Exploring the reactivity of L -tellurocystine, Te-protected tellurocysteine conjugates and diorganodiselenides towards hydrogen peroxide: synthesis and molecular structure analysis

The oxidation reaction of L -tellurocystine, [Te 2 {CH 2 CH(NH 3 + )COO − } 2 ] (4) with H 2 O 2 in the presence of HBr resulted in the formation of cyclic, zwitterionic organotellurolate( iv ) species, namely [Te − {CH 2 CH(NH 3 + )COO}(Br) 3 ] (5). The H 2 O 2 oxidation of Te-protected tellurocysteine derivatives [RTe{CH 2 CH(NH 2 )COOH}] [R = C 6 H 5 (6) and 4-MeC 6 H 4 (7)] in the presence of HCl resulted in the formation of chlorotellurane species [(C 6 H 5 )Te{CH 2 CH(NH 3 + )COOH}(Cl) 2 ]Cl (8) and [(4-MeC 6 H 5 )Te{CH 2 CH(NH 3 + )COO}(Cl)]Cl (9), respectively. The oxidation reaction of diorganodiselenides R 2 Se 2 [R = 4-MeC 6 H 4 (10), R = 4-OMeC 6 H 4 (11), R = 3,4-Me 2 C 6 H 3 (12) and R = 2,4,6-Me 3 C 6 H 2 (13)] with H 2 O 2 afforded homoleptic diorganoselenones R 2 SeO 2 [R = 4-MeC 6 H 4 (14), R = 4-OMeC 6 H 4 (15), R = 3,4-Me 2 C 6 H 3 (16) and R = 2,4,6-Me 3 C 6 H 2 (17)], respectively. The synthesized compounds were thoroughly characterized by multinuclear NMR ( 1 H, 13 C, 125 Te/ 77 Se), FT-IR spectroscopy, ESI-MS and elemental analysis. The molecular structures of the compounds were determined by single crystal X-ray diffraction studies.