Tetrahedral Coordination Research Articles

The Molecular Structures of Lithium Trichlate, Li[Cl3CSO3]∙2H2O, and Lithium Tribrate, Li[Br3CSO3]∙2H2O

Lithium trichlate, Li[Cl3CSO3]∙2H2O (triclinic, P1, Z = 2, a = 630.29(3) pm, b = 630.65(3) pm, c = 1246.10(6) pm, α = 100.657(2)°, β = 97.813(2)°, γ = 107.994(2)°) was obtained from the reaction of (H5O2)[Cl3CSO3] and LiOH in aqueous solution. Similarly, colourless single crystals of the tribrate Li[Br3CSO3]∙2H2O (triclinic, P1, Z = 4, a = 634.65(4) pm, b = 636.83(4) pm, c = 2496.8(2) pm, α = 83.518°, β = 86.081(5)°, γ = 72.061(5)°) form in the reaction of aqueous Br3CSO3H and LiOH. The acid (H2O2)[Cl3CSO3] was obtained from the chlorination of CS2, followed by oxidation of the intermediate Cl3CSCl with H2O2. The bromo derivative Br3CSO3H has been prepared by bromination of phenylsulfonate with KOBr and subsequent ion exchange of the obtained potassium salt. Both lithium compounds exhibit molecular dimers according to {Li2(X3CSO3)2/1(H2O)2/1(H2O)2/2} with the Li+ ions in tetrahedral coordination of oxygen atoms. The difference in the crystal structures result from the variation of the orientation of the dimers with respect to each other. The experimental findings for the dimers are in good agreement with DFT calculations.

Hydrogen-bond transformations of confined water and abnormal mechanical responses of hydrated AlPO4-11 framework under in situ high pressure

The behaviors of water under non-ambient conditions, especially in confinement environment, have long been of special interest due to the important roles in biological and geological processes. Here, we have performed an infrared spectroscopic investigation on the pressure-induced hydrogen-bond transformation of water in one-dimensional, elliptical channels of AlPO4-11. Upon compression, the hydrogen-bonds of confined water strengthen and water molecules transform from tetrahedral coordination configuration to low and intermediate configurations, which may be a high-density disordered state. This transformation is distinct from the commonly accepted liquid–solid and solid–solid phase transition in bulk water. Stronger hydrogen-bonds are formed and a further transformation of hydrogen-bonded water takes place in the hydrostatic environment of Ar than the case without pressure transmitting medium (PTM). In addition, the mechanical compressible behaviors and framework deformation of the host matrix are also discussed. X-ray diffraction study shows that the hydrated AlPO4-11 exhibits an unexpected high compressibility in Ar. Its bulk modulus before framework collapse is 14.1 GPa, 4 ∼ 5 times smaller than that in silicone. The anisotropic axial compressibilities of AlPO4-11 demonstrate that the ellipticity of the channel cross-section increases in silicone oil while it decreases in Ar because the relatively contractive behavior along minor axis direction is slowed down. Such pressure-induced responses are ascribed to the complex Ar-H2O-framework interaction after Ar penetration. This study offers us a new knowledge of crystal-fluid interaction in determining the mechanical behaviors of open-framework materials under high pressure and provides implications for the water evolution and circulation in water-carrying natural zeolites under extreme geological conditions in nature.

Ligand-Induced Intramolecular Redox Diversity in Titanium Complexes with Acenaphthene-1,2-diimine.

