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Volumn 121, Issue 4, 1999, Pages 632-637

Solvent binding to benzamide crystals: Morphology, induced twinning and direct observation by surface X-ray diffraction

Author keywords

[No Author keywords available]

Indexed keywords

BENZAMIDE DERIVATIVE; SOLVENT;

EID: 0033518565     PISSN: 00027863     EISSN: None     Source Type: Journal    
DOI: 10.1021/ja9822660     Document Type: Article
Times cited : (28)

References (37)
  • 12
    • 13044288646 scopus 로고    scopus 로고
    • With formamide the effect is far weaker, and a high concentration of formamide (ca. 5:1) is needed for obtaining an observable effect
    • With formamide the effect is far weaker, and a high concentration of formamide (ca. 5:1) is needed for obtaining an observable effect.
  • 13
    • 13044268380 scopus 로고    scopus 로고
    • Molecular peaks of the mixed benzamide-acetamide were observed by direct chemical ionisation (DI-CI) on a Finnigan quadrupole detector
    • Molecular peaks of the mixed benzamide-acetamide were observed by direct chemical ionisation (DI-CI) on a Finnigan quadrupole detector.
  • 14
    • 13044310057 scopus 로고    scopus 로고
    • Zero-level (h0l) Weissenberg camera diffraction photographs were taken of numerous crystals of benzamide, grown from all of the cosolvents mentioned above. Twinning was observed in all cases by virtue of doubled diffraction spots for reflections containing a nonzero h Miller index
    • Zero-level (h0l) Weissenberg camera diffraction photographs were taken of numerous crystals of benzamide, grown from all of the cosolvents mentioned above. Twinning was observed in all cases by virtue of doubled diffraction spots for reflections containing a nonzero h Miller index.
  • 15
    • 13044291324 scopus 로고    scopus 로고
    • note
    • 3OD revealed the presence of about 1% acetamide. Progressively rewashed portions of the affected crystals gave similar results.
  • 16
    • 13044270305 scopus 로고    scopus 로고
    • note
    • 17 The proposed structure involves the formation of a pair of hetero-bilayers of glycine and leucine.
  • 18
    • 13044276909 scopus 로고    scopus 로고
    • note
    • -1, respectively, yielding the calculated penetration depth.
  • 20
    • 13044271627 scopus 로고    scopus 로고
    • note
    • In such affected crystals, therefore, only the thin crystal layer that had been further grown along the c direction from a pure seed, is twinned.
  • 21
    • 13044278224 scopus 로고    scopus 로고
    • note
    • For nonspecular CTR measurements the surface was vertical and aligned with a laser such that the surface normal was parallel with the ω axis of the diffractrometer, which ensures a constant angle of incidence throughout the measurements. The angle of incidence was set at 0.5°. The CTR scans were measured by a rocking scan around the surface normal at each momentum transfer in the direction perpendicular to the surface in order to measure the integrated intensity. For the specular reflections (00l) the sample was remounted with the surface nearly horizontal to keep a vertical scattering plane. The scan along the specular rod was performed along the ridge of scattering. The background was measured along a slightly off-specular direction by off-setting the ω angle to lower the radiation damage. The intensities were corrected for Lorentzian and polarization factors and variations in active area in order to achieve a structure factor intensity for both specular and nonspecular CTRs.
  • 26
    • 13044278226 scopus 로고    scopus 로고
    • note
    • The parameter which determines the shape of the profile in the region l ≈ 2.2 is the molecular occupancy given to the surface layer.
  • 27
    • 13044259541 scopus 로고    scopus 로고
    • note
    • 30
  • 30
    • 13044255699 scopus 로고    scopus 로고
    • Grimbergen, R. F. P.; Bennema, P. In ref 10, p 28
    • Grimbergen, R. F. P.; Bennema, P. In ref 10, p 28.
  • 32
    • 13044270304 scopus 로고    scopus 로고
    • note
    • 33 We therefore rationalize that the presence of trifluoroacetamide in the surface layer induces reduction of the torsion angle.
  • 34
    • 13044280166 scopus 로고    scopus 로고
    • note
    • 35,36
  • 37
    • 13044289959 scopus 로고    scopus 로고
    • note
    • We repeated such a type of growth experiments of benzamide in the presence of 10% p-chlorobenzamide; the resulting crystals were thin (001) plates, as expected, but twinning was not observed.


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.