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Three new three-dimensional (3D) metal-organic frameworks [M 2 (ttdc) 2 (dabco)] (M = Zn(II), 1-Zn; Cu(II), 1-Cu; and Zn/Cu, 1-ZnCu) based on thieno[3,2- b ]thiophene-2,5-dicarboxylate (ttdc 2- ) were synthesized and characterized by a combination of physicochemical methods (single crystal X-ray diffraction, powder X-ray diffraction, chemical and thermogravimetric analyses and IR spectroscopy). 1-Cu demonstrated permanent porosity ( V pore = 0.790 cm 3 g -1 and S BET = 1725 m 2 g -1 ) and significant CO 2 , CH 4 , C 2 H 2 , C 2 H 4 and C 2 H 6 gas uptakes under ambient conditions. The adsorption selectivities for gas mixtures, calculated by IAST, were 10.8 (10.7), 14.6 (9.4), 1.7 (1.6) and 1.5 (1.6) for the equimolar gas mixture compositions CO 2 /N 2 , C 2 H 6 /CH 4 , C 2 H 6 /C 2 H 4 and C 2 H 6 /C 2 H 2 at 1 bar and 273 K (298 K), respectively. The mixed-metal compound 1-ZnCu was prepared by a crystal-to-crystal ion exchange metathesis reaction from 1-Zn with a 52% degree of ion substitution, confirmed by energy-dispersive X-ray spectroscopy, optical microscopy and single crystal X-ray diffraction analysis.

A new 3D metal-organic framework {[Cd 16 (tr 2 btd) 10 (dcdps) 16 (H 2 O) 3 (EtOH)]∙15DMF} n (MOF 1, tr 2 btd = 4,7-di(1,2,4-triazol-1-yl)benzo-2,1,3-thiadiazole, H 2 dcdps = 4,4'-sulfonyldibenzoic acid) was obtained and its luminescent properties were studied. MOF 1 exhibited bright blue-green luminescence with a high quantum yield of 74 % and luminescence quenching response to a toxic natural polyphenol gossypol and luminescence enhancement response to some trivalent metal cations (Fe 3+ , Cr 3+ , Al 3+ and Ga 3+ ). The limit of gossypol detection was 0.20 µM and the determination was not interfered by the components of the cottonseed oil. The limit of detection of gallium(III) was 1.1 µM. It was demonstrated that MOF 1 may be used for distinguishing between the genuine sunflower oil and oil adulterated by crude cottonseed oil through qualitative luminescent and quantitative visual gossypol determination., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Here, we present a series of Cd(II) coordination polymers containing two types of ligands: sterically rigid terephthalate derivatives (bdc-NO 2 2- and bdc-Br 2- ) and flexible bis(2-methylimidazolyl)propane (bmip). The combination of two types of ligands is used to obtain and characterize compounds by single crystal and powder X-ray diffraction, FT-IR, elemental analysis, and TGA. Guest exchange results in structural transformations. 2-fold interpenetrated 1 ·DMF and 2 ·DMF rapidly undergo to 4-fold interpenetrated 1 ·Et 2 O, 1 ·EtOH, and 1 ·H 2 O, or 2 ·Et 2 O, respectively. Also, changes in the coordinating numbers and length of the N , N '-donor bmip ligand were observed according to single crystal X-ray analysis. Activated guest-free compounds [Cd(bdc-NO 2 )(bmip)] ( 1 ) and [Cd(bdc-Br)(bmip)] ( 2 ) are shown to be porous with a BET surface area of 103 and 283 m 2 ·g -1 , respectively. Moreover, both compounds demonstrate gate-opening behavior of ethylene adsorption isotherms at low pressures (<1 bar) and highly selective adsorption of benzene over cyclohexane or lower alcohols. Also, both compounds demonstrate a strong dependence of the maximum of the photoluminescence emission on an excitation wavelength. As a result, the photoluminescence color changes from white to red and from blue to red through green and yellow for compounds 1 and 2 , respectively, with excitation wavelength changing from 360 to 540 nm.

We report on the design of 1D MOFs based on a nopinane-annelated organic ligand and Co(II) or Ni(II), the variation of which allows tuning the optical modulation bandwidth. Structural and time-resolved analysis revealed the optical modulation mechanism, the rates and its endurance, thereby enriching the list of sustainable MOFs for tunable optical modulators.

Exploiting 2-(alkylsulfonyl)pyridines as 1,3-N,S-ligands, herein we have constructed 1D CuI-based coordination polymers (CPs) bearing unprecedented (CuI) n chains and possessing remarkable photophysical properties. At room temperature, these CPs show efficient TADF, phosphorescence or dual emission in the deep-blue to red range with outstandingly short decay times of 0.4-2.0 μs and good quantum performance. Owing to great structural diversity, the CPs demonstrate a variety of emissive mechanisms, spanning from TADF of 1 (M + X)LCT type to 3 CC and 3 (M + X)LCT phosphorescence. Moreover, the designed compounds emit strong X-ray radioluminescence with the quantum efficiency of up to an impressive 55% relative to all-inorganic BGO scintillators. The presented findings push the boundaries in designing TADF and triplet emitters with very short decay times.

We introduce here a new subclass of copper(I) hybrid emitters simultaneously containing [Cu x I y ] z - anions and Cu + cations, separated in space by a Janus head ligand. When UV-irradiated at 298 K, these unique "Two-In-One" hybrids exhibit a short-lived green TADF with near-unity quantum yield and a strong solvatochromic effect. Moreover, they manifest a strong radioluminescence upon X-ray irradiation. These findings open up new possibilities for the design of highly performing TADF materials.

Five new metal-organic frameworks based on Mn(II) and 2,2'-bithiophen-5,5'-dicarboxylate (btdc 2- ) with various chelating N-donor ligands (2,2'-bipyridyl = bpy; 5,5'-dimethyl-2,2'-bipyridyl = 5,5'-dmbpy; 4,4'-dimethyl-2,2'-bipyridyl = 4,4'-dmbpy) [Mn 3 (btdc) 3 (bpy) 2 ]·4DMF, 1 ; [Mn 3 (btdc) 3 (5,5'-dmbpy) 2 ]·5DMF, 2 ; [Mn(btdc)(4,4;-dmbpy)], 3 ; [Mn 2 (btdc) 2 (bpy)(dmf)]·0.5DMF, 4 ; [Mn 2 (btdc) 2 (5,5'-dmbpy)(dmf)]·DMF, 5 (dmf, DMF = N,N-dimethylformamide) have been synthesized, and their crystal structure has been established using single-crystal X-ray diffraction analysis (XRD). The chemical and phase purities of Compounds 1 - 3 have been confirmed via powder X-ray diffraction, thermogravimetric, and chemical analyses as well as IR spectroscopy. The influence of the bulkiness of the chelating N-donor ligand on the dimensionality and structure of the coordination polymer has been analyzed, and the decrease in the framework dimensionality, as well as the secondary building unit's nuclearity and connectivity, has been observed for bulkier ligands. For three-dimensional (3D) coordination polymer 1 , the textural and gas adsorption properties have been studied, revealing noticeable ideal adsorbed solution theory (IAST) CO 2 /N 2 and CO 2 /CO selectivity factors (31.0 at 273 K and 19.1 at 298 K and 25.7 at 273 K and 17.0 at 298 K, respectively, for the equimolar composition and the total pressure of 1 bar). Moreover, significant adsorption selectivity for binary C 2 -C 1 hydrocarbons mixtures (33.4 and 24.9 for C 2 H 6 /CH 4 , 24.8 and 17.7 for C 2 H 4 /CH 4 , 29.3 and 19.1 for C 2 H 2 /CH 4 at 273 K and 298 K, respectively, for the equimolar composition and the total pressure of 1 bar) has been observed, making it possible to separate on 1 natural, shale, and associated petroleum gas into valuable individual components. The ability of Compound 1 to separate benzene and cyclohexane in a vapor phase has also been analyzed based on the adsorption isotherms of individual components measured at 298 K. The preferable adsorption of C 6 H 6 over C 6 H 12 by 1 at high vapor pressures ( V B / V CH = 1.36) can be explained by the existence of multiple van der Waals interactions between guest benzene molecules and the metal-organic host revealed by the XRD analysis of 1 immersed in pure benzene for several days ( 1≅ 2 C 6 H 6 ). Interestingly, at low vapor pressures, an inversed behavior of 1 with preferable adsorption of C 6 H 12 over C 6 H 6 ( K CH / K B = 6.33) was observed; this is a very rare phenomenon. Moreover, magnetic properties (the temperature-dependent molar magnetic susceptibility, χ p ( T ) and effective magnetic moments, μ eff ( T ), as well as the field-dependent magnetization, M ( H )) have been studied for Compounds 1 - 3 , revealing paramagnetic behavior consistent with their crystal structure.

