3D Supramolecular Structure Research Articles

Dinuclear cadmium(II) complexes with distorted octahedral/monocapped trigonal prism coordination geometries: synthesis, crystal structure, DFT/TD-DFT calculation and photocatalytic degradation of methylene blue

Two Cd(II) complexes [Cd2(L1)2(dca)(NO3)] (1) and [Cd2(L2)2(SCN)(NO3)] (2) (HL1 = 2-methoxy-6-[(2-phenylamino-ethylimino)-methyl]-phenol; and HL2 = 2-[(2-ethylamino-ethylimino)-methyl]-6-methoxy-phenol), have been synthesized and characterized by single crystal structure analysis, IR and mass spectroscopic studies. Both the complexes 1 and 2 possess a triclinic crystal system with space group P1¯. In complex 1, geometry around one metal centre is distorted octahedral and other centre is distorted monocapped trigonal prism, whereas in complex 2, both the metal centres possess distorted octahedral geometries. Strong NH⋅⋅⋅O and weak aromatic CH⋅⋅∙O hydrogen bonding interactions in 1 and strong NH⋅⋅⋅O and NH⋅⋅⋅S hydrogen bonding in 2 results 1D and 2D supramolecular structures, respectively. Experimentally determined electronic spectral data have been compared with the calculated data obtained by DFT and TD-DFT calculation. Photocatalytic abilities of 1 and 2 have been examined by using spectroscopic technique and found that in presence of UV light both the complexes catalytically decomposed methylene blue by 54.0 % and 50.3 %, respectively.

Synthesis, structure, theoretical calculation and antibacterial property of two novel Zn(II)/Ni(II) compounds based on 3, 5-dichlorosalicylaldehyde thiocarbamide ligand

Two new compounds namely [Zn(L1)phen]31 and Ni(L1)phen(MeOH) 2 (L1 = 3, 5-dichlorosalicylaldehyde thiosemicarbazone) were synthesized by the slow evaporation method at room temperature. The structure of ligand L1 was determined using 1H NMR and 13C NMR spectra. X-ray single crystal diffraction analysis revealed that compounds 1–2 can form 3D supramolecular network structures through π···π stacking and hydrogen bonding interactions. The DFT calculation shows that the coordination of ligand and metal is in good agreement with the experimental results. Hirshfeld surface analysis revealed that H…H and Cl…H interactions were the predominant interactions in compounds 1–2. Energy framework analysis indicated that dispersion energy played a dominant role in the energy composition of compounds 1–2. The inhibitory effects of compounds 1–2 against Escherichia coli (E. coli) and Methicillin-resistant Staphylococcus aureus (MRSA) were tested using the paper disk diffusion method (1: E. coli: 18 mm, MRSA: 17 mm, 2: E. coli: 15 mm, MRSA: 16 mm). Ion releasing experiments were conducted to assess the ion release capacity of compounds 1–2 (Zn2+, 4 days, 38.33 µg/mL; Ni2+, 4 days, 29.12 µg/mL). Molecular docking demonstrated the interaction modes of compounds 1–2 with UDP-N-acetylenolpyruvoylglucosamine reductase (MurB) and dihydrofolate reductase (DHFR) in bacteria, involving hydrophobic, stacking, hydrogen bonding and halogen bonding interactions. The generation of reactive oxygen species (ROS) in bacteria under the presence of compounds 1–2 were evaluated using a fluorescent dye known as dichlorodihydrofluorescein diacetate (DCFH-DA). Potential antibacterial mechanisms of compounds 1–2 were proposed.

Assembly of three new triphenylamine functionalized MOFs for the fluorescent sensing of nitrobenzene

The detection of nitrobenzene (NB) is very important because it has a series of irreversible effects on human health. Metal-organic frameworks (MOFs) show potential applications in this field due to their tunable and porous structures. In this work, three new MOFs, namely [Mn3(TCA)2(DMF)4]·DMF (JOU-28), [Cd21(TCA)14(H2O)9]·21DMF·21H2O (JOU-29), and [Cd3Cl3(TCA)(DMF)2]·H2O (JOU-30), were successfully prepared by solvothermal method (H3TCA = 4,4′,4″-tricarboxytriphenylamine; DMF = N,N′-Dimethylformamide). Single crystal X-ray diffractions showed that JOU-28 was a 3D porous supramolecular structure based on 2D coordination networks, while both JOU-29 and JOU-30 were 3D porous structures based on 1D chains. Due to its strong fluorescence emission, JOU-29 was selected as a representative to study the NB sensing performance. A linear relationship between the NB concentration and the fluorescence emission intensity of JOU-29 could be obtained as I0/I = 0.952 + 8089[NB]. This result showed that JOU-29 can be used for quantitative detection of NB. Further studies revealed that the fluorescence quenching of JOU-29 may be due to the fluorescence resonance transfer effect and the competitive absorption. This work provides clues for the design and synthesis of fluorescent MOFs for NB detection.

