A Thermally and Hydrolytically Stable Microporous Framework Exhibiting Single‐Chain Magnetism: Structure and Properties of [Co₂(H_0.67bdt)₃]⋅20 H₂O

Abstract

Fixing a hole: Hydrothermal chemistry has been exploited in the preparation of a 3D framework material exhibiting 48% accessible void volume and 1.5% hydrogen uptake by weight at 120 kPa (see picture). The title compound also exhibits single-chain magnetic behavior and reversible changes in magnetic properties upon solvation and desolvation.

Photoluminescent Porous Modular Lanthanide–Vanadium–Organic Frameworks

“…The spectra display a broad band at 380-580 nm, superimposed on both the intra-4f 6 self-absorption bands attributed to the 7 [28] The intra-4f 6 self-absorption suggests the presence of radiative vanadium-to-Eu 3+ energy transfer. By increasing the excitation wavelength from 290 nm to 350 nm, the relative intensity of the vanadium-related band increases and the energy, full-width-at-half-maximum (fwhm) and number of Stark components of the Eu 3+ -intra4f 6 lines change (see below). The selective excitation paths for the vanadium and Eu 3+ -related emission were studied through the acquisition of excitation spectra while monitoring both the broad band emission (at 460 nm) and the 5 D 0 Ǟ 7 F 2 transition (619 nm).…”

“…[28] Intra4f 6 self-absorption bands attributed to the 7 F 0,1 Ǟ 5 L 6 transitions are also observed. The excitation spectrum monitored within the Eu 3+ emission lines consists of a broad band with two components at 290 and 350 nm, attributed to the Eu-O CT bands, [29] and low intensity intra-4f 6 peaks, ascribed to the 7 F 0,1 Ǟ 5 L 6 transitions. The low relative intensity of the intra-4f 6 lines points out that the Eu 3+ excited states are essentially populated through the CT bands, rather than by direct intra-4f 6 excitation.…”

“…[1] The seemingly endless combination of various metal centres with multipodal organic ligands results in the formation of fascinating architectures, which may lead to applications of industrial interest. Examples of the applications of functional MOFs encompass sensors (for solvents, [2] pH or gases [3] ), gas storage, [4] batteries [5] and magnetic [6] and photoluminescent [7] materials. The design of MOF structures is currently based on typical bottom-up synthetic approaches that use the concept of rigid building blocks (secondary building units -SBUs).…”

“…[13,[16][17][18] Our work with this ligand encompasses 2D/3D systems exhibiting, for the first time, single-crystal-to-single-crystal crystal conversion, [13] chain-type photoluminescent materials templated by 1,4-diaminobutane [16] and the formation of hexameric [Ge 6 (µ 2 -OH) 6 (C 2 H 4 O 7 P 2 ) 6 ] 6-moieties that close pack with aromatic ambidentate molecules to form supramolecular organic-inorganic crystalline hybrids. [19] Whilst searching the literature, an unusual cyclic trinuclear anionic unit, described by Aleksandrov and coworkers, came to our notice, which is composed of H 5-xhedp -x residues and V 4+ centres.…”

“…Modularmixedmetal-organicframeworkswithlanthanidecentres, M 4 [M 1 2 V 2 4 O 2 4 (OH) 8 (H 2 hedp) 8 (Hhedp) 1 6 (H 2 O) 6 …”