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New linkages for covalent organic frameworks (COFs) have been continuously pursued by chemists as they serve as the structure and property foundation for the materials. Developing new reaction types or modifying known linkages have been the only two methods to create new COF linkages. Herein, we report a novel strategy that uses H3PO3 as a bifunctional catalyst to achieve amine-linked COFs from readily available amine and aldehyde linkers. The acidic proton of H3PO3 catalyzes the imine framework formation, which is then in situ reduced to the amine COF by the reductive P-H moiety. The amine-linked COF outperforms its imine analogue in promoting Knoevenagel condensation because of the more basic sites and higher stability.

Complex [Cu(phen)2Cl]Cl∙2PABA∙4H2O has been isolated, where phen ligand is 1,10-phenanthroline and PABA is p-aminobenzoic acid. The complex crystallizes in the centrosymetric (monoclinic) space group P2(1)/n. The unit cell dimensions are a = 10.479(4) A, b = 22.396(7) A, and c = 16.212(6) A. The basic unit structure of complex is distorted trigonal bipyramidal. Two hydrogen-bonded PABA molecules are enclosed through π−π interactions in filled aryl box FAB motif made by juxtaposition of four phen from two opposing cations. While π−π interaction between phen causes the formation of offset face-to-face overlap OFF primary motif. The result is formation of extended (OFF-FAB)n chains. Cyclic voltammetry showed one reversible oxidation reduction process followed by one irreversible oxidation process. Thermal analysis indicated successive loss of crystalline water and crystalline PABA molecules, chloride ions, and phen ligands. DFT study indicates that PABA interacts with phen with binding energy 68.87 kJ mol−1 reflecting strong π-stacking. The charge density in HOMO is localized on the metal halogen bond, whereas in LUMO, it is spread over two phen. The vibrational spectrum of complex was calculated at M05-2X/6-31G(d) and compared with the experimental vibrational spectrum data. The inhibitory concentrations IC50 against carcinoma cells A549 (lung adenocarcinoma) and MDA-MB-231 (breast adenocarcinoma) are 3.4 and 4.5 µM, respectively. IC50 values of new complex are comparable to those of cisplatin and smaller than the values for [Cu(phen)2Cl]Cl∙6.5H2O.

The ionic conductivity of solid polymer electrolytes is governed by the ionic association caused by the polymer···Li

New linkages for covalent organic frameworks (COFs) have been continuously pursued by chemists as they serve as the structure and property foundation for the materials. Developing new reaction types or modifying known linkages have been the only two methods to create new COF linkages. Herein, we report a novel strategy that uses H

Ionic liquids have been exploited to assist dissolution of poorly soluble (and poorly bioavailable) drugs, enhancing permeation through physiological barriers to deliver drugs to target sites. Herein, the solubility of 6-methyl-2-thiouracil – a common antithyroid drug, with low solubility in water and common organic solvents – was studied by employing six different imidazolium-based ionic liquids with variable anions. We demonstrate facile, regiospecific S-alkylation of 2-thiouracil with various lipophilic side chains in high yields (91–94%) and in the absence of catalysts. The reaction yields are correlated with the H-bond formation ability between the ILs' anions and the solute, indicating that the hydrogen bond is perhaps responsible for the high solubility of 2-thiouracil in [C2mim][OAc] and [C2mim][Cl].

Ionic liquids with bifluoride anions possess properties such as high conductivity, wide electrochemical windows, and low viscosity that make them attractive materials for various electrochemical devices. However, owing to the lack of reliable synthetic routes, bifluoride-based ionic liquids have seldom been explored. Herein, an autocatalytic strategy for the HF-free synthesis of bifluoride-based sulfonamide ionic liquids based on the sulfur(VI) fluoride exchange (SuFEx) reaction is reported. This reaction requires no chromatographic purification, and yields are quantitative. The thermophysical properties (phase transition behavior and decomposition temperature) and electrochemical stabilities of the resulting products were studied. The products with alkyl, aryl, and perfluoroalkyl side chains exhibited extraordinarily wide electrochemical windows (up to 6.0 V) with reproducible results among multiple replicate measurements.

