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On the basis of the structure of the unimolecular Zn3(OAc)4–3,3′-bis(aminoimino)binaphthoxide complex, a poly-Zn3(OAc)4–3,3′-bis(aminoimino)binaphthoxide (poly-Zn) complex was prepared from 3,3′-diformylbinaphthol, tetramine, and Zn(OAc)2. The first-generation poly-Zn catalyst (poly-Zn1) was prepared from poly(aminoiminobinaphthol) and Zn(OAc)2. Although poly-Zn1 showed high catalytic activity for iodolactonization, the catalyst could not be reused. The second-generation poly-Zn catalyst (poly-Zn2) was prepared by the self-organization of 3,3′-diformylbinaphthol, tetramine, and Zn(OAc)2. This produced a stable and active poly-Zn2 catalyst for asymmetric iodolactonization that was reused over five cycles.

On the basis of the structure of the unimolecular Zn3(OAc)4–3,3′-bis(aminoimino)binaphthoxide complex, a poly-Zn3(OAc)4–3,3′-bis(aminoimino)binaphthoxide (poly-Zn) complex was prepared from 3,3′-diformylbinaphthol, tetramine, and Zn(OAc)2. The first-generation poly-Zn catalyst (poly-Zn1) was prepared from poly(aminoiminobinaphthol) and Zn(OAc)2. Although poly-Zn1 showed high catalytic activity for iodolactonization, the catalyst could not be reused. The second-generation poly-Zn catalyst (poly-Zn2) was prepared by the self-organization of 3,3′-diformylbinaphthol, tetramine, and Zn(OAc)2. This produced a stable and active poly-Zn2 catalyst for asymmetric iodolactonization that was reused over five cycles.

The growth mechanism of water clusters in carbon nanopores is clearly elucidated by in situ small-angle X-ray scattering (SAXS) studies and grand canonical Monte Carlo (GCMC) simulations at 293-313 K. Water molecules are isolated from each other in hydrophobic nanopores below relative pressures (P/P(0)) of 0.5. Water molecules associate with each other to form clusters of about 0.6 nm in size at P/P(0)=0.6, accompanied by a remarkable aggregation of these clusters. The complete filling of carbon nanopores finishes at about P/P(0)=0.8. The correlation length analysis of SAXS profiles leads to the proposal of a growth mechanism for these water clusters and the presence of the critical cluster size of 0.6 nm leads to extremely stable clusters of water molecules in hydrophobic nanopores. Once a cluster of the critical size is formed in hydrophobic nanopores, the predominant water adsorption begins to fill carbon nanopores.

Porous copolymer beads of 2,3-epoxypropyl methacrylate (glycidyl methacrylate, GMA) crosslinked with 2-ethyl-2-(hydroxymethyl)-propan-1,3-diol trimethacrylate (trimethylolpropane trimethacrylate, TRIM) were prepared with toluene and octan-2-one as porogens by suspension polymerization. With an increase in the ratio of porogen to monomer, the total pore volume of poly(GMA-co-TRIM) increases significantly, whereas the surface area hardly changes. The total pore volume also depends on the nature of the porogen, exhibiting a maximum at the larger GMA contents in the monomer mixture of 50% v/v with octan-2-one and of 60% v/v with toluene, compared to that at the GMA content of 25% v/v with a 9/1 v/v mixture of cyclohexanol and dodecan-1-ol [Verweij, P. D.; Sherrington, D. C. J Mater Chem 1991, 1 (3), 371]. The surface area decreases significantly with an increase in the ratio of GMA to TRIM, almost regardless of the nature of the porogen. The porous properties of poly(GMA-co-TRIM) was well explained on the basis of phase separation, particularly taking into account not only the solubility parameters of the resulting polymer network and porogen but also the rigidity of TRIM. The porous poly(GMA-co-TRIM) may be a promising polymer matrix of novel materials for separation of boron isotopes. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2374–2381, 2002

The metal-organic framework is synthesized and successfully employed as catalyst in the cross-coupling reaction of phenylacetylene with 2-oxazolidinone.

