Chivers, TristramHilts, Robert2022-05-272022-05-271994Chivers, T., & Hilts, R. (1994). Coordination chemistry of unsaturated cyclic and acyclic PNs and PNSe ligands. Coordination Chemistry Reviews, 137, 201–232. doi: https://doi.org/10.1016/0010-8545(94)03002-8https://hdl.handle.net/20.500.14078/326This review is primarily concerned with the synthesis, structure and fluxional behaviour of cyclic and acyclic chalcogen-nitrogen systems containing phosphorus (V) or phosphorus (III). The cyclic Ph4P2N4S2R− and Ph4P2N4S2−2 anions (and their selenium analogues) are versatile ligands for both early and late transition metals. Mono-, di-, tri- and tetradentate bonding modes have been established for the eight-membered P2N4S2 ring in these inorganic heterocycles. Ligation occurs through sulphur (or selenium) and/or nitrogen, while the coordinatively saturated phosphorus (V) centres serve as an informative probe of fluxional processes. By contrast, coordination occurs exclusively through phosphorus in both the cyclic and acyclic phosphorus (III) systems.enAll Rights Reservedx-ray structuresubstituted sulfur diimidesmetal complexes transitionsP-31 NMR characterizationLewis base propertiesArticlehttps://doi.org/10.1016/0010-8545(94)03002-8