Two different 2D Zn (II) coordination polymers for highly selective detection of 2, 4, 6-trinitrophenol, tetracycline and fluazinam

Two new Zn(II) coordination polymers, namely, {[Zn2(L)(4,4′-bip)2] ·4H2O} n (1) {[Zn (H2L) (1,2-die)] · H2O} n (2) [H4L = 5, 5′-(ethane-1, 2-diyl) diisophthalic acid, 4, 4′-bip = 4, 4′ - bis (1-imidazolyl) biphenyl, 1, 2-die = 1,2-di(pyridin-4-yl)ethene] have been synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction, thermogravimetric analysis, IR spectra and fluorescent analysis. Coordination polymers 1 and 2 are 2D network structures. They both have 3D supramolecular structures based on the interspersion of 2D networks. They can detect 2, 4, 6-trinitrophenol (TNP), tetracycline (TET) and fluazinam (FLU) by fluorescence quenching. And the possible reasons for the quenching of TNP, TET, and FLU were discussed in detail, which may be energy resonance transfer. These new zinc coordination polymers could be used multifunctional sensors on NACs, antibiotics and pesticides in the future. In addition, the results of fluorescence sensing experiments show that Zn(II) coordination polymers composed of different auxiliary N donors have significant influence on the detection limits.

A water-stable 2D Y-MOF decorated with tris(3’-F-4’-carboxybiphenyl)amine for multi-responsive fluorescence sensing of CrVI and nitrofuran antibiotics

By using tris(3’-F-4’-carboxybiphenyl)amine (H3TFBA) and rare earth element Y(III), one 2D layered structure with the formula {[Y(TFBA)(H2O)2]·4H2O·DMF}n (1), has been solvothermal synthesized and fully characterized. Structural analyses demonstrated that the central Y(III) ions were interconnected by deprotonated TFBA3− to produce a 2D layer, and the neighboring layers were developed into a 3D supramolecular structure through hydrogen-bonding interactions. Powder X-ray diffraction (PXRD) of 1 exhibited excellent different pH and solvent stability. Luminescent experiment indicated that 1 could instantly and sensitively detect Cr2O72−, CrO42−, NFZ and NFT in aqueous solution with low detection limits of 2.27 × 10−5 M, 2.03 × 10−5 M, 3.4 × 10−6 M, 1.09 × 10−5 M, respectively. Moreover, convenient and naked-eye detection were also provided by exquisitely made 1 fluorescence test papers and mixed matrix membranes (MMMs). Importantly, the possible quenching reasons have been thoroughly examined, which were supported by PXRD analysis, UV-vis spectra, luminescence experiments and density functional theory (DFT) calculation.

Crystal structure and photocatalytic activity of luminescent 3D-Supramolecular metal organic framework of dysprosium

A 3D supramolecular metal organic framework of dysprosium has been fabricated through a facile hydrothermal procedure with the ligand, 2,6-naphthalene disulphonic acid and the co-ligand, 4,4′-bipyridine. The MOF has been characterized as [C60H81DyN8O30S4] by routine analytical procedures. SXRD studies of the MOF show the existence of a hydrogen-bonded 3D supramolecular structure with high porosity. It crystallizes in monoclinic space group P21/n with unit cell parameters, a = 16.5424(6) Å, b = 37.0052(14) Å, c = 24.4361(9) Å, β = 100.7410°, α = γ = 90°. The Dy-MOF has eight coordinated water molecules around the metal centre and exhibits square anti-prismatic geometry. The band gap is 3.11 eV. The degradation experiments under visible light confirmed that Dy-MOF can act as a photocatalyst. Addition of hydrogen peroxide remarkably increases the degradation efficiency of the MOF through an advanced oxidation process. The newly synthesized MOF produced sharp emission peaks characteristic of dysprosium ion.

