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In the current paper, we have successfully synthesized three new mercury coordination polymers with fascinating structures and properties via a flexible sulfur donor ligand, namely, {[Hg(μ2-Cl)(μ2-Ls)]}n[BF4]n(1), {[Hg(μ2-Cl)(μ2-Ls)]}n[ClO4]n(2), and [Hg(SCN)2(μ2-Ls)]n(3) [Ls = 1,1-bis(3-methyl-4-imidazoline-2-thione)methane]. These complexes have been characterized by means of different techniques such as single crystal X-ray crystallography, FT-IR, elemental analysis (CHNS), UV-Vis, PXRD, BET, and TGA. Suitable single crystals of all complexes were obtained using the branch tube method with a very high yield and good stability due to the high affinity of mercury to bind to the thione groups. The cationic moieties of polymers 1 and 2 were isostructural, with a HgCl2S2 coordination core structure. The voids of the quasi-hexagonal packing of the columnar chains were occupied by unbonded tetrahedral BF4- ions in 1 and perchlorate anions in polymer 2. Polymer 3 has a less distorted tetrahedral geometry than 1 and 2, with a HgS4 core structure. By considering the thiophilicity of mercury, a thioamide-based Ls ligand was used to detoxify Hg(II) into insoluble polymers 1-3. The results of an MTT assay for (HepG2) liver cells confirmed the excellent cytoprotective effect of this ligand against mercury. Based on IC50 calculations, their toxicity was in order of polymer 1 > polymer 2 > polymer 3. These polymers were also considered as adsorbents for the reversible removal of iodine from solution and the kinetics of the process has been studied in detail. Interestingly, all of them showed an excellent stability and high capacity, in order of 763.53 mg g-1, 877.10 mg g-1, and 905.31 mg g-1 for polymers 1-3, respectively.

An investigation of the impact of the shape, size and coordination ability of counterions was carried out on five silver(I) 1,2-bis(1-methylthioimidazolyl)ethane coordination polymers, namely, [Ag2L(NO3)2]n (1), [Ag2L(SO3CF3)2]n (2), {[AgL][ClO4]}n (3), {[AgL]2[BF4]2}n (4) and {[AgL]3[PF6]3}n (5). They have been characterized by elemental analysis, IR spectroscopy, PXRD and single-crystal X-ray diffraction. [Ag2L(NO3)2]n (1) was produced in the presence of a strongly coordinating anion (NO3−). In the 1D structure of 1, the ligand appears in a pentadentate form and the nitrate acts as a co-ligand in a bidentate coordination fashion. As in 1, in 2 CF3SO3− with a moderately coordinating potential builds up a natural structure with only one kind of coordination mode for the ligand and two types of coordination geometry for the silver atoms. The difference between structures 1 and 2 can be attributed to the size and coordination ability of their anions, which changed the coordination environment of silver ions without changing the coordination fashion of the ligand. In polymer 3, by decreasing the coordination ability and increasing the size of perchlorate relative to that of the previously considered anions, the coordination mode of the ligand and hence the coordination environment of the silver centers were changed. Unlike all the title compounds in the cationic structure of 3, one of the crystallographically independent AgI centers adopts a distorted trigonal planar environment. Complex 4 with an extended helical chain of [Ag2L]n2+ was obtained when AgBF4 with a small, non-coordinated anion was used to react with the L ligand. X-ray diffraction analysis reveals that the most changes were detected in polymer 5 with a rare triple chain structure and a scarce coordination mode of the ligand by using the bulky, uncoordinated PF6− anion. In fact, changing the type of the anion causes a change in the coordination mode of the ligand and in turn in the structural coordination geometry of the polymer. Additionally, the adsorption potential of the polymers was examined by using NH3 and H2S gases.

