A comparison of 2,7-dihydro-2,2,7,7-tetramethyl-3,6-diphenyl-1,4,5-thiadiazepine and the corresponding 1,1-dioxide.
The structures of the highly substituted title heterocycles, C(20)H(22)N(2)S and C(20)H(22)N(2)O(2)S, have been determined at 123 (1) K. Both molecules possess exact C(2) symmetry and the seven-membered rings have very similar twist-boat conformations. The magnitudes of the C-S-C bond angles, 107.13 (6) and 108.27 (7) degrees, respectively, are influenced significantly by the four substituent methyl groups on the seven-membered rings.
Cuthbertson
E
E
Department of Chemistry, University of Glasgow, Glasgow G12 8QQ, Scotland.
Frampton
C S
CS
MacNicol
D D
DD