Four novel coordination compounds based on N-acetyl-L-phenylalanine: Synthesis, characterization and fluorescence properties

Four novel d10 transition metal chiral coordination compounds Cd(L-acphe)2(H2O)2 (1), {[Cd(L-acphe)2(bpe)(H2O)]·2·5H2O}n (2), {[Cd(L-acphe)2 (4,4′-bipy)(H2O)]·H2O}n (3), {[Zn2(L-acphe)2(bpp)2(OH)]NO3·2H2O}n (4) (L-Hacphe = N-acetyl-l-phenylalanine, 4,4′-bipy = 4,4′-bipyridine, bpe = 1,2-bis (4-pyridyl)ethane, bpp = 1,3-bis(4-pyridyl)propane) have been synthesized by changing central metal ions and N-containing auxiliary ligands. Their structures were determined by single crystal X-ray diffraction analysis and characterized by elemental analysis, infrared spectroscopy, thermogravimetric analysis, powder X-ray diffraction and circular dichroism. The structures of compounds 1–3 with cadmium(Ⅱ) as the center metal ion change from 0D, 1D to 2D, ultimately compound 1 generates a 2D supramolecular structure via hydrogen bonding, while compounds 2 and 3 expand to 3D supramolecular structures through hydrogen bonding. The compound 4 with zinc(Ⅱ) as the center metal ion feature 1D chain structures, and 3D supramolecular structure of compound 4 is formed by hydrogen bonding. The present results indicate that selecting central metals with different electronic structures and introducing different N-containing auxiliary ligands could achieve the regulation of the structures of compounds. In addition, the fluorescence recognition properties of compounds 3 and 4 demonstrate that they can highly selectively detect Fe3+ and nitrobenzene in aqueous solutions through fluorescence quenching, indicating that compounds 3 and 4 are expected to become bifunctional fluorescence recognition sensors for the detection of Fe3+ ions and nitrobenzene.

Leveraging the relative strengths of hydrogen and halogen bonds to control nanostructures

Halogen bonds (XBs) and hydrogen bonds (HBs) present a straightforward yet effective strategy for controlling nanostructure morphology. The self-assembled nanopattern, modulated by the relative strengths of XBs and HBs, has rarely been studied using analogous molecules. This research systematically evaluates the relationship between the strengths of Br···O hetero-XBs and N···H HBs in directing the formation of 2D supramolecular co-assembled structures. In this work, tetracarboxylic acid (PEDA), featuring four carboxyl substitutions, forms a stable hydrogen-bonded Rosette network that can function as a template for trapping guest molecules of complementary shape and size. The star-shaped bromine-substituted 1,3,5-tris(3,5-dibromophenyl)benzene (TDB) and 2,4,6-tri(4-pyridyl)-1,3,5-triazine (TPT) serve as XB donor and HB acceptor respectively, thus capable of acting as guest molecules co-assembly with the PEDA at the heptanoic acid/HOPG interface. Bimolecular co-assembly patterns resulting from these combinations were investigated using scanning tunneling microscopy (STM) and supported by density functional theory (DFT) calculations. The findings indicate that TDB molecules can be accommodated within the triangular cavities of the Rosette network due to the weaker Br···O hetero-XB. Concurrently, the similar star-shaped TPT can co-assemble with PEDA to form an acid–pyridine–acid Ladder-like network based on stronger N···H HBs. Therefore, Br···O hetero-XBs seemingly play no decisive role in the coassembly process of PEDA and TDB. Conversely, N···H HBs hold evident significance in the coassembly of PEDA and TPT. This work potentially holds substantial value for the future design and customization of devices employing the interplay of XBs and HBs.

Synthesis, crystal structure, characterization, effective photocurrent response and photodegradation of a silver(I) diphosphine 3D supramolecular structure

A new three-dimensional (3D) supramolecular compound, [Ag(dppe)(CF3COO)]n (1), was prepared by using Ag(I) as the silver source and dppe as the organic ligand through the self-assembly approach. The bridging dppe ligand makes compound 1 appear as a one-dimensional (1D) wavy chain consolidated by the intramolecular hydrogen bonds. Two adjacent 1D chains are expanded to a two-dimensional (2D) layer passing through the intermolecular CH···π interaction between the dppe ligands, and the 2D layers further weave into a 3D supramolecular structure via another intermolecular CH···π interactions between the dppe ligands. The precise structure of 1 was determined by single crystal X-ray diffractometer (SCXRD), and it was well-characterized by Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR) spectroscopy, powder X-ray diffraction (PXRD), thermogravimetric analysis (TG) and differential thermogravimetry analysis (DTG), and UV–vis diffuse reflectance spectrum. In addition, the photocurrent response, electrochemistry characteristic and photodegradation of 1 were investigated. The degradation efficiency (82 %) of 1 as catalyst to degrade methylene blue (MB) was significantly higher than that without catalyst.

