�ber den Polymorphismus des Sulfanilamids

Watanabe, Atusi

doi:10.1007/bf01486162

Cited by 18 publications

(8 citation statements)

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“…Sulfanilamide was found to crystallize in at least four different polymorphs: α, β, γ, and δ (see Figure S1, Supporting Information). − The occurrence of polymorphism in SA has been ascribed to the relevance of several types of intermolecular interactions in determining the crystal structures of the compound, in particular intermolecular hydrogen bonds of the N–H···OS type and dispersion interactions between aromatic rings. These interactions allow for establishment of different types of cross-linked three-dimensional networks, in a similar way as found, for example, for pyrazinamide …”

Section: Introductionmentioning

confidence: 99%

Conformational Landscape, Photochemistry, and Infrared Spectra of Sulfanilamide

2013

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A combined matrix isolation FTIR and theoretical DFT(B3LYP)/6-311++G(3df,3pd) study of sulfanilamide (SA) was performed. The full conformational search on the potential energy surface of the compound allowed the identification of four different minima, all of them bearing the sulfamide nitrogen atom placed in the perpendicular orientation relatively to the aromatic ring and differing from each other in the orientation of the hydrogen atoms connected to the two nitrogen atoms of the molecule. All conformers were predicted to be significantly populated in the gas phase (at 100 °C, their relative populations were estimated as being 1:0.9:0.3:0.2). However, in agreement with the theoretically calculated low-energy barriers for conformational isomerization, in the low-temperature matrices, only the most stable conformer could be observed, with the remaining forms being converted into this form during matrix deposition (conformational cooling). The unimolecular photochemistry of matrix-isolated SA (in both argon and xenon) was also investigated. Upon broadband UV irradiation (λ > 215 nm), two photofragmentation pathways were observed: the prevalent pathway (A), leading to extrusion of sulfur dioxide and simultaneous formation of benzene-1,4-diamine, which then converts to 2,5-cyclohexadiene-1,4-diimine, and the minor pathway (B), conducting an γ-cleavage plus [1,3] H-atom migration from the sulfamide group to the aromatic ring, which leads to formation of iminosulfane dioxide and aniline, the latter undergoing subsequent phototransformation into cyclohexa-2,5-dien-1-imine. Finally, the crystalline polymorph of SA resulting from warming (265 K) the amorphous solid obtained from fast cooling of the vapor of the compound onto the cold (13 K) substrate of the cryostat was identified spectroscopically, and found to be the γ-crystalline phase, the one exhibiting in average longer H-bonds and an infrared spectrum resembling more that of the low temperature SA glass. Full assignment of the infrared spectra of this crystalline variety as well as of those of the β-polymorph room temperature crystalline sample and low temperature amorphous state was undertaken with help of theoretical results obtained for the crystallographically relevant dimer of SA.

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Section: Introductionmentioning

confidence: 99%

Conformational Landscape, Photochemistry, and Infrared Spectra of Sulfanilamide

2013

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“…Cette &ude a d'abord port6 sur le sulfanilamide, p-(H2NSO2)C6H4(NH2), qui pr6sente 3 formes cristallographiques, e, fl, 7 (Watanabe, 1941(Watanabe, , 1942. Les structures des formes c~ et fl ont 6t6 d6jh d6termin6es (O' Connor & Maslen, 1965;All6aume & Decap, 1965).…”

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Affinement tridimensionnel du sulfanilamide β

Alléaume¹,

Decap²

1965

Acta Cryst

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The crystal structure of y sulphanilamide has been determined from Patterson and heavy atom electrondensity projections on the (100) plane, and by the heavy atom method for the three-dimensional refinement.The parameters were refined by least-squares applied to 876 independent reflexions. The final R index was 0.10. The bonded distances and angles are comparable to those in ~ and B sulphanilamide. The hydrogen bond system is discussed.

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“…Four crystalline habits of sulphanilamide have been reported (Watanabe, 1941;Yakowitz, 1948;McLachlan, 1957). The structures of the c~ (O'Connor & Maslen, 1965) and the ~, form (All6aume & Decap, 1965a) * Present address: Institute of Medical Biochemistry, University of G6teborg, Sweden.…”

Section: Introductionmentioning

confidence: 99%

X-ray and neutron diffraction studies of β-sulphanilamide

O'Connell¹,

Maslen²

1967

Acta Cryst

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The crystal structure of/~-sulphanilamide has been refined from three-dimensional photographic X-ray data and two-dimensional neutron diffraction data. Positional and anisotropic thermal parameters of the non-hydrogen atoms and positional and isotropic thermal parameters of the hydrogen atoms were refined in the X-ray analysis to give a final R index of 4"9 %. Positional and isotropic thermal parameters of the hydrogen atoms were refined in the neutron study. The final residual factors were R(hOl) = 8-0 %, R(hkO)= 9.1%. The mean standard deviation in the C-C bonds is 0.0028 A and the e.s.d.'s in the hydrogen atom positional parameters are approximately 0-035 A. The bond lengths suggest that there is a small but significant contribution of a quinonoid resonance form to the structure of the molecule. The distribution of residual electron density within the benzene ring and in the tetrahedral sulphamide group is explained in terms of effects resulting from electron redistribution at bonding. The hydrogen bond system closely resembles that found in e-sulphanilamide and the N-H...O bonds are about 0.25/~ longer than in related zwitterion compounds.

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�ber den Polymorphismus des Sulfanilamids

Cited by 18 publications

References 0 publications

Conformational Landscape, Photochemistry, and Infrared Spectra of Sulfanilamide

Conformational Landscape, Photochemistry, and Infrared Spectra of Sulfanilamide

Affinement tridimensionnel du sulfanilamide β

X-ray and neutron diffraction studies of β-sulphanilamide

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