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Invited for this month's cover is the group of Prof. Shin-ichiro Noro from Hokkaido University, Japan. The cover picture shows a copper(II) porous coordination polymer that can adsorb CO2 over CH4 at high selectivity under CO2 /CH4 mixed gas conditions, even with the coexistence of water. Read the full text of the article at 10.1002/cplu.201500278.

Metal–organic network structure based on oxalate bridges {[MnIICrIII(oxalate)3]−}∞ and supramolecular cations (H2PPD2+)(benzo[18]crown-6)2[MnCr(oxalate)3](CH3OH)(CH3CN)2 (1) and (o-FAni+)2(DCH[18]crown-6)2[Mn(CH3OH)Cr(oxalate)3][MnCr(oxalate)3](CH3OH) (2), where H2PPD2+, o-FAni+, and DCH[18]crown-6 denote p-phenylenediammonium2+, o-fluoroanilinium+, and cis-syn-cis-dicyclohexano[18]crown-6, respectively, were synthesized. The crystal structure of 1 was the combination of [Mn(Λ)Cr(Λ)(oxalate)3]− and [Mn(Λ)Cr(Δ)(oxalate)3]−, whereas that of crystal 2 was the combination of [Mn(Λ)(CH3OH)Cr(Δ)(oxalate)3] and [Mn(Λ)Cr(Δ)(oxalate)3]. Large flexible supramolecular cations provide the three-dimensional structure of {[MnIICrIII(oxalate)3]−}∞, which is different from the two-dimensional honeycomb structure often observed for {[MnIICrIII(oxalate)3]−}∞ complexes. Temperature-dependent magnetic susceptibilities of the complexes 1 and 2 exhibited ferromagnetic behaviors following the Curie–Weiss law (C = 11.5 cm3 K mol...

Three electron-accepting dialkoxydicyanopyrazinoquinoxaline derivatives (1a, 1b, and 1c) showed properties of smectic (Sm) liquid crystals. Temperature-dependent X-ray diffraction studies were consistent with the formation of a bilayer structure through the π-overlap and interdigitation of alkoxy chains in the Sm liquid crystalline state. Intermolecular dipole–dipole interactions between the cyano groups played an important role in stabilizing the bilayer structure and liquid crystalline properties. Elongation of the alkoxy chains from C6H13O- (1a) and/or C12H25O- (1b) to C18H37O- (1c) changed the molecular arrangements and the liquid crystal phase from SmA to SmC, suggesting the importance of the van der Waals interaction of CnH2n+1O- chains for stabilizing the liquid crystalline phase. A hole-mobility value of 5 × 10−3 cm2 V−1 s−1 was observed for the SmA phase of 1b at 438 K based on transient photocurrent measurements.

The Bronsted acid–base reaction between 3-hydroxy-2-quinoxalinecarboxylic acid (Hhqxc) and imidazole (Im) in acetone–H2O yielded two 1 : 1 salts: anhydrous (HIm+)(hqxc−) (1) and hydrated (HIm+)(hqxc−)·(H2O) (2), where HIm+ and hqxc− are imidazolium and 3-hydroxy-2-quinoxalinecarboxylate, respectively. Single-crystal X-ray structural analyses and vibrational spectra were consistent with the lactam tautomer of the hqxc− anion, which formed π-dimers in both 1 and 2. Each π-dimer in crystal 1 was connected by intermolecular N–H⋯O hydrogen-bonding interactions to form a linear hqxc− chain, whereas the π-dimers in crystal 2 formed an intermolecular N–H⋯O hydrogen-bonding zigzag chain. The HIm+ cations existed in the crystalline space between the hydrogen-bonding hqxc− anionic chains. A reversible crystal-to-crystal structural transformation between crystals 1 and 2 was observed following H2O adsorption–desorption, which was confirmed by powder X-ray diffraction measurements, single-crystal X-ray structural analyses, and H2O adsorption–desorption isotherms at 323 K. The structural rearrangement of the hqxc− anions was achieved through changes in the intermolecular hydrogen-bonding interactions. The temperature- and frequency-dependent dielectric constants of crystal 2 revealed a dielectric peak at ~330 K owing to thermal fluctuations of H2O molecules within the crystal.

Four supramolecular cations (m-XAni+)(DB[18]crown-6) (X = F, Cl, Br or I; Ani+ = anilinium ion; DB[18]crown-6 = dibenzo[18]crown-6) were introduced into crystals of a Keggin [SMo12O402−] polyanion to form [(m-XAni+)(DB[18]crown-6)]2[SMo12O402−]·4CH3CN (1, 2, 3 or 4 for X = F, Cl, Br or I) through a hydrogen-bonding interaction. Crystals 1, 2, 3 and 4, which were isomorphous to each other, crystallized in the monoclinic space group P21/n. Supramolecular cations (m-XAni+)(DB[18]crown-6) were constructed by a N–H+⋯O hydrogen-bonding interaction. [SMo12O402−] polyoxoanions were infinitely extended in three dimensions through a weak C–H⋯O hydrogen-bonding interaction with DB[18]crown-6. Disorder of the halogen atoms at the meta-position was observed in crystals 1, 2 and 3. The rotational freedom of the (m-XAni+) cations was suppressed because of weak interactions with surrounding molecules.