A series of the chlorido and alkoxychlorido titanium complexes of the general formula (dpp-Bian)Ti(OiPr)nCl3-n, where dpp-Bian = 1,2-bis[(2,6-iPr2C6H3)imino]acenaphthene n = 0 (2), 1 (3), 2 (4), as well as (dpp-Bian)Ti(OiPr)2 (5) and (dpp-Bian)Ti(OiPr)Cl3 (3-Cl), were isolated and characterized using single-crystal X-ray diffraction analysis and spectroscopic studies combined with density functional theory (DFT) calculations. In the solid state, compounds 2-4 reveal a square-pyramidal geometry at the metal center supported with monoanionic dpp-Bian, whereas 3-Cl with a neutral diimine ligand and 5 bearing a dianionic enebisamide dpp-Bian show, respectively, an octahedral and tetrahedral coordination surrounding the metal ion. Paramagnetic complexes 2-4 exhibit electron paramagnetic resonance spectra in both toluene solution and solid state, confirming the transfer of spin density from the metal ion to the dpp-Bian ligand as the number of alkoxy groups increases. The increase in polarity of the Ti-N bonds in the row 2 < 3 < 4 contributes to enhanced stability of the metal complexes with respect to O-donor molecules. Thus, in tetrahydrofuran (THF), compounds 2 and 3 undergo reversible solvolysis, whereas complex 4 is stable. The charge and spin density distributions as well as molecular orbital energies in 2-4 were analyzed on the basis of DFT calculations which also provided information on the electronic transition energies, absorption band assignments, and thermodynamic parameters of the reactions between the complexes and THF.

Synthesis, Characterization, and Catalytic Behaviors in Isoprene Polymerization of Pyridine-Oxazoline-Ligated Cobalt Complexes.

A family of pyridine-oxazoline-ligated cobalt complexes L2CoCl23a-h were synthesized and characterized. Determined via single-crystal X-ray diffraction, complexes 3a and 3d, ligated by two ligands, displayed a distorted tetrahedral coordination of a cobalt center. The X-ray structure indicated the pyridine-oxazoline ligands acted as unusual mono-dentate ligands by coordinating only to Noxazoline. Upon activation with AlEt2Cl (diethylaluminum chloride), these cobalt complexes all exhibited high catalytic activity (up to 2.5 × 106 g·molCo-1·h-1), affording cis-1,4-co-3,4-polyisoprene with molecular weights of 4.4-176 kg mol-1 and a narrow Ð of 1.79-3.42, suggesting a single-site nature of the active sites. The structure of cobalt catalysts and reaction parameters, especially co-catalysts and the reaction temperature, all have significant influence on the polymerization activity but not on the microstructure of polyisoprene.

Unravelling the amorphous structure and crystallization mechanism of GeTe phase change memory materials

The reversible phase transitions in phase-change memory devices can switch on the order of nanoseconds, suggesting a close structural resemblance between the amorphous and crystalline phases. Despite this, the link between crystalline and amorphous tellurides is not fully understood nor quantified. Here we use in-situ high-temperature x-ray absorption spectroscopy (XAS) and theoretical calculations to quantify the amorphous structure of bulk and nanoscale GeTe. Based on XAS experiments, we develop a theoretical model of the amorphous GeTe structure, consisting of a disordered fcc-type Te sublattice and randomly arranged chains of Ge atoms in a tetrahedral coordination. Strikingly, our intuitive and scalable model provides an accurate description of the structural dynamics in phase-change memory materials, observed experimentally. Specifically, we present a detailed crystallization mechanism through the formation of an intermediate, partially stable ‘ideal glass’ state and demonstrate differences between bulk and nanoscale GeTe leading to size-dependent crystallization temperature.

Short-range order and chemical compositions of glasses along the basaltic-rhyolite sub-alkaline join by Raman and FTIR spectroscopies

Six sub-alkaline glasses with compositions progressively shifting from the tholeiitic basalt (B100) end-member to the rhyolite (R100) end-member were investigated and analysed in the same frequency domain by both Raman and FTIR. This approach highlights spectroscopic similarities and differences such as positions, widths and intensities of Raman and FTIR bands, which may also exhibit significant overlapping. Both the Raman and FTIR spectra show several peaks grouped in three main vibrational windows: 200–650 (low frequency region, named F-I in this study), 650–850 (intermediate region, F-II) and 850–1250 cm−1 (high-frequency region, F-III). In line with previous investigations, the F-I interval can be ascribed to vibrational modes involving rings of tetrahedrally coordinated cations linked by bridging oxygens. It can be fitted with three components, whereas F-II involves the motion of Si atoms within its oxygen cage and is adequately represented by two components. Finally, F-III contains different T-O (T = tetrahedrally coordinated network-forming cation) stretching bands that can be tied to the overall degree of polymerization of the glass and are fitted with four components. In some glasses, the three and the two components within F-I and F-II are identifiable in both Raman and FTIR spectra; in cases of strong peak overlap, these peaks can be complementary to one another towards our interpretation of the molecular arrangement(s) in these glasses. Indeed, the positions of the four components in F-III are first constrained in the Raman spectra, which are more identifiable, then further refined using available Raman spectra for corresponding chemically simple silicate systems. The nine fitted components can reproduce the Raman and FTIR spectra extremely well.As a function of the amount of SiO2, the positions and intensities of the three low frequency components progressively shift in both Raman and FTIR. Similarly, the two bands in the F-II intermediate region exhibit a monotonic shifting of their positions. Indeed, the components at high frequency display less significant shifting of their positions as a function of SiO2, while their intensities change more markedly in the Raman spectrum compared to those for FTIR. The vibrational components measured in this study provide a referenced dataset of assignations of the most abundant natural volcanic glasses. Therefore, it provides a diagnostic tool based on the cross-validation of Raman and FTIR spectra to quickly identify the glass chemistry, offering the possibility to expand the applicability of remote investigations.

