Chemical structures of the investigated DHNPH chromophores and their abbreviations.
Molecular structure of 2,4- and 3,4-DHNPH chromophores in the crystalline state projected onto the molecular plane. The dotted lines present intramolecular hydrogen bonds of with a distance of 1.94 Å for 2,4-DHNPH and with a distance of 2.22 Å for 3,4-DHNPH. The solid and dotted vectors present the directions of the maximum first hyperpolarizability and the dipole moment of the molecules as determined by FF calculations, respectively.
Acentric polymerlike chains projected along the (a) -axis and (b) -axis for the 2,4-DHNPH crystals and along the (c) -axis and (d) -axis for the 3,4-DHNPH crystals. The molecules in the chain are linked with intrachain intermolecular hydrogen bonds, indicated by dotted lines of with distance of 2.16 Å for both 2,4-DHNPH and 3,4-DHNPH.
Crystal packing diagram projected along the -axis for the 2,4- and 3,4-DHNPH crystals. The molecules make an angle of about 20° with respect to the polar axis that is for both isomers approximately parallel to the -axis.
Schematic of main supramolecular interactions for (a) 2,4-DHNPH and (b) 3,4-DHNPH crystals: Intermolecular hydrogen bonds in intrachain (thin dotted lines) and interchain (thick dotted lines). Only strong intermolecular hydrogen bonds with a distance of less than 2.4 Å are shown.
Molecular structures of 2,4-DHNPH projected along the molecular plane: EXP molecule as determined by the x-ray diffraction analysis and the conformers having different OH directions. The directions of the maximum first hyperpolarizability and the dipole moment determined by FF calculations are denoted by the solid and the dotted vectors, respectively. Note that in the case of 90° orientations, the direction of the dipole moment additionally rotates by a few degrees (5°–10°) out of the molecular plane.
Physical and structural properties of the investigated hydrazone crystals.
Results of the FF method: Dipole moments , static polarizability , the zero-frequency hyperpolarizability tensor , the vector component along the dipole moment direction of the hyperpolarizability tensor , the first hyperpolarizability , and the angle between the dipole moments and the main direction of the first-order hyperpolarizability .
Article metrics loading...
Full text loading...