Synthesis and Structure of a Macrocyclic Dinickel Complex Incorporating a Hypercoordinated Sulfenium(II) Cation

The synthesis and structure of a macrocyclic dinickel complex incorporating a hypercoordinated sulfenium(II) cation are reported. The novel complex [Ni2L3(Cl)](2+) was obtained from a reaction of the per-hydroxyethylated N6S2 macrocycle H2L2 with NiCl2(H2O)(6) in the presence of air, and isolated as its ClO4 or BPh4 salt: The structure reveals a three-coordinate sulfenium cation that is stabilized by two intramolecularly coordinating amino groups. The N-S bonds are 2.087(7) angstrom and 2.105(6) angstrom and the N-S-N bond angle is 168.2(2)degrees. The bonding is best described by a N,N-chelated sulfur(II) atom (3c-4e bond) bearing two lone pairs and a formal charge of +1.