title: Infrared spectroscopic studies of free-base tetraphenylporphine and its dication.
abstract: We present here the infrared absorption spectra of free-base tetraphenylporphine and its dication. Most of the allowed IR bands of porphyrin skeletal are observed in pairs due to two-fold symmetry of the free-base tetraphenylporphine. Observation of some new bands, disappearance of few bands in the IR spectrum of dication are interpreted on the basis of point group symmetry S4. Intensity change in the observed bands due to vibrational motion of the phenyl rings for dication is also explained on the basis of symmetry of dication. Sharing of electrons of the B(1u) orbitals by the two added protons are responsible for the shifts in the position of certain IR bands for dication.
authors.affiliation: Department of Physics, Panjab University, Chandigarh 160 014, India. gsssaini@pu.ac.in
authors.forename: G S S
authors.initials: GS
authors.lastname: Saini
authors.forename: Sandeep
authors.initials: S
authors.lastname: Sharma
authors.forename: Sarvpreet
authors.initials: S
authors.lastname: Kaur
authors.forename: S K
authors.initials: SK
authors.lastname: Tripathi
authors.forename: C G
authors.initials: CG
authors.lastname: Mahajan
mesh_terms: D008956:Models, Chemical; D015394:Molecular Structure; D011166:Porphyrins / Q000737:chemistry*; D013055:Spectrophotometry, Infrared; D014732:Vibration
chemical_list: D011166:Porphyrins; C107018:porphine; C049692:tetraphenylporphine