Two new Keggin-based copper-organic complexes constructed from pyrazole derivatives: Syntheses, structures and catalytic properties

By regulating the initial reactant molar ratio, two new Keggin-based copper-organic complexes formulated as [Cu2(H2O)(L)2(HL)2](HPMo12O40)·2H2O (1) and [Cu4L4(H2O)2](H3PMo12O40) (2) (HL = 1-(4-carboxylbenzyl)-3-(pyrazine-2-yl)]pyrazole) have been synthesized triumphantly under hydrothermal conditions. Single crystal X-ray diffraction analyses show that compound 1 is a 3D supramolecular structure constructed by 1D metal–organic chains [Cu2(H2O)(L)2(HL)2]n2n+ and PMo12 anions via hydrogen bonds. Compound 2 is a 2D [Cu2L2(H2O)]n coordination polymeric network containing left and right helical chains. By hydrogen bonding interactions between adjacent [Cu2L2(H2O)]n networks and PMo12 anions, the 2D network extends to a 3D supramolecular structure. The two compounds can not only photocatalytic degrade methylene blue and Rhodamine B, but also have electrocatalytic reduction of H2O2, BrO3- and NO2– and oxidation of ascorbic acid. Moreover, their electrochemical sensing properties have also been studied. These results suggest compounds 1 and 2 can be used as multifunctional materials.

Syntheses, structures and luminescent properties of five new Ag(I)-based coordination polymers

In this work, five Ag(I)-based coordination polymers (CPs), namely, [Ag(HL)(H2L)]n (1), [Ag(HL)(2,2′-bpy)(H2O)0.5] (2), [Ag(HL)(phen)(H2O)0.5] (3), {[Ag2(HL)2(4,4′-bpy)(H2O)2]∙H2O} (4) and [Ag(HL)(thpy)]n (5), were synthesized under hydrothermal conditions (H2L = 1-(3-carboxybenzyl)-1H-pyrazole-4-carboxylic acid, 2,2′-bpy = 2,2′-bipyridine, phen = 1,10-phenanthroline, 4,4′-bpy = 4,4′-bipyridine and thpy = 2-(2-thienyl)pyridine). These coordination polymers were characterized by single-crystal X-ray diffraction, elemental analyses, infrared spectroscopy, thermogravimetric analyses and powder X-ray diffraction. Compound 1 displays a one-dimensional (1D) chain structure which can be further extended into a three-dimensional (3D) supramolecular structure via intermolecular hydrogen bond. In compounds 2 and 3, the binuclear zero dimensional (0D) units are extended to 3D supramolecular frameworks by intermolecular hydrogen bond and π–π stacking interaction. In compound 4, the 0D units constructed by HL− anions, 4,4′-bpy and metal ions are expanded to form a two-dimensional (2D) supramolecular network. Compound 5 shows a different 2D supramolecular structure extended from 1D chain by intermolecular hydrogen bond. The results suggest that organic ligand plays a key role in the formation of the final structures. The solid-state luminescent properties of compounds 1–5 were studied in detail. The results show that the luminescent color of compounds 1–5 can be tunable by varying excitation wavelengths.

In Situ Oxidation of Pyridyl-Dihydrobenzoimidazoquinazoline and the Synthesis of a Highly Luminescent Cd(II) Coordination Polymer: A Promising Candidate for Mutagenic Nitroaromatic Detection and Device Fabrication.

