Overtone spectra of porphyrins and its substituted forms: an algebraic approach

We introduce an algebraic model to vibrations of polyatomic Bio-molecules and present, as an example, the vibrational analysis of Cm-H, Cm-C, Cm-D, Cb-Cb, pyrrol breathing and Cb-C, stretching modes of Metalloporphyrins and its substituted forms. The excited energy levels of Cb-C, pyrrol breathing stretching modes of Ni(OEP) and Ni(OEP)-d4 are calculated by using U(2) algebraic mode Hamiltonian. The higher excited energy levels of Cm-H, Cm-C, Cm-D and Cb-Cb vibrational modes of Porphyrin and its substituted forms are predicted upto second overtone. It shows that the energy levels are clustering at the higher overtones. The results obtained by this method are accuracy with experimental data.