A novel anagostic CH⋯Cu interaction and clustered water molecules in copper(II)–pyridine-2,5-dicarboxylate complex

Facile synthesis of a three-dimensional Ln-MOF@FCNT composite for the fabrication of a symmetric supercapacitor device with ultra-high energy density: overcoming the energy storage barrier

In order to quench the thirst for efficient energy storage devices, a novel praseodymium-based state-of-the-art three-dimensional metal-organic framework (MOF), {[Pr(pdc)2]Me2NH2}n (YK-1), has been synthesized by using a simple solvothermal method employing a readily available ligand. YK-1 was characterised by single-crystal XRD and crystallographic analysis. The electrochemical measurements of YK-1 show that it exhibits a specific capacitance of 363.5 F g-1 at a current density of 1.5 A g-1 with 83.8% retention after 5000 cycles. In order to enhance its electrochemical performance for practical application, two composites of YK-1 with graphene oxide (GO) and functionalised multi-walled carbon nanotubes (FCNTs), namely YK-1@GO and YK-1@FCNT, were fabricated by employing a facile ultrasonication technique. The as-synthesized MOF and the composites were characterized by PXRD, FTIR, SEM, and TEM techniques. YK-1@GO and YK-1@FCNT offer enhanced specific capacitances of 488.2 F g-1 and 730.2 F g-1 at the same current density with 93.8% and 97.7% capacity retention after 5000 cycles, respectively (at 16 A g-1). Fascinated by the outstanding results shown by YK-1@FCNT, a symmetric supercapacitor device (SSC) based on it was fabricated. The assembled SSC achieved a remarkable energy density (87.6 W h kg-1) and power density (750.2 W kg-1) at a current density of 1 A g-1, along with very good cycling stability of 91.4% even after 5000 GCD cycles. The SSC device was able to power up several LED lights and even operated a DC brushless fan for a significant amount of time. To the best of our knowledge, the assembled SSC device exhibits the highest energy density among the MOF composite-based SSCs reported so far.

Rare proximity enforced copper hydrogen interactions in copper(i)-chalcogenones

Homoleptic tetra-coordinated copper(i)-chalcogenone complexes have been reported with rare proximity-enforced intramolecular Cu⋯H–C(sp³) hydrogen bonding interactions.

Ferrocenyl thiazolidine-2-thione ornamented 1D coordination polymers derived from coinage metal halides and pseudohalides

Three new ferrocene-functionalized thiazolidine-2-thione coinage metal coordination polymers with halides and pseudo-halides were synthesized and the nature of their weak interactions was assessed.

Efficient removal of Cu(ii) from aqueous systems using enhanced quantum yield nitrogen-doped carbon nanodots

Low value waste resources have been converted into value-added luminescence carbon dots for copper adsorption from contaminated water.

N-Alkylfluorenyl-substituted N-heterocyclic carbenes as bimodal pincers

Two N-heterocyclic carbene precursors having their nitrogen atoms substituted by the expanded 9-ethyl-9-fluorenyl group, namely imidazolinium chloride 6 and imidazolium chloride 7, have been synthesized in high yields from fluorenone (1).

Synthesis and structure of Ag(i), Pd(ii), Rh(i), Ru(ii) and Au(i) NHC-complexes with a pendant Lewis acidic boronic ester moiety

Synthesis and characterization of novel NHC-boronic ester ligands and their corresponding TM-complexes.

Activation of C–H and B–H bonds through agostic bonding: an ELF/QTAIM insight

X–H agostic bonding: a topological insight.

Thermodynamics of the Cu(II) μ-thiolate and Cu(I) disulfide equilibrium: a combined experimental and theoretical study

The redox equilibrium between dinuclear Cu(II) μ-thiolate and Cu(I) disulfide structures has been analyzed experimentally and via DFT calculations. Two new ligands, L(2)SSL(2) and L(4)SSL(4), and their Cu(II) μ-thiolate and Cu(I) disulfide complexes were synthesized. For L(2)SSL(2), these two redox-isomeric copper species are shown to be in equilibrium, which depends on both temperature and solvent. For L(4)SSL(4) the μ-thiolate species forms as the kinetic product and further evolves into the disulfide complex under thermodynamic control, which creates the unprecedented possibility to compare both species under the same reaction conditions. The energies of the μ-thiolate and disulfide complexes for two series of related ligands have been calculated with DFT; the results rationalize the experimentally observed structures, and emphasize the important role that steric requirements play in the formation of the Cu(II) thiolate structure.

Exploring anagostic interactions in 5,15-porphodimethene metal complexes

By using 5,15-porphodimethene metal complexes, the weak noncovalent anagostic interaction is explored using variable temperature NMR studies and is further confirmed by single crystal X-ray analysis.

Spectroscopic and structural investigation of 2,5-dicarboxy-1-methylpyridinium inner salt

The structure of 2,5-dicarboxy-1-methylpyridinium inner salt (1), has been studied by X-ray diffraction, B3LYP/6-311G(d,p) calculations, FTIR, Raman and NMR spectroscopy. The molecules are linked by short intermolecular and asymmetric O-H⋯O hydrogen bonds of 2.486(2)Å between carboxyl and carboxylate groups of neighboring molecules into infinite chains. The hydrogen bonds in the molecules optimized by the B3LYP/6-311G(d,p) approach in trimer (2) and dimer (3) are slightly longer than in the crystal. The FTIR spectrum of the investigated inner salt is dominated by a broad and intense absorption in the 1500-800 cm(-1) region attributed to the ν(as)(OHO) and γ(OHO) vibrations of the strong hydrogen bond. In the Raman spectrum the broad absorption is absent. Linear correlations, δ(exp)=a+b σ(calc) between the experimental (1)H and (13)C NMR chemical shifts (δ(exp)) of the investigated inner salt in D2O and the calculated magnetic isotropic shielding constants (σ(calc)) for the optimized monomer (4a) solvated in water are reported. The pKa value for 1 of 2.31±0.02 was determined by the potentiometric titration.

Two photoluminescent silver(I) saccharinate complexes: The formation of a potassium-oxygen cluster, and Ag ··· π and (O—H) ··· Ag interactions

Two new Ag(I)-saccharinate complexes, K[Ag(sac)2] · H2O (1) and [Ag(sac)(ina)] · 1.5 H2O (2) (sac = saccharinate and ina = isonicotinamide), have been synthesized and characterized by elemental analyses, IR spectroscopy, thermal analysis and single crystal X-ray diffraction. The silver atoms adopt a linear AgN2 geometry in each case defined by two sac ligands in 1, and one sac and one ina ligand in 2. In 1, the anionic complex units are linked into a two-dimensional array by two potassium atoms, forming an eight-membered bimetallic ring and a K2O10 potassium−oxygen cluster. Complex 2 shows rare (O—H) ··· Ag and (N—H) ··· Ag interactions. The molecules are connected by Ag ··· Csac (η3) interactions involväing the saccharinate-phenyl rings.