Crystal and molecular structure of 4-chloro-2-methyl-3-phenylcyclobut-2-enone

Abstract

The crystal structure of 4-chloro-2-methyl-3-phenylcyclobut-2-enone has been determined by single-crystal X-ray diffraction. The crystals are monoclinic, space group P2₁/c with Z= 4 in a unit cell of dimensions a= 7·943, b= 7·661, c= 17·261 Å, and β= 110° 28′. The structure was determined by the symbolic addition method from visually estimated photographic data and has been refined by least-squares procedures to R 0·078 on 1567 non-zero independent structure amplitudes measured on an automatic diffractometer. The cyclobutenone moiety is slightly non-planar; the angle between planes through C(1)–C(2)–C(3) and C(1)–C(3)–C(4) is 4°, and the 4-chloro-substituent is in a pseudoequatorial position.