The electrical conductivity of mixed-valence [MoV2MoVI16O54(SO3)2]6− tetraalkylammonium salts was investigated through dependence on the inter-cluster distance that is controlled by tetraethylammonium, tetrapropylammonium, and tetrabutylammonium cations. The crystallographic analysis of single crystals revealed that the inter-cluster distances are dependent on the chain length of the alkyl groups on the counter cations. In addition, the electrical conductivities of the single crystals were found to be dependent on both temperature and chain length. Mixed-valence polyoxometalate (POM) clusters are considered to be a molecular particle of Mo bronze by which highly ordered networks will be developed using single crystals, where POMs are rather small and have a well-organized structure compared to colloidal nanostructures.

A new strategy for controlling the electron-accepting ability of an anthraquinone (AQ)-based π-molecular system is proposed to take advantage of intramolecular hydrogen bonding interactions. The electron-accepting properties of AQ are enhanced by the introduction of bulky arylsulfonamide groups into AQ derivatives due to the formation of effective intramolecular N–H⋯O hydrogen bonding interaction and stabilization of the anion radical state even in solution.

Simple organic salts based on aniline-derived cations and D-tartrate anions formed organogels and helical nanofibers. The organic salt (p-fluoroanilinium)(D-tartrate) was found to generate an organogel despite the absence of a hydrophobic alkyl chain, whereas (p-iodoanilinium)(D-tartrate) formed helical nanofibers in braided ropelike structures through a rolling-up process. The helicity of these nanofibers could be reversed by changing the growth solvent. The driving forces responsible for the formation of the nanofibers were determined to be 1D OH⋅⋅⋅O(-) hydrogen-bonding interactions between D-tartrate anions and π stacking of anilinium cations, as well as steric hindrance between the hydrogen-bonded chains.

The stereoselective synthesis of 1,2,3-triol derivatives having contiguous stereogenic centers from α,β-unsaturated acylsilanes 1 was described. The oxidation of an olefin moiety of 1 with osmium tetroxide proceeded smoothly to give the corresponding 2,3-syn-dihydroxyacylsilanes 2. The protection of two hydroxy groups of 2 followed by a nucleophilic reaction to the silyl carbonyl group gave the corresponding silylated triol derivatives (7 and 8) with high stereoselectivity, depending on the kind of nucleophilic reagents. The deprotection for 7 and 8 and the following protodesilylation gave two isomers of possible four 1,2,3-triol derivatives. The stereoselective triol synthesis by asymmetric diolization of α-silylated allyl alcohols 11 derived by nucleophilic addition to 1 was also investigated.

m-Fluorobenzoate (m-FBA), 2,3-difluorobenzoate (2,3-F2BA), m-methylbenzoate (m-MBA), and m-chlorobenzoate (m-ClBA) were introduced into the Cu(II) binuclear unit as bridging ligands between two Cu(II) sites, which were further connected by an axial pyrazine (pz) ligand to form one-dimensional coordination polymers of [Cu(II)2(m-FBA)4(pz)]∞ (1), [Cu(II)2(2,3-F2BA)4(pz)]∞ (2), [Cu(II)2(m-MBA)4(pz)]∞ (3), and [Cu(II)2(m-ClBA)4(pz)]∞ (4), respectively. The parallel arrangements of one-dimensional (1D) polymers result in 1D channels between the polymers that crystallization CH3CN molecules can occupy to form single crystals of 1·4CH3CN, 2·4CH3CN, 3·2CH3CN, and 4·2CH3CN. Both π–dimer and dipole–dipole interactions were simultaneously observed in the interchain interactions of m-FBA and/or 2,3-F2BA ligands in crystals 1 and 2. The sizes of the one-dimensional channels between the polymers are thus modulated according to the interchain interactions between the polar BA ligands. CH3CN molecules within the channels were easily replaced by H2O under ambient conditions. CO2 adsorption–desorption isotherms of crystals 1, 2, and 3 at 195 K indicated gate-adsorption with a hysteresis, whereas two-step gate-adsorption behavior was observed for CO2 in crystal 4. Temperature- and frequency-dependent dielectric responses were not observed in crystals 1–4 under vacuum conditions, whereas dielectric anomalies were observed around 290 K for crystals 1 and 2 with adsorbed CO2. CO2 desorption from the channels in crystals 1 and 2 activated the molecular motions of polar BA ligands and dielectric responses around 290 K, which were confirmed from CO2 adsorption–desorption isotherms around 290 K and differential scanning calorimetries under CO2 conditions.

