Kuniaki Ito, Keigo Moriya, S. Kashino
Nov 1, 1975
Citations
0
Influential Citations
7
Citations
Journal
Bulletin of the Chemical Society of Japan
Abstract
The crystal structures of tetrachlorophthalic acid hemihydrate (TCPH) and tetrabromophthalic anhydride (TBPA) have been determined from visually estimated CuKα data. The crystals of TGPH are monoclinic, space group A2/a, a=19.81(1), b=7.091(5), c=16.22(1) A, β=101.2(2)° and Z=8. Those of TBPA are monoclinic, space group P21/n, a=13.39(3), b=6.19(2), c=12.66(3) A, β=91.1(3)° and Z=4. The structures of TGPH and TBPA were solved from the sharpened Patterson maps, and refined by the block-diagonal least-squares method to R values of 0.112 and 0.112 for 1287 and 1278 non-zero reflections, respectively. The molecules of TCPH related by a twofold screw axis are linked together by hydrogen bonds between the carboxylic groups to form a chain along the b axis and the chains are held together by hydrogen bonds through water molecules to form a sheet parallel to the (100) plane. The sheets are stacked by van der Waals forces. The dihedral angles of the carboxylic groups with the benzene ring are 68.2 and 48.9°. The c...