Hemilabile silver(I) complexes containing pyridyl chalcogenolate (S, Se) ligands and their utility as molecular precursors for silver chalcogenides

摘要

A series of silver triphenylphosphine complexes containing pyridyl chacogenolate (S, Se) ligands has been synthesized by employing [AgCl(PPh3)(3)] and [Ag-2(mu-Cl)(2)(PPh3)(4)]. The complexes [Ag(S-4-pyH(0.5))(2)(PPh3)(2)] (1) and [Ag-2(mu-S-4-py)(2)(PPh3)(4)] (2) were obtained by the reactions of [Ag-2(mu-Cl)(2)(PPh3)(4)] with 4-pySH in the presence of Et3N and NaOH, respectively. The former has a hydrogen-bonded chain-like structure, while the latter possesses a discrete binuclear structure. 2 on heating in methanol afforded a two-dimensional coordination polymer, [Ag-2(mu-S-4-py)(2)(PPh3)(2)](n) (3). The reaction of [Ag2(mu-Cl)(2)(PPh3)(4)] with NaSe-4-py gave [Ag-3(mu-Se-4-py)(3)(PPh3)(4)] (4) as the primary product together with a minor mononuclear complex, [Ag(Se-4-py)(PPh3)(3)] (5). The latter could be obtained in excellent yield under the same conditions utilising [AgCl(PPh3)(3)] as the starting material. Complex 5 on recrystallization afforded 4. The reaction of [AgCl(PPh3)(3)] with NaS-2-py yielded [Ag(S-2-py)(PPh3)(3)] (6). Complexes 2-6 on refluxing in chloroform gave insoluble polymeric complexes of composition [Ag(Epy)](n) (7) (Epy = 4-pyS (7a), 4-pySe (7b), 2-pyS (7c)) which on thermolysis yielded Ag2E (E = S, Se). The molecular structures of these complexes (1-6) have been established unambiguously by single-crystal X-ray diffraction analyses. Non-bonding interactions in the molecular structures have been discussed.