Tunable polymerization of silver complexes with organosulfur ligand: counterions effect, solvent- and temperature-dependence in the formation of silver(I)-thiolate(and/or thione) complexes

The reaction of pyridine-2-thiol with AgBF4 and AgClO4 in MeCN gave rise to polymeric compounds [{Ag(HPyS)(2)}(2)(BF4)(2)](n) (1) and [{Ag(HPyS)(2)}(2)(ClO4)(2)](n) (2) (HPyS = pyridine-2-thione). respectively, while the similar reaction of pyridine-2-thiol with AgNO3 resulted in a polymeric compound [{Ag-4(HPyS)(6)}(NO3)(4)](n) (3). X-ray single-crystal diffraction analyses showed that the cations of both I and 2 possess a single-metal-atom chain structure but that of 3 is a double-metal-atom chain structure. The difference between 1 (or 2) and 3 showed counterion effect in polymerization of silver-thione compounds. In the presence of water. the treatment of pyridine-2-thiol with AgBF4 in DMF at 0 degreesC generated a polymeric compound [Ag(SPy)](n) (4) (Spy = pyridine-2-thiolate) with graphite-like layered array of silver ions. Compound 4 can convert into its isomer [Ag-6(SPy)(6)](n) (5) through soaking in DMF for 1 month. However. the similar reaction of pyridine-2-thiol with AgBF4 in MeCN-H2O (v:v=40:1) at room temperature gave another layered polymeric compound [{Ag-5(Spy)(4)(HPyS)}BF4](n) (6.). The preparation of 4, 5, and 6 showed that temperature and solvent exert influence on formation of silver-thiolate polymers. The reaction of AgNO3 with K(2)i-mnt (i-mnt=2,2-dicyanoethene-1,1,-dithiolate) and pyridine-2-thiol gave a polymer [Ag-4(mu(4)-i-mnt)(2)(mu-HPyS)(2)(mu-HPyS)(4 2)](n) (7) with one-dimensional (I-D) chain structure consisting of Ag, square planar cluster units linked by IH-pyriditie-2-thione ligand. The treatment of AgNO3 with NaS2CNEt2 and pyridine-2-thiol in DNIF resulted in another polymeric compound [Ag-4(mu(3)-S2CNEt2)(2)(mu(2)-SPy)(4) (2)](n) (8). The preparation and characterization of these polymeric compounds demonstrated that polymerization of silver(I)-thione and silver(I)-thiolate complexes is tunable through controlling reaction conditions. Semiconducting property studies of 1-8 demonstrated that the electrical conductivity of 4 is 2.04 x 10(-5) cm at 25 degreesC and increases as temperature rises. and those of 1-3 and 5-8 are in the range of 1 x 10(-12) - 1 x 10(-15) S cm(-1) at room temperature and independent on the temperature, indicating that 1 is a semiconductor and the others are insulators. (C) 2002 Elsevier Science B.V. All rights reserved.