科研之友
微信
新浪微博
Facebook
分享链接
摘要
The structures and properties of a family of different pi-conjugation tetra pyrrole Zn complexes are reported. The tetra pyrrole moiety can be divided as porphyrin, one tripyrrin and one pyrrole, two dipyrrines, one dipyrrin and two pyrroles, and four pyrroles. The Zn complexes possess different geometries and tunable spectral bands depending on the mode of the different metal-coordination. For Zn porphyrin, the frontier molecular orbitals (FMOs) are the major contribution to the intense B-like band and weak Q-like band absorptions, and this is in agreement with the Gouterman's four-orbital model. But because of the breakdown of the pi-conjugation from complex 1 to 5, the FMOs are no longer separated from the other MOs in energy, the orbital with metal distribution is approaching to lowest unoccupied molecular orbital (LUMO), the absorption band is no longer intense at B-like bond and weak at Q-like bond as Gouterman's four-orbital model mentioned. The calculated fluorescence spectra in toluene solution show that fluorescence can be observed in the visible region of complexes 1-4 because of the bright higher electronic excited states.
