Silver(I) coordination by variants of the bis(diphenylphosphino)-amine chalcogenide ligand

Treatment of silver() bromide with the ligands [Ph₂P(Se)HNP(E)Ph₂] (E = Se, S or O) and [Ph₂P(Se)HNPPh₂] results in the formation of the salts [{HN(Ph₂PSe)₂-Se,Se′}₂Ag]Br, [{HN(Ph₂PSe)(Ph₂PS)-Se,S}₂Ag]Br, [{HN(Ph₂PSe)(Ph₂PO)-Se}₂Ag]Br and [{HN(Ph₂PSe)(Ph₂P)-Se,P}₂Ag]Br, respectively. From analysis of spectroscopic data, it appears that the [Ph₂P(Se)HNP(O)Ph₂] ligand is coordinated through selenium donors only. The ligand [Ph₂P(Se)CH₂CH₂AsPh₂] forms a complex [{Ph₂P(Se)CH₂CH₂AsPh₂} ₂Ag]Br. These products constitute thefirst examples of metal complexes bearing these ligands in the neutral form (protonated at the nitrogen atom). The structures of three of the complexes were determined and found to contain homoleptic, spirocyclic inorganic chelates associated with hydrogen-bonded, bridging counteranions. The compound [{HN(Ph₂PSe)(Ph₂PS)-Se,S}₂Ag]Br underwent a transformation upon standing in solution through loss of a single [Ph₂P(Se)HNP(S)Ph₂] ligand to provide a bromide-bridged, neutral complex [{HN(Ph₂PSe)(Ph₂PS)-Se,S}AgBr]₂.