In the current work, we have managed to design and synthesize a set of four new sulfur coordination polymers, namely, [ZnCl2(Ls)2]n (1), [CdCl2(Ls)2]n(2), [Cd(NCS)(μ2-SCN)2(Ls)2]n(3), and {[Hg(μ2-Cl)(Ls)2]-[ClO4]}n(4) using a branch tube method. They have been fully characterized using several techniques including elemental analysis, Fourier transform infrared spectroscopy, powder X-ray diffraction, photoluminescence spectroscopy, UV−vis, and single-crystal X-ray diffraction. Polymer 1 was synthesized directly by the reaction of zinc ions with the L s ligand, while polymer 2, which is isostructural with 1, was synthesized by a single-crystal-to-single-crystal postsynthetic modification of polymer 1 where Zn(II) ions were substituted by Cd(II) ions. The effect of the anion on changing the topology has been carried out in polymer 3 using a thiocyanate anion in which SCN− groups were bonded to the metal centers in both terminal and bridging coordination fashions to form a two-dimensional network structure. The competition between halogen and uncoordinated perchlorate anions along with the Ls ligand constructed a cationic one-dimensional network structure in {[Hg(μ2-Cl)(Ls)2][ClO4]}n in which halogen atoms bridged between the metal centers and perchlorates counterbalanced the charge. The title polymers were considered as iodine and H2S adsorbents, and their kinetics were studied in detail. All polymers showed extreme stability toward both pollutants, and polymer 4 removed more than 99% of I2 from the solution. The presence of halogen and ClO4− anions in polymer 4 was the key factor for its best removal efficiency in this group.

In this work, we have prepared two new sulfur CPs with group 12 transition metals, namely, [Zn (NCS)Cl(μ2-L)]n (1) and [Hg (SCN)2(μ2-L)]n (3). [Cd (NCS)Cl(μ2-L)]n (2), which is isostructural with 1, was synthesized for a comparison from our published work. These compounds have been characterized by FT-IR, UV–Vis, powder X-ray diffraction (PXRD), elemental analysis (CHNS), scanning electron microscopy (Fe-SEM), TGA, BET, and single-crystal X-ray analysis for 1 and 3. In the structure of all polymers, the bbit ligand [L = bbit = 1,1-bis(3-methyl-4-imidazoline-2-thion)butane] is bridged between metal centers by the anti-anti-anti conformation to form an infinite 1D zigzag chain. The considered polymers were used for the removal of a substantial amount of I2 from cyclohexane solution. Despite the nonporous and low dimensional frameworks of title polymers, their maximum iodine adsorption capacities were notable and in order of 817.68, 906.48, and 911.08 mg/g for polymers 1–3, respectively, with an extraordinary stability toward iodine. The capacity of micro-sized structures was almost double as compared with their bulk ones.

Two new coordination polymers namely, [(AgCN)4LS]n (1) and [(AgCN)3LN]n (2), were successfully synthesized by the reaction of AgNO3 and cyanide as a co-anion with LS[1,1′-(hexane-1,4-diyl)bis(3-methylimidazoline-2-thione] and LN[1,1,3,3-tetrakis(3,5-dimethyl-1-pyrazole)propane] ligands in order to use them for the preparation of magnetic nanocomposites with MnFe2O4 nanoparticles by an efficient and facile method. They were then well characterized via numerous techniques, including elemental analysis, FT-IR spectroscopy, TGA, PXRD, SEM, TEM, EDX, VSM, BET, ICP, and single-crystal X-ray diffraction. The considered polymers and their magnetic nanocomposites with nearly the same antibacterial activity demonstrated a highly inhibitive effect on the growth of Gram-negative (Escherichia coli, Pseudomonas aeruginosa) and Gram-positive (Staphylococcus aureus, Bacillus subtilis) bacteria. By considering the simple separation and recyclable characters of the magnetic nanocomposites, these materials are suitable to be used in biological applications.

Six new coordination polymers, namely, [Ag2L(NO3)2]n (1), {[Ag6L4(CF3SO3)4][CF3SO3]2}n (2), {[Ag2L(NO3)][ClO4]}n (3), {[Ag2L(NO3)][BF4]}n (4), {[Ag2L(NO3)][PF6]}n (5), and {[Ag2L(NO3)][SbF6]}n (6),...

Two new isostructural Zn(II) and Cd(II) coordination polymers, namely {[Zn 2 (bbit) 3 Cl 2 ][ZnCl 4 ]} n ( 1 ) and {[Cd 2 (bbit) 3 Cl 2 ][CdCl 4 ]} n ( 2 ), have been synthesized and structurally characterized. These compounds represent the first examples of cationic coordination polymers with a tetrahedral MS 3 Cl [M = Zn(II) and Cd(II)] repeating unit. Each of these units is bridged to three symmetry-related ones through the bbit ligands. The 2D [M 2 (bbit) 3 Cl 2 ] 2+ cationic networks stack in an ABAB… sequence along the c -direction. From MIC, MBC and DNA cleavage activity studies, it can be concluded that the title compounds possess antibacterial activity.