Structural, spectral and thermal studies of N-2-(pyridyl)- and N-2-(picolyl)-N′-(3-chlorophenyl)thioureas

N-2-(pyridyl)-N'-3-chlorophenylthiourea, PyTu3Cl, monoclinic, P2(1), a = 9.9770(14), b = 6.1770(9), c = 9.9000(7) Angstrom beta = 97.301(8)degrees, V = 605.17(13) Angstrom(3) and Z = 2; N-2-(4-picolyl)-N'-3-chlorophenylthiourea, 4PicTu3Cl, triclinic, P-1, a = 4.7970(3), b = 10.7180(12), c = 12.7370(15) Angstrom, alpha = 77.919(4), beta = 85.959(6), gamma = 89.697(7)degrees, V = 638.74(11) Angstrom(3) and Z = 2; N-2-(5-picolyl)-N'-3-chlorophenylthiourea, 5PicTu3Cl, monoclinic, P2(1)lc, a = 11.1580(6), b = 15.233(2), c = 7.5118(15) Angstrom, beta = 93.336(8)degrees, V = 1274.5(3) Angstrom(3) and Z = 4 and N-2-(6-picolyl)-N'-3-chlorophenylthiourea, 6PicTu3Cl, triclinic, P - 1, a = 7.3620(12), b = 8.828(3), c = 11.675(3) Angstrom, alpha = 98.78(1), beta = 104.398(17), gamma = 109.651(16)degrees, V = 668.5(2) Angstrom(3) and Z = 2. The intramolecular hydrogen bonding between N'H and the pyridine nitrogen and intermolecular hydrogen bonding involving the thione sulfur and the NH hydrogen, as well as the planarity of the molecules, are affected by the presence and position of the methyl substituent on the pyridine ring. H-1 NMR studies in CDCl3 show the NH' hydrogen resonance considerably downfield from other resonances in their spectra indicating intramolecular hydrogen bonding is also present in solution. (C) 2002 Elsevier Science B.V. All rights reserved.