A new polymorph of the title compound 2-(η-C5H5)-2,1,7-closo-CoC2B9H11, [Co(C5H5)(C2H11B9)], in the space group P21/n has been characterized, including the unambiguous location of both cage C atoms. The precision of this study is an order of magnitude greater than that of the first polymorph [C2/c; Lopez et al. (2010). Collect. Czech. Chem. Commun. 75, 853-869].

C293 physico-chemical properties. NN414 is a very weak acid with pKa = 8.5, log P = 1.6, and molar weight Mw = 291.8 g/mol. Two true polymorphs, A and B, of this compound have been identified. Polymorph A crystallizes in needleshaped crystals with a triclinic unit cell by precipitation from a variety of solvents such as acetic acid, acetonitrile, diluted ammonia, methanol, N-methyl-pyrrolidone,...

A new polymorph of N,N'-bis-(2,6-diisopropyl-phen-yl)formamidine, C(25)H(36)N(2), is reported, which is different from the previously reported ortho-rhom-bic structure. The mol-ecule crystallizes in the E-anti configuration, with tautomeric disorder of the N-bonded H atoms and no clear distinction between imine and amine functionalities. The mol-ecules form hydrogen-bonded dimers with inter-mol...

In the title ortho-rhom-bic polymorph (space group Iba2), C17H13N, the dihedral angle between the benzene rings is 55.99 (10)° and the azepine ring adopts a boat conformation. In the crystal, mol-ecules are linked by C-H⋯π contacts. The previously-reported polymorph [Yousuf et al. (2012 ▶). Acta Cryst. E68, o1101] crystallizes in the monoclinic system (space group P21/c) with two mol-ecules in ...

The structures of the alpha, beta and gamma polymorphs of quinacridone (Pigment Violet 19) were predicted using Polymorph Predictor software in combination with X-ray powder diffraction patterns of limited quality. After generation and energy minimization of the possible structures, their powder patterns were compared with the experimental ones. On this basis, candidate structures for the polym...

In various shocked meteorites, low-pressure silica polymorph α-cristobalite is commonly found in close spatial relation with the densest known SiO2 polymorph seifertite, which is stable above ∼80 GPa. We demonstrate that under hydrostatic pressure α-cristobalite remains untransformed up to at least 15 GPa. In quasi-hydrostatic experiments, above 11 GPa cristobalite X-I forms-a monoclinic polymo...

Infrared absorption spectra of the precipitated solids separated from aluminiumhydroxide solutions below the pH of minimum solubility of AI(OH)3 demonstrate the slow ageing of polymeric A1 complexes to gibbsite. On comparison with the spectra of natural gibbsites, shifts in absorption frequency during crystal growth are interpreted in terms of changes in hydrogen bonding as a consequence of dep...

Organic molecules, such as pharmaceuticals, agro-chemicals and pigments, frequently form several crystal polymorphs with different physicochemical properties. Finding polymorphs has long been a purely experimental game of trial-and-error. Here we utilize in silico polymorph screening in combination with rationally planned crystallization experiments to study the polymorphism of the pharmaceutic...

The title compound, C(15)H(14)O(3), has been found to crystallize as a new triclinic polymorph. The asymmetric unit of the present structure, as in the previously reported monoclinic structure [Norment & Karle (1962 ▶). Acta Cryst. 15, 873-878], contains two independent mol-ecules, which differ slightly in the orientations of the two benzene rings. The crystal packing of the triclinic polymorph...

The structural, elastic, and electronic properties of the high-pressure FeTiO3 polymorphs and their relative phase stability under pressure are investigated using hybrid exchange density functional theory. For the currently known phases the computed structural and elastic parameters are in good agreement with those observed, as is the predicted stability of the phases. The transformation of the...