Experimental (XRD, IR and NMR) and theoretical investigations on 1-(2-nitrobenzoyl)3,5-bis(4-methoxyphenyl)-4,5-dihydro-1H-pyrazole

Abstract

The pyrazole compound 1-(2-nitrobenzoyl)3,5-bis(4-methoxyphenyl)-4,5-dihydro-1H-pyrazole (I) has been synthesized and characterized by IR, NMR and X-ray diffraction methods. The compound crystallizes in the monoclinic space group C2/c with a = 36.126(5) Ǻ, b = 8.1963(7) Ǻ, c = 14.3983(18) Ǻ, β = 100.825(10)° and Z = 8. The molecular geometry, vibrational frequencies and Gauge-Independent Atomic Orbital (GIAO) 1H and 13C NMR chemical shift values of 1-(2-nitrobenzoyl)3,5-bis(4-methoxyphenyl)-4,5-dihydro-1H-pyrazole in the ground state have been calculated using the density functional method (B3LYP) with the 6–311++G(d,p) basis set. The optimized parameters are in agreement with X-ray data. The calculated vibrational frequencies and chemical shift values were compared with experimental IR and NMR values. In addition, frontier molecular orbitals, molecular electrostatic potential and NBO analysis of (I) were investigated by DFT calculations.