1 H -Imidazole derivatives establish one of the iconic classes of ESIPT-capable compounds (ESIPT = excited state intramolecular proton transfer). This work presents the synthesis of 1-hydroxy-4-(2-hydroxyphenyl)-5-methyl-2-(pyridin-2-yl)-1 H -imidazole ( L OH,OH ) as the first example of ESIPT-capable imidazole derivatives wherein the imidazole moiety simultaneously acts as a proton acceptor and a proton donor. The reaction of L OH,OH with chloroacetone leads to the selective reduction of the imidazolic OH group (whereas the phenolic OH group remains unaffected) and to the isolation of 4-(2-hydroxyphenyl)-5-methyl-2-(pyridin-2-yl)-1 H -imidazole ( L H,OH ), a monohydroxy congener of L OH,OH . Both L OH,OH and L H,OH demonstrate luminescence in the solid state. The number of OH···N proton transfer sites in these compounds (one for L H,OH and two for L OH,OH ) strongly affects the luminescence mechanism and color of the emission: L H,OH emits in the light green region, whereas L OH,OH luminesces in the orange region. According to joint experimental and theoretical studies, the main emission pathway of both compounds is associated with T 1 → S 0 phosphorescence and not related to ESIPT. At the same time, L OH,OH also exhibits S 1 → S 0 fluorescence associated with ESIPT with one proton transferred from the hydroxyimidazole moiety to the pyridine moiety, which is not possible for L H,OH due to the absence of the hydroxy group in the imidazole moiety.

Herein, we report the direct selective C-H lactonization of fatty acids (C5-C16), catalyzed by manganese(II) complexes bearing bis-amino-bis-pyridine ligands. The catalyst system uses the environmentally benign hydrogen peroxide as oxidant and exhibits high efficiency (100-200 TON), providing under optimized conditions γ-lactones in 60-90% yields. Remarkably, by changing the reaction conditions, the oxidation of hexanoic acid can be diverted toward formation of δ-caprolactone in up to 67% yield. Furthermore, the possibility of obtaining (ω-1)-hydroxy derivatives from linear C7-C10 acids in up to 48% yields has been demonstrated.

Porous metal-organic framework [Zn 2 (ttdc) 2 (bpy)] ( 1 ) based on thieno [3,2-b]thiophenedicarboxylate (ttdc) was synthesized and characterized. The structure contains intersected zig-zag channels with an average aperture of 4 × 6 Å and a 49% ( v/v ) guest-accessible pore volume. Gas adsorption studies confirmed the microporous nature of 1 with a specific surface area (BET model) of 952 m 2 ·g -1 and a pore volume of 0.37 cm 3 ·g -1 . Extensive CO 2 , N 2 , O 2 , CO, CH 4 , C 2 H 2 , C 2 H 4 and C 2 H 6 gas adsorption experiments at 273 K and 298 K were carried out, which revealed the great adsorption selectivity of C 2 H 6 over CH 4 (IAST selectivity factor 14.8 at 298 K). The sulfur-rich ligands and double framework interpenetration in 1 result in a dense decoration of the inner surface by thiophene heterocyclic moieties, which are known to be effective secondary adsorption sites for carbon dioxide. As a result, remarkable CO 2 adsorption selectivities were obtained for CO 2 /CH 4 (11.7) and CO 2 /N 2 (27.2 for CO 2 :N 2 = 1:1, 56.4 for CO 2 :N 2 = 15:85 gas mixtures). The computational DFT calculations revealed the decisive role of the sulfur-containing heterocycle moieties in the adsorption of CO 2 and C 2 H 6 . High CO 2 adsorption selectivity values and a relatively low isosteric heat of CO 2 adsorption (31.4 kJ·mol -1 ) make the porous material 1 a promising candidate for practical separation of biogas as well as for CO 2 sequestration from flue gas or natural gas.

We report here a series of original ligand-supported trigonal planar Au@Ag 3 clusters exhibiting bright solid-state phosphorescence in violet to deep-blue range (λ max =410-442 nm) with remarkably short decay times (0.36-1.36 μs) and up to 96 % emission quantum yield at 298 K., (© 2022 Wiley-VCH GmbH.)

We report herein a family of polynuclear complexes, [Au@Ag 4 (Py 3 P) 4 ]X 5 and [Au@Cu 4 (Py 3 P) 4 ]X 5 [X = NO 3 , ClO 4 , OTf, BF 4 , SbF 6 ], containing unprecedented Au-centered Ag 4 and Cu 4 tetrahedral cores supported by tris(2-pyridyl)phosphine (Py 3 P) ligands. The [Au@Ag 4 ] 5+ clusters are synthesized via controlled substitution of the central Ag(I) ion in all-silver [Ag@Ag 4 ] 5+ precursors by the reaction with Au( tht )Cl, while the [Au@Cu 4 ] 5+ cluster is assembled through the treatment of a pre-organized [Au(Py 3 P) 4 ] + metallo-ligand with 4 equiv of a Cu(I) source. The structure of the Au@M 4 clusters has been experimentally and theoretically investigated to reveal very weak intermolecular Au-M metallophilic interactions. At ambient temperature, the designed compounds emit a modest turquoise-to-yellow luminescence with microsecond lifetimes. Based on the temperature-dependent photophysical experiments and DFT/TD-DFT computations, the emission observed has been assigned to an MLCT or LLCT type depending on composition of the cluster core.

Inorganic-organic hybrid luminescent materials have received great attention for their potential applications in a wide range of clean/renewable energy-related areas, including photovoltaics and solid-state lighting. Herein, we present a unique and general "Mn + Cu" approach by blending two earth-abundant luminogenic metals, manganese and copper, within a single ionic structure to construct a remarkable family of low-cost and multifunctional hybrid materials featuring dual emission, as well as triboluminescence and second-harmonic generation response. The novel hybrid materials are made of diphosphine dioxide-chelated [Mn(O∧O) 3 ] 2+ cations and various anionic [Cu x I y ] ( y - x )- clusters, ensuring manifestation of dual phosphorescence streamed from octahedral Mn 2+ ions (605-648 nm) and iodocuprate anions (480-728 nm). Noteworthily, the relative ratio of the emission bands, and hence a resulting emission chromaticity, can be tuned in a wide range through modification of cluster [Cu x I y ] ( y - x )- modules. The structural diversity, enhanced robustness, and up to 100% luminescence quantum yield make the designed materials promising phosphors for lighting and sensing applications.

