Defective disordered crystal structure of (2-hydroxyphenyl)diphenylphosphineoxide

A disordered defective crystal structure of (2-hydroxyphenyl)diphenylphosphineoxide (I) has been studied by XRD method. The rhombic structure of I (space group Pna2₁, a = 18.271 Å, b = 8.337 Å, c = 19.629 Å, Z = 8) was solved by a direct method and refined by a full-matrix LSM having taken into account its crystal packing defects (by introducing two additional independent low-populated molecules) to R = 0.060 for all 3517 independent reflections measured (a CAD-4 autodiffractometer, λMoK _α. There are two independent molecules A and B with population 0.90 and two additional independent molecules C and D with population 0.10 in the structure of I.