Saini G S S
Department of Physics, Panjab University, Sector 14, Chandigarh 160 014, India.
Spectrochim Acta A Mol Biomol Spectrosc. 2006 Jul;64(4):981-6. doi: 10.1016/j.saa.2005.09.008. Epub 2006 Feb 3.
Resonance Raman spectra of free-base tetraphenylporphine and its dication obtained with 441.6, 476.5, 488.0 and 514.5 nm excitation lines in the frequency region 100-1625 cm(-1) are reported. Some bands due to in-plane and out-of-plane vibrational modes, which are symmetry forbidden under ideal D(2h), are also seen in the Raman spectra of these molecules. These bands arise due to dynamic and/or static coupling of out-of-plane modes with the allowed in-plane modes. Dynamic coupling may be facilitated by the proton tunneling, while static coupling is due to out-of-plane distortion in the geometrical structure of the molecule. Shift in the positions for certain bands in the Raman spectra of dication are interpreted on the basis of electronic changes due to sharing of electrons of the B(1u) orbital by the two added protons.
报道了在100 - 1625厘米⁻¹频率范围内，用441.6、476.5、488.0和514.5纳米激发线获得的游离碱四苯基卟啉及其二价阳离子的共振拉曼光谱。在这些分子的拉曼光谱中也可以看到一些由于面内和面外振动模式产生的谱带，这些谱带在理想的D(2h)对称性下是禁阻的。这些谱带是由于面外模式与允许的面内模式的动态和/或静态耦合而产生的。质子隧穿可能促进动态耦合，而静态耦合则是由于分子几何结构中的面外畸变。基于两个额外质子共享B(1u)轨道电子引起的电子变化，解释了二价阳离子拉曼光谱中某些谱带位置的移动。
