Search

Two novel carbazole derivatives, 3-acetyl-9-n-hexylcarbazole (AHCZ) and 3, 6- diacetyl-9-n-hexylcarbazole (DHCZ) were synthesized through Friedel-Crafts reaction. The compounds were characterized by IR spectra, 1H NMR, MS and elemental analysis. UV-visible spectra of AHCZ and DHCZ were measured and compared with those of their precursors, 9-hexylcarbazole(HCZ) and carbazole(CZ). DHCZ and AHCZ exhibited strong absorption band, revealing the extent of pi conjugation in the system. TD-DFT method was performed to analyze the electronic absorption spectra of AHCZ and DHCZ, and the calculated excitation energies and oscillator strengths were compared with the experimental results.

A new ligand, S-benzyl-(-N-[10-ethylphenothiazinyl-3yl]-methylene] dithiocarbazate (abbreviated as HL), and its complexes ML2 (M=Co and Hg) have been synthesized and fully characterized by elemental analyses, EI-MS, 1H NMR, IR, UV-Vis spectra, and photoluminescence measurement. All of the compounds emit an olivine color in DMF solution. The emission maximum (lambdamax(em)), and fluorescence quantum (phif) of each compound were measured. Nonlinear Optical properties of the HL and ML2 were studied by z-scan technique. Nonlinear absorption coefficient beta were measured to be 0.71, 0.19 and 0.395 cm x GW(-1). Theoretical calculations (RHF/PM3) were consistent with the experimental results.

Comparative studies were carried out by using electrochemistry and in-situ FTIR spectroelectrochemistry for nonlinear optical complexes, S-benzyl-N-(ferrocenyl-1-methyl-metylidene)-dithiocarbazate nickel (II)/cobalt (II) complexes (Ni(LSB)2/Co (LSB)2). The results indicated that Ni(LSB)2 involves two consecutive reversible one-electron oxidation steps, while Co(LSB)2 involves only one two-electron oxidation step. Ni(LSB)2 complex that has a square planar configuration exhibits a moderately strong electronic communication between the two-ferrocene moieties, taking place through the skeleton chain of the ligand due to the extensive electron delocalization in the whole molecule and leads to the appearance of a strong nu c-c vibration band at 1,453 cm-1 during the oxidation process, while Co(LSB)2 complex that has a tetrahedral configuration shows low electron delocalization and has two almost identical ferrocene moieties.

Two-photon absorption (TPA) spectrum of a new organic compound has been directly measured by an approach of using tunable laser from an optical parameter amplifier as an excitation source. The output intensity of optical parameter amplifier can cover a broad spectra range of 400-2,000 nm, and identical intensity in the whole spectral range can be easily adjusted. Therefore, the measurement based on this method is directly and reliable. The experimental results show that this compound exhibit large TPA cross section in a broad spectral range from 750 to 1,100 nm. The profiles of TPA spectrum is quite similar to that of the linear absorption spectra. The peak wavelength of TPA band has a little blue-shift compared with the twice of the peak wavelength of the linear absorption due to the different selection rules for two-photon transition and one-photon transition.