Static Retention of Dynamic Chiral Arrangements for Achiral Shear Thinning Metal-Organic Colloids.

Chiral compounds are known to be important not only because they are the fundamental components of living organisms, but also for their unique chiroptical properties. In recent years, scientists have fabricated several chiral organic supramolecular aggregates by using chiral physical fields, such as vortex flow. Herein, the relationship between dynamic chiroptical properties and rheological nature is discussed, suggesting the shear thinning properties of non-Newtonian fluids might help colloidal particles adopt a chiral arrangement in vortices. Furthermore, the storage modulus of colloids could be increased by adding a linking agent, which successfully kept the dynamic chiroptical properties in the static state. Moreover, the salt effect on the host-guest interaction involved in the colloids was studied, the results suggested a significant enhancement of the transferred dynamic circular dichroism for the achiral guest molecule.

Two novel donor-acceptor hybrid heterostructures with enhanced visible-light photocatalytic properties.

The ternary combination of metal cations, CuI and viologen based carboxylate leads to two donor-acceptor hybrid heterostructures with novel cuprous iodide clusters and narrow energy gaps. Thanks to the facilitated electron transfers between both donor and acceptor components, these unique hybrids exhibit enhanced photocatalytic degradation activities towards organic dyes under visible light irradiation in comparison with those of bulk CuI and viologen semiconductors.

Assembly of donor-acceptor hybrid heterostructures based on iodoplumbates and viologen coordination polymers.

The insertion of electron-rich iodoplumbate nanowires and nanolayers into layered electron-deficient metal-viologen frameworks leads to two donor-acceptor hybrid structures, respectively, which exhibit interesting semiconductor behaviors. Due to the bicontinuous donor and acceptor components, both of them exhibit highly efficient photocatalytic degradation activities over organic dyes under visible light irradiation compared to those of other iodoplumbate hybrid materials.

Construction of a bicontinuous donor-acceptor hybrid material at the molecular level by inserting inorganic nanowires into porous MOFs.

Herein, we report an unprecedented hybrid structure of electron-rich iodoplumbate nanowires precisely inserted into the periodic pores of electron-deficient pyridinium metal-organic frameworks (MOFs). To the best of our knowledge, this is the first example of semiconductive MOFs in situ loaded with inorganic semiconductive nanowires via a simple self-assembly method. Due to the dissimilar semiconductivities between the host and guest components, this hybrid also represents the first bicontinuous donor-acceptor hybrid at the molecular level based on host-guest interactions.

Encapsulating Naphthalene in an Electron-Deficient MOF to Enhance Fluorescence for Organic Amines Sensing.

Host-guest encapsulation of electron-rich naphthalene molecules into a weakly emissive porous metal-organic framework based on π-electron-deficient (π-acidic) naphthalene diimide tectons leads to orange-emissive crystals, which can be used to sense strongly basic organic amines in a fast response, high photostability, and tunable sensitivity. Moreover, such host-guest inclusion crystals are also a good photochromic probe for the detection of weakly basic N-methyl-2-pyrrolidone and N,N-dimethylformamide molecules.

Two-semiconductive-component hybrid coordination polymers with controllable photo-induced electron-transfer properties.

Two semiconductive inorganic-organic hybrid coordination polymers constructed from metal iodide clusters and naphthalene diimide semiconductive components, [Cu2I2(DPNDI)]n () and [PbI2(DPNDI)]n () (DPNDI = N,N'-di-(4-pyridyl)-1,4,5,8-naphthalene diimide), have been synthesized and characterized. Although possessing similar 2D heterostructures, hybrids exhibited different photo-induced electron-transfer properties. Due to the higher HOMO energy level of the [Cu2I2]n chain than that of the [PbI2]n cluster, only hybrid can easily undergo intramolecular electron transfer to form a long-lived charge separated state, which may be applied in artificial photosynthesis.

Syntheses and structures of discrete copper(II) and cadmium(II) supramolecular complexes based on 1,4-diacylthiosemicarbazone ligands.

