Triggering Lewis Acidic Nature through the Variation of Coordination Environment of Cd-Centers in 2D-Coordination Polymers

Abstract

The rational design and successful synthesis of novel functional metal−organic frameworks relies on careful selection of metals and versatile organic ligands. A newly designed pyrazole-based dicarboxylate ligand, 5-(3,5-dimethyl-1H-pyrazol-1-yl) 1,3-benzenedicarboxylic acid (H 2 L), was utilized to obtain two new Cd-based coordination polymers I [Cd(L)(H 2 O)]•H 2 O and II [Cd(L)] under similar reaction conditions via solvothermal strategy. Single-crystal Xray data confirmed that compound I exhibits a two-dimensional (2D) skeleton comprising pentagonal bipyramidal Cd-ions and an organic ligand moiety. Compound II has also formed a two-dimensional layer arrangement with the connectivity between trigonal bipyramidal Cdions and the organic ligand. Topological analysis revealed that compound I has formed unique 4 3 .6 3 net topology while compound II has displayed a 4 4 .6 2 sql net topology with 2D frameworks. The Lewis acidic nature of both I and II containing a Cd 2+ metal center has been correlated with the coordination number through dye adsorption−desorption and catalysis studies. The selective adsorption of anionic dye and the extent of adsorption are interrelated with the Cd-ion geometry. For the first time, the role of coordinated water molecule has been analyzed through heterogeneous catalysis reaction (i.e., cyanosilylation) with Cd-based 2Dcoordination polymers (CPs). The plausible mechanisms have been proposed to explain the subsequent role of coordination number and environment in CPs.

Complete and Versatile Post‐Synthetic Modification on Iron‐Triazole Spin Crossover Complexes: A Relevant Material Elaboration Method

“…Nevertheless, we believe that the specific organization of the 1D chains of certain complexes that depend on the nature of the counter‐anion (specific steric hindrance and supramolecular interactions) and which is more or less modulated in suspension by the nature of the solvent, is sufficient to permit a full substitution. This hypothesis is supported by different results described in the literature: 1) it is well known that molecules can be inserted between 1D polymer chains; [104–106] 2) different examples of PSM on polymers [107,108] and on montmorillonite sheets [109] have been also reported 3) full PSM modification in Fe‐triazole chains has been already reported for solid vapor reactions [50] . The study of the spin crossover properties is also in line with a complete PSM reaction.…”

Two-Dimensional Metal-Organic Framework Materials: Synthesis, Structures, Properties and Applications

“…Recently, Paul et al . reported cyanosilylation of imines in DCM solvent catalyzed by [Cd­(L)­(H 2 O)]·H 2 O and [Cd­(L)] (L = 5-(3,5-dimethyl-1 H -pyrazol-1-yl) 1,3-benzenedicarboxylate) 2D frameworks owing to Lewis acidic metal sites . For N -benzylideneaniline substrate, 81% and 70% yield were obtained in 4 h at room temperature, respectively.…”

Synthesis, Structure and Topology of Copper(I) Tetrazolate Framework: Facile Approach to Design Multiple Dye Adsorbent with Carbon Composites

“…The manner of surface adsorption has been pursued by different outer surface mechanistic pathways such as electrostatic interactions involving by adsorbate and adsorbent, strong and weak interactions among acidic and basic species, hydrogen‐bonding, π‐π stacking and hydrophobic interactions (see the ESI, Figure S17). In addition to this, ionic strength, shape and planarity of adsorbate are also responsible factors for adsorption phenomenon [47,55–56] . The available literature also support that more than one interaction may also be feasible for enduring with the physisorption process.…”

“…The dye‐adsorped composite was taken in ethanol and few drops of saturated NaCl solution was added to it followed by sonication for 1 h to complete the desorption process. The similar desorption strategy was applied as communicated earlier [47] . The results of the desorption experiments are depicted in Table S3 and Figure S15 (see the ESI).…”

“…Taking into above consideration and along with continuation of our earlier work [45–47] we have now synthesized a porous Cu MOF incorporating 5‐methyltetrazolate ligand {Cu(C 2 N 4 H 3 ), denoted as CUT1} via in‐situ ligand production applying hydrothermal strategy. Furthermore, we have sucessfully developed an easy and cost‐effective synthetic route for the preperation of MOF‐based activated carbon (AC) composites (1 wt.% and 5 wt.%) using different proportions of activated carbon (AC) along with our present synthesized MOF (CUT1) as represented in Scheme 1 and Scheme 2, respectively.…”