The double-helicate terpyridine silver(I) compound [Ag2L2](SO3CF3)2 (L = 4′-phenyl-terpyridine) as a building block for di- and mononuclear complexes

The double-helicate dinuclear silver(I) complex [Ag2L2](SO3CF3)2 (1) was obtained by reaction of AgSO3CF3 with 4′-phenyl-terpyridine (L). Each Ag+ ion is coordinated by two N-atoms from one of the ligands and by one N-atom of the other ligand, forming an irregular Ag2N6 bi-triangle geometry, with a metallic bond between the two silver ions. Complex 1 reacts with potentially bidentate ligands (L1), such as 9,10-bis(diphenylphosphino)anthracene (PAnP), 4,4′-dipyridyl or bis(diphenyl phosphino)methane (DPPM), to give the corresponding dinuclear complexes with bridging L1, [Ag2L2(μ-L1)](SO3CF3)2 (L1 = PAnP 2, 4,4′-dipyridyl 3 or DPPM 4), whereas on reaction with PPh3 forms the mononuclear complex [AgL(PPh3)](SO3CF3) 5. Reaction of 1 with the potentially tridentate ligand tris(2-diphenylphosphinoethyl)amine (NP3) results in complete decomposition of the coordination spheres to form [Ag(NP3)](SO3CF3) 6. Compound 1 shows a strong fluorescence in the solid state with its excitation band at 383.5 nm, the emission band at 535.5 nm and the lifetime of 4.20 ns, but the derived complexes do not show fluorescent properties. The photoluminescence of 1 in various solvents was also studied. The complexes were characterized by 1H NMR, elemental analysis, IR, MS, UV and single crystal X-ray diffraction.