4-Methylanilinium derivatives were used to introduce spaces for molecular rotation in crystals. The [Ni(dmit)2]− (dmit2– = 2-thioxo-1,3-dithiole-4,5-dithiolate) salts with supramolecular cations of dibenzo[18]crown-6 (DB[18]crown-6) and 4-methylanilinium derivatives, (4-methylanilinium+)(DB[18]crown-6)[Ni(dmit)2]− (1), (2-fluoro-4-methylanilinium+)(DB[18]crown-6)[Ni(dmit)2]− (2), and (3-fluoro-4-methylanilinium+)(DB[18]crown-6)[Ni(dmit)2]− (3) were synthesized. The potential energy curves for the molecular rotations of the cations in the crystals had double minimum shapes with maxima of 100, 210, and 230 kJ mol–1 for crystals 1, 2, and 3, respectively. Introduction of a methyl substituent at the p-position was effective in reducing the potential energy maxima. For crystals 2 and 3, large dielectric responses originating from the flip-flop motions of the cationic molecules were observed upon applying an AC voltage. The temperature-dependent magnetic susceptibilities of complexes 1, 2, and 3 followed the Cu...

Single crystal of supramolecuar cation salt (adamantylammonium+)2(benzo[18]crown-6)2[Pd(dmit)2]2−(acetone)2 were synthesized by an electrochemical crystallization. In the crystal, two supramolecular cations and two acetones and one [Pd(dmit)2]2− dianion were crystallographically asymmetric. Molecular rotation of adamantyl groups was suggested from anisotropic thermal factors in the X-ray analysis at 173 K.

Preparation and characterization of epitaxial growth of ZnO nanotip arrays are essential for field emission applications due to its high emission rate of electron and fast electron-transfer rate. At first, nanocrystalline ITO thin films were prepared on glass substrates by ion-beam sputter deposition (IBSD) method. ZnO seed layer was prepared on the ITO coated glass substrates by IBSD at room temperature, and then, ZnO nanotip arrays were epitaxially grown on the as-prepared ZnO seed layer coated ITO/Glass substrates by hydrothermal method. The surface morphology study confirmed that the ZnO nanotip array films were epitaxially grown on ITO/Glass substrates, and it clearly showed the formation of well-aligned ZnO nanotip arrays on ITO/Glass substrate. The as-prepared samples were annealed at different temperatures (100, 150 and 270 °C). After annealing, the surface morphology of ZnO nanotip arrays did not show any remarkable change. X-ray diffraction pattern of ZnO nanotip array films prepared on ITO/Glass showed a main peak at 2 θ = 34.3°, which corresponds to (0 0 2) plane. The photoluminescence spectra showed the strong intensity of UV emission and weak intensity of green emission. The J–V characteristic of Ag/NPB/PMMA/ZnO/ITO showed good rectification behavior.

Supramolecular assemblies of anilinium (Ani(+)) and fluoroanilinium derivatives (FAni(+)) with [18]crown-6 were introduced into electrically conducting [Ni(dmit)(2)] crystals (dmit(2-) is 2-thioxo-1,3-dithiole-4,5-dithiolate). The crystal structures, electrical conductivities, and magnetic susceptibilities of four new crystals of (Ani(+))([18]crown-6)[Ni(dmit)(2)](3) (1), (o-FAni(+))([18]crown-6)[Ni(dmit)(2)](3) (2), (m-FAni(+))([18]crown-6)[Ni(dmit)(2)](3) (3), and (p-FAni(+))([18]crown-6)[Ni(dmit)(2)](3) (4) were examined from the viewpoint of dynamic supramolecular rotator structures within the crystals. The crystal structures, electrical conduction, and magnetic properties were classified into group-I (crystals 1 and 4) and group-II (crystals 2 and 3). The hydrogen-bonding interaction between -NH(3)(+) and the oxygen atoms of [18]crown-6 formed the stand-up configuration of rotator-stator structures of (Ani(+))([18]crown-6) and (FAni(+))([18]crown-6) supramolecules. The potential energy barriers for the 2-fold flip-flop motion of phenyl- and p-fluorophenyl-rings in crystals 1 and 4 had a relatively small magnitude of ∼150 kJ mol(-1), suggesting that rotations of Ani(+) and p-FAni(+) cations around the C-NH(3)(+) axis occurred in the crystals. In contrast, a large magnitude of the potential energy barriers for the rotations of o-FAni(+) and m-FAni(+) cations in crystals 2 and 3 (>600 kJ mol(-1)) resulted in static supramolecular cationic structures. The cation:anion ratio of 1:3 in these crystals yielded a trimer π-stack of [Ni(dmit)(2)] with a semiconductor-like temperature dependence. The magnetic susceptibilities of the static crystals 2 and 3 were reproduced by the one-dimensional antiferromagnetic linear Heisenberg chain through the one-dimensional linear trimer arrangement. The magnetic susceptibilities of dynamic crystals 1 and 4 enhanced electron delocalization through the intratrimer and intertrimer interactions within the trimer stack, where the molecular rotations of Ani(+) and p-FAni(+) cations played an important role.

