Augusto Cingolani, Effendy, Maura Pellei, Claudio Pettinari, Carlo Santini, Brian W. Skelton, Allan H. White
Adducts of triorganophosphine, triphenylarsine, and triphenylstibine with silver(I) nitrite have been synthesized and characterized both in solution 1H, 31P NMR) and in the solid state (IR, single-crystal X-ray structure analysis). In addition aggregates of AgNO2 and ER3 (E = P, As, Sb) have been identified in solution by electrospray ionization mass spectrometry (ESI-MS). The topology of the structures in the solid state was found to depend on the nature of ER3 and on the stoichiometric ratio AgNO2:ER3. The adducts AgNO2:EPh3 (1:1) (E = P or Sb) are one-dimensional polymers, the role of NO2- being to bridge successive metal atoms by coordination of the two oxygens to one silver atom and the nitrogen lone pair to a successive Ag. The adduct AgNO2:P(o-tolyl)3 (1:1) is mononuclear, due to steric hindrance of the phosphine, the nitrite being O,O′-bidentate, a rare example of a quasi-linear P-Ag-X array. AgNO2:P(p-F-C6H4)3 (1:1) is a dimer, the nitrite being coordinated through both oxygens, the first unidentate, the second bridging bidentate. P(o-tolyl)3 and Pcy3 form 1:2 adducts, also mononuclear, the nitrite still an O,O′chelate. In contrast, the adduct AgNO2:AsPh3 (1:2) is a centrosymmetric dimer, essentially an aggregate of a pair of [Ag(O2N)(AsPh3)2] arrays with one nitrite oxygen being the bridging atom. The adducts AgNO2:EPh3 (1:3) (E = As, Sb) are mononuclear, the nitrite behaving as a consistently strong O,O′-chelate. The E = As adduct is a triclinic solvated form, whereas the unsolvated E = Sb species is monoclinic. ESI-MS spectra of acetonitrile solutions of these complexes show the existence of [Ag(ER3)]+, [Ag(CH3CN)]+, [Ag(CH3CN)2]+, [AgCl2]-, [Ag(NO2)2]-, [Ag(ER3)(CH3CN)]+, and [Ag(ER3)2]+ as well as higher aggregates [Ag2(NO2)(ER3)2]+, [Ag2(NO2)3]- and [Ag2Cl2(NO2)]- which are less prevalent.
Dipartimento di Scienze Chimiche, Universita degli Studi di Camerino, 62032 Camerino MC, via S. Agostino 1, Italy; Jurusan Kimia, FMIPA Universitas Negeri Malang, Malang 65145, Jalan Surabaya 6, Indonesia; Department of Chemistry, University of Western Australia, Crawley, WA 6009, Australia
