Showing papers by "Susumu Kitagawa published in 2005"
TL;DR: High levels of selective sorption of acetylene molecules as compared to a very similar molecule, carbon dioxide, onto the functionalized surface of a MOM are reported.
Abstract: Metal-organic microporous materials (MOMs) have attracted wide scientific attention owing to their unusual structure and properties, as well as commercial interest due to their potential applications in storage, separation and heterogeneous catalysis. One of the advantages of MOMs compared to other microporous materials, such as activated carbons, is their ability to exhibit a variety of pore surface properties such as hydrophilicity and chirality, as a result of the controlled incorporation of organic functional groups into the pore walls. This capability means that the pore surfaces of MOMs could be designed to adsorb specific molecules; but few design strategies for the adsorption of small molecules have been established so far. Here we report high levels of selective sorption of acetylene molecules as compared to a very similar molecule, carbon dioxide, onto the functionalized surface of a MOM. The acetylene molecules are held at a periodic distance from one another by hydrogen bonding between two non-coordinated oxygen atoms in the nanoscale pore wall of the MOM and the two hydrogen atoms of the acetylene molecule. This permits the stable storage of acetylene at a density 200 times the safe compression limit of free acetylene at room temperature.
1,301 citations
TL;DR: This tutorial review focuses on the hydrogen bonding type arrangements for dynamic porous coordination polymers exhibiting elastic guest accommodations, in contrast to rigid three-dimensional (3-D) frameworks.
Abstract: In a decade, many porous coordination polymers have been synthesized, providing a variety of properties ranging from storage, separation, exchange of guests in their cavities, magnetism, conductivity and catalysis by their frameworks. In this tutorial review, we focus on the hydrogen bonding type arrangements for dynamic porous coordination polymers exhibiting elastic guest accommodations, in contrast to rigid three-dimensional (3-D) frameworks. Such dynamic porous properties induce highly-selective guest accommodation and magnetic modulation, and could now be considered a new class of practical materials.
1,297 citations
TL;DR: Recently, flexible porous coordination polymers (3-17) have been synthesized, providing a variety of properties ranging from storage, separation and exchange of guests in their cavities, magnetism, conductivity and catalysis by their frameworks as discussed by the authors.
341 citations
TL;DR: A metal-organic honeycomb-like 2D pillared-bilayer open framework has been constructed which shows dynamic sponge-like single-crystal-to-single-Crystal transformation upon dehydration and rehydration.
Abstract: A metal−organic honeycomb-like 2D pillared-bilayer open framework has been constructed which shows dynamic sponge-like single-crystal-to-single-crystal transformation upon dehydration and rehydration. The dehydrated acentric nonporous phase transformed to the porous centric phase with the selective adsorbate concomitant with the structural transformation correlated with the single-crystal structure determination.
305 citations
TL;DR: In this paper, the first direct observation of elusive H2 molecules adsorbed in the nano-channels of a metal-organic porous material was made by the in situ synchrotron powder diffraction experiment of gas adsorption and by MEM (maximum entropy method)/Rietveld charge-density analysis.