The reactions of CuX 2 (X = Cl, Br) with dipinodiazafluorenes yielded four new complexes [CuX 2 L 1 ] 2 (X = Cl ( 1 ), Br ( 2 ), L 1 = (1R,3R,8R,10R)-2,2,9,9-Tetramethyl-3,4,7,8,9,10-hexahydro-1H-1,3:8,10-dimethanocyclopenta [1,2-b:5,4-b']diquinolin-12(2H)-one) and [(CuX 2 ) 2 L 2 ]n (X = Cl ( 3 ), Br ( 4 ), L 2 = (1R,3R,8R,10R,1'R,3'R,8'R,10'R)-2,2,2',2',9,9,9',9'-Octamethyl-1,1',2,2',3,3',4,4',7,7',8,8',9,9',10,10'-hexadecahydro-1,3:1',3':8,10:8',10'-tetramethano-12,12'-bi(cyclopenta [1,2-b:5,4-b']diquinolinylidene). The complexes were characterized by IR and EPR spectroscopy, HR-ESI-MS and elemental analysis. The crystal structures of compounds 1 , 2 and 4 were determined by X-ray diffraction (XRD) analysis. Complexes 1 - 2 have a monomeric structure, while complex 4 has a polymeric structure due to additional coordinating N,N sites in L 2 . All complexes contain a binuclear fragment {Cu 2 (μ-X) 2×2 } (X = Cl, Br) in their structures. Each copper atom has a distorted square-pyramidal coordination environment formed by two nitrogen atoms and three halogen atoms. The Cu-N ax distance is elongated compared to Cu-N eq . The EPR spectra of compounds 1 - 4 in CH 3 CN confirm their paramagnetic nature due to the d 9 electronic configuration of the copper(II) ion. The magnetic properties of all compounds were studied by the method of static magnetic susceptibility. For complexes 1 and 2 , the effective magnetic moments are µ eff ≈ 1.87 and 1.83 µ B (per each Cu 2+ ion), respectively, in the temperature range 50-300 K, which are close to the theoretical spin value (1.73 µ B ). Ferromagnetic exchange interactions between Cu(II) ions inside {Cu 2 (μ-X) 2 X 2 } (X = Cl, Br) dimers ( J / k B ≈ 25 and 31 K for 1 and 2 , respectively) or between dimers ( θ ' ≈ 0.30 and 0.47 K for 1 and 2 , respectively) were found at low temperatures. For compounds 3 and 4 , the magnetic susceptibility is well described by the Curie-Weiss law in the temperature range 1.77-300 K with µ eff ≈ 1.72 and 1.70 µ B for 3 and 4 , respectively, and weak antiferromagnetic interactions (θ ≈ -0.4 K for 3 and -0.65 K for 4 ). Complexes 1 - 4 exhibit high catalytic activity in the oxidation of alkanes and alcohols with peroxides. The maximum yield of cyclohexane oxidation products reached 50% (complex 3 ). Based on the data on the study of regio- and bond-selectivity, it was concluded that hydroxyl radicals play a decisive role in the oxidation reaction. The initial products in reactions with alkanes are alkyl hydroperoxides.

A series of heteroleptic square-planar Pt and Pd complexes with bis(diisopropylphenyl) iminoacenaphtene (dpp-Bian) and Cl, 1,3-dithia-2-thione-4,5-dithiolate (dmit), or 1,3-dithia-2-thione-4,5-diselenolate (dsit) ligands have been prepared and characterized by spectroscopic techniques, elemental analysis, X-ray diffraction analysis, and cyclic voltammetry (CV). The intermolecular noncovalent interactions in the crystal structures were assessed by density functional theory (DFT) calculations. The anticancer activity of Pd complexes in breast cancer cell lines was limited by their solubility. Pd(dpp-Bian) complexes with dmit and dsit ligands as well as an uncoordinated dpp-Bian ligand were devoid of cytotoxicity, while the [Pd(dpp-Bian)Cl 2 ] complex was cytotoxic. On the contrary, all Pt(dpp-Bian) complexes demonstrated anticancer activity in a low micromolar concentration range, which was 8-20 times higher than the activity of cisplatin, and up to 2.5-fold selectivity toward cancer cells over healthy fibroblasts. The presence of a redox-active dpp-Bian ligand in Pt and Pd complexes resulted in the induction of reactive oxygen species (ROS) in cancer cells. In addition, these complexes were able to intercalate into DNA, indicating the dual mechanism of action.

Two series of highly luminescent yttrium(iii), europium(iii) and terbium(iii) metal-organic frameworks containing diimine aromatic ligands and the dicarboxylate linker trans-1,4-cyclohexanedicarboxylate (chdc 2- ) which can be described by the general formulas [M 2 (bpy) 2 (chdc) 3 ], where M = Y 3+ (1), Eu 3+ (2), and Tb 3+ (3) and bpy = 2,2'-bipyridyl, and [M 2 (phen) 2 (chdc) 3 ], where M = Y 3+ (4), Eu 3+ (5), and Tb 3+ (6) and phen = 1,10-phenanthroline, were synthesized and characterized. All compounds are based on the same dinuclear {M 2 (L) 2 (OOCR) 6 } building blocks and possess a similar topology of the 3D framework with narrow pores. The chelate aromatic ligands act as efficient light-harvesting antennas for subsequent energy transfer to the emitting metal center (M = Eu 3+ , Tb 3+ ) or intraligand photoemission (M = Y 3+ ). As a result, the reported compounds display intense emission in the red (Eu 3+ ), green (Tb 3+ ) or blue (Y 3+ ) regions representing three basic colors (RGB) of visible light. The measured quantum yields (QYs) of the solid-state luminescence for individual compounds were found to be 63% (1), 46% (2), 59% (3), 2.3% (4), 55% (5) and 49% (6). The drastic reduction of the luminescence efficiency for 4 is explained by the strong disorder of phen ligands. The high thermal stability (up to 300 °C) and exceptional moisture resistance of the bpy-based frameworks 1-3 were confirmed by TG and PXRD measurements. Various bimetal or trimetal compositions were also prepared for the bpy-series. The luminescence properties of these mixed-metal compounds depend on both the chemical composition and excitation wavelength (λ ex ). Remarkably, pure white emission with color temperature = 6126 K was achieved for [Y 1.68 Eu 0.08 Tb 0.24 (bpy) 2 (chdc) 3 ] at λ ex = 360 nm with QY = 20%. The reported results suggest that the obtained coordination framework series is a convenient platform for the design of highly efficient light emitting materials with tunable properties.

Three isostructural metal-organic frameworks ([Ln 2 (phen) 2 (NO 3 ) 2 (chdc) 2 ]·2DMF (Ln 3+ = Y 3+ for 1 , Eu 3+ for 2 or Tb 3+ for 3 ; phen = 1,10-phenanthroline; H 2 chdc = trans -1,4-cyclohexanedicarboxylic acid) were synthesized and characterized. The compounds are based on a binuclear block {M 2 (phen) 2 (NO 3 ) 2 (OOCR) 4 } assembled into a two-dime nsional square-grid network containing tetragonal channels with 26% total solvent-accessible volume. Yttrium ( 1 )-, europium ( 2 )- and terbium ( 3 )-based structures emit in the blue, red and green regions, respectively, representing the basic colors of the standard RGB matrix. A doping of Eu 3+ and/or Tb 3+ centers into the Y 3+ -based phase led to mixed-metal compositions with tunable emission color and high quantum yields (QY) up to 84%. The bright luminescence of a suspension of microcrystalline 3 in DMF (QY = 78%) is effectively quenched by diluted cinnamaldehyde (cinnamal) solutions at millimolar concentrations, suggesting a convenient and analytically viable sensing method for this important chemical.

