Structures of (methyl)phenylhydrazone derivatives and their nonlinear optical properties

Abstract

calculations for aniline (Niu & Boggs, 1984) found that the C--N bond lies in the aromatic plane when the dihedral angle between the N lone-pair orbital and the aromatic zr orbitals is 90 ° and that the out-of-plane angle for the C--N bond increases to 2.4 ° when the dihedral angle between the orbitals is 0 °. The maximum out-of-plane angle for the C(aryl)--N bonds in the o-and p-chlorophenyl compounds is at N(3) in the p-chlorophenyl compound, where the N lone-pair/zr-orbital dihedral angle is 0 °, in qualitative agreement with the MO calculations.The CH2--N--CH2 angles in the triazacyclohexane rings are 109-3-110.8(2) ° (o-C1 compound) and 108.7-110-6 (5) Introduction. 3-Methylbenzaldehyde N-methyl-Nphenylhydrazone (Me-BMPH) and 3-methoxybenzaldehyde N-methyl-N-phenylhydrazone (MeO-BMPH) are composed of non-centrosymmetric molecules, which resemble each other in structure and electronic states, whereas the SHG (second-harmonic generation) efficiency of MeO-BMPH was found to be 12-5 times that of urea standard, while Me-BMPH showed no effect. It is known that the SHG efficiency is related not only to the hyperpolarizability/3 of a molecule but to the space symmetry of the crystal. In order to confirm these points, the crystal structures of the two compounds were determined by X-ray diffraction and the /3 values were calculated with the MO-MNDO method.

4′‐Hydrazone Derivatives of 2,2′:6′,2"‐Terpyridine: Protonation and Substituent Effects

“…Other simple N-methyl hydrazones also show this preference. [32][33][34][35] Pairs of molecules (related by a crystallographic inversion centre) assemble so that the pyridine rings containing N2 are π-stacked (distance between planes of rings: 3.36 Å). Atom N2 makes a weak contact to a phenyl CH group in an adjacent pair of molecules (N2···H231 i C23 i 2.70 Å, symmetry code i = 1 / 2 + x, 3 / 2 -y, 1 / 2 + z).…”