A two-dimensional (2D) layered Mg(II) coordination polymer (CP) with a high tolerance for H2 O was designed, synthesised, and crystallographically characterised. The synthesis was achieved by the introduction of a flexible 2D layered structure composed of Mg(II) ions and isonicotinate N-oxide ligands. Owing to its high H2 O tolerance, the obtained 2D layered structure has the flexibility to repeatedly adsorb a large amount of H2 O associated with interlayer expansion and enable the removal of H2 O from a H2 O/2-propanol mixed vapour. These results indicate that the CP could be an excellent dehydrating agent.

Polar crystals exhibiting second-order harmonic generation (SHG) were designed by adjusting the intermolecular interactions of mononuclear Cu(ii) complexes in which one H2O, two pyridines (py), and two p-substituted benzoate (p-RBA) ligands (R = F, Cl, Br, I, CH3, and OCH3) were coordinated to a Cu(ii) ion, forming a penta-coordinated asymmetric [Cu(ii)(p-RBA)2(py)2(H2O)] mononuclear structure with a permanent dipole moment along the direction of the Cu-OH2 coordination axis. Each asymmetric [Cu(ii)(p-RBA)2(py)2(H2O)] complex formed a polar one-dimensional hydrogen-bonded chain, [Cu(ii)(p-RBA)2(py)2(H2O)]∞, between the non-coordinated carboxylate oxygen atom of the p-RBA ligand and the hydrogen atom of the H2O molecule. The formation of a polar crystal depended on the arrangement of polar hydrogen-bonded chains; the parallel arrangement of each polar chain resulted in a polar crystal. The chemical design of the R group in the p-RBA ligand enabled tuning of the magnitude of the interchain interactions and crystal polarity; polar crystals were obtained using p-RBA ligands with R = Cl, Br, I, and OCH3. In contrast, apolar crystals were grown from complexes containing p-RBA ligands with R = F and CH3. In all crystals, a polar two-dimensional (2D) layer constructed from the parallel polar [Cu(ii)(p-RBA)2(py)2(H2O)]∞ chain arrangement was formed based on weak van der Waals C-H...(-)O- interactions between the hydrogen atom of py and the carboxylate oxygen atom of the p-RBA ligand. Weak interlayer halogen (X)...π and multipoint C-H...π interactions played important roles in forming parallel arrangements of polar 2D layers and polar crystals, but there were no effective intermolecular interactions between the polar 2D layers in apolar [Cu(ii)(p-FBA)2(py)2(H2O)] and [Cu(ii)(p-CH3BA)2(py)2(H2O)] crystals. The magnitudes of the interlayer interactions in the polar crystals were larger than those in the apolar ones because of the effective intermolecular interactions. The SHG intensities of the four polar crystals were approximately 0.7 times larger than that of sucrose.

Reactions exchanging the cation in (nBu4N)[Ni(dmit)2] to cis-cyclohexane-1,4-diammonium (cis-CHDA) in the presence of [18]crown-6, benzo[18]crown-6 (B[18]crown-6) and dibenzo[18]crown-6 (DB[18]crown-6) yielded crystals of the monovalent [Ni(dmit)2] complex, namely (cis-CHDA)([18]crown-6)2[Ni(dmit)2]2 (1), (cis-CHDA)(B[18]crown-6)2[Ni(dmit)2]2 (2) and (cis-CHDA)(DB[18]crown-6)2[Ni(dmit)2]2 (3). The two ammonium groups (–NH3+) of the cis-CHDA dication at axial and equatorial positions interact with oxygen atoms of the corresponding upper and lower crown ethers to form sandwich-type supramolecular cationic structures. The lateral [Ni(dmit)2]− anion arrangements through S–S contacts along the short and long axis of [Ni(dmit)2] anions were realised in crystals of 1, 2, and 3 by the asymmetrical cis-CHDA dication. The temperature- and frequency-dependent anisotropic dielectric constants of a crystal of 1 were evaluated along the a, b and c axes, where the thermally activated motion of the structurally flexible cis-CHDA dication was consistent with the dielectric responses.

[Ni(dmit)2]− salt (dmit2− 2-thioxo-1,3-dithiole-4,5-dithiolate) with flexible supramolecular cation (4-cyanomethylanilinium)(dibenzo[18]crown-6) has been synthesized and investigated its structure, magnetism and rotation. The comparable large steric hindrances limit the rotation of cyanomethyl group to result in no phase transition occurred. Magnetic and potential energy calculations by DFT method were consistent with the magnetic and structure measurements.

