Raman Spectroscopic Investigation and Coordination Behavior of the Polyimido SVI Anions [RS(NR)3]− and [S(NR)4]2−

Synthetic access to the [R′S(NR)3]− and [S(NR)4]2− ions (R = tert-butyl, R′ = Me) permits the study of their coordination behavior. As isoelectronic NR analogues of the sulfonate [RSO3]− and sulfate SO42− ions they contain nitrogen donor atoms in the periphery of the ligand. The barium metal complexes of these ligands are soluble molecular-contact ion pairs rather than solid-state aggregates. Tripodal coordination is precluded by steric requirements, and the bidentate coordination mode is favored.