Cu(I) 3,5-Diethyl-1,2,4-Triazolate (MAF-2): From Crystal Engineering to Multifunctional Materials

Abstract

Among various types of nonporous and porous coordination polymers, and as a subset of metal azolate frameworks (MAFs), Cu(I) 1,2,4triazolates are unique for their simple three-connected network topologies which can be controlled by their significant steric hindrance effects between the noncoordinative side groups. This perspective article discusses the crystal engineering, structures, and diversified properties of Cu(I) 1,2,4-triazolates, particularly focusing on the porous coordination polymer [Cu(detz)] (MAF-2, Hdetz = 3,5-diethyl-1,2,4-triazole) showing unique/multimode flexibility, high hydrophobicity, bright phosphorescence, and exceptionally high stabilities toward not only guest change but also water and oxygen, which have demonstrated as a good platform for realizing high-performance applications related to gas/vapor confinement, storage, separation, and sensing. The exceptional O 2 reactivity and the tunable framework flexibility, pore surface polarity, and gas separation performances of [Cu 4 (btm) 2 ] (MAF-42, H 2 btm = bis(5-methyl-1,2,4-triazol-3-yl)methane) are also summarized.

Syntheses, Crystal Structures, Luminescent Properties, and Electrochemical Synthesis of Group 12 Element Coordination Polymers with 4-Substituted 1,2,4-Triazole Ligands

“…Azoles and their derivatives are widely used as organic connectors in supramolecular coordination chemistry, leading to a variety of networks due to their numerous coordination modes. − This includes monodentate, bidentate chelating, or bidentate bridging modes, depending on the position and the nature of the substituent at the azole ring. The types of architecture range from 1D azole coordination polymers (ACPs) to 2D or 3D metal-azolate networks (MANs) and frameworks (MAFs). − It is quite challenging to control the construction of polynuclear complexes, as structural modifications of building blocks influence the final structural motifs through covalent bonding and various weak interactions. Therefore, the selection of organic connectors with proper length, flexibility, and symmetry is critical to obtain special topology structures.…”

Control of Structures and Emission Properties of (CuI)n 2-Methyldithiane Coordination Polymers

“…The design of coordination polymers with a predictable secondary building unit (SBU) and dimensionality is a quasi-impossible task, but the quest remains of great interest for the discovery of new materials with desired properties such as gas adsorption, − sensing, − thermo-chromism, − magnetism, − conductivity, − redox-activity, , catalysis, ,− nonlinear optical behavior, , and luminescence. ,− Recent reviews on CPs formed by mono- and dithioethers with CuX salts (X = Cl, Br, I) − revealed that, when X = I, the SBU had a strong tendency to form closed cubanes (Cu 4 I 4 ) and 1D staircase polymeric structures, whereas the rhomboid Cu 2 X 2 S 4 SBU is predominately noted when X = Cl or Br. The key property is that the cubanes show luminescence regardless of the ligand, whereas the rhomboids and staircase motifs are almost always weakly or not emissive. ,, Also, the presence of 2D and 3D CPs increases drastically when semirigid or rigid dithioethers are used as assembling ligands. ,, The interest in 2D and 3D CPs stems from the possibility to form MOF-like materials .…”

Made in Water: A Stable Microporous Cu(I)-carboxylate Framework (CityU-7) for CO2, Water, and Iodine Uptake

“…The synthesis of CityU-7 as a water-stable MOF also offers fundamental insight into materials design. In general, better water stability can be achieved by enlisting hard–hard (e.g., as in Cr 3+ , Zr 4+ -carboxylate) bonding − or using softer coordination bonds based on, for example, nitrogen donors and metal ions including Cu­(I) and other transition metals. − That is to say, most Cu­(I)-based MOF solids are constructed through N-donor linkers such as pyrazolate and pyridine, − while Cu­(I)-carboxylate links are rarely featured in MOF structures. , This observation is partly due to the soft nature of Cu­(I) that tends to refrain from the hard carboxyl group and partly due to Cu­(I) being prone to oxidization and disproportionation.…”