Two pairs of 4-aminoazoxybenzene polymorphs
نویسندگان
چکیده
منابع مشابه
Two polymorphs of 1,8-dichloroanthracene.
A second, monoclinic, polymorph of the title compound, C(14)H(8)Cl(2), has been found. In addition to the structure of this monoclinic form, the structure of the previously described orthorhombic form [Desvergne, Chekpo & Bouas-Laurent (1978). J. Chem. Soc. Perkin Trans. 2, pp. 84-87; Benites, Maverick & Fronczek (1996). Acta Cryst. C52, 647-648] has been redetermined at low temperature and usi...
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Conditions to obtain two polymorphic forms by crystallization from solution were determined for the analgesic drug hydro-morphone [C17H19NO3; systematic name: (4R,4aR,7aR,12bS)-9-hy-droxy-3-methyl-1,2,4,4a,5,6,7a,13-octa-hydro-4,12-methano-benzofuro[3,2-e]iso-quinolin-7-one]. These two crystalline forms, designated as I and II, belong to the P212121 ortho-rhom-bic space group. In both polymorph...
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Two polymorphs of 2,6-dichloropurine, C(5)H(2)Cl(2)N(4), have been crystallized and identified as the 9H- and 7H-tautomers. Despite differences in the space group and number of symmetry-independent molecules, they exhibit similar hydrogen-bonding motifs. Both crystal structures are stabilized by intermolecular N-H···N interactions that link adjacent molecules into linear chains, and by some non...
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We address the problem of two pairs of fermions living on an arbitrary number of single particle levels of a potential well (mean field) and interacting through a pairing force in the framework of the Richardson’s equations. The associated solutions are classified in terms of a number vl, which reduces to the seniority v in the limit of a large pairing strength G and yields the number of pairs ...
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The crystal structure of L-2-aminobutyric acid, an L-alanine analogue with an ethyl rather than a methyl side chain, has proved elusive owing to problems growing diffraction quality crystals. Good diffraction data have now been obtained for two polymorphs, in space groups P2(1) and I2, revealing surprisingly complex, yet fully ordered crystalline arrangements with Z' = 4. The closely related st...
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ژورنال
عنوان ژورنال: Acta Crystallographica Section A Foundations of Crystallography
سال: 2002
ISSN: 0108-7673
DOI: 10.1107/s0108767302091109