Thiosemicarbazides and their metal complexes have attracted considerable interest because of their biological activities and their flexibility, which allows the ligands to bend and rotate freely to accommodate the coordination geometries of various metal centres. Discrete copper(II) and cadmium(II) complexes have been prepared by crystallization of N-[2-(2-hydroxybenzoyl)hydrazinecarbonothioyl]propanamide (H3L) with Cu(CH3COO)2 or Cd(NO3)2 in a dimethylformamide/methanol mixed-solvent system at room temperature, affording the complexes di-µ-acetato-bis{µ4-1-[(2-oxidophenyl)carbonyl]-2-(propanamidomethanethioyl)hydrazine-1,2-diido}tetracopper(II) dimethylformamide disolvate, [Cu4(C11H10N3O3S)2(C2H3O2)2]·2C3H7NO, (I), and bis{µ2-[(2-hydroxyphenyl)formamido](propanamidomethanethioyl)azanido}bis[(4,4'-bipyridine)nitratocadmium(II)] dihydrate, [Cd2(C11H12N3O3S)2(NO3)2(C10H8N2)2]·2H2O, (II). Complex (I) consists of four Cu(II) cations, two µ4-bridging trianionic ligands and two µ2-bridging acetate ligands, while complex (II) is composed of two Cd(II) cations, two µ2-bridging monoanionic ligands, two nitrate ligands and two 4,4'-bipyridine ligands. These discrete complexes are connected by hydrogen bonds and van der Waals interactions to form a three-dimensional supramolecular architecture. Compared with (I), the phenolic hydroxy group and hydrazide N atom of the thiosemicarbazide ligand of (II) are not involved in coordination and lead to a binuclear Cd(II) complex. This different coordination mode may be attributed to the larger ionic radius of the Cd(II) ion compared with the Cu(II) ion.

The impact of lone pair-π interactions on photochromic properties in 1-D naphthalene diimide coordination networks.

Lone pair-π interaction is an important but less studied binding force. Generally, it is too weak to influence the physical properties of supramolecular systems. Herein we reported the first example exhibiting the impact of lone pair-π interactions on photochromic properties of naphthalene diimide based coordination networks. In three isostructural 1-D networks, [(DPNDI)ZnX2] (DPNDI = N,N-di(4-pyridyl)-1,4,5,8-naphthalene diimide, X = Cl for 1, X = Br for 2 and X = I for 3), they exhibit different electron-transfer photochromic behaviors due to different lone pair-π interactions between the capped halogen atoms and electron-deficient DPNDI moieties. Specifically, 1 and 2 but not 3 are photochromic, which is attributed to a stronger lone pair-π interaction in 3 than those in 1 and 2. This study anticipates breaking a new path for designing novel photochromic materials through such unnoticeable supramolecular interactions.

Mixed-metal metallocavitands: a new approach to tune their electrostatic potentials for controllable selectivity towards substituted benzene derivatives.

We have successfully developed a new synthetic approach to modulate the electrostatic potentials of metallocavitands and thus their selective recognition towards substituted benzene derivatives via integrating two metal cations of different electronegativity into a self-assembled system.

A three-dimensional cadmium(II) coordination polymer with unequal homochiral double-stranded concentric helical chains.

A homochiral helical three-dimensional coordination polymer, poly[[(µ2-acetato-κ(3)O,O':O)(hydroxido-κO)(µ4-5-nicotinamido-1H-1,2,3,4-tetrazol-1-ido-κ(5)N(1),O:N(2):N(4):N(5))(µ3-5-nicotinamido-1H-1,2,3,4-tetrazol-1-ido-κ(4)N(1),O:N(2):N(4):N(5))dicadmium(II)] 0.75-hydrate], {[Cd2(C7H5N6O)2(CH3COO)(OH)]·0.75H2O}n, was synthesized by the reaction of cadmium acetate, N-(1H-tetrazol-5-yl)isonicotinamide (H-NTIA), ethanol and H2O under hydrothermal conditions. The asymmetric unit contains two crystallographically independent Cd(II) cations, two deprotonated 5-nicotinamido-1H-1,2,3,4-tetrazol-1-ide (NTIA(-)) ligands, one acetate anion, one hydroxide anion and three independent partially occupied water sites. The two Cd(II) cations, with six-coordinated octahedral and seven-coordinated pentagonal bipyramidal geometries are located on general sites. The tetrazole group of one symmetry-independent NTIA(-) ligand links one of the independent Cd(II) cations into 61 helical chains, while the other NTIA(-) ligand links the other independent Cd(II) cations into similar but unequal 61 helical chains. These chains, with a pitch of 24.937 (5) Å, intertwine into a double-stranded helix. Each of the double-stranded 61 helices is further connected to six adjacent helical chains through an acetate µ2-O atom and the tetrazole group of the NTIA(-) ligand into a three-dimensional framework. The helical channel is occupied by the isonicotinamide groups of NTIA(-) ligands and two helices are connected to each other through the pyridine N and carbonyl O atoms of isonicotinamide groups. In addition, N-H···O and O-H···N hydrogen bonds exist in the complex.

