Design and synthesis of two luminescent Zn(II)-based coordination polymers with different structures regulated by different solvent system

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 Ls 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.

Section: Introductionmentioning

confidence: 99%

Section: ■ Introductionmentioning

confidence: 99%

Synthesis, Crystal Structures, H₂S, and Iodine Uptake Properties of Four New Coordination Polymers Constructed from Group 12 Transition Metal Ions and a Bidentate Sulfur Donor Ligand

Beheshti

Bahrani‐Pour

Sedaghat

et al. 2022

“…Thus, it is pertinent to understand and control the subtle factors that have some impact on the formation of these materials. The self-assembly progress is highly influenced by several factors such as the ligand and metal nature, − the counterions, − the experimental conditions, − the solvents, − and the metal to ligand ratio. , It is noteworthy to mention that, in metal–organic crystal engineering, predicting the coordination polymer topology when mixed anions are used is more difficult because several factors are controlling the framework formation of coordination polymers including the size, geometry, coordinating ability, and selectivity of anions to participate in the structure. − On the other hand, the role of the anions in the macromolecule chemistry is of a great interest because of its application in ion-pair recognition and especially in anion exchange. − Although a good number of metal mixed-ligand complexes were reported, − to the best of our knowledge there is no report in the literature about the synthesis of metal mixed-anion complexes. Mixed anion complexes are attractive due to their potential applications and their new structures.…”

Section: Introductionmentioning

confidence: 99%

Synthesis, Structural Characterization, Photophysical Properties, and Antibacterial Assessment of Silver(I)-Thione Coordination Polymers Based on a Competition between Nitrate Anion and Coanions CF₃SO₃^–, ClO₄^–, BF₄^–, PF₆^–, and SbF₆^–

Soleymani-Babadi

Beheshti

Bahrani‐Pour

et al. 2019

Six new coordination polymers, namely, [Ag 2 L-(NO 3 ) 2 ] n (1), {[Ag 6 L 4 (CF 3 SO 3 ) 4 ][CF 3 SO 3 ] 2 } n (2), {[Ag 2 L-(NO 3 )][ClO 4 ]} n (3), {[Ag 2 L(NO 3 )][BF 4 ]} n (4), {[Ag 2 L(NO 3 )]-[PF 6 ]} n (5), and {[Ag 2 L(NO 3 )][SbF 6 ]} n (6), have been successfully synthesized by the reaction of AgNO 3 and selected coanions CF 3 SO 3 − , ClO 4 − , BF 4 − , PF 6 − , and SbF 6− with 1,3-bis(1methylthioimidazolyl) propane under the same experimental conditions in order to illustrate coordination ability of nitrate ion relative to the other considered coanions. To evaluate this competition, compound 1 as a reference structure was synthesized in the absence of coanions. In its two-dimensional structure, the thione ligand appears in a hexadentate mode, and the nitrate as a coligand is coordinated in a bidentate fashion. In a competition between the silver nitrate and triflate, despite the coordination ability expected for both anions, these anions did not appeared together in the structure of compound. The moderately coordinating anion CF 3 SO 3 − build up a cationic structure with only one kind of anion. In contrast to polymers 1 and 2, in the valuable networks 3−6, for the first time extraordinarily two kind of anions were involved in their structures. The difference between the coordination ability of the considered coanions is the most effective factor that impacts the coordination and linkage modes of the flexible ligand and nitrate anion and in turn directs the construction of coordination polymers. In general, X-ray diffraction analysis reveals that the most changes in the structure of compounds 3−6 relative to the structure of 1 were generated by the bulky, uncoordinated anions PF 6 − and SbF 6 − . The thermogravimetric analysis experimental data reveal that these compounds start to decompose in the temperature range of 140−328 °C. In their electronic spectra, a sharp band at 246 nm due to the π → π* transitions in the CS moiety of the ligand is slightly red-shifted upon coordination of the ligand to Ag I ions via sulfur atoms. All of the synthesized compounds display strong blue emissions in the solid state. The title complexes possess antibacterial activity against the selected strain of Gram-negative (Escherichia coli, Pseudomonas aeruginosa) and Grampositive (Staphylococcus aureus, Bacillus subtilis) bacteria.

“…In the investigation of coordination polymers, it is important to understand the major factors that affect the metal coordination and crystal packing of the final product. For a given metal and ligand set, the factors that play an important role in controlling the structure of coordination polymers include structure and conformation of the ligands, − the coordinating potential of the anions, − oxidation state , and hard/soft properties of the metal ions, − the reaction conditions, − the solvent, − the metal-to-ligand ratio, , and so on. In the structural design of coordination polymers, predicting the topology when using flexible multidentate bridging ligands is more difficult than that of a rigid one because their flexibility and conformational freedom allow them to coordinate to metal centers in unpredictable coordination modes and form unexpected structures with specific properties.…”

Section: Introductionmentioning

confidence: 99%

Design, Synthesis, and Antibacterial Assessment of Silver(I)-Based Coordination Polymers with Variable Counterions and Unprecedented Structures by the Tuning Spacer Length and Binding Mode of Flexible Bis(imidazole-2-thiones) Ligands

Beheshti¹,

Soleymani-Babadi²,

Mayer

et al. 2017

An investigation of the impact of alkyl spacer length of the flexible ligands and influence of shape and coordination ability of the counterions has been done on a series of five silver(I)-bis(imidazole-2-thione) coordination polymers. The five compounds, namely, and [Ag 2 L 6 Br 2 ] n (L 4 = 1,1′-(butane-1,4-diyl)bis(3methylimidazoline-2-thione) and L 6 = 1,1′-(hexane-1,4-diyl)bis(3-methylimidazoline-2-thione) have been characterized by elemental analysis, IR spectra, thermogravimetric analysis (TGA), powder X-ray diffraction, and single crystal X-ray diffraction. In the title polymers, the L 4 and L 6 ligands exhibit unprecedented coordination modes, and the Ag(I) centers adopt a range of coordination geometries. The single crystal structural analysis of the title compounds shows that polymers based on the L 4 ligand predominately adopt AgS 4 core structure which does not appear in the polymers containing L 6 ligand. The TGA experimental data reveal that these compounds start to decompose in the temperature range of 240−341 °C. All of the synthesized compounds, in particular, polymer 2, possess antibacterial activity against the selected strain of Gram-negative (Escherichia coli, Pseudomonas aeruginosa) and Gram-positive (Staphylococcus aureus, Bacillus subtilis) bacteria.