We describe the proficient synthesis and thermotropic mesomorphicity of thioether–functionalized imidazolium–type ionic liquids containing C12 and C18 chains associated with Br− and OTf− anions. The mesomorphic behavior and phase transition temperatures were studied by Polarizing Optical Microscopy (POM), Differential Scanning Calorimetry (DSC) and Small-Angle X-ray Scattering (SAXS). The ionic liquids with bromide anion display Smectic A lamellar phase giving homeotropic and fan-shaped textures. The layered crystallographic structure is reported by Single-Crystal XRD. The electrochemical characteristics of the ionic liquids with C18 side chain have been determined via Cyclic Voltammetry.

Fundamental to the field of ionic liquids is the understanding that structure begets function. In this work, we reported the development of thioether-based ionic liquids, with enhanced hydrophobicity and low melting point (Tm), via the thiol‒yne reaction. Cationic lipids can simply be converted to macroscopically hydrophobic ionic liquids by replacing their native chloride counteranion with Tf2N. Features that specifically increase or decrease fluidity are identified by juxtaposing the wide-ranging Tm values of these highly lipophilic salts with elements of their cation structures. Most importantly, when these Tm-increasing and -decreasing features are incorporated into the same cation, an “averaged” Tm value is observed. These findings may prove to be elements of the “know-how” needed to design functional ionic liquids that liquefy within relatively predictable temperature ranges.

Metal complexes of divalent copper (1–2), cobalt (3), and nickel (4) with mixed ligands acetylacetone (acac) and adenine were prepared and characterized by IR, mass spectra, elemental and thermal analysis. The X-ray crystal structures of {[Cu(acac)2(adenine)]·EtOH} complex (1) and {[Cu(acac)2(adenine)]·DMF·H2O} (2) were determined. Compound (1) crystallizes in the triclinic space group P − 1 with a = 7.547(3) A, b = 7.828(3) A, c = 17.791(6) A, α = 79.538(6)°, β = 82.240(7)°, γ = 86.010(6)°, V = 1023.1(6) A3, and Z = 2. Complex (1) forms a hydrogen bonded 2:2 complex {[Cu(acac)2(adenine)]2:[EtOH]2} arranged in bilayers. Complex (2) crystallizes in the triclinic space group P − 1 with a = 7.828(2) A, b = 8.095(2) A, c = 16.995(5) A, α = 78.508(5)°, β = 84.949(5)°, γ = 89.285(5)°, V = 1051.2(5) A3, and Z = 2. Complex (2) also forms bilayers with H-bonded DMF. Thermal analysis TG and DSC of the compounds (25–800 °C, under N2) reveals the disproportionation of ligands with the associated heat. Metal complexes of divalent copper, cobalt, and nickel with mixed ligands acetylacetone (acac) and adenine were prepared and characterized by IR, mass spectra, elemental and thermal analysis. The X-ray crystal structures of {[Cu(acac)2(adenine)]·EtOH} complex (1) and {[Cu(acac)2(adenine)]·DMF·H2O} (2) were determined. Complex (1) forms a hydrogen bonded 2:2 complex {[Cu(acac)2(adenine)]2:[EtOH]2} arranged in bilayers. Complex (2) also forms bilayers with H-bonded DMF.

NSC 333003 has been identified from the NCI Diversity Set as an inhibitor of the MDM2-p53 protein-protein interaction by in silico docking (virtual screening). Its potency and chemical characteristics render it well suited for lead optimization studies that can result in more potent analogs with improved drug-like properties. Its synthesis was achieved using an acid catalyzed condensation reaction from commercially available benzothiazole hydrazine and pyridyl phenyl ketone in refluxing methanol. Stereochemical implications for this compound are described.