A panchromatic hybrid crystal of iodoplumbate nanowires and J-aggregated naphthalene diimides with long-lived charge-separated states.

A panchromatic hybrid crystal of anionic iodoplumbate nanowires and J-aggregated protonated naphthalene diimides has been formed through charge-assisted anion-π and lone pair-π interactions, which exhibits unusually long-lived charge-separated states even upon the irradiation of indoor lighting.

Lone pair-π interaction-induced generation of non-interpenetrated and photochromic cuboid 3-D naphthalene diimide coordination networks.

Interpenetration is an intrinsic behaviour for the porous coordination networks. To prevent the interpenetration, a common strategy is the imposition of geometric or steric restrictions by incorporating bulky moieties into organic tectons. So far, most of the available incorporations have been achieved through a covalent connection, while few involved in the non-covalent weak interactions. In this paper, we have reported that such interpenetration can be prevented by the less common lone pair-π interactions. By imposing the lone pair-π interactions through the addition of lone-pair-bearing N-methylpyrrolidin-2-one or iodine, combinations of rigid naphthalene diimide tectons bearing two divergently oriented pyridyl units at both imide extremities with ZnSiF6 led to non-interpenetrated cuboid 3-D coordination networks that should have been interpenetrated. In addition, such close-contacting lone pair-π interactions between electron donors and acceptors have also been demonstrated to play a key role in their photochromic properties.

Photogeneration of two reduction-active charge-separated states in a hybrid crystal of polyoxometalates and naphthalene diimides.

The combination of naphthalene diimide tectons with zinc cations in the presence of polyanions, Mo6O19(2-), leads to a hybrid crystal composed of two-dimensional porous coordination networks and polyoxometalates, which can generate two kinds of long-lived charge-separated states for the reduction reactions upon irradiation.

A pillared framework coordination polymer based on the Cd3(µ3-OH) unit: poly[[(µ4-5-aminotetrazolato-κ(4)N(1):N(2):N(3):N(4))chlorido-µ3-hydroxido-(µ3-isonicotinato-κ(3)N:O:O')dicadmium(II)] 0.14-hydrate].

The title coordination polymer, {[Cd2(CH2N5)(C6H4NO2)Cl(OH)]·0.14H2O}n, (I), was synthesized by the reaction of cadmium acetate and N-(1H-tetrazol-5-yl)isonicotinamide in aqueous ammonia, using hydrochloric acid to adjust the pH. Under hydrothermal conditions, N-(1H-tetrazol-5-yl)isonicotinamide slowly hydrolyzes to form isonicotinic acid (Hisonic) and 5-aminotetrazole (Hatz). The deprotonated form of isonicotinic acid (denoted isonic) acts as a bridging ligand in the structure. The polymer crystallizes in the monoclinic space group C2/m. In the structure, there is one Cd3(µ3-OH) unit of Cs symmetry, with one of the Cd(II) atoms and the O and H atoms located on a mirror plane. The other crystallographically independent Cd(II) cation is located on an inversion centre. Each edge of the Cd3(µ3-OH) isosceles triangle is bridged by an atz ligand in a µ1,2 or µ2,3/µ3,4 mode. The Cd3(µ3-OH) units are laced around with a belt of chloride ligands. The belts are further connected into undulating layers via weak inter-belt Cd-Cl bonds. The two organic ligands reside across mirror planes. The construction of a three-dimensional framework is completed by the pillaring isonic ligand. Water molecules partially occupy the voids of the framework.

A photochromic naphthalene diimide coordination network sensitized by polyoxometalates.

Metal-ion-directed assembly of naphthalene diimide tectons cooperatively enhanced by anion-π interactions of giant anions, PMo12O40(3-), leads to a novel organic-inorganic hybrid with ultrafast-responsive photochromic properties, which is attributed to the polyoxometalate-sensitized photo-induced radical generation of naphthalene diimide units.

Enantioselective synthesis of a chiral coordination polymer with circularly polarized visible laser.

