 5*CB or 8*OCB, as well as their ability of forming the glassy state at low temperatures.…”