Pyridyl-substituted imidazoquinoline, a potent fluorescent framework, is advantageous to architect multifunctional coordination networks for sensing and fabricating emergent electrical conductors. In this work, a Cd(II)-based one-dimensional (1D) coordination polymer (1D CP), [Cd(glu)2(pbiq)2(H2O)]n (1), [H2glu = glutaric acid and pbiq = 4-(6-(pyridin-4-yl)benzo[4,5]imidazo[1,2-c]quinazoline)], has been structurally confirmed by single-crystal X-ray crystallography. The H-bonding and π···π interactions built a three-dimensional (3D) supramolecular structure that strongly emits at 416 nm in acetonitrile suspension. Potentially intrusive nitroaromatics (NAs) and trinitrophenol (TNP) selectively quench the strong emission of 1, and the highest quenching is noted in the case of TNP. A detection limit (limit of detection (LOD)) of 1.51 × 10-7 M for TNP is determined. The band gap (3.31 eV) of 1 recognizes semiconducting behavior, and an electronic device is fabricated. The correlation of current vs voltage (I-V plot) reveals a substantial non-ohmic electrical conductivity of 1 (Λ: 1.10 × 10-5 S m-1) along with a low energy barrier (ΦB: 0.69), and the series resistance (Rs) becomes 6.21 kΩ.

Two novel lead(ii) coordination complexes incorporating phenanthroline derivate: Synthesis and characterization

Abstract Two lead(ii) coordination complexes with 2-(4-fluoro-phenyl)-1H-imidazo[4,5-f][1,10]phenanthroline formulated as [Pb(L)2(tlba)2)] (1) and [Pb(L)(dpea)]2 (2) (HTLBA = 2,3,4,5-tetrachlorobenzoic acid, H2dpea = diphenic acid) were synthesized under hydrothermal conditions. In 1, the neighboring [Pb(L)2(tlba)2)] molecules formed into a two-dimensional (2D) layer structure with C–Cl⋯π interactions and N–H⋯O hydrogen bond interactions. For 2, Pb1 and Pb1i ions are connected by four carboxylate groups from two dpea anions to yield a binuclear unit. Two L ligands are situated in two flanks of the dimer. The L ligands from dimers in the vicinity pile up by two π–π interactions to form a 2D supramolecular structure. Moreover, PXRD of 2 was also studied.

Structure and conformation of individual molecules upon adsorption of a mixture of benzoporphyrins on Ag(111), Cu(111), and Cu(110) surfaces.

We investigated the adsorption behavior of a mixture of six 2H-tetrakis-(3, 5-di-tert-butyl-phenyl)(x)benzoporphyrins (2H-diTTBP(x)BPs, x = 0, 1, 2-cis, 2-trans, 3, and 4) on Ag(111), Cu(111) and Cu(110) at room temperature by scanning tunneling microscopy (STM) under ultra-high vacuum conditions. On Ag(111), we observe an ordered two-dimensional square phase, which is stable up to 400 K. On Cu(111), the same square phase coexists with a stripe phase, which disappears at 400 K. In contrast, on Cu(110), 2H-diTTBP(x)BPs adsorb as immobile isolated molecules or dispersed short chains along the [10] substrate direction, which remain intact up to 450 K. The stabilization of the 2D supramolecular structures on Ag(111) and Cu(111), and of the 1D short chains on Cu(110) is attributed to van der Waals interactions between the tert-butyl and phenyl groups of neighboring molecules. From high-resolution STM, we can assign all six 2H-diTTBP(x)BPs within the ordered structures. Moreover, we deduce a crown shape quadratic conformation on Ag(111) and Cu(111), an additional saddle-shape on Cu(111), and an inverted structure and a quadratic appearance on Cu(110). The different conformations are attributed to the different degree of interaction of the iminic nitrogen atoms of the isoindole and pyrrole groups with the substrate atoms.

A sulfonylcalix[4]arene-based metal–organic cage with octahedral porous structure for guest adsorption and separation

A novel sulfonylcalix[4]arene-based metal-organic cage (MOC), [{Co4(µ4-H2O)(TBSC)}6L12] (Co-1), was synthesized by self-assembly of the ligand 2,3-dihydroxyterephthalic acid (H2L), p-tert-butylsulfonylcalix[4]arene (H4TBSC), and Co(NO3)2 using a solvothermal method. Based on single-crystal X-ray analysis, the molecular structure of Co-1 features a truncated octahedron cage with one inner and six outer cavities. Discrete MOCs are further stacked into a 3D porous supramolecular structure through abundant intermolecular hydrogen-bonding interactions. Additionally, the guest adsorption and separation properties of Co-1 were investigated by using UV-vis spectrophotometer. The results demonstrated that Co-1 exhibits high adsorption capacity of methylene blue and excellent dye selective separation performance.