The synthesis and X-ray crystal structure of [Cu(C7H3NO4)(C6H7NO)], [Cu(dipic)(4-MeO-Py)], (dipic = pyridine-2,6-dicarboxylate, 4-MeO-Py = 4-methoxypyridine), is described. Molecules of [Cu(dipic)(4-MeO-Py)] are formed {via} coordination of the copper(II) cation to two nitrogen atoms, from the dipic and 4-MeO-Py ligands respectively, and to two oxygen atoms from the carboxylate groups of the dipic ligand. The molecules pack in a non-centrosymmetric manner, stacked eclipsed with respect to one another along the b-axis and aligned parallel in a head-to-tail motif. The title compound crystallizes in the orthorhombic space group, Pca2(1), with a = 27.339(3) A, b = 3.7130(4) A, c = 11.6859(12) A, V = 1186.2(2) A3, and Z = 4. The structure was solved by direct methods and refined by least-squares methods to a final R-factor of 0.0327 for 2648 independent reflections.

The fluorescence intensity of 7-methoxycoumarin (7MC) in aqueoussolution is found to significantly decrease upon addition of variouscyclodextrins. This observed phenomenon is described asfluorescence suppression, to distinguish it from fluorescencereduction via bimolecular quenching. The decrease in fluorescenceof 7MC is proposed to be the result of the formation of ahost–guest inclusion complex with cyclodextrin. Since 7MC isa polarity-sensitive fluorophore, which is less fluorescent ina nonpolar environment, its fluorescence decreases uponinclusion into the relatively nonpolar internal cavity of thecyclodextrin. The same equation used for extracting the associationconstant in the case of 1 : 1 host–guest inclusion-induced fluorescenceenhancement is shown to be applicable to the case of fluorescencesuppression. In the case of β-cyclodextrin, the degree of fluorescencesuppression, as well as the value of the binding constant for formationof the inclusion complex, are found to be unaffected by modificationof the cyclodextrin rims, suggesting that the molecule iscompletely included within the β-cyclodextrin cavity. In the case ofγ-cyclodextrin, the degree of fluorescence suppression, butnot the value of the binding constant, is found to be significantlyaffected by modification of the cyclodextrin rims, suggesting thatthe molecule is experiencing a less polar environment in the modifiedγ-cyclodextrin cavity. The binding constant is three timeslarger in β- as compared to γ-cyclodextrin, indicatinga much better size match in the smaller β-cyclodextrin cavity.

The fundamental precept of crystal engineering is that all the information necessary for the design of a network is already stored in the molecular building blocks used. Coordination polymers represent an example of how crystal engineering has become a paradigm for the synthesis of new architectures and compositions. We report herein ten structures that are supramolecular isomers of one another. The structures are prepared from the same building blocks under mild reaction conditions. The modularity of coordination polymers imparts structural diversity that otherwise would not be possible.

Nanoball structures decorated by 24 sulfonate or 24 methoxy moieties, 1 and 2, respectively, are able to act as nodes for the generation of infinite networks.

Imidazolium salts containing salicylaldoxime or salen ligands readily form ionic metal complexes with copper and manganese; hence offering applications in metal extractions and biphasic catalysis.

A novel metal-organic network [Cu(4)(5-NH(2)-1,3-bdc)(4)(pyridine)(2)(H(2)O)(2)](n), displaying an unprecedented topology has been constructed utilizing the different coordinating functional groups of 5-NH(2)-1,3-bdc to generate a ternary network based upon vertex-linked triangular, square and tetrahedral molecular building blocks (MBBs).

A novel 3D metal−organic coordination polymer constructed from hollow, spherical, nanometer-sized molecular faceted polyhedra and a flexible tetracarboxylate ligand designed to simultaneously assemble and cross-link these nanoballs in situ has been synthesized and structurally characterized. The crystal structure involves 2-fold interpenetration with each framework exhibiting pores of dimensions which vary from less than 1 nm to just over 2.5 nm.

