Synthesis and Characterization of New porphyrins and Porphyrin Derivatives with Fluorine.

以2-（2-三氟-1-羟乙基）吡咯为原料，以中等收率氧化环化得到5,10,15,20 -四（三氟甲基）卟啉1。在DMF中，用三氟甲基碘化物光化学三氟甲基化制备了中（三氟甲基）辛基卟啉5。在本反应中未检测到三氟甲基化产物。同样，δ-（三氟甲基）-辛乙基氯6和中-（三氟甲基）中卟啉IX二甲酯的产率中等。后一产物的^1H-NMR和^<19>F-NMR表明形成了四个区域异构体，9-12。由于中三氟甲基的空间约束和电子效应，这些化合物表现出各种不同寻常的性质。电化学研究和分子轨道能量计算表明，1、5和6的HOMO和LUMO比三氟甲基未取代化合物的HOMO和LUMO明显稳定。此外，对于5来说，LUMO的稳定性要大得多。这种差异是由于乙基和三氟甲基之间的相互作用造成卟啉环的部分畸变。

5, 10, 15, 20-Tetrakis (trifluoromethyl) porphyrin, 1, was obtained by oxidative cyclization of 2-(2-trifluoro-1-hydroxyethyl) pyrrole in moderate yield.Meso-(trifluoromethyl) octaethylporphyrin, 5, was readily prepared by photochemical trifluoromethylation of octaethylporphyrin with trifluoromethyl iodide in DMF.No pertrifluoromethylation products have been detected in the present reaction. Similarly, δ-(trifluoromethyl)-octaethylchlorin, 6, and meso-(trifluoromethyl) mesoporphyrin IX dimethyl ester were obtained in moderate yields. ^1H-NMR and ^<19>F-NMR of the latter products indicated formation the four regioisomers, 9-12.These compounds showed a variety of unusual properties due to steric constrain and electronic effect of the meso-trifluoromethyl group. Both electrochemical studies and energy calculations of molecular orbitals indicated that the HOMO and LUMO of 1, 5, and 6 were markedly stabilized than those of trifluoromethyl group unsubstituted compounds. Moreover, for 5 the stabilization is much greater for the LUMO.This difference is attributable to the partial distortion of the porphyrin ring by interaction between the ethyl and trifluoromethyl groups.