A 2D antiferromagnetic coordination polymer constructed by benzotriazole-5-carboxylic acid

A 2D coordination polymer (CP) has been synthesized by the hydrothermal reactions of H2btca and Cu2+ ions in the presence of pyridine, {[Cu(btca)(py)2]·H2O}n (1) (py = pyridine, H2btca = benzotriazole-5-carboxylic acid), which is further characterized by the combination of various methods including single-crystal X-ray diffraction, powder X-ray diffraction (PXRD), elemental analysis, infrared (IR) spectrum, and thermogravimetric (TG) analysis. Structural analyses demonstrate that the asymmetric skeleton of CP 1 consists of one five-coordinated Cu2+ ion with square pyramid geometry, one btca2- ligand, two py molecules, and one lattice water molecule. Adjacent Cu2+ ions are bridged by 1,3-site N atoms of btca2− ligands to present a 1D chain, and neighboring 1D chains interconnected each other to generate a 3-connected ‘fes’-type network, which could be further stacked to present a 3D supramolecular structure through hydrogen bonds and π···π stacking interactions. The magnetic interaction among Cu2+ ions has been employed a 1D chain model, and the results indicate that the presence of antiferromagnetic interactions among Cu2+ ions.

SUPRAMOLECULAR NANOSTRUCTURED COORDINATION POLYMER BASED ON A NICKEL COORDINATION COMPOUND WITH PYROMELLITIC ACID

{[Ni2C6H2(COO)4(H2O)4]·H2O2,5}n binuclear coordination compound with supramolecular structure has been synthesized. The composition and chemical structure of the coordination compound have been determined by the elemental, X-ray, IR spectroscopic and differential thermal analyzes. The unit cell parameters have been determined by identifying the diffraction pattern and the inferred schematic structure of the two-dimensional polymer layer of the coordination polymer, which is the building block for all the studied coordination compounds from this series, has been given. The layers are connected with each other and shifted relative to each other depending on the direction and strength of the hydrogen bonds; and this leads to a change in the parameters of the unit cells. Thus, two-dimensional polymer layers (2D) are transformed into a 3D supramolecular structure

Cocrystallization-Driven Double-Optimized Stratagem toward Directional Self-Assembly for the First Ternary Salt Cocrystal of Cardiotonic Drug Milrinone with Different Phenolic Acids Exhibits Optimal In Vitro/Vivo Biopharmaceutical Peculiarities.

The current research leverages the structural features and property superiorities along with benefits in protecting cardiovascular system of gallic acid (GLC) and gentisic acid (HGA) to optimize in vitro/vivo peculiarities of cardiotonic drug milrinone (MIL) through developing a stratagem of cocrystallization-driven double-optimized ternary salt cocrystal. This strategy assembles MIL ternary salt cocrystal by shaping a cocrystallization moiety relying on noncovalent interplays with GLC to obtain permeability advancement and molding a salt segment via the salification of proton transfer between HGA and MIL molecules to facilitate solubility enhancement. While the ameliorative in vitro properties further modulate the in vivo pharmacokinetic behaviors, thus fulfilling a dual optimization of MIL's biopharmaceutical characteristics on both in vitro and in vivo aspects. Along this line, the first MIL ternary salt cocrystal, viz., [HMIL+-GA-]-MIL-GLC-H2O (denoted as MTSC hereinafter), has been satisfactorily constructed and precisely structurally identified by diversified techniques. The single-crystal X-ray diffraction experiment validates that a molecular salt [HMIL+-GA-] species cocrystallizes with one neutral MIL, two GLC, and five solvent water molecules, among which the organic constituents compose laminated hydrogen bond networks, and then are self-assembled by water molecules to a 3D supramolecular structure. The unique structural feature and stacking pattern of MTSC make both the permeability and solubility be respectively enhanced by 9.69 times and 5.17- to 6.03-fold compared with the parent drug per se. The experimental outcomes are powerfully supported by associated calculations based on density functional theory. Intriguingly, these optimal in vitro physicochemical natures of MTSC have been potently converted into strengths of in vivo pharmacokinetics, showcasing the elevated drug plasma concentration, elongated half-life, alongside advanced bioavailability. Consequently, this presentation not just contributes a brand-new crystalline form with utility values, but ushers in a new dimension of ternary salt cocrystals for improving in vitro/vivo limitations of poor drug bioavailability.