The first example of a triply bridging (μ 3 -P) phosphine ligand has been discovered in the crown-shaped [Cu 3 (μ 2 -Hal) 3 L] (Hal=Cl, Br, or I) complexes supported by tris[2-(2-pyridyl)ethyl]phosphine (L). Theoretical analysis completely confirms the observed μ 3 -P-bridging pattern, revealing the interaction of the same lone pair of phosphorus with three valence 4s-orbitals of Cu atoms. The presented complexes exhibit outstanding blue phosphorescence (λ em =442-465 nm) with the quantum efficiency reaching 100 %. The complex [Cu 3 (μ 2 -I) 3 L] also exhibits remarkable thermo- and mechanochromic luminescence resulting in a sharp change in the emission colour upon external stimuli. These findings essentially contribute to coordination chemistry of the pnictine ligands., (© 2021 Wiley-VCH GmbH.)

A series of isoreticular Ag(I) luminescent metal-organic frameworks (LMOFs), {[Ag 2 L 2 (CH 3 CN) 2 ](X) 2 } n (X = ClO 4 , OTf, and BF 4 ), has been designed, exploiting diphenyl(2-pyrazyl)phosphine (L) as a multidentate linker. At ambient temperature, these compounds emit a bright long-lived phosphorescence (λ em = 545-555 nm) with a quantum efficiency as high as 22%, which is the highest value for phosphorescent Ag-LMOFs. The prepared LMOFs also exhibit pronounced thermochromic luminescence, reversibly changing their emission color in the 300-77 K range. These LMOFs also demonstrate prominent solvato- and vapochromic luminescence, which manifest as a reversible change in the emission properties during the removal and recovery of the coordinated and guest MeCN molecules, respectively. Moreover, we have discovered a reversible solvent-driven 3D-to-0D transformation of the framework {[Ag 2 L 2 (CH 3 CN) 2 ](ClO 4 ) 2 } n into a brightly emissive complex [Ag 4 L 4 (ClO 4 ) 4 ]. To the best of our knowledge, the compounds obtained are the first Ag-LMOFs that exhibit thermo-, solvato-, and vapochromic luminescence.

Separation of hydrocarbon molecules, such as benzene/cyclohexane and o -xylene/ m -xylene/ p -xylene, is relevant due to their widespread application as chemical feedstock but challenging because of their similar boiling points and close molecular sizes. Physisorption separation could offer an energy-efficient solution to this problem, but the design and synthesis of sorbents that exhibit high selectivity for one of the hydrocarbons remain a largely unmet challenge. Herein, we report a new heterometallic MOF with a unique tortuous shape of channels decorated with aromatic sorption sites [Li 2 Zn 2 (bpy)(ndc) 3 ] ( NIIC-30(Ph) , bpy = 4,4'-bipyridine, ndc 2- = naphthalene-1,4-dicarboxylate) and study of its benzene/cyclohexane and xylene vapor and liquid separation. For an equimolar benzene/cyclohexane mixture, it is possible to achieve a 10-fold excess of benzene in the adsorbed phase. In the case of xylenes, microporous framework NIIC-30(Ph) demonstrates outstanding selective sorption properties and becomes a new benchmark for m -/ o -xylene separation. In addition, NIIC-30(Ph) is stable enough to carry out at least three separation cycles of benzene/cyclohexane mixtures or ternary o -xylene/ m -xylene/ p -xylene mixtures both in the liquid and in the vapor phase. Insights into the performance of NIIC-30(Ph) are gained from X-ray structural studies of each aromatic guest inclusion compound.

Supramolecular derivatives of chlorostannate(IV) and -plumbate(IV) with {Cl 2 } units, Cat 2 {[MCl 6 ](Cl 2 ) x } ( 1 - 5 ; M = Sn, Pb, cat = 1-methylpyridinium (1-MePy), tetramethylammonium (TMA)) were prepared and characterized by X-ray diffractometry and Raman spectroscopy. In particular, the TMA-containing complexes demonstrate remarkable thermal stability, releasing Cl 2 only at elevated temperatures.

Rational design of a series of new heterometallic MOFs was carried out by the judicious choice of the corresponding synthesis conditions and ligand geometry. Three heterometallic MOFs (H2NMe2)[LiZn(dmf)(tdc)2]·DMF·H2O (1), [{LiZn}2Li2Zn2(dmf)6(tdc)6]·6DMF·H2O (2) and [Li2Zn2(dmf)2(fdc)3]·2DMF·2H2O (3) were obtained on the basis of the pre-synthesized pivalate complex [Li2Zn2(py)2(piv)6]. The angle between carboxylic groups greatly affects the possibility of retaining the initial tetranuclear node in the structure of the obtained MOFs. Compound 3 demonstrates permanent porosity with a calculated BET surface area value of 287 m2 g-1. Compounds 2 and 3 are capable of heavy metal sorption from their nitrate solution, and a significant flare-up of the luminescence of the obtained inclusion compounds is observed, where the quantum yield of luminescence increases by an order of magnitude in the case of cadmium inclusion.

Two solvent-controlled topological isomers of scandium-organic frameworks [Sc(Hpzc)(pzc)]·DMF·2H 2 O ( 1 ·DMF·2H 2 O) and [Sc(Hpzc)(pzc)]·DMA·4H 2 O ( 2 ·DMA·4H 2 O) were synthesized using 2,5-pyrazinedicarboxylate (pzc 2- ) (DMF = dimethylformamide; DMA = dimethylacetamide). Despite the isomeric nature of the obtained metal-organic frameworks (MOFs), they possess different structural features and unique adsorption properties toward gases and iodine. The compound 1 has widely spread among MOF structures a dia topology with ultranarrow channels, which together with inner surface functionalization leads to enhanced CO 2 adsorption and high selectivity factors in CO 2 /CH 4 and CO 2 /N 2 gas mixtures (25.9 and 35.6, respectively, 1/1 v/v). Moreover, a rare preferable adsorption of CO 2 over C 2 H 2 was demonstrated. The biporous isomeric framework 2 has a crb topology inherent in zeolites. A remarkable adsorption affinity to C 2 H 2 with the ideal adsorbed solution theory selectivity factor of 127.1 for a C 2 H 2 /C 2 H 4 mixture (1/99 v/v) was achieved for 2 . Both compounds have exceptional chemical stability in a wide range of pH from acidic to basic media.

Three new 3D metal-organic porous frameworks based on Co(II) and 2,2'-bithiophen-5,5'-dicarboxylate (btdc 2- ) [Co 3 (btdc) 3 (bpy) 2 ]·4DMF, 1 ; [Co 3 (btdc) 3 (pz)(dmf) 2 ]·4DMF·1.5H 2 O, 2 ; [Co 3 (btdc) 3 (dmf) 4 ]∙2DMF∙2H 2 O, 3 (bpy = 2,2'-bipyridyl, pz = pyrazine, dmf = N , N -dimethylformamide) were synthesized and structurally characterized. All compounds share the same trinuclear carboxylate building units {Co 3 (RCOO) 6 }, connected either by btdc 2- ligands ( 1 , 3 ) or by both btdc 2- and pz bridging ligands ( 2 ). The permanent porosity of 1 was confirmed by N 2 , O 2 , CO, CO 2 , CH 4 adsorption measurements at various temperatures (77 K, 273 K, 298 K), resulted in BET surface area 667 m 2 ⋅g -1 and promising gas separation performance with selectivity factors up to 35.7 for CO 2 /N 2 , 45.4 for CO 2 /O 2 , 20.8 for CO 2 /CO, and 4.8 for CO 2 /CH 4 . The molar magnetic susceptibilities χ p ( T ) were measured for 1 and 2 in the temperature range 1.77-330 K at magnetic fields up to 10 kOe. The room-temperature values of the effective magnetic moments for compounds 1 and 2 are μ eff (300 K) ≈ 4.93 μ B . The obtained results confirm the mainly paramagnetic nature of both compounds with some antiferromagnetic interactions at low-temperatures T < 20 K in 2 between the Co(II) cations separated by short pz linkers. Similar conclusions were also derived from the field-depending magnetization data of 1 and 2 .