Stabilizing Sulfur Sites in Tetraoxygen Tetrahedral Coordination Structure for Efficient Electrochemical Water Oxidation.

Ion regulation strategy is regarded as a promising pathway for designing transition metal oxide-based electrocatalysts for oxygen evolution reaction (OER) with improved activity and stability. Precise anion conditioning can accurately change the anionic environment so that the acid radical ions (SO4 2- , PO3 2- , SeO4 2- , etc.), regardless of their state (inside the catalyst, on the catalyst surface, or in the electrolyte), can optimize the electronic structure of the cationic active site and further increase the catalytic activity. Herein, we report a new approach to encapsulate S atoms at the tetrahedral sites of the NaCl-type oxide NiO to form a tetraoxo-tetrahedral coordination structure (S-O4 ) inside the NiO (S-NiO -I). Density functional theory (DFT) calculations and operando vibrational spectroscopy proves that this kind of unique structure could achieve the S-O4 and Ni-S stable structure in S-NiO-I. Combining mass spectroscopy characterization, it could be confirmed that the S-O4 structure is the key factor for triggering the lattice oxygen exchange to participate in the OER process. This work demonstrates that the formation of tetraoxygen tetrahedral structure is a generalized key for boosting the OER performances of transition metal oxides.

Stabilizing Sulfur Sites in Tetraoxygen Tetrahedral Coordination Structure for Efficient Electrochemical Water Oxidation

AbstractIon regulation strategy is regarded as a promising pathway for designing transition metal oxide‐based electrocatalysts for oxygen evolution reaction (OER) with improved activity and stability. Precise anion conditioning can accurately change the anionic environment so that the acid radical ions (SO42−, PO32−, SeO42−, etc.), regardless of their state (inside the catalyst, on the catalyst surface, or in the electrolyte), can optimize the electronic structure of the cationic active site and further increase the catalytic activity. Herein, we report a new approach to encapsulate S atoms at the tetrahedral sites of the NaCl‐type oxide NiO to form a tetraoxo‐tetrahedral coordination structure (S‐O4) inside the NiO (S‐NiO ‐I). Density functional theory (DFT) calculations and operando vibrational spectroscopy proves that this kind of unique structure could achieve the S‐O4 and Ni‐S stable structure in S‐NiO‐I. Combining mass spectroscopy characterization, it could be confirmed that the S‐O4 structure is the key factor for triggering the lattice oxygen exchange to participate in the OER process. This work demonstrates that the formation of tetraoxygen tetrahedral structure is a generalized key for boosting the OER performances of transition metal oxides.

Gallium induced effect on magnetic, magnetostrictive and electrical properties of sintered NiFe2O4