Single crystals formed from hydrogen-bonding supramolecular cations of o-aminoanilinium (HOPD+)–crown ethers, (HOPD+)([12]crown-4), (HOPD+)([15]crown-5), and (HOPD+)([18]crown-6), and one-electron-...

Structurally flexible trans-cyclohexane-1,4-diammonium (CHDA2+) forms a hydrogen-bonded sandwich-type supramolecule with benzo[18]crown-6 in (CHDA2+)(benzo[18]crown-6)2[Ni(dmit)2]2 (1) (dmit2–: 2-thioxo-1,3-dithiole-4,5-dithiolate). During the crystallization, the three crystal polymorphs 1a, 1b, and 1c were obtained in the space groups P21/c, P1, and P1, in which the orientation of the benzene rings of benzo[18]crown-6 in the sandwich-type supramolecular cations and the [Ni(dmit)2]− arrangements were different. Crystal 1c had a structural phase transition at ∼200 K, at which the unit cell volume of the low-temperature phase (1d) became twice that of the high-temperature phase (1c). The [Ni(dmit)2] π-dimer was observed in crystals 1a, 1b, 1c, and 1d. A double-minimum-type potential energy profile was observed for the rigid rotation of CHDA2+ around the N–N axis. Among four new crystals, the relatively low potential energy barrier of ∼120 kJ mol–1 for crystal 1b was consistent with the temperature- and f...

Hydrogen-bonded assemblies of the two-electron reduced mixed-valence Keggin clusters [PMo(12)O(40)](5-) and [SiMo(12)O(40)](6-) were obtained by the one-pot electron-transfer reactions between p-phenylenediamine (PPD) or 2,3,5,6-tetramethyl-PPD (TMPPD) (donors) and H(+)(3)[PMo(12)O(40)](3-) or H(+)(4)[SiMo(12)O(40)](4-) (acceptors) in CH(3)CN. The redox states of the [PMo(12)O(40)](5-) and [SiMo(12)O(40)](6-) clusters were confirmed by the redox titrations and electronic absorption measurements. In (HPPD(+))(3)(H(+))(2)[PMo(12)O(40)](5-)(CH(3)CN)(3-6) (1), the N-H ~ O hydrogen-bonded interactions between the monoprotonated HPPD(+) (or diprotonated H2PPD(2+)) and the [PMo(12)O(40)](5-) resulted in a windmill-like assembly and hydrophilic one-dimensional channels are formed with a cross-sectional area of 0.065 nm(2), and these are filled by the CH(3)CN molecules. Also, the CH(3)CN molecules in salt 1 were removed by immersing the single crystals of 1 into H(2)O, CH(3)OH, and C(2)H(5)OH solvents. In the compound, (HTMPPD(+))(6)[SiMo(12)O(40)](6-)(CH(3)CN)(6) (2), the N-H ~ O hydrogen-bonded interactions between the monoprotonated HTMPPD(+) molecules and the [SiMo(12)O(40)](6-) formed a "Saturn-ring"-like assembly. Each Saturn-ring was arranged into an hexagonally packed array via hydrogen-bonded and π-stacking interactions of HTMPPD(+), while the CH(3)CN solvent present in salt 2 are only found in the zero-dimensional isolated cavities.

A one-dimensional Cu(II) coordination polymer {[Cu(bpetha)(2,2′-bpy)(MeOH)]·2PF6}n (bpetha =1,2-bis(4-pyridyl)ethane; 2,2′-bpy =2,2′-bipyridine) with wide coordination space at the axial site was rationally synthesized and crystallographically characterized, in which [Cu(2,2′-bpy)] units are bridged by bpetha ligands, forming a one-dimensional zigzag chain that shows smooth adsorption for EtOH, MeOH, and H2O vapors.

The one-dimensional Zn(II) coordination polymer, {[Zn2(chdc)2(mepy)4]·6H2O}n (1⊃6H2O, chdc: trans-1,4-cyclohexanedicarboxylate and mepy: 4-methylpyridine), stabilized unique water aggregate, finite...

Using the Cu II -imidazole(Him) complex [Cu(Him) 4 Cl]Cl as the starting material, the imidazolate (im)- and azide-bridged Cu II coordination polymer [Cu 3 (Him) 4 (im) 2 (N 3 ) 4 ] n was successfully obtained. Single-crystal X-ray analysis revealed that it possesses an im-bridged linear-chain structure consisting of alternating dinuclear units with a symmetric end-on azide-bridged [Cu(μ 1,1 -N 3 ) 2 Cu] 2+ core and mononuclear units. All of the Cu ions adopt a square pyramidal geometry with an azide at the Jahn-Teller elongated apical position. Some of the azides act as end-to-end interchain bridging ligands from the mononuclear unit to the nearest neighbouring dinuclear unit of the adjacent chain forming a two-dimensional network. Temperature-variable magnetic susceptibility measurements showed that it exhibits one-dimensional ferrimagnetic-like behaviour, which can be ascribed to two types of exchange couplings with opposite signs, namely a weak ferromagnetic coupling through the end-on azide bridges within the dinuclear units and a stronger antiferromagnetic coupling through the im bridges between the di- and the mononuclear units.