Abstract: design and synthesis of high-performance hydrogenstorage materials. Although the weakest X-ray scattering amplitude of hydrogen made it difficult to determine their structure, we have succeeded in the first direct observation of elusive H2 molecules adsorbed in the nano-channels of a metal-organic porous material by the in situ synchrotron powder diffraction experiment of gas adsorption and by MEM (maximum entropy method)/Rietveld charge-density analysis [4]. The sample used in this study is microporous coordination polymer 1 with a pillared layer structure (CPL-1) with uniform ordered nano-channels of 4 Å × 6 Å. The in situ synchrotron powder diffraction experiment for hydrogen gas adsorption was carried out using the large Debye-Scherrer camera installed at beamline BL02B2. The hydrogen gas was dosed into the capillary sample through a stainless steel tube connected to the gas-handling system. The amount of adsorbed gas was controlled by adjusting the sample temperature under a constant hydrogen gas pressure of 102 kPa. The structure was investigated by MEM/Rietveld analysis [5]. The amount of H2 molecules adsorbed in CPL-1 at 90 K at 102 kPa was determined to be 0.3 molecules per Cu atom from the hydrogen adsorption isotherm. The reliability (R) factors based on the powder profile RWP and the Bragg integrated intensities RI were 2.45% and 3.33%, respectively. The cell parameters for CPL-1 with H2 gas were determined as a = 4.7101(1) Å, b = 20.0289(2) Å, c = 10.7704(1) Å, and β = 95.472(2)° (space group P21/c). The R factor based on the structure factors in the final MEM analysis RF was 1.86%. In the MEM charge density of CPL-1 without H2 molecules shown in Fig. 1(a), only the nano-channel structure was clearly seen and no electron density was observed in the nano-channels, even at lower electron-density levels. On the other hand, in the MEM charge density of CPL-1 with H2 molecules (Fig. 1(b)), the small peak maxima of the electron densities with an elongated shape distribution, which are due to the adsorbed H2 molecules, were observed in the nano-channels. It should be noted that the posit ion and orientation of the H2 molecules are mean values obtained by statistical analysis. The
205 citations
TL;DR: Two novel isomorphous porous frameworks of Ln(III) have been synthesized hydrothermally using multifunctional 4,5-imidazoledicarboxylic acid (imidc) as a connector and exhibit selective adsorption properties for H2O over N2, CO2 and MeOH.
179 citations
TL;DR: Two isomeric inorganic−organic hybrid materials formulated as [Cd2(OH)2(2,4-pyda)] (2, 4-pyridinedicarboxylate) have been hydrothermally synthesized via transformation of one-dimensional coordination chains formulated as[Cd(H2O)2, 2, 4 pyda] into threedimensional coordination polymers at different temperatures and characterized by crystallography.
Abstract: Two isomeric inorganic−organic hybrid materials formulated as [Cd2(OH)2(2,4-pyda)] (2,4-pyda = 2,4-pyridinedicarboxylate) have been hydrothermally synthesized via transformation of one-dimensional coordination chains formulated as [Cd(H2O)2(2,4-pyda)] into three-dimensional coordination polymers at different temperatures and characterized by crystallography.
141 citations
TL;DR: A variety of magnetic properties are obtained: 4, 5, and 9, which have the 4-carboxypyridinate bridge between magnetic centers, have weak antiferromagnetic interaction, whereas 7 and 8 with the carboxylate bridge between magnets reveal 1-d ferromagnetic behavior.
Abstract: By utilizing the novel metalloligand l(Cu), [Cu(2,4-pydca)(2)](2)(-) (2,4-pydca(2)(-) = pyridine-2,4-dicarboxylate), which possesses two kinds of coordination groups, selective bond formation with the series of the first-period transition metal ions (Mn(ii), Fe(ii), Co(ii), Cu(ii), and Zn(ii)) has been accomplished. depending on the coordination mode of 4-carboxylate with Co(ii), Cu(ii), and Zn(ii) ions, L(Cu) forms a one-dimensional (1-d) assembly with a repeating motif of [-M-O(2)C-(py)N-Cu-N(py)-Co(2)-]: {[ZnL(Cu)(H(2)O)(3)(DMF)].DMF}(N)() (2), [ZnL(Cu)(H(2)O)(2)(MeOH)(2)](N)() (3), and {[ML(Cu)(H(2)O)(4)].2H(2)O}(N)() (M = Co (4), Cu (5), Zn (6)). the use of a terminal ligand of 2,2'-bipyridine (2,2'-bpy), in addition to the cu(ii) ion, gives a zigzag 1-d assembly with the similar repeating unit as 4-6: {[Cu(2,2'-bpy)L(Cu)].3H(2)O}(N)() (9). on the other hand, for Mn(ii) and Fe(ii) ions, L(Cu) shows a 2-carboxylate bridging mode to form an another 1-d assembly with a repeating motif of [-M-O-C-O-CU-O-C-O-]: [ML(Cu)(H(2)O)(4)](N)() (M = Mn (7), Fe (8)). this selectivity is related to the strength of lewis basicity and the electrostatic effect of L(Cu) and the irving-williams order on the present metal ions. according to their bridging modes, a variety of magnetic properties are obtained: 4, 5, and 9, which have the 4-carboxypyridinate bridge between magnetic centers, have weak antiferromagnetic interaction, whereas 7 and 8 with the carboxylate bridge between magnetic centers reveal 1-d ferromagnetic behavior (Cu(II)-M(II); M(II) = Mn(II), J/k(B) = 0.69 K for 7; M(II) = Fe(II), J/k(B) = 0.71 K for 8).
