Synthesis and structures of two N,N′-bis(2-pyridinyl)thioureas and N-(2-pyridinyl)-N′-(benzoyl)thiourea

N,N-'bis(4,6-lutidyl)thiourea, (4,6Lut)(2)Tu, triclinic, P-1, a = 7.4930(8), b = 8.7210(8), c = 12.6040(14) Angstrom, alpha = 93.437(5), beta = 94.919(5), gamma = 110.246(5)', V = 766.35(14) Angstrom(3) and Z = 2; N,N'-bis(5-picolyl)thiourea, (5PiC)(2)Tu, monoclinic, P2(1)/c, a = 17.205(2), b = 4.4970(5), c = 17.425(2) Angstrom, beta = 117.763(5)degrees, V = 1272.6(3) Angstrom(3) and Z = 4 and N-(2-pyridyl)-N'-benzoylthiourea, PyTubenzo, monoclinic, P2(1)/n, a = 5.345(3), b = 20.343(6), c = 11.808(2) Angstrom, beta = 90.23(3)degrees, V = 1290.8(1) Angstrom(3) and Z = 4. Intramolecular hydrogen bonding between N'H and the pyridyl nitrogen, intermolecular hydrogen bonding involving the thione sulfur and the NH hydrogen, and the planarity of the molecule is affected by substitution on the pyridine rings of the bis(2-pyridyl)thioureas. PyTubenzo has intramolecular hydrogen bonding to the carbonyl oxygen, intermolecular hydrogen bonding to a thione sulfur and is the least planar of the molecules under study. H-1 NMR studies in CDCl3 show the NH' hydrogen resonance considerably downfield from other resonances in the spectrum of the bis(2-pyridyl)thioureas. (C) 2002 Elsevier Science B.V. All rights reserved.