The structure of 1-formyl-3-phenyl-Δ2-pyrazoline in the gas phase (DFT calculations), in solution (NMR) and in the solid state (X-ray crystallography)

The molecular structure of 1-formyl-3-phenyl-Delta(2)-pyrazoline was determined by X-ray crystallography (triclinic, P-1). The geometry thus obtained was compared with that obtained by DFT calculations. The GIAO method was used to calculate absolute shieldings, which agree conveniently with those measured by C-13 and N-15 NMR. The title compound appears to be an essentially planar molecule. (C) 2003 Elsevier B.V. All rights reserved.