135 citations
TL;DR: The first radical polymerisation of styrene in porous coordination polymers has been carried out, providing stable propagating radicals (living radicals), and a specific space effect of the host frameworks on the monomer reactivity is demonstrated.
134 citations
TL;DR: Two novel coordination polymers of Cu(II) have been synthesized and structurally characterized by changing only the pillar motifs, and it is revealed that both are weakly antiferromagnetically coupled.
Abstract: Two novel coordination polymers of Cu(II), viz. [Cu(bipy)(1,4-napdc)(H2O)2]n (1) and {[Cu(bpe)1.5(1,4-napdc)](H2O)}n (2) (bipy = 4,4‘-bipyridine; bpe = 1,2-bis(4-pyridyl)ethane; 1,4-napdc2- = 1,4-naphthalenedicarboxylate), have been synthesized and structurally characterized by changing only the pillar motifs. Both the compounds crystallize by slow evaporation from the ammoniacal solution of the as-synthesized solid. Framework 1 crystallizes in monoclinic crystal system, space group P2/n (No. 13), with a = 11.028(19) A, b = 11.16(3) A, c = 7.678(13) A, β = 103.30(5)°, and Z = 2. Framework 2 crystallizes in triclinic system, space group, P1 (No. 2), a = 10.613(4) A, b = 10.828(10) A, c = 13.333(9) A, α = 85.25(9)°, β = 82.59(6)°, γ = 60.37(5)°, and Z = 2. The structure determination reveals that 1 has a 2D network based on rectangular grids, where each Cu(II) is in 4 + 2 coordination mode. The 2D networks stacked in a staggered manner through the π−π interaction to form a 3D supramolecular network. In the...
94 citations
TL;DR: The intermolecular O-H...N hydrogen bonds and pi-pi stacking interactions further extend the complexes (except 1 and 6), forming 3D structures.
Abstract: To explore the relationships between the structures of ligands and their complexes, we have synthesized and characterized a series of metal complexes with two structurally related ligands, 9-acridinecarboxylic acid (HL1) and 4-quinolinecarboxylate acid (HL2), [Cu2(μ2-OMe)2(L1)2(H2O)0.69]n 1, [Cu2(L1)4(CH3OH)2] 2, [Cu3(L1)6(CH3OH)6]·3H2O 3, [Mn3(L1)6(CH3OH)6]·3H2O 4, [Co3(L1)6(CH3OH)6]·3H2O 5, [Cu(L2)2]n 6, [Mn(L2)2(H2O)]n 7, and [Co(L2)2(H2O)]n 8. 1 is a three-dimensional (3D) polymer with an interpenetrating NbO type network showing one-dimensional (1D) channels, whereas 2 and 3 take bi- and trinuclear structures, respectively, because of the differences in basicity of the reaction systems in preparing the three complexes. 4 and 5 have trinuclear structures similar to that of 3. In 1−5, ligand L1 performs different coordination modes with N,O-bridging in 1 and O,O‘-bridging in 2−5, and the metal ions also show different coordination geometries: square planar in 1, square pyramidal in 2, and octahedral i...
TL;DR: The title compound is generated, which contains the largest [Ni(mu(1,1)-N3)]6 circles in the discrete ferromagnetically-coupled M(II)-azide cluster family, and shows an unprecedented in situ cyanomethylation of ketone.
TL;DR: In this paper, a review highlights the recent progress of nanosize crystals based on coordination polymers (CP) and development of synthetic method with controllable size and shape in nanometer regime as well as...
Abstract: This review highlights the recent progress of nanosize crystals based on coordination polymers (CP). Development of synthetic method with controllable size and shape in nanometer regime as well as ...
