SYNTHESIS, CHARACTERIZATION AND CRYSTAL STRUCTURES OF BENZOHYDRAZONE COMPOUNDS DERIVED FROM 5-METHYLSALICYLALDEHYDE

A series of three new benzohydrazone derivatives, N'-(2-hydroxy-5-methylbenzylidene)-4-methylbenzohydrazide (1), N'-(2-hydroxy-5-methylbenzylidene)-4-hydroxybenzohydrazide (2), and N'-(2-hydroxy-5-methylbenzylidene)-4-dimethylaminobenzohydrazide (3), were prepared and characterized by elemental analysis, 1 H and 13 C NMR, and single crystal X-ray diffraction.Compound (1) crystallizes in the monoclinic space group C2/c with unit cell dimensions a = 27.421(1)Å, b = 9.9843(4) Å, c = 24.302(1)Å, β = 119.416(2)°,V = 5795.7(5)Å 3 , Z = 16, R 1 = 0.0520, and wR 2 = 0.1172.Compound (2) crystallizes in the orthorhombic space group Pna2 1 with unit cell dimensions a = 9.511(2) Å, b = 9.866(2) Å, c = 13.871(3)Å, V = 1301.6(5)Å 3 , Z = 4, R 1 = 0.0342, and wR 2 = 0.0912.Compound (3) crystallizes in the monoclinic space group C2/c with unit cell dimensions a = 26.957(2)Å, b = 10.0612(9)Å, c = 25.526(2)Å, β = 114.405(3)°,V = 6304.5(10)Å 3 , Z = 16, R 1 = 0.0532, and wR 2 = 0.1079.X-ray diffraction indicated that the benzohydrazone molecules of the compounds display trans configuration with respect to the C=N double bonds.The crystal structures of the compounds are stabilized by hydrogen bonds and weak π•••π interactions.