A pale-yellow crystal of parallelepiped habit, produced by crystallization from methanol and having approximate dimensions of 0.2, 0.2, 0.8 mm, was selected for X-ray work. Intensity data were collected using a Siemens-Nicolet R3m/V automated diffractometer and highly oriented graphite crystal monochromatized Mo Ka radiation (fine tube, 50 KV, 30 mA, lambda = 0.71073 À). The X-rays diffracted from the crystal were recorded by a Polaroid cassette mounted in front of the detector (at 19.5 cm), and a rotation photograph around the phi axis gave twenty 2X, 2Y values for evaluating the quality of the crystal and calculating angular positions for the reflections; they were centered later with a centering algorithm. An indexing routine, based on forty equivalent reflections in the range 20 < 2theta <40°, selected a unit cell of the tetragonal system, with the dimensions a = 18.821(5), c = 13.882(8) angstrom and V = 4919(4) cubic angstrom The observed volume and density (1.31(1) g cm-3 corresponded to Z = 16, while the reflection conditions were consistent with the space group 141 cd (No. 110).
Crystal structure of 2,5,6-trimethyl-9-methoxy-4H-pyrrolo[3,2,1-ij ] quinolin-4-one
DOLMELLA, ALESSANDRO;NICOLINI, MARINO
1990
Abstract
A pale-yellow crystal of parallelepiped habit, produced by crystallization from methanol and having approximate dimensions of 0.2, 0.2, 0.8 mm, was selected for X-ray work. Intensity data were collected using a Siemens-Nicolet R3m/V automated diffractometer and highly oriented graphite crystal monochromatized Mo Ka radiation (fine tube, 50 KV, 30 mA, lambda = 0.71073 À). The X-rays diffracted from the crystal were recorded by a Polaroid cassette mounted in front of the detector (at 19.5 cm), and a rotation photograph around the phi axis gave twenty 2X, 2Y values for evaluating the quality of the crystal and calculating angular positions for the reflections; they were centered later with a centering algorithm. An indexing routine, based on forty equivalent reflections in the range 20 < 2theta <40°, selected a unit cell of the tetragonal system, with the dimensions a = 18.821(5), c = 13.882(8) angstrom and V = 4919(4) cubic angstrom The observed volume and density (1.31(1) g cm-3 corresponded to Z = 16, while the reflection conditions were consistent with the space group 141 cd (No. 110).Pubblicazioni consigliate
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