Effect of nanodispersed zinc oxide concentrations on the structural, optical, dielectric, viscous, and acoustic properties of ethylene glycol– glycerol mixture based nanofluids

Nanofluids (NFs) are green-formulated innovative soft materials, enormously used for thermal management medium in energy harvesting/ storage and heat transport, as high breakdown voltage insulators/ nanodielectrics in electrical and energy storage systems, and in the advances of soft condensed matter device technologies. In this study, NFs consisting of ethylene glycol (EG) and glycerol (Gly) mixture in equal volumes as the base fluid and semiconductive zinc oxide (ZnO) nanoparticles with increasing concentrations from 0.005 to 1.00 wt% are prepared and characterized by employing different advanced techniques. X-ray diffraction (XRD) patterns recorded directly on these NFs confirmed the homogeneity and nanosuspension stability of ZnO particles in the hydrogen-bonded supramolecular 3D structure of viscous EG–Gly base fluid. The UV-Vis absorbance spectra explained the ZnO concentration tunable photo sensing and UV blocking properties of these semiconductive nanofluids. The 20 Hz to 1 MHz range dielectric spectra revealed high static dielectric permittivity of these NFs, at 298.15 K, confirming them as promising nanodielectric for electric energy storage devices. The dielectric dissipation factor, electric modulus, and impedance spectra confirmed that these EG–Gly/ZnO NFs have electrode polarization and conductivity relaxation processes around 200 Hz and 20 kHz, respectively. The electrical conductivity is observed in the range of 0.32– 0.65 μS/cm with a noticeable increase at the higher ZnO concentration which infers appreciable insulation performance of these NFs. The rheological measurements demonstrated Newtonian behavior of these NFs with a dynamic viscosity of about 69 mPa.s, at 298.15 K. Ultrasound velocity and various acoustic parameters of these NF materials are marginally altered with varying the ZnO concentration and revealed appreciable thermal conductivity of 0.31 W·m–1·K–1, at ambient temperature. The temperature dependent viscosity measurements of EG–Gly/1.00 wt% ZnO sample demonstrated its Arrhenius behavior with high activation energies for both the viscous and relaxation processes. These experimental results establish the EG–Gly/ZnO nanofluids as multifunctional materials for highlighting current applications and also in futuristic soft condensed matter technologies.

Two Proton Conductive Coordination Polymers Constructed by an Unprecedented Structural Transformation of a Phosphine-Based Tricarboxylate Ligand

The phosphine-based tricarboxylate 2-(3,3′-dioxo-1λ5-1,1′-(3H,3′H)-spirobi[2,1-benzoxaphosphol]-1-yl)benzoic acid (L) has been intensely studied due to its unique configuration and readily oxidizable phosphorus center. However, the coordination of L with metals have been largely ignored in the field of coordination polymers (CPs). Herein, we report two CPs, [Zn3(L1)2(dib)2(H2O)]·9H2O (1) and [Cu3(L2)2(dib)2]·3H2O (2) (H3L1 = tris(2-carboxyphenyl)phosphine oxide, H3L2 = 2,2′-phosphinico-dibenzoic acid, dib = 1,4-di(1H-imidazol-1-yl)butane), synthesized based on L. Strikingly, despite the initial use of L, the structures of 1 and 2 reveal that L undergoes two unprecedented in situ structural changes after coordination with the metal ion. In 1, L is transformed to the phosphine oxide derivative L1, while in 2, it is transformed to the phosphinic acid derivative L2. With the aid of the flexible ligand dib, the one-dimensional (1D) chain structure of 1 and three-dimensional (3D) supramolecular structure of 2 were constructed. For 1 and 2, especially in 1, there are abundant hydrogen bonds between the framework and the lattice water molecules, which are conducive to the formation of excellent hydrophilic channels and the transport of protons. Electrochemical experimental results show that 1 and 2 exhibit high proton conductivities (σ) of more than 10–4 S cm–1 over a wide temperature range of 303–353 K and low activation energies (Ea) at 98% relative humidity. Compared with the σ value of the initial ligand L (3.12 × 10–5 S cm–1), the best σ values of 1 and 2 are improved by 28 times and 6 times, respectively, and Ea is also reduced from 0.39 to 0.13 eV for 1 and 0.12 eV for 2. This is the first report of proton-conducting polymers based on a phosphine-based carboxylate ligand, involving two in situ structural transitions of the ligand.