Compounds based on new cyanide cluster anions [{Mo 6 I 8 }(CN) 6 ] 2- , trans -[{Mo 6 I 8 }(CN) 4 (MeO) 2 ] 2- and trans -[{W 6 I 8 }(CN) 2 (MeO) 4 ] 2- were synthesized using mechanochemical or solvothermal synthesis. The crystal and electronic structures as well as spectroscopic properties of the anions were investigated. It was found that the new compounds exhibit red luminescence upon excitation by UV light in the solid state and solutions, as other cluster complexes based on {Mo 6 I 8 } 4+ and {W 6 I 8 } 4+ cores do. The compounds can be recrystallized from aqueous methanol solutions; besides this, it was shown using NMR and UV-Vis spectroscopy that anions did not undergo hydrolysis in the solutions for a long time. These facts indicate that hydrolytic stabilization of {Mo 6 I 8 } and {W 6 I 8 } cluster cores can be achieved by coordination of cyanide ligands.

The NIIC-20 (NIIC stands for Nikolaev Institute of Inorganic Chemistry) is a family of five isostructural metal-organic frameworks (MOFs) based on dodecanuclear wheel-shaped carboxylate building blocks {Zn 12 (RCOO) 12 (glycol) 6 } (glycol is deprotonated diatomic alcohol: ethylene glycol, 1,2-propanediol, 1,2-butanediol, 1,2-pentanediol or glycerol), quantitatively crystallized from readily available starting chemicals. The crystal structures contain large mesoporous cages of 25 Å connected through {Zn 12 } rings, of which inner diameter and chemical nature depend solely on the chosen glycol. The NIIC-20 compounds feature high surface area and rarely observed inversed adsorption affinity for saturated hydrocarbon (ethane) over the unsaturated ones (ethylene, acetylene). The corresponding IAST (Ideal Adsorbed Solution Theory) adsorption selectivity factors reach as much as 15.4 for C 2 H 6 /C 2 H 4 and 10.9 for C 2 H 6 /C 2 H 2 gas mixtures at ambient conditions, exceeding those for any other porous MOF reported so far. The remarkable combination of high adsorption uptakes and high adsorption selectivities makes the NIIC-20 series a new benchmark of porous materials designed for ethylene separation applications., (© 2020 Wiley-VCH GmbH.)

A mixed-ligand metal-organic framework [Zn 2 (chdc) 2 (dabco)]·2NMP (chdc 2- = trans -1,4-cyclohexanedicarboxylate; dabco = 1,4-diazabicyclo[2.2.2]octane; NMP = N -methylpyrrolidone) was synthesized under solvothermal conditions. This coordination compound demonstrates a guest-driven framework breathing due to a conformational change between e , e -chdc and a , a -chdc forms of the linkers with a reversible restoration of crystallinity. Both the local and longer-range coordination environment of the metal centers were extensively studied by electron paramagnetic resonance on a Cu(II)-doped compound. This approach allowed the detailed investigation of the ligand structural conformations and the framework structural dynamics, supported by an X-ray diffraction method. Carbon dioxide and methane adsorption measurements as well as vapor sorption of benzene and cyclohexane at 298 K of the activated compound were studied. While adsorption of small gas molecules, such as CO 2 , CH 4 , and N 2 , is moderate and does not induce the phase transition, the multistepped character of C 6 H 6 and C 6 H 12 adsorption isotherms characterize the breathing nature of [Zn 2 (chdc) 2 (dabco)]. The uptake of benzene from the vapor phase reaches 125 mL·g -1 at 298 K, which surpasses most of benzene uptake values reported for microporous metal-organic frameworks.

A series of lanthanide and yttrium MOFs of two structural types [M 2 (H 2 O) 2 (nmp) 2 (pzc) 3 ] (1M) and [M 2 (H 2 O) 4 (pzc) 3 ]·NMP·5H 2 O (2M) (where M - lanthanide or yttrium cation, nmp - N -methyl-2-pyrrolidone, pzc 2- - 2,5-pyrazinedicarboxylate) was synthesized and characterized by single crystal and powder X-ray diffraction crystallography, TG, elemental analyses and IR-spectroscopy. The effect of lanthanide contraction has led to the fact that lanthanides at the beginning of the series (from lanthanum to gadolinium) have a structure different from the structure of lanthanides at the end of the series and yttrium (from terbium and beyond). According to PXRD patterns of the obtained samples mixed metal materials could be obtained not only as crystalline mixtures of two structure types but also as crystalline products of single structure type. Varying the ratio of lanthanides in the initial reaction mixture allowed us to obtain a wide color range of luminescence, including several near-white-light emitting samples., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

A new metal-organic coordination polymer [Zn 2 (sedc) 2 (dabco)] ( 1se ; sedc 2- = selepophene-2,5-dicarboxylate; dabco = 1,4-diazabicyclo[2.2.2]octane) was synthesized and characterized by single-crystal X-ray diffraction analysis. This MOF is based on {Zn 2 (OOCR) 4 N 2 } paddle wheels and is isoreticular to the family of [Zn 2 (bdc) 2 (dabco)] derivatives ( 1b ; bdc 2- = 1,4-benzenedicarboxylate) with pcu topology. The gas adsorption measurements revealed that 1se shows a 15% higher CO 2 volumetric uptake at 273 K and 28% higher CO 2 uptake at 298 K (both at 1 bar) compared to the prototypic framework 1b . Methane and nitrogen adsorption at 273 K was also investigated, and IAST calculations demonstrated a pronounced increase in CO 2 /CH 4 and CO 2 /N 2 selectivity for 1se , compared with 1b . For example, the selectivity factor for the equimolar CO 2 /CH 4 gas mixture at 1 bar = 15.1 for 1se and 11.9 for 1b . The obtained results show a remarkable effect of the presence of selenium atom on the carbon dioxide affinity in the isoreticular metal-organic frameworks with very similar geometry and porosity.

Four palladium(ii) complexes with tripodal ligands of the tpa family (tpa = tris(2-pyridylmethyl)amine) have been synthesized and X-ray characterized. These complexes efficiently catalyze benzylic C-H oxidation of various substrates with peracetic acid, affording the corresponding ketones in high yields (up to 100%), at <1 mol% catalyst loadings. Complex [(tpa)Pd(OAc)](PF 6 ) with the least sterically demanding ligand tpa demonstrates the highest substrate conversions and ketone selectivities. Preliminary mechanistic data provide evidence in favor of metal complex-mediated rate-limiting benzylic C-H bond cleavage by an electron-deficient oxidant.

