J. Valdesmartinez et al., DIFFERENT STRUCTURES FOR 2 VERY SIMILAR 2-BENZOYLPYRIDINE AZACYCLOTHIOSEMICARBAZONES, Zeitschrift fur Kristallographie, 213(4), 1998, pp. 246-248
2-Benzoylpyridine piperidinyl- and hexamethyleneiminylthiosemicarbazon
es, HBzpip and HBzhexim, respectively, crystallize in a hydrogen bonde
d Z isomeric conformation with respect to the C7-N2 bond. The intramol
ecular hydrogen bond is between N3-H...N1, but the S atom is E to the
azomethine nitrogen, N2, for HBzpip and Z for HBzhexim. HBzpip is the
second ZE isomer known, but the first that does not have a formal hydr
ogen bond to N2.