Supramolecular cationic structures of (CHDA2+)(DCH[18]crown-6)2 were introduced into [Ni(dmit)2]− salts (where CHDA2+, DCH[18]crown-6, and dmit2− represent cis-cyclohexane-1,4-diammonium, meso-dicy...

Structurally flexible (1R,2R)-cyclohexanediammonium (CHDA(2+)) dication formed hydrogen-bonding supramolecules with [18]crown-6, benzo[18]crown-6 (B[18]crown-6), dibenzo[18]crown-6 (DB[18]crown-6), and dicyclohexano[18]crown-6 (DCH[18]crown-6) in [Ni(dmit)(2)](-) salts (dmit(2-) = 2-thioxo-1,3-dithiole-4,5-dithiolate). The two ammonium moieties of CHDA(2+) interacted with the crown ethers to form open-mouth-shaped sandwich-type cationic structures of (CHDA(2+))(crown ethers)(2), that is, (CHDA(2+))([18]crown-6)(2)[Ni(dmit)(2)](2)(-)() (1), (CHDA(2+))(B[18]crown-6)(2)[Ni(dmit)(2)](2)(-)() (2), (CHDA(2+))(DB[18]crown-6)(2)[Ni(dmit)(2)](2)(-)() (3), and (CHDA(2+))(DCH[18]crown-6)(2)[Ni(dmit)(2)](2)(-)() (4). The chiral structure of CHDA(2+) induced asymmetrical [Ni(dmit)(2)](-) arrangements in the crystals. A large frequency and temperature dependence of the dielectric response was observed in (CHDA(2+))(B[18]crown-6)(2), due to the pendulum motion of the cyclohexane ring along the nitrogen-nitrogen direction of CHDA(2+). Since the inversion center of the [Ni(dmit)(2)](-) arrangements was lost in the unit cell due to the chiral space group, the salts 1-4 showed rather complicated magnetic behaviors. The temperature-dependent magnetic properties of salts 3 and 4 were explained by the sum of the Curie-Weiss and singlet-triplet thermal excitation models, with positive (ferromagnetic) and negative (antiferromagnetic) magnetic exchange energies, respectively.

We investigated the molecular arrangement and surface morphology of organized molecular films of alkylammonium-M bis(1,3-dithiole-2-thione-4,5-dithiolate) ((dmit)(2), M = Ni, Au, and Pd) charge-transfer complexes using the surface pressure-area (pi-A) isotherm, polarized visible spectroscopy, in-plane and out-of-plane X-ray diffractions (XRD), and atomic force microscopy (AFM). Since Langmuir-Blodgett films of alkylammonium-M(dmit)(2) generally exhibit superconductivity, it may be possible to develop novel electronic molecular devices on the subnanometer scale. In the bulk state, several alkylammonium-M(dmit)(2) molecules could not form a highly ordered layered structure along the c-axis and a subcell structure of the alkyl chain in the ab-plane; however, almost all molecules formed a layered structure in the film multilayers. Monolayers of alkylammonium-M(dmit)(2) molecules on the water surface were extremely condensed. Out-of-plane and in-plane XRD measurements revealed that over a long period, systematic changes occurred in the two-dimensional lattice structure of alkylammonium-M(dmit)(2) molecules and not in their bulk state. These structural changes appear to be caused by enhancement of the van der Waals interaction among long hydrocarbons and the pi-pi interaction among (dmit)(2) units arranged two dimensionally. In addition, both the molecular arrangement and the structural morphology of the films showed dependence on the hydrocarbon chain length, number of long alkyl chains, and kind of central metal. In particular, the molecular arrangement of materials having didecyl chains changed drastically and (dmit)(2) units were highly oriented in the ab-plane. Such structural formations are suggested to significantly influence the stacking of functional dmit units presiding over the conductive properties.

We studied the thickness dependence of electronic structure and molecular orientation of neutral, square planar, diamagnetic diradical metal complex, bis( o -diiminobenzosemiquinonate) nickel(II) complexes (Ni(DIBSQ) 2 ), thin films grown on a SiO 2 substrate by using ultraviolet photoelectron spectroscopy in combination with metastable atom electron spectroscopy. We observed that the small hole-injection barrier of 0.46 eV for the monolayer film, and the barrier increases continuously with the film thickness and becomes larger than the electron-injection barrier. We further found that molecules are oriented with their long-axes nearly perpendicular to the surface both in the monolayer and multilayer films independent of the film thickness.

are of great interestbecause of their unique properties such as adsorption,separation, exchange, and catalysis, which are all associatedwith the presence of a functional nanospace. In this respect,polyoxometalate clusters, which are nanosized metal-oxidemacroanions built from molecular precursors with a range ofunique redox and acidic properties, are ideally suited for thedevelopment of functional nanospaces but have not yet beenthus explored.

