Synthesis, Spectroscopic, Spectrophotometric and Crystallographic Investigations of 4-{[(1E)-(3,4-dimet-hoxyphenyl)methylene]amino}-1,5-dimethyl-2-phenyl-1,2-dihydro-3H-pyrazol-3-one and 4-{[(1E)-(2-hydroxy-5-met-hoxyphenyl)methylene]amino}-1,5-dimethyl-2-phenyl-1,2- dihydro-3H-pyrazol-3-one

摘要

Two new Schiff base ligands 4-{[(1E)-(3,4-dimethoxyphenyl)methylene]amino}-1,5-dimethyl-2-phenyl-1,2-dihydro-3H-pyrazol-3-one (1) and 4-{[(1E)-(2-hydroxy-5-methoxyphenyl)methylene]amino}-1,5-dimethyl-2-phenyl-1,2-dihy-dro-3H-pyrazol-3-one (2) have been prepared and characterized using elemental analysis, UV-vis, FT-IR, ~1H and ~(13)C NMR spectroscopy, and X-ray crystallographic technique. Tautomeric equilibria (phenol-imine, O-H ··· N and keto-ami-ne, O···H-N forms) have been studied by using UV-vis absorption spectra for the compound 2 in some solutions. Crystal structure analyses showed that the title molecules 1 and 2 crystallize in the monoclinic space group P2_1/c and P2. with the unit cell parameters: a = 12.5665(3) A and 5.6666(2) A; b = 10.4791(2) A and 12.2444(5) A; c = 14.6240(3) A and 12.1556(4) A; V =1820.65(7) A~3 and 826.84(5) A~3; D_x= 1.282 g.cm~(-3) and 1.355 g.cm~(-3); and Z = 4 and 2, respectively.