TL;DR: In situ synchrotron powder X-ray diffraction measurements indicate that guest molecules are confined in a linear fashion to form crystalline-like regular ordered arrays, in contrast to the situation in the gas and liquid state, even at temperatures above the boiling point.
Abstract: Molecules and atoms confined in a nanospace may have properties distinctly different from those of the bulk fluid, owing to the formation of a specific molecular array characteristic of nanospace In situ synchrotron powder X-ray diffraction measurements have been used to observe confined guest molecules such as N2, O2, Ar, and CH4 in the well-regulated ultramicropore of a copper coordination polymer, 1 ([Cu2(pzdc)2pyz]: pzdc = 2,3-pyrazinedicarboxylate and pyz = pyrazine) The obtained crystal structures indicate that guest molecules are confined in a linear fashion to form crystalline-like regular ordered arrays, in contrast to the situation in the gas and liquid state, even at temperatures above the boiling point, and the ordered arrays are characteristic of the kind of gas molecule and the geometrical and potential properties of the ultramicropore of 1
TL;DR: The semiconducting film based on bis(o-diiminobenzosemiquinonate) nickel(II) complex showed uniaxial orientation structure along the normal to the substrate and good p-type metal-organic thin-film transistor (MOTFT) character.
Abstract: The semiconducting film based on bis(o-diiminobenzosemiquinonate) nickel(II) complex showed uniaxial orientation structure along the normal to the substrate and good p-type metal-organic thin-film transistor (MOTFT) character.
TL;DR: Two novel 3D isomorphous organic-inorganic hybrid frameworks have been hydrothermally synthesized and structurally characterized, and the magnetic results exhibit metamagnetic behaviour and a weak antiferromagnetic interaction, which are structurally correlated.
TL;DR: Azpy mediates pi-pi and pi-p interactions between these low-dimensional structures and is a good candidate for the construction of new assembling systems of coordination compounds through its aromatic interactions.
Abstract: Coordination compounds with a 4,4‘-azobis(pyridine) (azpy) ligand, {[M2(azpy)6(H2O)5]·4PF6·azpy·H2O}n (M = NiII (1) or CoII (2)) (0-dimensional (0-D) dimer), {[Zn(azpy)3(H2O)2]·2PF6·2azpy·4H2O}n (3...
TL;DR: A novel 2-D coordination polymer with honeycomb (6-3) net topology is constructed from a paramagnetic paddlewheel diruthenium tetrabenzoate, [RuII2(O2CPh)4], as a linear linker motif and triazine as a three-connected node.
TL;DR: Bilindiones and biladienones carrying aryl groups at the meso positions were prepared using coupled oxidation reactions of iron tetraarylporphyrins in 20-63% yield.
TL;DR: In this article, the molecular motions of methanol and aromatic molecules (benzene, toluence p -xylene) adsorbed in 1D nanochannels of 1D coordination polymers with paramagnetic metal ions have been studied by 2 H NMR together with X-ray crystallography NMR spectra at various temperatures.
Abstract: Molecular motions of methanol and aromatic molecules (benzene, toluence p -xylene) adsorbed in 1D nanochannels of pillared-layer coordination polymers with paramagnetic metal ions have been studied by 2 H NMR together with X-ray crystallography NMR spectra at various temperatures and Rietveld analyses of powder X-ray diffractions represented that the characteristic shape and periodic potential of each micropore confined guests in highly restricted motions and ordering even though the guests are physisorbed
TL;DR: The magnetic properties of O2 adsorbed in nanochannels of porous metal-organic solids CPL-1 and CPLp1 have been investigated by means of high-field magnetization process measurement.
Abstract: The magnetic properties of O2 adsorbed in nanochannels of porous metal-organic solids CPL-1 and CPL-p1 have been investigated by means of high-field magnetization process measurement. The contribution from adsorbed O2 shows the metamagnetic-like behavior in both compounds. We propose “the field-induced rearrangement mechanism” as the explanation for the metamagnetic-like behavior. It is known for the O2-O2 dimer that the magnetic interaction depends strongly on the intermolecular distance and the orientation of molecular axes. It is considered naturally that the stable arrangement with saturated magnetic moment in the sufficient high field is different from the H-structure which is stable at zero field.
