Hydrogen Atom Abstraction and Reduction Study of 21-Thiaporphyrin and 21,23-Dithiaporphyrin.

The metal-free porphyrins protonation has gained interest over five decades because its structure modification and hardly monoacid intermediate isolation. Here, upon the hydrogen atom abstraction processes, one step diproptonated H 3 STTP(BF 4 ) 2 (STTP = 5,10,15,20-tetraphenyl-21-thiaporphyrin) ( 3 ) and stepwise protonated HS 2 TTPSbCl 6 ( 5 ) and diprotonated H 2 S 2 TTP(BF 4 ) 2 ( 6 ) (S 2 TTP = 5,10,15,20-tetraphenyl-21,23-thiaporphyrin) compounds were obtained using HSTTP and S 2 TTP with oxidants. The closed-shell protonated compounds were fully characterized using XRD, UV-vis, IR and NMR spectra. In addition, the reduced 19π compounds [K(2,2,2)]HSTTP ( 2 ) and [K(2,2,2)]S 2 TTP ( 7 ) were synthesized by the ligands with reductant KC 8 in THF solution. These two open-shell compounds were characterized with UV-vis, IR and EPR spectroscopies. The semiempirical ZINDO/S method was employed to analyze the HOMO/LUMO gap lever and identify the electronic transitions of the UV-vis spectra of the closed- and open-shell porphyrin compounds.