Model Compound Studies of Rigid Rod Aromatic Heterocyclic Polymer Systems, the X-Ray Crystal Structure of 2,6-Diphenylbenzo (1,2-d; 5,4-d') Diimidazole Tetrahydrate, C2OH14N4. 4H2O, a Model System for the Study of Polymer-Water Interaction in Polybenzimidazoles.
Final rept. 1 Aug 81-30 Sep 82,
DAYTON UNIV OH RESEARCH INST
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The crystal and molecular structure of 2,6-diphenylbenzo 1,2-d5,4-d diimidazole tetrahydrate, C2OH14N4. 4H2O, is determined by single crystal x-ray diffraction. The benzodiimidazole compound is used as a model compound for polyp-phenylenebenzodiimidazole, a rigid rod polymer. The crystals grown from ethanol are well formed, translucent, and amber tinted. The space group is P21c monoclinic, with cell constants a 9.0082A, b 24.9677Angstroms, c 9.8705Angstroms, Beta 119.823deg. There are four molecules per unit cell of volume 1925.81.3A3, and the measured density is 1.295 gcc. 4850 unique reflections out to 56 deg in 2 theta were collected with an automated diffractometer using niobium filtered MoK alpha, radiation. The 2 theta scan technique was employed. Absorption corrections were made and approximately 11,000 reflections were averaged to give a hemisphere of independent observations. The direct method of phase determination was used to solve the structure, and full matrix least squares refinement gave a final Rw factor of 0.084 based on the 3570 reflections with Fobs or 3sigmaF.
- Atomic and Molecular Physics and Spectroscopy