Spectral and structural studies of N -(2)-pyridylethyl- N ′-arylthioureas

N -(2-pyridylethyl)- N ′-phenylthiourea, triclinic, P-1, a=8.616(1) A , b=9.663(1) A , c=9.761(1) A , α =102.05(1)°, β =102.36(1)°, and γ =116.17(1)°, V=668.5(1) A 3 , Z =2, μ=2.022 mm −1 , N -(2-pyridylethyl)- N ′- p -tolylthiourea, triclinic, P-1, a=8.804(3) A , b=9.951(2) A , c=10.255(2) A , α =115.03(2)°, β =105.93(2)°, γ =104.04(2)°, V=713.43(1) A 3 , Z =2, μ=2.173 mm −1 , N -(2-pyridyl-ethyl)- N ′- p -bromophenylthiourea, triclinic, P-1, a=9.536(1) A , b=9.809(1) A , c=10.042(2) A , α =115.88(1)°, β =96.80(1)°, and γ =110.44(1)°, V=750.0(6) A 3 , Z =2, μ=28.73 mm −1 , N -(2-pyridyl-ethyl)- N ′- p -nitrophenylthiourea, triclinic, P-1, a=8.046(2) A , b=8.602(3) A , c=10.938(3) A , α =80.74(3)°, β =89.77(2)°, γ =77.00(3)°, V=727.6(6) A 3 , Z =2, μ=2.325 mm −1 and N -(2-pyridylethyl)- N ′- p -methoxyphenylthiourea, monoclinic, P2 1 /n, a=11.526(2) A , b=9.723(2) A , c=13.460(2) A , β =100.49(2)°, V=1483.3(2) A 3 , Z =4, μ=1.929 mm −1 . All five molecules possess an intramolecular hydrogen bond between NH and the pyridyl nitrogen, as well as intermolecular hydrogen bonding between N′H and a thione sulfur of a second molecule to form centrosymmetric dimers. Solution 1 H NMR studies (CDCl 3 ) show the N′H resonance downfield for each thiourea and its shift, as well as that of NH, is affected by substituents on the phenyl ring.