Pan, Crystal structures and biological activities of a symmetrical quinoline thioether ligand and its transition metal complexes, Inorganic Chemistry Communications (2015), Abstract: The ligand 2, 6-bis (8-quinolinylthiomethyl) pyridine and its four transition metal complexes have been synthesized and characterized by elemental analysis (EA), infrared spectra (IR) and single-crystal diffraction. It was revealed that compounds 1-3 were comprised of discrete mononuclear units and double nuclear structure in compound 4. The antibacterial activities and pesticide activities of the ligand and the complexes 1-4 were tested. The results showed some compounds had absolute specificity for certain bacteria, and could have good application prospect in pharmaceutical and agricultural use.Chemical structure of the compounds containing quinoline thioether group has been the focus of attention. Because of the particularity of the structures, this kind of compounds have a good coordination performance which we can find in Chen and Su's works [1-5], and their fluorescence activity [6], adsorptive property [7] have been reported before. Recently, this kind of compounds are widely researched in the field of molecular biology, such as ubiquitin agent inhibitors [8], 11-beta-hydroxysteroid dehydrogenase type I inhibitor [9],JAMM proteins inhibitor [10] , potential 5-HT 6 receptor [11] , CRTh 2 antagonists [12] , Keap1-Nrf2 Small-Molecule Inhibitors [13], et al. However, reports on the bioactivities of such kinds of complexes still remain rare. The asymmetric thioether ligand, prepared by Akerkar A. S. in 1970s,has been proven to be an excellent antitubercular agent [14]. In order to probe the potential drug activity of such kind of compounds, the pyridine terminal group was taken as a carrier, which might be a synergisitic activity group we have probed before [15][16][17][18], and reacted with 2 times of equivalent of quinoline thiol groups, the symmetry of quinoline sulfur ether ligand 2, 6-bis (8-quinolinylthiomethyl) pyridine (L) was synthesized. The complexes of [Cu(L)(CF 3 SO 3 )]·(CF 3 SO 3 ) (1), [Cd(L)](ClO 4 ) 2 (H 2 O) 2 (2), [Zn(L)(CO 2 CF 3 )]·(ClO 4 )·CH 3 CN (3), and [Co(L)CoCl 4 ]·CH 3 OH (4) were obtained by coordinating with a series of transition metal salts. All the compounds were characterized by elemental analysis (EA), infrared spectra (IR) and single-crystal diffraction, their antibacterial and pesticides activities were tested. Single-crystal X-ray diffraction measurements of the ligand and complexes 1-4 were carried out on an Oxford Gemini S Ultra CCD diffractometer equipped with a graphite monochromator at 150 K. The determination of unit cell parameters and data collections were performed with Mo-K α radiation (λ = 0.71073 Å). The unit cell parameters were obtained with least-squares refinements and all structures were solved by direct methods [19]. The metal atoms in each complex were located from E-maps. The other non-hydrogen atoms were located in successive difference Fourier syntheses. The final refine...