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

Abstract

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, Ή and 13C 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) A, b = 9.9843(4) A, c = 24.302(1) A, β = 119.416(2)°, V = 5795.7(5) A3, Z = 16, R1 = 0.0520, and wR2 = 0.1172. Compound (2) crystallizes in the orthorhombic space group Pna21 with unit cell dimensions a = 9.511(2) A, b = 9.866(2) A, c = 13.871(3) A, V = 1301.6(5) A3, Z = 4, R1 = 0.0342, and wR2 = 0.0912. Compound (3) crystallizes in the monoclinic space group C2/c with unit cell dimensions a = 26.957(2) A, b = 10.0612(9) A, c = 25.526(2) A, β = 114.405(3)°, V= 6304.5(10) A3, Z = 16, R1 = 0.0532, and wR2 = 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.