The title compound, C13H13NO2, was previously described in space group P21/c by He et al. [Acta Cryst. (1993), C49, 2000-2002]. The ethyl group is disordered over two sets of sites in a 0.615 (10):0.385 (10) ratio. The C-O-C-C torsion angles containing the ethyl group are -111.6 (10) and 177.9 (7)°, while in the previously reported polymorph, the torsion angle is -167.3 (2)°. The molecules pack...

Recently, we reported the first monoclinic [Kuai & Cheng (2011). Acta Cryst., E67, o2787] and the ortho-rhom-bic polymorph [Kuai & Cheng (2011). Acta Cryst., E67, o3014] of the title compound, C(15)H(12)N(2)O(2). Another monoclinic polymorph was obtained accidentally by the hydro-thermal reaction of the title compound with manganese chloride in the presence of potassium hydroxide at 413 K. The ...

An ortho-rhom-bic polymorph of the title compound, [Fe(C(5)H(5))(C(8)H(17)B(10)O)] or C(13)H(22)B(10)FeO, is described here in addition to the known monoclinic polymorph [Crundwell et al. (1999 ▶). Acta Cryst.C55, IUC9900087]. The asymmetric unit contains four independent mol-ecules with C(cage)-C(cage) distances of 1.636 (16)-1.700 (16) Å, and with the methyl-hydr-oxy groups disordered over tw...

A polymorph of In2La was discovered by observing a change in the quadrupole interaction at nuclei of 111In/Cd probe atoms at high temperature using the technique of perturbed angular correlation of gamma rays. Point-symmetry information from the measured electric field gradient and chemical considerations suggests that the high-temperature polymorph has the hexagonal AlB2 structure. The transfo...

The title compound, C14H16N6O2, is a second monoclinic polymorph of 2-[1-(3,5-dimeth-yl)pyrazol-yl]-2-hy-droxy-imino-N'-[1-(2-pyrid-yl)ethyl-idene] acetohydrazide, with two crystallographically independent mol-ecules per asymmetric unit. The non-planar mol-ecules are chemically equal having similar geometric parameters. The previously reported polymorph [Plutenko et al. (2012 ▶). Acta Cryst. E6...

A new polymorph of dimesitylborinic acid (or hydroxy-dimesitylborane), C(18)H(23)BO, showcasing different crystal packing and symmetry, complements the previously reported polymorph [Weese, Bartlett, Murray, Olmstead & Power (1987 ▶). Inorg. Chem.26, 2409-2413; Entwistle, Batsanov & Marder (2007 ▶). Acta Cryst. E63, o2639-o2641]. The structure of the title compound contains only one mol-ecule i...

The polymorphonuclear leucocyte (PMN) response to a chemotactic or chemokinetic stimulus is enhanced in men with ankylosing spondylitis (AS). This effect does not parallel the severity of disease activity or the size of the acute phase response, and it is independent of non-steroidal anti-inflammatory drug treatment. Polymorph function is normal in HLA-B27 positive brothers of probands with AS ...

: The mechanisms of the formation and transformation of calcium carbonates and the inhibition by the phosphorus containing compounds were studied. Supersaturated solutions form the unstable polymorph, amorphous calcium carbonate, at first, followed by the transformation to the metastable polymorph which finally transforms to stable form, calcite. Transformation proceeds by a mechanism of recrys...

A new method for assessing the similarity of crystal structures is described. A similarity measure is important in classification and clustering problems in which the crystal structures are the source of information. Classification is particularly important for the understanding of properties of crystals, while clustering can be used as a data reduction step in polymorph prediction. The method ...

During an attempt to prepare a cocrystal of N-phenyl-phthalimide, C(14)H(9)NO(2), with N-(2,3,4,5,6-penta-fluoro-phen-yl)phthalimide, a new ortho-rhom-bic polymorph of the first component was obtained. This new form has Z' = 0.5 and the mol-ecule is located around a twofold axis, whereas in the previously reported polymorph (space group Pbca), the mol-ecule has no crystallographically imposed s...