Crystal and molecular structure of [n-'Bu IND.4''N POT.+']['S IND.3''N IND.3 POT.-'] and vibrational assignments and electronic structure of the planar six-membered ring of the trisulfur trinitride anion - Bojes, J; Chivers, T; Laidlaw, William G; Trsic, Milan (Journal of the American Chemical Society, 1979)