TL;DR: Results indicate that proton-transferred hydrogen bonding plays an important role in constructing a highly ordered chiral assembly.
Abstract: Axial chirality was induced in biphenyldiol upon binding chiral amines with the efficiency of chiral induction much improved at low temperature. At low temperatures, two molecules of amine were bound to biphenyldiol. The value of the dissymmetric g-factor increased as proton-transferred hydrogen bonds formed between biphenyldiol and amine. These results indicate that proton-transferred hydrogen bonding plays an important role in constructing a highly ordered chiral assembly.
TL;DR: In this paper, Me2CO adsorption isotherms on 1 have a threshold pressure (Pth) for abrupt accommodation of molecules, which is regarded as the equilibrium pressure for the inclusion reaction of Me 2CO molecules.
Abstract: Thermogravimetry (TG) and Me2CO adsorption measurements for flexible porous crystalline coordination polymers with 2-dimensional (2-D) frameworks, {[Co(NCS)2(3-pia)2]·4Me2CO}n (1⊃4Me2CO, 3-pia=N-(3-pyridyl)isonicotinamide), were carried out. Taking advantages of capability of hydrogen bonding of amide groups for a dynamic properties, 1⊃4Me2CO show crystal (non-porous)-to-crystal (porous) structural rearrangement in Me2CO adsorption/desorption processes. The activation energy for the Me2CO desorption process of 1⊃4Me2CO was obtained using Flynn-Wall-Ozawa’s (FWO) method. The Me2CO adsorption isotherms on 1 have a threshold pressure (Pth) for abrupt accommodation of Me2CO molecules, which is regarded as the equilibrium pressure for the inclusion reaction of Me2CO
Journal Article•
TL;DR: The magnetic properties of O2 adsorbed in nanochannels of porous metal-organic solids CPL-1 and CPLp1 have been investigated by means of high-field magnetization process measurement as discussed by the authors.
Abstract: The magnetic properties of O2 adsorbed in nanochannels of porous metal-organic solids CPL-1 and CPL-p1 have been investigated by means of high-field magnetization process measurement. The contribution from adsorbed O2 shows the metamagnetic-like behavior in both compounds. We propose “the field-induced rearrangement mechanism” as the explanation for the metamagnetic-like behavior. It is known for the O2-O2 dimer that the magnetic interaction depends strongly on the intermolecular distance and the orientation of molecular axes. It is considered naturally that the stable arrangement with saturated magnetic moment in the sufficient high field is different from the H-structure which is stable at zero field.
TL;DR: In this article, the reactions of isonicotinic acid analogues, 4-quinoline carboxylic acid (HL1) and 9-acridine carboxyl acid (CARB) with M(NO3)2 in the presence of Et3N in MeOH (or EtOH) led to the formation of four new complexes, [Zn(L1)2(H2O)]∞======ForgeModLoader ]-
Abstract: The reactions of isonicotinic acid analogues, 4-quinolinecarboxylic acid (HL1) and 9-acridinecarboxylic acid (HL2) with M(NO3)2
(M = ZnII and CdII) in the presence of Et3N in MeOH (or EtOH) led to the formation of four new complexes, [Zn(L1)2(H2O)]∞
(1), [Zn(L2)2(MeOH)2]3·(H2O)1.5
(2) and [Cd(L2)2(MeOH)2]3·(H2O)1.5
(3) and [Cd(L2)2(EtOH)2]3·(H2O)0.5
(4). Single crystal X-ray diffraction analyses revealed that the ZnII and CdII complexes of the same ligand (L1 or L2) are isostructural, with 1 taking a 1D chain structure, with 2–4 being trinuclear complexes. In such complexes, the carboxylate groups adopt a bidentate syn,syn-bridging coordination fashion to bridge adjacent metal centers. The N donors do not take part in the coordination, but form O–H⋯N hydrogen bonds with the coordinated water or MeOH (or EtOH), leading to the formation of 3D frameworks. The effects of π–π stacking and the structural differences between these complexes and those with isonicotinic acid were also discussed.
