The typical crystal structures of a few representative α‐aryl‐α‐hydroxyphosphonates

• Published in: Acta crystallographica. Section C, Crystal structure communications Crystal structure communications, 2019-03, Vol.75 (3), p.283-293
• Main Authors: Rádai, Zita, Kiss, Nóra Zsuzsa, Czugler, Mátyás, Karaghiosoff, Konstantin, Keglevich, György
• Format: Article
• Language: English
• Subjects: Aromatic compounds; Chains; Chemical synthesis; Crystal structure; Crystals; Dimers; hydrogen bonding; Inorganic salts; Pudovik reaction; Shape effects; α‐hydroxy‐α‐arylphosphonates
• ISSN: 2053-2296; 0108-2701; 2053-2296; 1600-5759
• DOI: 10.1107/S2053229619001839

The crystal structures of seven α‐aryl‐α‐hydroxyphosphonates synthesized by the Pudovik reaction of substituted benzaldehydes and dialkyl phosphites, namely dimethyl [(hydroxy)(phenyl)methyl]phosphonate, C9H13O4P, dimethyl [(3,4‐dimethoxyphenyl)(hydroxy)methyl]phosphonate, C11H17O6P, dimethyl (1‐hydroxy‐1‐phenylethyl)phosphonate, C10H15O4P, dimethyl [1‐hydroxy‐1‐(4‐nitrophenyl)ethyl]phosphonate, C10H14NO6P, dibenzyl [hydroxy(2‐nitrophenyl)methyl]phosphonate, C21H20NO6P, dibenzyl [(3‐chlorophenyl)(hydroxy)methyl]phosphonate, C21H20ClO4P, and dibenzyl [hydroxy(4‐methylphenyl)methyl]phosphonate, C22H23O4P, were studied to gain a better understanding of the organization in this type of molecule in the solid state. The crystals obtained for this series of compounds show a balance between C—OH…O=P chain‐linked packing and the dimeric types of hydrogen‐bond bridges of intermolecular pairs of such functions. The description is based on primary graph‐set descriptors. Using graph‐set descriptors one level deeper (i.e. secondary graph sets of the C—H…O type) revealed a similarity in the graph‐set descriptors, suggesting a fine interplay of substituent‐ and shape‐dependent effects on strong–weak interactions. It seems that the formation of chains or dimers is governed not only by the presence of a tertiary Cα atom, but also by the nature and crowding of the ortho substituents of the α‐aryl group. The crystal structures of seven α‐aryl‐α‐hydroxyphosphonates synthesized by the Pudovik reaction of substituted benzaldehydes and dialkyl phosphites were studied to gain a better understanding of the organization in this type of molecule in the solid state. The crystal structures show a balance between the C—OH…O=P chain‐linked packing and the dimeric types of hydrogen‐bond bridges of intermolecular pairs of such functions.