Sodium diphenylacetate, an infinite columnar structure

Abstract

In the title compound, Na+·C14H11O2−, the di­phenyl­acetate ions have a conformation where the two phenyl rings and the carboxyl­ate group are oriented like the blades of a propeller, each ion having a well defined helicity. The crystal structure of the title compound is achiral, although non‐centrosymmetric (space group ); thus, ions with both (+) and (−) helicities are present in the crystal. Each Na+ ion is coordinated by four carboxyl­ate O atoms at distances in the range 2.207 (2)–2.467 (3) Å to form cubes of Na and O atoms which are linked via the carboxyl­ate C atoms into a columnar structure along the rotoinversion axis.

Propeller-like Conformation of Diphenylacetic Acid

“…Ohta et al have shown that sodium diphenylacetate is one of this rare liquid crystals showing a hexagonal columnar mesophase [1]. The arrangement of the molecules in the liquid crystal phase correlates with and resembles that observed in the solid state, according to our study [2]. In the crystal structure of sodium diphenylacetate, each Na + ion is coordinated by four carboxylate O atoms at distances in the range 2.207 (2)-2.467 (3) Å to form cubes of Na and O atoms which are linked via the carboxylate C atoms into a columnar structure.…”

“…Refinements were carried out with SHELXL-97 [6] package. All refinements were made by full-matrix least-squares on F [2], with anisotropic displacement parameters for all nonhydrogen atoms. Hydrogen atoms were included in the refinement in calculated positions.…”

Columnar Formation in Sodium Triphenylacetate

“…In 2000, we have elucidated the structure of a crystalline phase of sodium diphenylacetate showing that the ions and cations are aggregated in columns [2]. In such structure, the diphenylacetate ions have a conformation where the two phenyl rings and the carboxylate group are oriented like the blades of a propeller, each ion having a well-defined helicity Each Na ?…”