TL;DR: The results presented in this manuscript clearly demonstrate that the complexes with ligand-unsupported Ru-Ru bonds can sensitively respond to redox reactions and ligand substituents on the basis of the greater degree of freedom in their molecular structures.
Abstract: A family of diruthenium complexes with ligand-unsupported Ru-Ru bonds has been systematically synthesized, and their crystal structures and physical properties have been examined. A simple, useful reaction between Ru 2 (OAc) 4 Cl (OAc- = acetate) and catechol derivatives in the presence of bases afforded a variety of diruthenium complexes, generally formulated as [Na n {Ru 2 (R 4 Cat) 4 }] (n = 2 or 3; R 4 = -F 4 , -Cl 4 , -Br 4 , -H 4 , -3,5-di-t-Bu, and -3,6-di-t-Bu; Cat 2 - = catecholate). The most characteristic feature of the complexes is the formation of short ligand-unsupported Ru-Ru bonds (2.140-2.273 A). These comprehensive studies were carried out to evaluate the effects of the oxidation states and the substituents governing the molecular structures and physicochemical properties. The Ru-Ru bond distances, rotational conformations, and bending structures of the complexes were successfully varied. The results presented in this manuscript clearly demonstrate that the complexes with ligand-unsupported Ru-Ru bonds can sensitively respond to redox reactions and ligand substituents on the basis of the greater degree of freedom in their molecular structures.
TL;DR: The complex clearly demonstrates first that the ligand-unsupported Ru-Ru bonds are essentially stabilized by the dianionic nature of the catecholate derivatives without any other bridging or supporting species and secondly that the redox potentials and absorption spectra of the complexes can sensitively respond to the countercations depending upon the polarity of the solvents.
Abstract: The molecular structures and physicochemical properties of diruthenium complexes with ligand-unsupported Ru−Ru bonds, generally formulated as [A2{Ru2(DTBCat)4}] (DTB = 3,5- or 3,6-di-tert-butyl; Cat2- = catecholate), were studied in detail by changing the countercations. First, the binding structures of the cations in a family of [{A(DME)n}2{Ru2(3,5-DTBCat)4}] (n = 2 for A+ = Li+ and Na+ and n = 1 for A+ = K+ and Rb+) were systematically examined to reveal the effects of the cations on the molecular structures and electrochemical properties. Second, the complex (n-Bu4N)2[Ru2(3,6-DTBCat)4] with a cation-free structure was synthesized using tetra-n-butylammonium cations. The complex clearly demonstrates first that the ligand-unsupported Ru−Ru bonds are essentially stabilized by the dianionic nature of the catecholate derivatives without any other bridging or supporting species. In contrast, the redox potentials and absorption spectra of the complexes can sensitively respond to the countercations depending u...
Patent•
22 Sep 2005
TL;DR: In this paper, the molar ratio of a metal ion, an organic compound, and a pillar ligand is 2:2:1 and a porous structure has regularly arranged pores of fixed size is preferable.
Abstract: PROBLEM TO BE SOLVED: To obtain an organometallic complex structure suitable as a new material in various fields including electron, magnetism, adsorption, catalyst, etc., a composite material, a membrane, a structure, a detection means such as a sensor, etc. SOLUTION: The organometallic complex structure comprises a metal ion, an organic compound to be combined with a metal ion, a pillar ligand to be combined with a metal ion and an organic polymer having interaction on a metal ion and has a porous structure. Embodiments in which the molar ratio of a metal ion, an organic compound and a pillar ligand is 2:2:1, an organometallic complex represented by formula a[M 2 Y 2 L] 2 -xH 2 O}n (M is a metal ion; Y is an organic compound; L is a pillar ligand; x and y are each an integer) is contained and a porous structure has regularly arranged pores of fixed size are preferable. COPYRIGHT: (C)2005,JPO&NCIPI
TL;DR: In this article, new hydrogen-bonding assemblies were synthesized from the reaction of a metalloligand, with a Fe II ion or an imidazole in an aqueous medium and crystallographically characterized.