This study investigates how the incorporation of Ga ions into the tetrahedral coordination sites affects the magnetic, magnetostrictive, and electrical properties of sintered NiFe2O4. All characterization was performed on the sintered NiFe2-xGaxO4 samples, which were synthesized using the autocombustion method. The sintered samples exhibit a single phase, wherein the lattice parameter decreases, and the particle size increases with the augmentation of Ga-content within the Ni-ferrite lattice. Saturation magnetization (MS) was found to be higher for x = 0.25 compared to the parent sample (x = 0), while for x = 0.5, MS was slightly lower than that of the parent sample. Both coercivity (HC) and Curie temperature (TC) exhibited a decrease with increasing 'x,' which can be attributed to the weakening of superexchange interactions (A-O-B) due to the presence of non-magnetic Ga ions. Furthermore, the maximum magnetostriction (λmax) also decreased with increasing 'x,' reflecting a magnetic dilution effect within the system. Electric modulus analysis of the dielectric response and the Jonscher power law fits AC conductivity propounded the long-range hoping for charge transportation. Also, the Cole-Cole fit of impedance spectra showed a combined effect of electrode-grain boundary, grain interior, and grain-grain boundary.

Synthesis ranges for YBaFe4O7 and its topotactic oxidation in ambient air to YBaFeIII4O8.5

Conditions for YBaFe4O7 synthesis from oxide/carbonate amorphous precursors are investigated versus temperature and partial pressure of oxygen at high-temperature equilibrium with the sample in flowing atmosphere of humidified Ar and H2 gas mixtures. Upon topotactic oxidation in ambient air of the cooled-down product, YBaFeIII4O8.5 forms in a couple of minutes. Neutron powder diffraction suggests that added oxygens enter octahedral holes in the cubic closest packing of O and Ba atoms of YBaFe4O7. Up to two oxygen atoms add to some Fe coordination tetrahedra in the kagome-like layer of YBaFe4O7 in a disordered distribution described as partially occupied crystal-structure sites. The oxidized YBaFeIII4O8.5 is metastable and decomposes at high temperatures into FeIII oxides of barium or yttrium. The synthesized YBaFe4O7 is a powerful room-temperature O2 getter that can be reverted by annealing in the above gas mixture.

Tunable light emission of Bi and V-doped borosilicate glasses for application in white light-emitting diodes

Melt-quenched borosilicate glasses, co-doped with Bi and V ions, exhibited broad visible spectrum emissions. Bi ions primarily existed as Bi3+, acting as network modifiers, lowering the glass transition temperature linearly with increasing Bi content. V5+ ions adopted tetrahedral coordination as [VO4]3- units. Photoluminescence of Bi ions is shifted from blue to longer wavelengths with higher Bi content, associated with the stabilization of Bi2+ and the presence of Bi3+ in different local environments. Combined with V ions, the glasses emitted light covering the entire visible spectrum, offering the potential for white LED applications with correlated color temperatures ranging from 6135 to 4010 K. The highest QY was 11.9 and 8.0 % upon excitation at 325 and 340 nm.

The role of vanadium substitution in the oxygen sublattice disorder of Ba7Nb4MoO20-based hexagonal perovskite oxide-ion conductors.

Ba7Nb4MoO20-based hexagonal perovskite derivatives are promising oxygen-ion conductors for solid electrolytes in solid-oxide fuel cells and electrolysers. A thorough understanding of chemical substitution and its impact on structural features conducive to high ionic conductivity is fundamental for decreasing the operation temperature of such devices. Here, a new 7H polytype-based composition, namely Ba7Nb3.9-x V x Mo1.1O20.05, is investigated to assess the effect of vanadium substitution. Structural changes upon V incorporation are studied using X-ray and neutron diffraction, as well as 51V and 93Nb solid-state nuclear magnetic resonance spectroscopy. For the undoped composition at room temperature, two distinct oxygen sites (O1 and O5) are found along the palmierite-like layer, corresponding to a mix of four- and six-fold coordination for adjacent M2 cations. At high temperature (527 °C), reorganization of oxygen results in the major occupation of O1 and four-fold (tetrahedral) coordination of the M2 cations. The same rearrangement is observed upon V-substitution, but already at room temperature. From 51V NMR, we identified a tetrahedral coordination for V5+ cations, indicating their preferential occupation of the M2 site. This preferential occupation by V5+ cations is correlated with increasing tetrahedral coordination of Nb5+ cations as observed from 93Nb NMR. Altogether, these observations indicate that V-substitution impacts the oxygen sublattice so as to mimic the high-temperature structure. Additionally, BVSE calculations demonstrate a decreasing energy barrier for O2- migration associated with the presence of vanadium in the structure. This conclusion corroborates the hypothesis that vanadium's propensity for a lower coordination number is beneficial for promoting high O2- mobility in this promising class of oxide-ion conductors.

