The title compound was synthesized by the reaction of (R)-N-acetylthiazolidine-2-thione-4-carboxlic acid with 1,3-thiazolidine- 2-thione in the presence of cyanuryl chloride (CC) and Et~3N. The crystal structure was determined by X-ray diffraction method. The crystal is monoclinic system, space group P2~1/c, with a=0.9959(4)nm, b=1.1469(4)nm, c=1.1108(3)nm, β=92.72(3)°, V=1.2673(8)nm^3, Z=4. The C=O and C=S group are located at the opposite sides of C(1)-N(1)-C(4) and C(6)-N(2)-C(7) bonds. The electronic structure of the title compound was studied by molecular orbital PM3 method. The nature of the near frontier orbital and distribution of the calculated net charges and bond orders were obtained. The electronic spectra was discussed.

Key words: TRIAZINE P, ELECTRONIC STRUCTURE, CRYSTAL STRUCTURE, THIAZOLE P, ORGANIC SYNTHESIS, CARBOXYLIC ACID, X-RAY DIFFRACTION ANALYSIS, THIOKETONE, THIOKETONE, THIAZOLE P