A suite of paddle-wheel shaped [Cu 2 (PymPPh 2 ) 3 (L an ) n ](PF 6 ) 2 complexes showing efficient thermally activated delayed fluorescence (TADF) has been synthesized. In these complexes, Cu(I) ions are P , N -bridged by three diphenyl(2-pyrimidyl)phosphine (PymPPh 2 , L) ligands in a "head-to-tail" fashion, and one or both metals are also capped by the ancillary ligand (L an = MeOH, Me 2 CO, MeCN, PhCN). At ambient temperature, the solid complexes emit TADF with the quantum yield of up to 85% and the lifetimes of from 9.6 to 27 μs. The ancillary ligands, whose orbitals negligibly contribute to the radiative 1 (M + L + L an )LCT state, remarkably adjust emission energies and Δ E (S 1 -T 1 ) energy splitting magnitudes of the emitters obtained. Thus, depending on structure and/or number of the L an molecules, the emission maxima vary from 500 to 563 nm, and the Δ E (S 1 -T 1 ) gaps range 550-1100 cm -1 . Such tunable TADF characteristics coupled with the excellent solubility and air-stability make the complexes presented to be promising TADF materials.

Using a series of isoreticular MOFs with void connections of varying diameters, the selective separation of benzene and cyclohexane in both liquid and vapor phases is shown. The driving force of the highly efficient adsorption process is the formation of weak interactions between the adsorbed benzene molecules and the host framework.

The optical properties of metal-organic frameworks [M 2 (bdc) 2 (dabco)] (M = Co, Ni, Cu, Zn) in the wavelength region of 300-1000 nm were studied, and the electronic band-to-band transitions were determined and characterized by the Kubelka-Munk approach and DFT calculations. Urbach edges for band-to-band transitions were determined. The effect of spin-phonon interactions on the width of Urbach edges in paramagnetic [M 2 (bdc) 2 (dabco)] is discussed. The obtained data may be useful to interpret polymerization, hybridization, and catalytic reactions in [M 2 (bdc) 2 (dabco)] pores and to design electronic and optical devices.

A series of Cu(i) halide complexes derived from tris(2-pyridyl)phosphine (Py3P), [Cu2(Py3P)2X2] (X = Cl, Br, I), have been synthesized by a straightforward reaction in solution or through a mechanochemical route. At room temperature, the solid complexes exhibit bright dual-mode photoluminescence (λmax = 520-550 nm, τ = 14.5-20.0 μs, and ΦPL ≈ 53%), expressed by thermally activated delayed fluorescence (TADF) combined with phosphorescence (PH), originating from 1(M + X)LCT and 3(M + X)LCT excited states, respectively. Remarkably, the balance of these radiative processes at 300 K is regulated by halogen atom nature, switching from TADF-assisted phosphorescence to PH-admixed TADF. The emission of [Cu2(Py3P)2Cl2] at 300 K is largely contributed by PH (73%) admixed with the TADF fraction (27%) and [Cu2(Py3P)2Br2] also emits mainly PH (65%) admixed with the larger TADF fraction (35%). Meanwhile, for [Cu2(Py3P)2I2], the TADF channel becomes dominating (61%) and PH contribution drops to 39%. The photophysical study corroborated by (TD)DFT computations has revealed that this effect arises mainly from the narrowing of the ΔE(S1 - T1) gap of the [Cu2(Py3P)2X2] complexes in the order Cl (1500 cm-1) > Br (1250 cm-1) > I (1000 cm-1) which facilitates the TADF pathway and suppresses PH in the same order.

Five trans-1,4-cyclohexanedicarboxylate (chdc 2- ) metal-organic frameworks of transition metals were synthesized in aqueous systems. A careful control of pH, reaction temperature and solvent composition were shown to direct the crystallization of a particular compound. Isostructural [Co(H 2 O) 4 (chdc)] n ( 1 ) and [Fe(H 2 O) 4 (chdc)] n ( 2 ) consist of one-dimensional hydrogen-bonded chains. Compounds [Cd(H 2 O)(chdc)] n ∙0.5nCH 3 CN ( 3 ), [Mn 4 (H 2 O) 3 (chdc) 4 ] n ( 4 ) and [Mn 2 (Hchdc) 2 (chdc)] n ( 5 ) possess three-dimensional framework structures. The compounds 1 , 4 and 5 were further characterized by magnetochemical analysis, which reveals paramagnetic nature of these compounds. A presence of antiferromagnetic exchange at low temperatures is observed for 5 while the antiferromagnetic coupling in 4 is rather strong, even at ambient conditions. The thermal decompositions of 1 , 4 and 5 were investigated and the obtained metal oxide (cubic Co 3 O 4 and MnO) samples were analyzed by X-ray diffraction and scanning electron microscopy., Competing Interests: The authors declare no conflict of interest.

The first observation of luminescence for Mn(ii) complexes with a square-pyramidal geometry (C 4v ) of the metal is reported. The complexes of such type, namely [Mn(L) 2 Hal]X, where L is an O,O'-chelating ligand Me 2 N-CH(Ph 2 P[double bond, length as m-dash]O) 2 , Hal = Cl or Br, and X = Br, I or [MnCl 4 ], show at ambient temperature red photoluminescence (λ≈ 620 nm) with millisecond lifetimes (3.8-7.6 ms). This emission, stemming from spin-forbidden 4 E(G) → 6 A 1 (S) transitions in square-pyramidally coordinated Mn 2+ , is found to be responsive to temperature. Upon cooling the complexes from 300 to 77 K, the red-shift of the emission band by ≈20 nm takes place, which is accompanied by the increase of its integral intensity and lifetime. The peculiarities of the discovered Mn 2+ (C 4v ) luminescence are discussed against the classical luminescence that occurs in octahedral (O h ) and tetrahedral (T d ) surroundings.

A series of new zinc(II)-thiophene-2,5-dicarboxylate (tdc) MOFs based on novel dodecanuclear wheel-shaped building blocks has been synthesized in almost quantative yields. Single-crystal X-ray diffraction analyses reveal 3D porous frameworks with a complex composition [Zn 12 (tdc) 6 (glycolate) 6 (dabco) 3 ] where glycolate is a deprotonated polyatomic alcohol (ethylene glycol, EgO 2 , 1 ; 1,2-propanediol, PrO 2 , 2 ; 1,2-butanediol, BuO 2 , 3 ; 1,2-pentanediol, PeO 2 , 4 ; glycerol, GlO 2 , 5 ) and dabco is 1,4-diazo[2.2.2.]bicyclooctane. All compounds 1 - 5 are isostructural except for pendant groups of the diols decorating the surface of channels. The adsorption of small gases (N 2 , CO 2 , CH 4 , C 2 H 2 , C 2 H 4 , C 2 H 6 ) and larger hydrocarbons (benzene, cyclohexane) both in liquid and vapor phases was thoroughly investigated for all compounds. The zero-coverage adsorption enthalpies, Henry constants, and selectivity factors by various models are calculated and discussed. The versatile adsorption functionality of the title series results from the variable nature of the diol and could be tailored for a specific adsorbate system. For example, 1 shows excellent selectivity of benzene over cyclohexane (20:1 for vapors, 92:1 for liquid phase), while 4 demonstrates unprecedented adsorption preference of cyclohexane over benzene (selectivity up to 5:1). The compound 5 demonstrates great adsorption selectivity for CO 2 /N 2 (up to 75.1), CO 2 /CH 4 (up to 7.7), C 2 H 2 /CH 4 (up to 14.2), and C 2 H 4 /CH 4 (up to 9.4). Also, due to polar nature of the pores, 5 features size-selective sorption of alkaline metal cations in order Li + > Na + > K + > Cs + as well as a notable luminescent response for cesium(I) ions and urea.

