The stereochemistry of chiral-at-metal complexes is much more abundant, albeit complicated, than chiral-at-carbon compounds, but how to make use of stereolabile metal-centers remains a formidable challenge due to the highly versatile coordination geometry of metal ions and racemization/epimerization problem. We demonstrate herein a stepwise assembly of configurationally stable [Pd 6 (FeL 3 ) 8 ] 28+ (Δ/Λ-MOCs-42) homochiral octahedral cages from unstable D 3 -symmetry trischelate-Fe type metalloligands via strong face-directed stereochemical coupling and facile chiral-induced resolution processes based on stereodifferentiating host−guest dynamics. Kinetic studies reveal that the dissociation rate of MOC-42 cages is 100-fold slower than that of Femetalloligands and the racemization is effectively inhibited, making the cages retain their chirality over extended periods of time (>5 months) at room temperature. Recyclable enantioseparation of atropisomeric compounds has been successfully achieved, giving up to 88% ee.

The design of white‐light phosphors is attractive in solid‐state lighting (SSL) and related fields. A new strategy in obtaining white light emission (WLE) from dual‐way photon energy conversion in a series of dye@MOF (LIFM‐WZ‐6) systems is presented. Besides the traditional UV‐excited one‐photon absorption (OPA) pathway, white‐light modulation can also be gained from the combination of NIR‐excited green and red emissions of MOF backbone and encapsulated dyes via two‐photon absorption (TPA) pathway. As a result, down‐conversion OPA white light was obtained for RhB+@LIFM‐WZ‐6 (0.1 wt %), BR‐2+@LIFM‐WZ‐6 (2 wt %), and APFG+@LIFM‐WZ‐6 (0.1 wt %) samples under 365 nm excitation. RhB+@LIFM‐WZ‐6 (0.05 wt %), BR‐2+@LIFM‐WZ‐6 (1 wt %) and APFG+@LIFM‐WZ‐6 (0.05 wt %) exhibit up‐conversion TPA white light under the excitation of 800, 790, and 730 nm, respectively. This new WLE generation strategy combines different photon energy conversion mechanisms together.

Long persistent luminescence (LPL) materials have been fascinating from ancient times till today, whereas the generation and modulation of LPL are still uncontrollable in most cases. In this paper, a smart responsive metal–organic framework (MOF, LIFM-WZ-1) was reported to combine resilient structural dynamics with reversible LPL modulation. At room temperature in air, the as-prepared LIFM-WZ-1 has a staggered packing structure with inhaled water molecules between cavities, exhibiting fluorescence (F)-dominated blue emission. Under vacuum or by mild heating, the water molecules can be exhaled by the lattice, resulting in a crystal structure (LIFM-WZ-1a) with a reduced a axis and intensified intermolecular interactions. This brings transition to green excimer (E) emission related with lowered energy states. Meanwhile, orange-colored room temperature phosphorescence (RTP) is also enhanced, giving an overall balanced F/E/RTP emission. More fascinatingly, red LPL is ignited in the dehydrated sample, which is dumb in the original LIFM-WZ-1 because of intensified singlet to triplet intersystem crossing, damped high-energy oscillation, and compatible heat dissipation. The above breathing-induced LPL turn-on process is reversible by facile cooling, exposing to wet air, or purging in water vapor. This constitutes a successful exemplification in modulating LPL by the dynamic MOF, which provides potential applications in sensing, anti-counterfeiting, display, and so on.

Long persistent luminescence (LPL) materials have au nique photophysical mechanism to store light radiation energy for subsequent release.H owever,i nc omparison to the common UV source,w hite-light (WL) and near-infrared (NIR) excited LPL is scarce.Herein we report ametal-organic supramolecular boxbased on aD-p-A-type ligand. Owing to the integrated one-photon absorption (OPA) and two-photon absorption (TPA) attributes of the ligand, the heavy-atom effect of the metal center,a sw ell as p-stackinga nd Jaggregation states in the supramolecular assembly,L PL can be triggered by all wavebands from the UV to the NIR region. This novel designed supramolecular kit to affordLPL by both OPAa nd TPAp athwaysp rovides potential applications in anti-counterfeiting,c amouflaging,d ecorating,a nd displaying, among others. Figure 4. a) TDDFT energy levels and possible ISC channels of Cd 2 L 2 . b-e) Demonstration models for the application of Cd 2 L 2 in b) camouflaging, c) anti-counterfeiting, d) decorating, and e) displaying.

