Structures of (1) N-(2-pyridyl)-, (2) N-(3-pyridyl)- and (3) N-(4-pyridyl)-N'-(4-chlorophenyl)urea

Abstract

The three compounds (C 12 H 10 ClN 3 O) have similar molecular structures but differ in the position of the N atom in the pyridyl ring. The effects are reflected in the existence of some intra- or intermolecular hydrogen bonds between the urea N atoms and the pyridyl N atom {1.89 (4) [(1) intra], 2.21 (3) and 2. 14 (3) [(2) inter], 2, 17 (2) [(3) inter]} and between the carbonyl O and the pyridyl N atom {2.07 (4) A [(1) inter]}. From the intermolecular distances the crystal structure of (1) can be viewed as a succession of «dimers» in three dimensions, and that of (2) or (3) as a one-dimensional molecular chain