The first luminescent twelve-nuclear rhenium cluster complexes were obtained. Three new clusters, namely, [Re 12 CS 14 (μ-Cl) 3 Cl 6 ] 5- , [Re 12 CS 14 (μ-Br) 3 Cl 6 ] 5- and [Re 12 CS 14 (μ-Br) 3 Br 6 ] 5- , were synthesized using the non-isovalent substitution of μ-O ligands within the {Re 12 CS 14 (μ-O) 3 } 0 cluster core by halide anions. The geometry of the new clusters was investigated by X-ray structural analysis, and the electronic structures were evaluated by the use of DFT calculations. It was found that compounds based on these anions showed red luminescence in both the solid state and solution that was never observed before for previously studied twelve-nuclear rhenium clusters.

Two new isostructural microporous coordination frameworks [Mn 3 (Hpdc) 2 (pdc) 2 ] (1) and [Mg 3 (Hpdc) 2 (pdc) 2 ] (2) (pdc 2- = pyridine-2,4-dicarboxylate) showing primitive cubic (pcu) topology have been prepared and characterized. The pore aperture of the channels is too narrow for the efficient adsorption of N 2 ; however, both compounds demonstrate substantially higher uptake of CO 2 (119.9 mL·g -1 for 1 and 102.5 mL·g -1 for 2 at 195 K, 1 bar). Despite of their structural similarities, 2 shows a typical reversible type I isotherm for adsorption/desorption of CO 2 , while 1 features a two-step adsorption process with a very broad hysteresis between the adsorption and desorption curves. This behavior can be explained by a combination of density functional theory calculations, sorption, and X-ray diffraction analysis and gives insights into the further development of new sorbents showing adsorption/desorption hysteresis.

Rational synthesis of a series of new heterometallic MOFs was carried out by the judicious choice of the corresponding pivalate complexes [Li2M2(piv)6(py)2] (M = Zn2+, Co2+, piv- = pivalate anion and py = pyridine) as a source of secondary building units, {LiM(O2CR)3} and an organic tricarboxylate linker as a node defining the dimensionality of the framework by the orientation of the carboxylic group in or out of the central aromatic ring plane. Thus the trimesate (btc3-) linker results in 3D srs topology frameworks with intersecting systems or isolated channels, and 1,3,5-benzenetribenzoate (btb3-) results in layered hcb isostructural compounds additionally stabilized with H-π interactions between the layers. The layered compounds demonstrate a permanent porosity with a BET surface area of up to 688 m2·g-1 with the possibility of selective gas adsorption (CO2 over N2 and CH4). Zn-Based coordination polymers show notable color changes and drastic (up to 30 times) quenching of luminescence upon inclusion of different nitroaromatics.

Unprecedented organic-inorganic hybrid complexes, [Mn(L)3]MnHal4, containing both four- and hexacoordinated Mn2+ ions were synthesized by reacting MnCl2 or MnBr2 with bis(phosphine oxide) ligands (L) such as dppmO2, dppeO2, and 2,3-bis(diphenylphosphinyl)-1,3-butadiene (dppbO2). In the [Mn(L)3]2+ cation of the complexes, the Mn2+ ion features a [MnO6] octahedral coordination environment (Oh), and the [MnHal4]2- anion adopts a tetrahedral geometry (Td). These "two-in-one" complexes exhibit strong long-lived luminescence (τav = 12-15 ms at 300 K) having interesting thermochromic behavior attributed to the thermal equilibrium between two emission bands. So, in an emission spectrum of the typical complex [Mn(dppbO2)3]MnBr4, the intense "red" (ca. 620 nm) and weak "green" (ca. 520 nm) bands, originating from Mn2+ ions in Oh and Td environments, respectively, are observed. Cooling from 300 to 77 K simultaneously leads to (i) redshift of both bands by ca. 20 nm, (ii) increasing their intensities, and (iii) causing a substantial change of their integral intensity ratio from about 4 : 1 to 2 : 1. As a result, the colour of the emission changes from orange (CIE 0.56, 0.45) at 300 K to deep red (CIE 0.62, 0.39) at 77 K. This behavior was rationalized using steady-state and time-resolved fluorescent spectroscopy at various temperatures. The high photoluminescence quantum yields (up to 61% at 300 K) and fascinating dual-emissive phosphorescence coupled with high thermal stability and solubility suggest a high potential of this novel class of emissive Mn2+ complexes as promising emitters for OLED devices and potential stimuli-responsive materials.

The complex [Zn 2 (tdc) 2 dabco] (H 2 tdc = thiophene-2,5-dicarboxylic acid; dabco = 1,4-diazabicyclooctane) shows a remarkable increase in carbon dioxide (CO 2 ) uptake and CO 2 /dinitrogen (N 2 ) selectivity compared to the nonthiophene analogue [Zn 2 (bdc) 2 dabco] (H 2 bdc = benzene-1,4-dicarboxylic acid; terephthalic acid). CO 2 adsorption at 1 bar for [Zn 2 (tdc) 2 dabco] is 67.4 cm 3 ·g -1 (13.2 wt %) at 298 K and 153 cm 3 ·g -1 (30.0 wt %) at 273 K. For [Zn 2 (bdc) 2 dabco], the equivalent values are 46 cm 3 ·g -1 (9.0 wt %) and 122 cm 3 ·g -1 (23.9 wt %), respectively. The isosteric heat of adsorption for CO 2 in [Zn 2 (tdc) 2 dabco] at zero coverage is low (23.65 kJ·mol -1 ), ensuring facile regeneration of the porous material. Enhancement by the thiophene group on the separation of CO 2 /N 2 gas mixtures has been confirmed by both ideal adsorbate solution theory calculations and dynamic breakthrough experiments. The preferred binding sites of adsorbed CO 2 in [Zn 2 (tdc) 2 dabco] have been unambiguously determined by in situ single-crystal diffraction studies on CO 2 -loaded [Zn 2 (tdc) 2 dabco], coupled with quantum-chemical calculations. These studies unveil the role of the thiophene moieties in the specific CO 2 binding via an induced dipole interaction between CO 2 and the sulfur center, confirming that an enhanced CO 2 capacity in [Zn 2 (tdc) 2 dabco] is achieved without the presence of open metal sites. The experimental data and theoretical insight suggest a viable strategy for improvement of the adsorption properties of already known materials through the incorporation of sulfur-based heterocycles within their porous structures.

In contrast to aromatic carboxylates, the coordination polymers based on their perfluorinated analogues are not numerous. Here we present a series of six Zn(ii) coordination polymers of different dimensionalities (1D, 2D, and 3D) and porosities based on octafluorobiphenyl-4,4'-dicarboxylate (oFBPDC 2- ) and N-containing co-ligands (ur, dabco, and bpy). These complexes are characterized by single-crystal X-ray diffraction, PXRD, FT-IR, elemental analysis, and TGA. The metal-organic frameworks [Zn 2 (CH 3 CONH 2 ) 2 (oFBPDC) 2 ] (1) and [Zn 2 (oFBPDC) 2 (dabco)] (4) are shown to be porous with BET surface areas of 470 m 2 g -1 and 441 m 2 g -1 , respectively. In addition, compound 4 shows selectivity factors of 11.3, 4.9 and more than 6 for the binary gas mixtures CO 2 /N 2 , CO 2 /CH 4 and benzene/cyclohexane, respectively. The measurements for pressed powders and water droplet give water contact angles of 136° for 4 and 133° for (H 2 bpy)[Zn 2 (bpy)(oFBPDC) 3 ] (5). Low water uptake indicates that both 4 and 5 belong to highly hydrophobic solids.