Triclinic La7Zn2P11 with P3-, P24-, and P35- units: a combined study by 31P solid-state NMR spectroscopy and single crystal X-ray diffraction.

The ternary polyphosphide La7Zn2P11 was synthesized from the elements by using a salt flux or via a ceramic method in sealed quartz ampoules. The obtained samples were investigated by X-ray powder and single crystal diffraction: own type, P1̄, a = 775.33(13), b = 827.45(13), c = 1502.8(3) pm, α = 82.111(3), β = 77.034(3), γ = 89.996(3)°, wR2 = 0.1553, 5852 F2 values and 183 variables. This peculiar structure is characterized by the simultaneous presence of three distinct anionic phosphide species, namely P3-, P24-, and P35- units. La7Zn2P11 is an electron precise Zintl phase: (7La3+)21+(2Zn2+)4+(4P3-)12-(2P24-)8-(P35-). The P-P single bond distances range from 219.2 to 223.0 pm. The zinc sites show tetrahedral phosphorus coordination by three P3- and one P24- species. The tetrahedra are condensed to chains via common corners. The P35- units with P-P-P angles of 113.7° have exclusively lanthanum coordination. 31P solid-state NMR was used to probe the phosphorus local environments, connectivities and spatial proximities. The eleven crystallographically distinct phosphorus atoms were assigned with the help of two-dimensional homonuclear dipolar correlation experiments. Even though the application of 2D measurements on such phosphorus-based polyanionic compounds is exceedingly challenging because of the wide dispersion of chemical shifts, the fast irreversible decay of the transverse magnetization, and slow spin-lattice relaxation, a complete assignment is possible using radiofrequency-driven dipolar recoupling (RFDR), J-RESOLVED and total-through-bond correlation with R-sequence (R-TOBSY) techniques.

Особенности строения продуктов реакций деарилирования пентаарилсурьмы полифункциональными кислотами

It has been established that in reactions with pentaphenylantimony, 2,3-dihydroxybenzoic and 5-hydroxypyridine-2-carboxylic acids behave as bifunctional compounds and form binuclear products [Ph4Sb]+[Ph4Sb(O,O¢-C6H3COOH-3]- (I), Ph4SbOC(O)C5H3NOSbPh4-4 (II), respectively. The reaction with 2,3-dihydroxybenzoic acid occurs with the participation of just hydroxy groups, while the interaction with 5-hydroxypyridine-2-carboxylic acid proceeds with the participation of hydroxy and carboxy groups. 2,6-Dihydroxybenzoic acid reacts with penta(para-tolyl)antimony only at the carboxyl group, giving tetra(para-tolyl)antimony 2,6-dihydroxybenzoate p-Tol4SbOC(O)C6H3(OH)2-2,6 (III). The structures of compounds I–III have been characterized by IR spectroscopy and X-ray diffraction. According to the X-ray diffraction data, crystal I contains [Ph4Sb]+ cations with a slightly distorted tetrahedral coordination of the antimony atom (the CSbC angles are 99.18(14)°-118.07(16)°, the Sb-C bonds are 2.093(4)-2.119(3) Å) and anions containing a five-membered metallocycle [SbO2C2], in which the antimony atom is hexacoordinated (the CSbC cis-angles are 91.52(13)°-102.90(13)°; the CSbО angles equal 85.06(12)°-94.73(13)°, the ОSbО angle is 76.22(9)°). The Sb–O distances in the ring are 2.122(2) and 2,215(2) Å. The Sb–C bonds vary in the range 2.175(3)–2.187(4) Å. In molecule II, the antimony atoms are structurally nonequivalent. One of the atoms, associated with the oxygen atom of the hydroxy group, has the coordination of a distorted trigonal bipyramid (the OSbC axial angle equals 174.5(2)°, the CSbC angles in the equatorial plane are 116.2(3)°-120.9(3)°; the Sb-O and Sb-C distances are 2.256(5) Å and 2.108(7)–2.174(7) Å, respectively). The coordination number of the second antimony atom associated with the oxygen of the carboxyl group is increased to 6 due to coordination of the nitrogen atom of the pyridine ring located in the ortho position with respect to the carboxyl group (the Sb∙∙∙N distance is 2.402(6) Å). The coordination polyhedron of the atom is a distorted octahedron (cis-angles at the antimony atom vary in the range 72.22(19)°-103.6(3)°). The Sb–O bond length is 2.194(5) Å, the Sb–C distances are 2.165(7)–2.189(7) Å. In molecule III the coordination of the antimony atom is a distorted trigonal bipyramid: the OSbC axial angle equals 170.30(8)°, the CSbC angles in the equatorial plane are 112.17(9)°-122.09(9)°; the Sb-O bond is 2.527(2) Å, and the Sb-C bond equals 2.031(2)–2.258(3) Å.

