Electrochemical and Reactivity Studies of N→Sn Coordinated Distannynes

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 [C 6 H 3 ‐2,6‐(Me 2 NCH 2 ) 2 ] − , L 2 is [C 6 H 2 ‐2,4‐ t Bu 2 ‐6‐(Et 2 NCH 2 )] − and L 3 is [C 6 H 2 ‐2,4‐ t Bu 2 ‐6‐(DippN=CH)] − ; Dipp=2,6‐diisopropylphenyl), containing the tin atom in oxidation state +I. Distannynes 1 – 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 distannynes 1 – 5 was studied by cyclic voltammetry measurements and the oxidation potentials of tin atoms in 1 – 5 were determined. The redox potentials are influenced by either ligands L 1–3 or Sn I →Fe coordination. Oxidation reactions of 1 – 3 were also studied. The reaction of 2 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 of 7 with TEMPO provided the expected complex {L 2 Ge ⋅ TEMPO} ( 8 ).