The crystal structure of α-pyrazinamide

Takaki, Yoshito; Sasada, Yoshio; Watanabe, Takahito

doi:10.1107/s0365110x60001680

Cited by 71 publications

(48 citation statements)

References 5 publications

(10 reference statements)

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“…The maximum deviation of the individual values from the average is 0.001 A, which cannot be considered as significant. Somewhat larger fluctuations, possibly significant, were found in the structure of a-PCA by Takaki et al (1960). The value of the C-N bond length found in this work, 1.334 A, is slightly shorter than that found for c~-PCA i.e.…”

Section: H(5)mentioning

confidence: 37%

“…The crystal structure of ~-pyrazincarboxamide, abbreviated ~-PCA, was solved and refined by Takaki, Sasada & Watanab6 (1960). While the crystal structures of ~-and J-pyrazincarboxamide are formed by simple sheets of molecules, the structure offl-pyrazincarboxamide (hereafter called fl-PCA) is supposed to be of the two-dimensional sheet type, also referred to as the 'herring bone' packing, as suggested by Takaki et al (1960). No detailed structure analysis has so far been published for the fl-, ~,-and J-forms.…”

Section: Introductionmentioning

confidence: 99%

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The crystal and molecular structure of β-pyrazinecarboxamide

Rø¹,

Sørum²

1972

Acta Crystallogr Sect B

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fl-Pyrazincarboxamide crystallizes in the space group P21/c with unit-cell dimensions a= 14.372 (7), b= 3"711 (3), c= 10.726 (5) A. and fl= 101.92 (5) °. The structure was solved on the basis of 813 observed independent reflexions by the aid of the symbolic addition procedure and refined by the full-matrix least-squares method, including anisotropic temperature factors and the use of a weighting scheme, to a final R1 index of 0"055. The molecules have a closely planar pyrazine ring, and the carboxamide group, which is also planar, deviates 3.2 ° from the plane of the ring. The molecules exist as dimers formed by hydrogen bonds between carboxamide groups, the dimers being linked together in chains by other weaker hydrogen bonds between the carboxamide groups.

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Section: H(5)mentioning

confidence: 37%

Section: Introductionmentioning

confidence: 99%

The crystal and molecular structure of β-pyrazinecarboxamide

Rø¹,

Sørum²

1972

Acta Crystallogr Sect B

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“…For the solution of one-dimensional disorder problems several methods have been developed, particularly for the simple close-packed structures: the method of difference equations (Wilson, 1942;Jagodzinski, 1949a,b,e;Gevers, 1954) and the matrix method (Hendricks & Teller, 1942;Kakinoki & Komura, 1952, 1954a,b, 1965Kakinoki, 1967;Takaki, 1977) are shown to be equivalent (Kakinoki & Komura, 1952;Jagodzinski, 1954). Planar faults described in terms of fault vectors plus differing scattering matter were considered in a theory which used a generalized Patterson function of the faulted crystal (Cowley, 1976).…”

Section: One-dimensional Disordermentioning

confidence: 99%

Disorder in cobalt single crystals

Frey¹,

Boysen²

1981

Acta Cryst Sect A

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Disorder in both allotropic phases of pure singlecrystalline cobalt was studied by elastic neutron scattering in order to separate bulk from surface effects and to remove diffuse inelastic contributions. The intensity variation along 10l, measured at different temperatures, was analysed quantitatively in terms of Jagodzinski's disorder theory. The values found for the degree of disorder in the h.c.p, phase were lower than those reported before for powder samples and remain nearly unaffected when approaching the transition temperature. The f

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“…19 Other authors have further studied this crystal later on. [20][21][22] The -PZA polymorph was first investigated by Ro and Sorum.…”

Section: Introductionmentioning

confidence: 99%

Low Temperature Infrared Spectroscopy Study of Pyrazinamide: From the Isolated Monomer to the Stable Low Temperature Crystalline Phase

et al. 2009

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A structural and spectroscopic analysis of the anti-tuberculosis drug pyrazinamide (PZA) was carried out. The PZA molecule was predicted theoretically to possess two conformers differing by internal rotation around the C-C(dO) bond, with the E conformer (C s symmetry point group; N-C-CdO dihedral: 180°) being ca. 30 kJ mol -1 more stable than the Z form (C 1 point group; N-C-CdO dihedral: ca. ( 42°). In consonance with both the large energy difference and low energy barrier between the Z and E conformers, upon isolation in low temperature argon and xenon matrices, only the E form could be observed and characterized spectroscopically. In the argon matrix, this conformer was found to exist in at least three matrix sites, of different stability. In a supersonic jet, besides the monomer (E), the most stable dimer of PZA with two equivalent NH · · · Od hydrogen bonds could also be identified. Its spectrum reveals rapid energy flow out of the excited NH stretching mode mediated by one of the heteroatoms in the ring. Finally, the IR spectra of the amorphous solid resulting from fast cooling of the vapor of the compound (initially in the R crystalline phase) onto the cold substrate of the cryostat (10 K) and of the crystalline phase resulting from warming the amorphous solid were also recorded and interpreted. The obtained crystalline phase was found to be the thermodynamically most stable δ polymorph of PZA.

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The crystal structure of α-pyrazinamide

Cited by 71 publications

References 5 publications

The crystal and molecular structure of β-pyrazinecarboxamide

The crystal and molecular structure of β-pyrazinecarboxamide

Disorder in cobalt single crystals

Low Temperature Infrared Spectroscopy Study of Pyrazinamide: From the Isolated Monomer to the Stable Low Temperature Crystalline Phase

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