Исследование кристаллических структур 7-иод-8-оксихинолин-5-сульфонатов алкилтрифенилфосфония [Ph3PAlk][OSO2C9NH4(I-7)(OH-8)], Alk = CH2Ph, CH=CHMe, CH2C≡CH

From alkyltriphenylphosphonium bromides and 7-iodo-8-hydroxyquinoline-5-sulfonic acid in water, ionic alkyltriphenylphosphonium 7-iodo-8-hydroxyquinoline-5-sulfonates Ph3PAlk][OSO2C9NH4(I-7)(OH-8)], Alk = CH2Ph (1), CH=CHMe (2), CH2C≡CH (3) have been obtained. Crystals 1 [C34H27NO4PSI, M 703.50; monoclinic system, symmetry group P21/c; cell parameters: a = 8.805(4), b = 16.146(10), c = 20.833(11) Å; β = 93.410(17), V = 2956(3) Å3, Z = 4; rcalc = 1.581 g/cm3], 2 [C30H25NO4PSI, M 653.44; rhombic system, symmetry group P212121; cell parameters: a = 9.382(3), b = 14.033(4), c = 21.035(6) Å; a = β = g = 90.00 deg., V = 2769.5(15) Å3, Z = 4; rcalc = 1.567 g/cm3], 3 [C30H27NO6PSI, M 687.46; monoclinic system, symmetry group P21/n; cell parameters: a = 9.426(3), b = 19.239(5), c = 16.088(5) Å; β = 97.296(14) deg., V = 2894.0(15) Å3, Z = 4; rcalc = 1.578 g/cm3]. According to the X-ray diffraction data, the phosphorus atoms in cations 1–3 have a distorted tetrahedral coordination, while the sulfonate anions have a regular geometry with a tetrahedral sulfur atom. The P–C bond lengths vary in the range 1.772(3)−1.815(2) Å; the CPC bond angles take values of 106.08(11)°−112.33(11)°. In the arenesulfonate anions of the complexes, the S–C distances are close to each other [1.781(2)–1.7920(19) Å], the S–O bonds are practically aligned [1.4464(16)–1.4590(17) Å]. In the crystal of hydrate 3 [Ph3PCH2C≡CH][OSO2C9NH4(I-7)(OH-8)] ∙ 2H2O, water molecules participate in formation of a dimeric anion (the O∙∙∙H and N∙∙∙H distances are 1.93 and 2.03 Å, while the arene rings of the sulfonate ligands are almost parallel (the angle between them is 3.24°)). Other water molecules link the dimeric anions into a chain with hydrogen bonds (the O∙∙∙H distances equal 2.12 and 2.15 Å). The structural organization in complexes 1–3 is mainly due to weak intermolecular contacts of the O···H type: 2.04–2.69 Å (1), 2.05–2.69 Å (2), 2.12–2.15 Å (3).

Crystal structure and Hirshfeld surface analysis of 2-picolyllithium·3thf.

In the title compound, (2-methyl-idene-1,2-di-hydro-pyridinium-κN)tris-(tetra-hydro-furan-κO)lithium, [Li(C6H6N)(C4H8O)3], the lithium ion adopts a distorted LiNO3 tetra-hedral coordination geometry and the 2-picolyl anion adopts its enamido form with the lithium ion lying close to the plane of the pyridine ring. A methyl-ene group of one of the thf ligands is disordered over two orientations. In the crystal, a weak C-H⋯O inter-action generates inversion dimers. A Hirshfeld surface analysis shows that H⋯H contacts dominate the packing (86%) followed by O⋯H/H⋯O and C⋯H/H⋯C contacts, which contribute 3% and 10.4%, respectively.

