The Crystal Structures of Some Organic Compounds

Citation

Takei, William Junkichi (1957) The Crystal Structures of Some Organic Compounds. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/E6PW-AB98. https://resolver.caltech.edu/CaltechETD:etd-08302004-154057

Abstract

NOTE: Text or symbols not renderable in plain ASCII are indicated by [...]. Abstract is included in .pdf document. The crystal structure of acetamide hemihydrochloride has been determined by x-ray diffraction techniques. Three dimensional data were utilized for obtaining the final parameters by least squares and Fourier synthesis refinement techniques with an average positional standard deviation of 0.009 A. The results for acetamide molecule show bond distances closer to those previously accepted than to those from the investigation of acetamide itself. There is a distance of 2.40 A between two oxygen atoms related by a center of symmetry. This has been interpreted as a hydrogen bond and as such would be the shortest such distance reported. Potassium dicyanoguanidine crystallizes in an orthorhombic space group, either Pbcm (centrosymmetric) or [...] (non-centrosymmetric). A structure has been determined conforming to Pbcm using least squares and generalized Fourier projections. The average positional standard deviation is 0.006 A for carbon and nitrogen. One of the C-N distances of the guanidine group is significantly shorter than the others. The two terminal NCN groups are not exactly linear, contrary what might be expected. Each potassium ion is surrounded by eight nitrogens in a distorted Archimedes antiprism. A study of the structure of the dimer phenylisocyanate was initiated but discontinued for reasons which are discussed.

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