Cluster compounds based on a new {Re 3 Mo 3 Se 8 } n core were obtained and studied. The polymeric solid K 6 [Re 3 Mo 3 Se 8 (CN) 4 (CN) 2/2 ] (1) containing 24 cluster valence electrons (CVE) was isolated as a result of high-temperature reaction. Water-soluble salts K 5 [Re 3 Mo 3 Se 8 (CN) 6 ]·11H 2 O (2) and Cs 5 [Re 3 Mo 3 Se 8 (CN) 6 ]·H 2 O (3) were prepared from compound 1. Crystal structures of the diamagnetic compounds 2 and 3 contain a cluster anion [Re 3 Mo 3 Se 8 (CN) 6 ] 5- with a 22-electronic core {Re 3 Mo 3 Se 8 } + . Metathesis reaction followed by recrystallization from CH 3 CN yielded paramagnetic salt (Ph 4 P) 4 [Re 3 Mo 3 Se 8 (CN) 6 ]·2CH 3 CN (4) containing the {Re 3 Mo 3 Se 8 } 2+ core with 21 CVE. Cyclic voltammetry of the solution of 4 displayed three quasi-reversible waves with E 1/2 = -0.325, -0.818 and -1.410 V vs. Ag/AgCl electrode indicating the presence of [Re 3 Mo 3 Se 8 (CN) 6 ] 4-/5-/6-/7- transitions. Electronic structure calculations showed that both mer- and fac-isomers of [Re 3 Mo 3 Se 8 (CN) 6 ] n- clusters undergo great distortion when the number of CVE decreases.

Three novel polybromide complexes of bismuth(iii) - (2,6-MePyH) 3 [BiBr 5 (Br 3 )] (1), (H 2 bpp){[BiBr 5 ](Br 2 )} (2) and (3-ClPyH) 2 {[BiBr 5 ](Br 2 )} (3) - were synthesized. The results of an extended screening involving a set of organic cations resulting in the formation/non-formation of Bi(iii) polybromides are presented and discussed. The nature of BrBr interactions in Bi(iii) polybromides was investigated by theoretical methods, enabling the estimation of their energies.

The redox-active rhenium octahedral cluster unit [Re 6 Se 8 (CN) 6 ] 4- was combined with Gd 3+ ions and dicarboxylate linkers in novel types of metal-organic frameworks (MOFs) that display a set of functional properties. The hydrolytically stable complexes [{Gd(H 2 O) 3 } 2 (L)Re 6 Se 8 (CN) 6 ]·nH 2 O (1, L = furan-2,5-dicarboxylate, fdc; 2, L = thiophene-2,5-dicarboxylate, tdc) exhibit a 3D framework of trigonal symmetry where 1D chains of [{Gd(H 2 O) 3 } 2 (L)] 4+ are connected by [Re 6 Se 8 (CN) 6 ] 4- clusters. Frameworks contain spacious channels filled with H 2 O. Solvent molecules can be easily removed under vacuum to produce permanently porous solids with high volumetric CO 2 uptake and remarkable CO 2 /N 2 selectivity at room temperature. The frameworks demonstrate an ability for reversible redox transformations of the cluster fragment. The orange powders of compounds 1 and 2 react with Br 2 , yielding dark-green powders of [{Gd(H 2 O) 3 } 2 (L)Re 6 Se 8 (CN) 6 ]Br·nH 2 O (3, L = fdc; 4, L = tdc). Compounds 3 and 4 are isostructural with 1 and 2 and also have permanently porous frameworks but display different optical, magnetic, and sorption properties. In particular, oxidation of the cluster fragment "switches off" its luminescence in the red region, and the incorporation of Br - leads to a decrease of the solvent-accessible volume in the channels of 3 and 4. Finally, the green powders of 3 and 4 can be reduced back to the orange powders of 1 and 2 by reaction with hydrazine, thus displaying a rare ability for fully reversible chemical redox transitions. Compounds 1-4 are mentioned as a new class of redox-active cluster-based MOFs with potential usage as multifunctional materials for gas separation and chemical contamination sensors.

The metal-organic framework (MOF) complex (H 3 O) 2 [Zn 4 (ur)(Hfdc) 2 (fdc) 4 ] (1, ur=urotropine, H 2 fdc=furan-2,5-dicarboxylic acid) incorporates cryptand-like cavities, which can be used to separate and detect Rb + and Cs + optically. This is the first example of the effective employment of a MOF material for optical detection of these cations., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The tetranuclear heterometallic complex [Li 2 Zn 2 (piv) 6 (py) 2 ] (1, where piv - = pivalate and py = pyridine) has been successfully employed as a presynthesized node for the construction of four porous metal-organic frameworks (MOFs) [Li 2 Zn 2 (R-bdc) 3 (bpy)]·solv (2-R, R-bdc 2- ; R = H, Br, NH 2 , NO 2 ) by reaction with 4,4'-bipyridine (bpy) and terephthalate anionic linkers. The [Li 2 Zn 2 ] node is retained in the products, representing a rare example of the rational step-by-step design of isoreticular MOFs based on complex heterometallic building units. The permanent porosity of the activated frameworks was confirmed by gas adsorption isotherm measurements (N 2 , CO 2 , CH 4 ). Three compounds, 2-H, 2-Br, and 2-NH 2 (but not 2-NO 2 ), feature extensive hysteresis between the adsorption and desorption curves in the N 2 isotherms at low pressures. The substituents R decorate the inner surface and also control the aperture of the channels, the volume of the micropores, and the overall surface area, thus affecting both the gas uptake and adsorption selectivity. The highest CO 2 absorption at ambient conditions (105 cm 3 ·g -1 or 21 wt % at 273 K and 1 bar for 2-NO 2 ) is above the average values for microporous MOFs. The photoluminescent properties of the prototypic 2-H as well as the corresponding host-guest compounds with various aromatic molecules (benzene, toluene, anisole, and nitrobenzene) were systematically investigated. We discovered a rather complex pattern in the emission response of this material depending on the wavelength of excitation as well as the nature of the guest molecules. On the basis of the crystal structure of 2-H, a mechanism for these luminescent properties is proposed and discussed.

Chromeazurol B (Na 2 HL) is a pH-sensitive (halochromic) dye based on a hydroxytriarylmethane core and two carboxylate functional groups, which makes it suitable for the synthesis of coordination polymers. Two new coordination polymers [NaZn 4 (H 2 O) 3 (L) 3 ]·3THF·3H 2 O (1) and [Zn 3 (H 2 O) 3 (μ 2 -OH 2 )(μ 3 -OH)(HL) 2 (H 2 L)]·2THF·3H 2 O (2) incorporating Chromeazurol B linkers have been prepared and characterised. The structure of 1 comprises pentanuclear heterometallic {Zn 4 Na} nodes linked by six L 3- anions to give a layered structure with a honeycomb topology. 2 crystallizes as a double-chain ribbon (ladder) structure with two types of metal node: a mononuclear Zn(ii) cation and tetranuclear {Zn(ii)} 4 cluster. Chromeazurol B anions link each tetranuclear cluster to four individual Zn(ii) cations and each Zn(ii) cation with four tetranuclear clusters. Both compounds show pH-sensitivity in water solution which can be observed visually, giving the first example of a halochromic coordination polymer. The halochromic properties of 1 towards HCl vapors were systematically investigated. As-synthesized violet-grey 1 reversibly changes color from orange to pink in the presence of vapors of 2 M and 7 M HCl, respectively. The coordination of the Chromeazurol B anion at each color stage was examined by diffuse reflectance spectroscopy and FT-IR measurements. The remarkable stability of 1 to acid and the observed reversible and reproducible color changes provide a new design for multifunctional sensor materials.