A new organic photochromic compound, 1-phenyl-3-methyl-4-(4-fluoro)-benzal-5-pyrazolone ethanyl-thiosemicarbazone (PM4FBP-ETSC) was found to undergo photochromic reactions in the solid state. Upon irradiation with 365nm light the white powder sample turned light yellow. The photochromic properties were characterized by the time-dependent UV-vis reflective spectra. The structure of PM4FBP-ETSC was determined by single crystal X-ray diffraction.……
A novel compound PMPP-SAL （1-phenyl-3-methyl-4-（salicylidene hydrazide）- propenylidene-pyrazolone-5） has been synthesized and characterized by elemental analysis, IR,^1H NMR and single-crystal X-ray diffraction. The X-ray diffraction reveals that the compound is of orthorhombic, space group Pbca with a=16.132（5）, b=10.113（3）, c=23.143（7） A, V=3776（2）A°^3, Z=8, C20H20N4O3, Mr=364.40, Dc =1.282 g/cm^3, F（000）=1536,μ（MoKa）=0.089 mm^-1, S=0.992, R=0.0578 and wR=0.1362 for 1871 observed reflections with I〉2σ（I）. In the crystal, the compound possesses two C=O bonds and exists in the NH-form＇ other than NH-form.
A new photochromic organic compound of thiosemicarbazone, 4-（p-bromo-α-methylaminothiocarbonyl hydrazonobenzal）-2,5-dihydro-3-mcthyl-5-oxo-1-phcnyl pyrazolc, was synthesized and characterized by elemental analyses, IR, ^1H NMR spectra, and X-ray single-crystal diffraction analysis. The compound exhibited an interesting photochromism in the solid state when irradiated by ultraviolet light at 365 nm. The photochromic kinetics was studied by the time-dependent powder UV-Vis reflectance spectra. The intcrmolecular and intramolecular hydrogcn-bonding interactions may be responsible for the photochromic phenomenon.
