2D Cu(I)-I Coordination Polymer with Smart Optoelectronic Properties and Photocatalytic Activity as a Versatile Multifunctional Material

This work presents two isostructural Cu(I)-I 2-fluoropyrazine (Fpyz) luminescent and semiconducting 2D coordination polymers (CPs). Hydrothermal synthesis allows the growth of P-1 space group single crystals, whereas solvent-free synthesis produces polycrystals. Via recrystallization in acetonitrile, P2₁ space group single crystals are obtained. Both show a reversible luminescent response to temperature and pressure. Structure determination by single-crystal X-ray diffraction at 200 and 100 K allows us to understand their response as a function of temperature. Applying hydrostatic/uniaxial pressure or grinding also generates significant variations in their emission. The high structural flexibility of the Cu(I)-I chain is significantly linked to the corresponding alterations in structure. Remarkably, pressure can increase the conductivity by up to 3 orders of magnitude. Variations in resistivity are consistent with changes in the band gap energy. The experimental results are in agreement with the DFT calculations. These properties may allow the use of these CPs as optical pressure or temperature sensors. In addition, their behavior as a heterogeneous photocatalyst of persistent organic dyes has also been investigated.

Advancement in functionalized luminescent frameworks and their prospective applications as inkjet-printed sensors and anti-counterfeit materials

Supramolecular luminescent frameworks with conjugated architectures exhibits interesting photophysical properties with phenomenal chemical and thermal stability. This has instigated global researchers towards its extensive application in toxic analyte detection and the formulation of anti-counterfeit materials. In correlation with this present scenario, luminescent metal-organic frameworks (LMOFs), possessing tailorable structural and functional properties and exceptional physicochemical features, have been categorized as emerging 'smart materials'. Interestingly, LMOFs have assisted in the rapid development of an effectual sensing platform and swift fabrication of anti-counterfeit materials on desirable substrates with the aid of 'Inkjet Printing', which is a viable, low-cost, and high-resolution technology. Inkjet printing is an excellent material deposition technique in the modern era owing to its easy settling over flexible substrates, simplistic emergence of large area image patterns with improved throughput, minimal cost, explicit resolution, and least waste generation. The present review provides state-of-the-art progress on LMOFs based (i) luminescent security ink fabrication with static and dynamic multinodal luminescent materials and (ii) sensory device formulation for the easy and instantaneous recognition of hazardous analytes through the 'Inkjet Printing' technology. This techno-chemical integration will be certainly beneficial to prevent the growth of counterfeit materials and monitor the bioaccumulation of hazardous analytes in our ecological system.

Heterometallic {ZnEu}-metal-organic framework for efficient chemical fixation of CO2

Based on a ligand-directed synthetic strategy, the acidic solvothermal reaction of ZnO, Eu2O3, and 4,4',4''-(pyridine-2,4,6-triyl)tri(1,3-benzenedicarboxylic acid) (H6PTTBA) generated a targeted robust double-walled honeycomb material {[EuIIIZnII(HPTTBA)(H2O)]·4DMF·3H2O}n (simplified as NUC-9), which featured excellent characteristics such as dual tubular nanochannels, high porosity, specific surface area, abundant exposed active metal sites, etc. Although both types of nano-channels (I and II) alternately arranged in the lattice and shaped by six rows of [EuIIIZnII(CO2)6(H2O)] SBUs possessed an equal amount of exposed active metal sites, they could be differentiated according to the discrepant inner surface functionalized by free carboxyl oxygen atoms or coordinated aqueous molecules. Moreover, an activated sample of NUC-9 exhibited better catalytic performance than documented Zn- or Eu-based MOFs for the chemical transformation of various epoxides into the related carbonates under comparatively mild conditions of 1 atm CO2 flow and 70 °C, which should be ascribed to the unsaturated Zn2+ and Eu3+ ions acting as strong Lewis acid sites and free carboxyl oxygen atoms as basic sites synergistically polarizing and activating the substrates of epoxides and CO2 and consequently promoting the reaction. Furthermore, the water-resistant framework of NUC-9 could selectively and sensitively discriminate Fe3+ in aqueous solution according to the fluorescence quenching effect. In addition, it is worth mentioning that the successful self-assembly of NUC-9 provides an effective synthetic technique by employing the designed favorable organic ligand for achieving the targeted functional model of MOFs.

State of the art methods and challenges of luminescent metal–organic frameworks for antibiotic detection

This review focuses on recent developments in the design and synthesis of luminescence MOFs for monitoring antibiotics.

A Zn(II) Metallocycle as Platform to Assemble a 1D + 1D → 1D Polyrotaxane via π···π Stacking of an Ancillary Ligand

A new [Zn2L2] metallocycle bearing two metal centers that can coordinate ancillary ligands and a pocket suitable to host guest molecules is reported. These two features are exploited by reacting the metallocycle with a pyridine ligand to self-assemble in the solid state an extended intertwined system with the rare 1D + 1D → 1D topology. This interpenetrated architecture is supported by π···π stacking between two pyridine units of two different metallocycles in the pocket of a third metallocycle.

Structural characterization and optical properties of two copper(i)-iodide BODIPY coordination polymers

BODIPY chromophores with pyridyl or pyrimidinyl substituents exhibit strong solid-state fluorescence which is quenched in CuI coordination polymers.