Ab initio Molecular Orbital Study of Dithiopyrrolopyrrole and Its Structural Isomers

Abstract

Ab initio molecular orbital calculations at HF/6-31G*, HF/6-311+G**, and B3LYP/6-311+G** levels of theory for geometry optimization are reported for 1,4-dithiopyrrolo[3,4-c]pyrrole (DtPP, 1) and its twelve structural isomers (2–13). Compounds 1–3 include 2 C─CH and 2 NH─CS structural units. Structural isomers 4–7 include 2 C–CH units, together with 2 NH and 2 C–S groups. Isomers 8–13 possess 2 CH, 2 C, 2 NH, and 2 C─S fragments. According to these calculations, isomers 2, 4, and 8, are more stable than 1.

Keywords:

• Ab initio calculation
• dithiopyrrolopyrrole
• pigments
• structural isomers

Notes

^a Relative energy with respect to 1 from HF/6-31G**//HF/6-31G**.

^b Relative energy with respect to 1 from HF/6-311+G**//HF/6-311+G**.

^c Relative energy with respect to 1 from B3LYP/6-311+G**//B3LYP/6-311+G**.

^a Relative energy with respect to 1 from HF/6-31G**//HF/6-31G**.

^b Relative energy with respect to 1 from HF/6-311+G**//HF/6-311+G**.

^c Relative energy with respect to 1 from B3LYP/6-311+G**//B3LYP/6-311+G**.

^a Relative energy with respect to 1 from HF/6-31G**//HF/6-31G**.

^b Relative energy with respect to 1 from HF/6-311+G**//HF/6-311+G**.

^c Relative energy with respect to 1 from B3LYP/6-311+G**//B3LYP/6-311+G**.