Electrochemical and Reactivity Studies of N→Sn Coordinated Distannynes. Issue 5 (13th December 2017) - Novák, Miroslav
Abstract: Studies are focused on the redox potentials of N→Sn coordinated distannnynes {L 1–3 Sn}2 (L 1 =1, L 2 =2 and L 3 =3, in which L 1 is [C6 H3 ‐2, 6‐(Me2 NCH2 )2 ] −, L 2 is [C6 H2 ‐2, 4‐ t Bu2 ‐6‐(Et2 NCH2 )] − and L 3 is [C6 H2 ‐2, 4‐ t Bu2 ‐6‐(DippN=CH)] − ; Dipp=2, 6‐diisopropylphenyl), containing the tin atom in oxidation state +I. Distannynes1 –3 were used as ligands for transition metals, and complexes [{L 1 Sn}2 ⋅ Fe(CO)4 ] (4 ) and [{L 2 Sn}2 ⋅ Fe(CO)4 ] (5 ) were prepared. The set of N→Sn coordinated distannynes1 –5 was studied by cyclic voltammetry measurements and the oxidation potentials of tin atoms in1 –5 were determined. The redox potentials are influenced by either ligands L 1–3 or Sn I →Fe coordination. Oxidation reactions of1 –3 were also studied. The reaction of2 with (2, 2, 6, 6‐tetramethylpiperidin‐1‐yl)oxyl (TEMPO) provided mixed organotin oxide {(L 2 SnO)(L 2 )Sn(μ‐O)}2 (6 ) as a consequence of the instability of the expected {L 2 Sn⋅ TEMPO} complex. To support this proposed mechanism, the N→Ge coordinated digermyne {L 2 Ge}2 (7 ) was prepared. The reaction of7 with TEMPO provided the expected complex {L 2 Ge⋅ TEMPO} (8 ). Abstract : Focus on tin : Different N→Sn coordinated distannnynes, {L 1–3 Sn}2, containing tin atoms in oxidation state +I were prepared and used as ligands for transition metals to provide complexes, [{L 1−2 Sn}2 ⋅ Fe(CO)4 ] (see figure). Cyclic voltammetry measurements revealed the oxidation potentials of tin atoms and the influence of N→Sn I and Sn I →Fe coordination.