Arrays of PO Dipoles As a Recurrent Structural Motif in Bis-Diphenylphosphine Oxides, Established from Powder X-ray Diffraction

• Published in: Crystal growth & design Vol. 10; no. 8; pp. 3814 - 3818
• Main Authors: Lim, Gin Keat, Zhou, Zhongfu, Fujii, Kotaro, Calcagno, Patrizia, Tedesco, Emilio, Kitchin, Simon J, Kariuki, Benson M, Philp, Douglas, Harris, Kenneth D. M
• Format: Journal Article
• Language: English
• Published: Washington,DC American Chemical Society 04.08.2010
• Subjects: Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Growth from solutions; Materials science; Methods of crystal growth; physics of crystal growth; Physics; Structure of solids and liquids; crystallography; Structure of specific crystalline solids; Rietveld method; Monocrystals; Solvate; Solution structure; Toluene; Crystal growth from solutions; XRD; Arrays; Genetic algorithms; Hydrates; Crystal structure
• ISSN: 1528-7483; 1528-7505
• DOI: 10.1021/cg100715v

Rationalization of the solid-state structural properties of odd members (n = 3, 5, 7) of the series Ph2P(O)(CH2) n P(O)Ph2 leads to insights concerning the structural determinants of this class of material, particularly with regard to the formation of preferred arrangements of PO dipoles. The odd members of this series are recalcitrant to the formation of single crystals of suitable size and quality for single-crystal X-ray diffraction, and modern techniques for carrying out crystal structure determination directly from powder X-ray diffraction data were essential for determining the structural properties of these materials. In the present work, nonsolvate crystal phases of the materials with n = 3 and 5 were prepared by appropriate solid-state desolvation processes (starting from hydrate and toluene solvate phases, respectively), yielding microcrystalline powders of the nonsolvate phase in each case. Structure determination was carried out directly from powder X-ray diffraction data, employing the direct-space genetic algorithm technique for structure solution followed by Rietveld refinement.