[Synthesis, characterization, spectroscopy and theoretical calculation of two novel carbazole derivatives].

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.

UV near-resonance Raman spectroscopic study of 1,1'-bi-2-naphthol solutions.

The normal and UV near-resonance Raman (UVRR) spectra of 1,1'-bi-2-naphthol (BN) in basic solution were measured and analyzed. Density functional theory (DFT) calculations were carried out to study the ground state geometry structure, vibrational frequencies nu, off-resonance Raman intensities I, and depolarization ratios rho of 1,1'-bi-2-naphtholate dianion (BN(2-)). On the basis of the calculated and experimental results of nu, I, and rho, the observed Raman bands were assigned in detail. The 1612 cm(-1) Raman band of BN in basic solution was found dramatically enhanced in the UV resonance Raman spectrum in comparison with the normal Raman spectrum. Analyzing the depolarization ratios of the 1366 and 1612 cm(-1) bands in the RR spectra manifests that both the symmetric and antisymmetric parts of transition polarizabilities contribute to the 1366 cm(-1) band, but that only the symmetric part contributes to the 1612 cm(-1) band.

Density functional theory studies on the electronic and vibrational spectra of octaethylporphyrin diacid.

The ground-state structure and electronic and vibrational spectra of octaethylporphyrin diacid (H4OEP2+) have been studied with the density functional theory. The geometrical parameters computed with B3LYP, PBE1PBE and mPW1PW91 functionals and 6-31G* basis sets are well consistent with the experimental values. Electronic absorption spectrum of H4OEP2+ has been studied with the time-dependent DFT method, and the calculated excitation energies and oscillator strengths are compared with the experimental results. The Raman and IR spectra of H4OEP2+ and the Raman spectrum of its N-deuterated analogue (D4OEP2+) were measured. The observed Raman and IR bands have been assigned based on the frequency calculations at the B3LYP/6-31G* level of theory.

Density functional theory studies on the Raman and IR spectra of meso-tetraphenylporphyrin diacid.

The vibrational spectra of meso-tetraphenylporphyrin diacid (H4TPP2+) have been studied with the density functional theory. Raman and IR spectra of H4TPP2+ and its N-deuterated analogue (D4TPP2+) are measured and compared with the computational results. Complete assignments of observed IR and Raman bands were proposed on the bases of calculation results. The DFT calculations reproduce 140 observed fundamentals with the RMS 8.6 cm-1. The computational as well as the experimental results reveal that the saddle-distortion of porphyrin macrocycle for the diacid leads to a significant effect on its vibrational spectra. Especially, several out-of-plane skeletal modes, which were either unobserved or very weak in the Raman spectra of CuTPP and H2TPP, are activated in the Raman spectra of the diacids. In addition, enhancement for the Raman bands of phenyl CC stretching modes were observed and attributed to the conjugation effect of pi-systems of the phenyl and the porphyrinato macrocycles.