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Two novel polymeric silver()-triphenylphosphine complexes with nitrogen-containing heterocycles, [Ag(1,2,3-L)-(PPh 3 ) 2 ] n 3 and [Ag(1,2,4-L)(PPh 3 ) 2 ] n 4 (HL = triazole) were synthesized from reactions of polymeric precursors [Ag(1,2,3-L)] n 1 and [Ag(1,2,4-L)] n 2 with 3 equivalents of PPh 3 in CH 2 Cl 2 , respectively. The polymeric precursors 1 and 2 have been obtained as non-crystalline, colorless powder-solids: 2 showed a wide spectrum of excellent antibacterial activities, but 1 did not. The antimicrobial activities of the complexes 1-4, evaluated by minimum inhibitory concentration, were compared and key factors affecting them discussed. The crystal structures of the complexes 3 and 4 were determined by single-crystal X-ray diffraction. The complexes 3 and 4 in the solid state were helical polymers consisting of AgN 2 P 2 cores formed by bridging triazolate anions and two PPh 3 ligands. The complexes 3 and 4 were also fully characterized by elemental analyses, TG/DTA and FT-IR in the solid state and by various solution NMR ( 31 P, 109 Ag, 1 H and 13 C) spectroscopies and molecular weight measurements in solution.

Two types of silver(I)-triphenylphosphine complexes with 2-mercaptonicotinic acid (H2mna) were prepared as [Ag(Hmna)(PPh3)n] (1, n = 2; 2, n = 3); their crystal structures determined by single-crystal X-ray diffraction. These complexes were obtained from reactions of the precursor, [Ag(Hmna)]n, with less excess (3 equiv) and large excess (20 equiv) amounts of PPh3, respectively. Complex 1 was also obtained from a reaction among another precursor [AgCl(PPh3)3], H2mna and aqueous NaOH. The coordination geometry of 1 was a trigonal pyramid with an AgSP2 core; there was a weak interaction between the silver(I) center and the pyridine nitrogen atom, while that of 2 was a distorted tetrahedron with an AgSP3 core. In both 1 and 2, the carboxyl group was protonated and its oxygen atoms did not participate in the coordination. In contrast to the formation of 1 and 2, a related complex, [Ag(Hmba)(PPh3)3] 4 (H2mba = 2–mercaptobenzoic acid), has been obtained from a reaction of [Ag(Hmba)]n with a stoichiometric amount (3 equiv) of PPh3. On the other hand, the gold(I) complex, [Au(Hmna)(PPh3)] 3, with a 2-coordinate AuSP core, was prepared by a stoichiometric reaction among [AuCl(PPh3)], H2mna and aqueous NaOH. Complex 3 in the solid state showed a supramolecular array based on a repetition of hydrogen-bonding interactions between the carboxyl group and the pyridine nitrogen atom, also being contrasted to the related complex, [Au(Hmba)(PPh3)] 5, with a hydrogen-bonding dimer structure in the solid state. In CHCl3, both 1 and 2 were present as several equilibrium species due to a successive dissociation of PPh3 ligands, while 3 was present as an almost monomer. The antimicrobial activities in aqueous media of 1—5, evaluated by minimum inhibitory concentration (MIC), were also tested.

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