Coordination polymers based on Zn(II)-4,4'-bipyridine (Zn-bipy) frameworks containing pyrene intercalated between adjacent layers and aromatic solvent molecules enclathrated within the framework cavities have been prepared and characterized for the first time. These compounds are highly fluorescent, and show broad, featureless emission spectra significantly red-shifted relative to pyrene monomer fluorescence; this has been assigned to pyrene-bipy exciplex emission. Single-crystal X-ray structural analysis shows that the presence of the aromatic solvent molecule within the cavities has a profound effect on the architecture of these frameworks: in the case of benzene, toluene, p-xylene, and chlorobenzene, the Zn-bipy framework consists of 1-D ladders, whereas in the case of o-dichlorobenzene (the largest solvent guest), the framework was based on a 2-D square grid. This difference in stoichiometry and architecture was also reflected in significant differences in the fluorescence of these coordination polymers, with three of the four compounds with 1-D ladder geometries having similar fluorescence maxima (ca. 520 nm) and lifetimes (ca. 70 ns), whereas the compound with square grid topology had a significantly blue-shifted maximum (ca. 460 nm) and shorter lifetime (ca. 42 ns). It is proposed that exciplexes form upon excitation of ground-state complexes, involving face-to-face bipy/pyrene complexes (pi-pi stacking interactions) in the case of the 1-D ladder structures, but edge-to-face bipy/pyrene and pyrene/o-dichlorobenzene complexes (C-H...pi interactions) in the case of the 2-D square grid structure.

In this report, the photophysical properties of self-assembled [Cu(2)(5-OH-bdc)(2)L(2)](12) [where (5-OH-bdc)(2-) = 5-hydroxybenzene-1,3-dicarboxylate and L is a dimethyl sulfoxide, methanol, or water ligand] hydroxylated nanoballs (OH-nanoball) were examined in methanol using optical absorption and steady-state and time-resolved fluorescence methods. The optical spectrum of the OH-nanoball is dominated by ligand absorbance at 305 nm and a weaker Cu(2+)-to-ligand charge-transfer transition at approximately 695 nm, which are distinct from the absorption of either the free ligand (approximately 312 nm) or Cu(2+)(NO(3))(2) (750 nm) in methanol. The corresponding emission spectrum of the OH-nanoball originates from the emission of the ligand and is centered at approximately 360 nm with a shoulder at approximately 390 nm. The emission from the OH-nanoball is significantly quenched relative to the free ligand [Phi(5-OH-H(2)bdc) = 0.014 and Phi(OH-nanoball) = (5.6 +/- 0.5) x 10-5]. The addition of bases such as imidazole results in an increase in the emission intensity of the OH-nanoball solution, indicating dissociation of the [Cu(2)(5-OH-bdc)(2)L(2)](12) units. Although the mechanism of (5-OH-bdc)(2-) quenching within the OH-nanoball is not clear, it is likely due to interactions between the ligand pi system and the Cu d orbitals. Fluorescence polarization studies further suggest that the OH-nanoball retains a spherical shape in solution. This is evident by the fact that the fluorescence anisotropy of the nanoball is nearly identical with that of the free ligand, suggesting rapid energy transfer (homogeneous fluorescence resonance energy transfer) between ligands within the OH-nanoball.

A novel Kagome lattice that demonstrates the modular nature of metal-organic networks has been prepared and is to our knowledge the first example of a metal-organic coordination polymer that incorporates the sextuplet phenyl embrace as a supramolecular synthon.

We report the first use of fluorescence spectroscopy to probe the environment of the cavities that are present in open framework coordination polymers.

Cocrystal-controlled solid-state synthesis (C3S3) of imides occurs via heating of cocrystals formed between anhydride and aromatic amine cocrystal formers.

We report the crystal structures of two new coordination polymers that have similar composition but, despite having the same circuit symbol and Schlafli notation, different topologies: a novel 3D topology (USF-1) and a CdSO4-like topology.