Circular dichroism is known to be the feature of a chiral agent which has inspired scientist to study the interesting phenomena of circularly polarized light (CPL) modulated molecular chirality. Although several organic molecules or assemblies have been found to be CPL-responsive, the influence of CPL on the assembly of chiral coordination compounds remains unknown. Herein, a chiral coordination polymer, which is constructed from achiral agents, was used to study the CPL-induced enantioselective synthesis. By irradiation with either left-handed or right-handed CPL during the reaction and crystallization, enantiomeric excesses of the crystalline product were obtained. Left-handed CPL resulted in crystals with a left-handed helical structure, and right-handed CPL led to crystals with a right-handed helical structure. It is exciting that the absolute asymmetric synthesis of a chiral coordination polymer could be enantioselective when using CPL, and provides a strategy for the control of the chirality of chiral coordination polymers.

A copper(I) coordination polymer incorporation the corrosion inhibitor 1H-benzotriazole: poly[µ3-benzotriazolato-κ(3)N(1):N(2):N(3)-copper(I)].

The title complex, [Cu(C6H4N3)]n, was synthesized by the reaction of cupric nitrate, 1H-benzotriazole (BTAH) and aqueous ammonia under hydrothermal conditions. The asymmetric unit contains three crystallographically independent Cu(I) cations and two 1H-benzotriazolate ligands. Two of the Cu(I) cations, one with a linear two-coordinated geometry and one with a four-coordinated tetrahedral geometry, are located on sites with crystallographically imposed twofold symmetry. The third Cu(I) cation, with a planar three-coordinated geometry, is on a general position. Two Cu(I) cations are doubly bridged by two BTA(-) ligands to afford a noncentrosymmetric planar [Cu2(BTA)2] subunit, and two [Cu2(BTA)2] subunits are arranged in an antiparallel manner to form a centrosymmetric [Cu2(BTA)2]2 secondary building unit (SBU). The SBUs are connected in a crosswise manner via the sharing of four-coordinated Cu(I) cations, Cu-N bonding and bridging by two-coordinate Cu(I) cations, resulting in a one-dimensional chain along the c axis. These one-dimensional chains are further linked by C-H···π and weak van der Waals interactions to form a three-dimensional supramolecular architecture.

An electron-deficient metallocavitand with an unusual selectivity towards substituted benzene derivatives during co-crystallizations.

A double-wall-hourglass-shaped metallocavitand bearing an electron-deficient cavity was self-assembled, which exhibited an unusual selectivity to substituted benzene derivatives of different electron density during co-crystallizations.

Di-µ2-chlorido-dichloridobis(dimethylformamide)tetrakis[µ3-1-(2-oxidobenzoyl)-2-(2-oxo-2-phenylethanethioyl)hydrazine-1,2-diido]octacopper(II) dimethylformamide disolvate.

The title compound, [Cu8(C15H10N3O3S)4Cl4(C3H7NO)2]·2C3H7NO, consisting of eight Cu(II) cations, four trianionic 1-(2-oxidobenzoyl)-2-(2-oxo-2-phenylethanethioyl)hydrazine-1,2-diide ligands, four chloride ligands and two coordinated and two solvent dimethylformamide molecules, crystallizes with the octanuclear molecule located on an inversion centre. The two halves of the molecule are connected by two bridging Cl atoms. This is the first example of an octanuclear complex based on a thiosemicarbazone-derived ligand.

A template-free solution route for the synthesis of well-formed one-dimensional Zn2GeO4 nanocrystals and its photocatalytic behavior.

Well-defined Zn2GeO4 hexagonal nanorods and nanofibers with high aspect ratios have been readily realized in high yield via a simple and general hydrothermal synthesis method free of any surfactant or template. Field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectrometry (EDX), powder X-ray diffraction (XRD), and ultraviolet-visible light diffuse reflectance spectroscopy (UV-vis DRS) revealed a unique hexagonal-prism-shaped one-dimensional (1-D) structure, surface features, anisotropic crystal growth, and crystal phase of Zn2GeO4. Detailed investigations indicated that the prismatic Zn2GeO4 nanocrystals are uniform single crystal with the longitudinal direction along the [001] and were dominated by (110) and (110) surfaces. The addition of increasing amounts of NaOH was found to facilitate the morphology transition from a hexagonal nanorod shape to a hexagonal fiber shape. As an important wide-band-gap photocatalyst, the products of regular Zn2GeO4 nanocrystals with a hexagonal 1-D structure exhibit superior photocatalytic activities for the photocatalytic decomposition of water-methanol solution to hydrogen under UV irradiation.