SYNTHESES, CHARACTERIZATION, CRYSTAL STRUCTURES AND ANTIMICROBIAL PROPERTIES OF A NEW ORGANIC−INORGANIC HYBRID [4FBzTPP]2[CuBr4

This article presents a study on the synthesis and character of a new organic-inorganic hybrid [4FBzTPP]2[CuBr4](1) ([4FBzTPP]+ is 4-fluorobenzyltriphenylphosphinium) by XRD, SEM, FT-IR and UV-Vis. The XRD analysis showed that the hybrid 1 belongs to the triclinic space group P21 with b = 8.8600(10) Å, c = 16.4867(17) Å, α = 16.639(2) °, β = 96.342(4) °, V = 2415.6(5) Å3, and Z = 2. The hybrid consists of two [4FBzTPP]+ cations and one [CuBr4]2– anion, and the [CuBr4]2– exhibits a twisted tetrahedral coordination geometry with the average bond length between Cu−Br is 2.393 Å. The 3D network structure of 1 is formed by electrostatic terms and other intermolecular interactions. The hybrid material undergoes a direct optical transition and has energy gap values of 1.66 eV and 2.18 eV, indicating its potential as a semiconductor material for optical research. The hybrid material undergoes a direct optical transition and has energy gap values of 1.66 eV and 2.18 eV, showing that the hybrid material is a potential semiconductor material for optical research. In addition, the compound exhibited good antibacterial activity against E. coli and S. aureus.

Highly efficient circularly polarized electroluminescence based on chiral manganese(ii) complexes.

Currently reported circularly polarized luminescent devices are primarily based on rare earth and noble metal complexes or lead perovskite materials. Reports on electroluminescent devices employing eco-friendly luminescent materials are notably scarce. In this study, we strategically designed and synthesized manganese complexes featuring Binapo as the chiral ligand. The complex structure reveals a tetrahedral coordination configuration, with the R/S configurations exhibiting a mirror relationship. Leveraging the strong ligand field and chiral structural characteristics of Binapo, the enantiomers display red emission and exhibit significant circularly polarized luminescence with a circularly polarized luminescence asymmetric factor (g lum) of 5.1 × 10-3. The circularly polarized electroluminescent performance was investigated by using a solution processing method and host-guest doping strategy. Our efforts resulted in device performance with an external quantum efficiency (EQE) exceeding 4%, and its electroluminescent asymmetric factor (g EL) reached an impressive -8.5 × 10-3. This surpasses the performance of most devices relying on platinum (Pt) and iridium (Ir) metal complexes and perovskite related materials. Our work establishes a pathway for the development of cost-effective and environmentally friendly chiral electroluminescent materials and devices.

Anticancer, antioxidant, and antimicrobial studies and molecular docking of a new hexanuclear Zn(II) complex, together with its X-ray crystal analysis.

A new hexanuclear Zn(II) complex with the ligand 2,2'-(piperazine-1,4-diyl)bis(ethan-1-amine), [L3Zn6(OH)6][ClO4]6·3MeOH·7H2O, was synthesized. The crystal structure of this complex showed that each Zn atom is in a distorted tetrahedral coordination environment, surrounded by two nitrogen atoms from each ligand and two hydroxide groups, each of which bridges to another Zn atom. The anticancer activities of the ligand and its metal complex against the breast cancer cell line (MCF-7) indicated that the zinc complex had a greater anticancer activity. The free ligand and its metal complex were evaluated for antioxidant activity using the DPPH scavenging method. In addition, the antibacterial activities of both compounds were screened against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. The interaction of these compounds with DNA and AChE was also investigated using molecular docking.

Heteroatom Lewis acid zeolites: synthesis, characterization and application in the conversion of biomass-derived oxygenates

This review summarizes recent advances in the synthesis, characterization and application of heteroatom (Ti, Zr, Sn, and Hf) Lewis acid zeolites in the conversion of biomass-derived oxygenates.