Materials with tunable long persistent luminescence (LPL) properties have wide applications in security signs, anti‐counterfeiting, data encrypting, and other fields. However, the majority of reported tunable LPL materials are pure organic molecules or polymers. Herein, a series of metal‐organic coordination polymers displaying color‐tunable LPL were synthesized by the self‐assembly of HTzPTpy ligand with different cadmium halides (X=Cl, Br, and I). In the solid state, their LPL emission colors can be tuned by the time‐evolution, as well as excitation and temperature variation, realizing multi‐mode dynamic color tuning from green to yellow or green to red, and are the first such examples in single‐component coordination polymer materials. Single‐crystal X‐ray diffraction analysis and theoretical calculations reveal that the modification of LPL is due to the balanced action from single molecule and aggregate triplet excited states caused by an external heavy‐atom effect. The results show that the rational introduction of different halide anions into coordination polymers can realize multi‐color LPL.

In a study motivated by considerations associated with heart murmurs and cardiac auscultation, numerical simulations are used to analyse the haemodynamics in a simple model of an aorta with an aortic stenosis. The aorta is modelled as a curved pipe with a $180^{\circ }$ turn, and three different stenoses with area reductions of 50 %, 62.5 % and 75 % are examined. A uniform steady inlet velocity with a Reynolds number of 2000 is used for all of the cases and direct numerical simulation is employed to resolve the dynamics of the flow. The poststenotic flow is dominated by the jet that originates from the stenosis as well as the secondary flow induced by the curvature, and both contribute significantly to the flow turbulence. On the anterior surface of the modelled aorta, the location with maximum pressure fluctuation, which may be considered as the source location for the murmurs, is found to be located around $60^{\circ }$ along the aortic arch, and this location is relatively insensitive to the severity of the stenosis. For all three cases, this high-intensity wall pressure fluctuation includes contributions from both the jet and the secondary flow. Spectral analysis shows that for all three stenoses, the Strouhal number of the vortex shedding of the jet shear layer is close to 0.93, which is higher than the shedding frequency of a corresponding free jet or a jet confined in a straight pipe. This frequency also appears in the pressure spectra at the location postulated as the source of the murmurs, in the form of a ‘break frequency.’ The implications of these findings for cardiac auscultation-based diagnosis of aortic stenosis are also discussed.

It is of significant importance to capture and separate organic pollutants from water sources to combat the growing environmental problems.

The conversion of carbon dioxide (CO) to fuels or value-added chemicals by a photocatalytic system has recently been of growing research interest. One of the challenges is the development of new catalysts with high activity and low cost. Cobalt complexes have long been used as catalysts for the reduction of CO in either electrochemical or photochemical systems. Recently, a series of cis-Co complexes of tetradentate pyridine-amine ligands (N-ligands) exhibited high activity in the reduction of CO in homogeneous photocatalytic systems. However, only CO was obtained as the reduction product. In this regard, herein, we report a novel cis-Co complex C1 supported by an N ligand derivatized with TPA (TPA = tris(2-pyridylmethyl)amine). In contrast to the aforementioned Co catalysts, which contain two halogen atoms at cis-positions, C1 contains one oxygen atom at one cis-coordination site. The structure of C1 was fully characterized by MS, elemental analysis, and single-crystal X-ray diffraction. Experiments on the photocatalytic reduction of CO revealed that C1 is able to convert CO to not only CO but also formate in a homogeneous system containing C1 as a catalyst, Ir(ppy) as a photosensitizer, and triethylamine as an electron donor under visible-light irradiation. The catalytic activity and distribution of reduction products of this system are highly affected by the solvent environment. The presence of water in this system enhances the efficiency of 2H-to-H and CO-to-formate conversions. Electrochemical and steady-state emission quenching experiments indicate that photoinduced electron transfer from excited Ir(ppy) to C1 is thermodynamically feasible. A photogenerated Co species is suggested to be the active species involved in the reduction of CO and protons. DFT calculations were performed to elucidate the catalytic pathways of the formation of CO, formate, and H in this system; four pathways, namely, one for the formation of CO, one for the formation of hydrogen, and two for the formation of formate, were suggested. The results revealed that the oxygen atom at the cis-coordination site in C1 plays an important role in stabilizing the transition state during the transformation of CO at the cobalt center.