Jon A. Kapecki

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

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 A, 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.

Crystal and molecular structure of the cyclo-adduct from exo-3-phenyl-3,4,5-triazatricyclo[5,2,1,02,6]dec-4-ene and p-bromophenyl isocyanate

The molecular structure of the adduct formed from exo-3-phenyl-3,4,5-triazatricyclo[5,2,1,02,6]dec-4-ene and p-bromophenyl isocyanate, with concomitant loss of nitrogen, has been established as the 3-p-bromophenyl-10-phenyl-3,10-diazatricyclo[4,2,1,12,5]decan-4-one with the one-atom bridges trans, by the results of a single-crystal X-ray examination. The crystals belong to the monoclinic system, a= 18·27 ± 0·02, b= 6·34 ± 0·01, c= 15·16 ± 0·02 A, β= 106° 30′± 12′. The space group is P21/c with four molecules in the unit cell. The final R-factor is 0·12 for 1658 reflexions. The principal geometrical features of the molecule are described.