Tetrathiafulvalenes (TTF) S-TTF and R-TTF having four chiral amide end groups self-organize into helical nanofibers in the presence of 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyano-p-quinodimethane (F(4)TCNQ). The intermolecular hydrogen bonding among chiral amide end groups and the formation of charge-transfer complexes results in a long one-dimensional supramolecular stacking, and the chirality of the end groups affects the molecular orientation of TTF cores within the stacks. Electronic conductivity of a single helical nanoscopic fiber made of S-TTF and F(4)TCNQ is determined to be (7.0+/-3.0)x10(-4) S cm(-1) by point-contact current-imaging (PCI) AFM measurement. Nonwoven fabric composed of helical nanofibers shows a semiconducting temperature dependence with an activation energy of 0.18 eV.

Charge-transfer (CT) complexes between ethylenedithio-substituted bis-TTF macrocycle 1a, as an amphiphilic electron donor, and 7,7,8,8-tetracyano-p-quinodimethane (TCNQ) derivatives, as electron ac...

We have developed a high temperature superconductor (HTS) micro SQUID magnetometer for molecular-based magnets. By employing the dipole approximation, we verified the flux value of 40Φ0 from the saturation magnetic moment of the ferrimagnetic microcrystal of [Mn2(H2O)2(CH3COO)][W(CN)8] · 2H2O (15 × 15 × 13 μm). Considering the relative arrangement of the sample and the SQUID loop, including the influence of the film and grease, the calculated the flux values were Φ = 71Φ0 and 31Φ0 at distances of 20 and 30 μm between the sample bottom face and the SQUID plane, respectively. Thus, the experimentally obtained flux value is reasonable.

A nonmagnetic compound, [NO2BzPy][Cu(mnt)2] (mnt2− = maleonitriledithiolate; NO2BzPy+ = 1-(4′-nitrobenzyl)pyridinium), is isostructural with [NO2BzPy][Ni(mnt)2], which is a quasi-1D spin system and exhibits a spin-Peierls-like transition with J = 192 K in the gapless state and spin energy gap = 738 K in the dimerization state, respectively. Further, five nonmagnetic impurity doped compounds [NO2BzPy][CuxNi1−x(mnt)2] (x = 0.04–0.74) were prepared, and their crystal structures as well as magnetic properties were investigated. The nonmagnetic doping causes the suppression of the spin transition with an average rate of 139(13) K/percentage of dopant concentration, and the transition collapse is estimated at around x > 0.5.

The chemistry of coordination polymers has been extensively advanced in recent decades, producing various architectures that are rationally constructed from a variety of molecular building blocks and interactions between them. Researchers have worked to create a diverse range of coordination frameworks and have raised the structural chemistry to a mature level. The next challenge is to explore their chemical and physical functionalities, which are associated with the microporous properties of frameworks. This review focuses on crystal structures and microporous properties of coordination polymers containing organic N-containing heterocyclic molecules as bridging ligands.

Fullerene derivative C60TT, which is substituted with the low-molecular-weight organogelator tris(dodecyloxy)benzamide, formed nanowire structures on application of the Langmuir-Blodgett (LB) method. The surface morphology of the C60TT LB film was dependent on the holding time before deposition at a surface pressure of 5 mN m(-1); it changed from a homogeneous monolayer to a bilayer fibrous structure via a fibrous monolayer structure, which was estimated to have dimensions of 1.2 nm in height, 8 nm in width, and 5-10 microm in length. From the structural and spectroscopic data, it is inferred that close packing of the fullerene moiety occurs along with intermolecular hydrogen bonding within the monolayer fibrous structure. The morphological changes in the LB film are explained kinetically by the Avrami theory, based on the decrease in the surface area of the monolayer at the air/water interface. The growth of the quasi-one-dimensional fibrous monolayer structures at holding times from 0 to 0.2 h is considered to be an interface-controlled process, whereas the growth of the quasi-one-dimensional bilayer fibrous structures from 0.2 to 18 h is thought to be a diffusion-controlled process.

The solvatochromic indicator [Cu(acac)(tmen)(H 2O)].PF 6 ( 1.H 2O) has been synthesized and crystallographically characterized. 1.H 2O binds an H 2O molecule at the Cu(II) axial site, while the PF 6 (-) anion is coordination free. The binding properties of [Cu(PF 6)(acac)(tmen)] ( 1) and [Cu(BF 4)(acac)(tmen)] ( 2) have been investigated in solution and the solid state. The donor number of the PF 6 (-) anion (DN PF6) was determined from the UV-vis spectra of 1 in 1,2-dichloroethane. The value of DN PF6 of the PF 6 (-) anion is slightly larger than that of the tetraphenylborate anion (BPh 4 (-)), which is known as a noncoordinating anion. In the solid state, 1 and 2 reversibly bind and release H 2O molecules at the Cu(II) axial sites. The coordinated H 2O molecules in 2 are more easily removed than those in 1 because of the strong Lewis basicity of the BF 4 (-) anion compared to the PF 6 (-) ion. The lower melting point of 1 versus 2 is attributed to the loose binding of the PF 6 (-) anions to the Cu(II) centers, which induces the dynamic nature of the crystal.

