Construction of Coordination Polymers from Semirigid Ditopic 2,2′-Biimidazole Derivatives: Synthesis, Crystal Structures, and Characterization

Abstract

Eight coordination polymers (CPs), {[Ag(L1)]ClO 4 } n (1), {[Ag(L2) 1.5 ]ClO 4 ·C 2 H 3 N} n (2a), {[Ag(L2)]ClO 4 } n (2b), [Zn(L1)Cl 2 ] n (3), {[Zn(L2)Cl 2 ]·CHCl 3 } n (4), {[Cu(L1) 2 Cl]Cl·H 2 O} n (5), [Cu 2 (L2)(µ-Cl) 2 ] n (6) and [Cu 4 (L2)(µ-Cl) 4 ] n (7) were synthesizedvia self-assembly of corresponding metal ions and biimidazole based ditopic ligands, 1,1´bis(pyridin-3-ylmethyl)-2,2´-biimidazole L1 and 1,1´-bis(pyridin-4-ylmethyl)-2,2´-biimidazole L2. These ligands possess conformational flexibility and two pairs of coordination sites: pyridine nitrogen (N Py ) atoms and imidazole nitrogen (N Im ) atoms. Depending on the metal center in CPs, the biimidazole compounds act as tetra -(1, 7), tri-(2a) or bidentate (2a, 2b, 3-6) ligands binding to the metal either via N Py or N Im , or both. All these CPs were structurally fully characterized with single crystal X-ray structure, mass spectrometry, and NMR spectroscopy. The solid state photophysical properties and thermal stabilities of the CPs were also briefly studied in the solid state.

Ag(I) Complexes of Imine Derivatives of Unexpected 2-Thiophenemethylamine Homo-Coupling and Bis-(E)-N-(furan-2-ylmethyl)-1-(quinolin-2-yl)methanimine

“…Moreover, the τ 4 value of complex 2 is equal to 0.83, indicating its distorted trigonal pyramidal geometry [17] with N-Ag-N bond angles ranging between 99.46(7) • and 143.77(8) • . Other selected bond parameters in 1 and 2 are listed in Table 1 and are comparable with those of closely related compounds in the literature [18,19].…”

Chiral Coordination Polymers from a New 2-Deoxy-d-ribose Derivative Linker: Syntheses, Structures, and Fe3+ Fluorescent Probe Functions

“…CPs are a hot research topic and possess diverse structures and properties such as asymmetric catalysis, photocatalysis, gas storage, optical properties, magnetic properties, sensing properties, and so on. − Due to their fast response speed and simple operation, many CPs with fluorescence properties have been utilized as chemical probes for the detection of cations, anions, organic molecules, and so forth. − Nevertheless, most fluorescent CPs have rare-earth metals or transition metals with a d 10 electron structure as their metal centers. , The CPs based on non-d 10 transition-metal ions with fluorescent ligands are usually found to be emission silent due to the d–d transition, − though there are still some such CPs having good luminescence properties and some of them have fluorescence sensing capabilities. , Apart from the metal centers, the other compositions and structures of CPs have important effects on their properties and functions. The structures of CPs are closely related to the ligands, formation temperatures, solvents, pH, counterions, and other factors. , Even if the same ligand is used to react with different metal ions, the product complexes often have different structures, − and thus it is often difficult to synthesize a series of CPs with the same structure from different metal ions and the same ligand.…”

Series of Cadmium(II) Coordination Polymers Based on a Versatile Multi-N-Donor Tecton or Mixed Carboxylate Ligands: Synthesis, Structure, and Selectively Sensing Property

“…Similarly, the crystalline product of [Cd­(L 2 )­0.5­(bipy)] shows highly selective sensing property for Fe 3+ ions . As for the organic ligands, both of the nitrogen-rich ligands and carboxylic acids are most effective building units for the assembly of various MOFs because the multi-N and -O coordination atoms are easily apt to link with metal centers. − Particularly, the polyazaheteroaromatic ligands can exhibit flexible coordination modes to build diverse MOFs. − In our previous study, we have deliberately designated multi-N-donor ligands containing 1 H -imidazol-4-yl groups to construct a series of porous frameworks exhibiting favorable gas adsorption properties because of the increasing interaction between the adsorbate and uncoordinated N binding sites as elaborately elucidated by Grand Canonical Monte Carlo simulation calculations. − Besides the polyazaheteroaromatic ligands, carboxylic acid ligands are another kind of building units for constructing MOFs due to the variable coordination modes for the carboxyl group. − Furthermore, the mixed polyazaheteroaromatic ligands and carboxylic acid ligands have favorable compatibility, benefiting to construct diverse MOFs . Using the mixed ligands strategy including polyazaheteroaromatic and carboxylic acids ligands, a series of MOFs with novel structures have been constructed based on 4-imidazolyl ligands and auxiliary carboxylic acid ligands together with varied metal salts. − In this paper, we focus our attention on the study of reactions of the π-conjugated 1-(1 H -imidazol-4-yl)-4-(4 H -tetrazol-5-yl)­benzene (H 2 L) ligand together with varied carboxylate ligands to react with metal Cd­(II) salts and obtain a series of Cd­(II) complexes.…”