A solid-state molecular rotator comprising [18]crown-6 was assembled into a crystalline array of (Cs+)3([18]crown-6)3(H+)2[PMo12O40]5−, whereby two Cs+([18]crown-6) supramolecular rotators were complexed with a two-electron-reduced α-[PMo12O40]5− Keggin cluster. The size-compatible rotators of [18]crown-6 were directly complexed to an α-[PMo12O40]5− axle through Cs+−O interactions. The investigation of the dynamics of the system revealed that two rotation frequencies for [18]crown-6 were observed by using temperature-dependent 1H NMR studies, and these were dominated by intermolecular interactions in the solid state.

A charge-transfer complex between an amphiphilic bis(tetrathiafulvalene) (bis-TTF) annulated macrocycle (1) and 2,3,5,6-tetrafluoro-7,7,8,8-tetracyano-p-quinodimethane (F4-TCNQ), (12+)(F4-TCNQ-)2, which can form molecular-assembly nanowires by application of the Langmuir−Blodgett (LB) method, was hybridized with gold nanoparticles with an average diameter of 13 nm. LB films of (12+)(F4-TCNQ)2 were transferred onto a substrate surface from a subphase containing gold nanoparticles at concentrations ranging from 10-6 to 10-4 M, based on the number of gold atoms in the subphase (cAu). One-dimensional nanowires and zero-dimensional gold nanoparticles were found to coexist in films transferred onto mica by a single withdrawal from a subphase with cAu less than 1 × 10-5 M, whereas films transferred from a subphase with cAu greater than 1 × 10-4 M formed network structures of gold nanoparticles, which was confirmed by AFM measurements as well as electronic spectroscopy. The room-temperature electrical conductivit...

The design of new materials by directing the self-assembly of organic–inorganic hybrid molecular assemblies of polyoxometalate crown-ether complexes with supramolecular cations is reviewed with a particular focus on mixed-valence [PMo12O40]4− building blocks. Structurally configurable supramolecular cations of organic ammonium and crown ethers, i.e. protonated aromatic amines complexed by crown ethers are also outlined. The design principles for the one-electron reduced mixed-valence polyoxomolybdate cluster of [PMo12O40]4− are also deduced. The construction principles behind these assemblies and also the concept of using cluster-based “crowns” to complex the cations to extend the design concept further is discussed, especially in the development of inorganic crowns that could combine the properties of the electronically interesting building block along with the receptor building blocks.

Two new H-bonding molecular magnets based on [Ni(mnt) 2 ] − monoanion have been synthesized and characterized structurally. In crystal of 1 , [Ni(mnt) 2 ] − monoanions form the π-stacked sheets and the neighboring anionic sheets are held together via H-bonding interactions between –NH groups of diprotonated benzene-1,4-diamine and CN groups of mnt 2− ligands. In crystal of 2 , the neighboring anionic dimers form an anionic column via Ni…S contacting interactions, and these anionic stacks arrange into a sheet which is parallel to crystallographic ab -plane. The H-bonding interactions between diprotonated 1,4-diazabicyclo[2.2.2]octane cations and [Ni(mnt) 2 ] − monoanions as well as between cations and solvent MeCN molecules stabilize the lattice. Magnetic susceptibility measurement for 1 indicates an activated magnetic behavior in the high-temperature range together with a Curie tail at the lower temperature range, but the magnetic feature deviates from the magnetic exchange model for a spin dimer with S = 1/2. The magnetic nature of 2 reveals the presence of strongly antiferromagnetic interactions between the nearest-neighboring spins, the larger energy gap between spin ground and excited states results in a weakly paramagnetic property.

Two quasi-1D molecular magnets, [RBzPy][Ni(mnt) 2 ] (RBzPy + = 1-(4′-nitrobenzyl)pyridinium ( 1) and 1-(4′-brominobenzyl)pyridinium ( 2 ); mnt 2− = maleonitriledithiolate), are isostructural and possess a spin-Peierls-like transition at T c ≈ 184 K for 1 and ≈112 K for 2 at ambient pressure. The magnetic susceptibility measurements under different applied pressures disclosed two compounds exhibiting similar magnetic behaviors. For each compound, the spin transition shifts to higher temperature with pressure and the paramagnetism in high-temperature phase is suppressed. These trends seem to be explicable by the shortened distances induced by the pressure between magnetic [Ni(mnt) 2 ] − anions and thus leading to enhancements of antiferromagnetic interactions.