Coordination polymers (CPs) or metal-organic frameworks (MOFs) have attracted considerable attention because of the tunable diversity of structures and functions. A 4,4'-bipyridine molecule, which is a simple, linear, exobidentate, and rigid ligand molecule, can construct two-dimensional (2D) square grid type CPs. Only the 2D-CPs with appropriate metal cations and counter anions exhibit flexibility and adsorb gas with a gate mechanism and these 2D-CPs are called elastic layer-structured metal-organic frameworks (ELMs). Such a unique property can make it possible to overcome the dilemma of strong adsorption and easy desorption, which is one of the ideal properties for practical adsorbents.

This article reviews the structure, synthesis, host-guest reaction in aqueous phase, and ion-sieve and molecular-sieve properties of porous manganese oxide crystals. Tunnel and layered manganese oxides constitute a large family of porous materials having pore size from ultramicropores to mesopores. The manganese oxide crystals consist of MnO 6 octahedral units shared by corners and/or edges. They can be prepared by using various metal ions or organic surfactants as templates. The templates are extracted/inserted topotactically from/into the tunnels or interlayer spaces of the manganese oxides by two different mechanisms: redox-type and ion-exchange-type. These manganese oxides show excellent ion-sieve and molecular-sieve properties for the adsorptions of cations or organic molecules. The adsorptive selectivities are dependent on their structures.

Silica-pillared layered manganese oxides with high surface area and high thermal stability have been synthesized for the first time by the two step intercalation of octylamine followed by tetraethylorthosilicate into birnessite type manganese oxide.

Silica-pillared layered manganese oxide with high surface area and high thermal stability was first synthesized from birnessite(H)-type manganese oxide by intercalation of octylamine followed by tetraethyl orthosilicate (TEOS) molecules and then by solvothermal treatment in TEOS liquid. Layered phases of manganese oxide with basal spacings of 2.01 and 2.43 nm, respectively, were obtained for each intercalation reaction. The Si/Mn molar ratio increased from 0.63 to 0.84 by the solvothermal treatment, but the basal spacing (2.44 nm) of the layer barely increased. The increase of silica content stabilized the pillared structure against thermal treatment. Porous layered manganese oxides were obtained by heating the silica-pillared material at appropriate temperatures. The manganese oxide sample obtained at 400 °C had a BET surface area of 260 m2/g with a gallery height of about 1.6 nm between layers.

A study of the electronic structure and chemical bonding of the Li ions and protons inserted in manganese oxides was performed by a first-principles molecular-orbital method using model clusters (M...

Direct α-hydroxylation of ketones using molecular oxygen was accomplished by organic–inorganic hybrid polymers. A newly prepared Cu-piperazine hybrid polymer was tolerant to the basic conditions, a...

Quantum sieving of activated carbon fibers (ACFs) and their fluorides was observed for H(2) and D(2) adsorption at 20 K. Fluorination reduced the slit-shaped pore width of ACFs by 0.2 nm. The activated carbon fibers can act as highly efficient quantum sieves for H(2) and D(2), because the effective size of an H(2) molecule is larger than that of a D(2) molecule due to the uncertainty principle and the molecular size difference between H(2) and D(2) is significant in the micropore space. The D(2)/H(2) selectivity of ACFs evaluated by ideal adsorption solution theory was larger than that of the fluorinated ACFs.

Oxidation of silyl enolates was found to be smoothly catalyzed by [Cu(bpy)(BF4)2(H2O)2(bpy)]n (bpy = 4,4′-bipyridine) under molecular oxygen, and provided the corresponding α-hydroxy carbonyl compo...

A new type of adsorbent, MnO2·0.5H2O, was synthesized from Li1.6Mn1.6O4 followed by acid treatment. The hydrothermal reaction of monoclinic type γ-MnOOH with LiOH solution at 120 °C resulted in a H+/Li+ ion exchange, giving orthorhombic LiMnO2. The orthorhombic LiMnO2 was transformed to cubic Li1.6Mn1.6O4 (Li2Mn2O5) at a temperature higher than 400 °C. The conversion of Li1.6Mn1.6O4 to MnO2·0.5H2O by acid treatment resulted in contraction of the lattice constant a0 from 8.14 to 8.05 A with little dissolution of manganese. The new adsorbent showed a markedly high ion-exchange capacity (7.5 mmol/g) for lithium ions due to its ion-sieve property. The pH titration study suggested the formation of large numbers of uniform sorption sites having relatively high acidity. The uptake of Li+ ions from lithium-enriched seawater was found to be 5.3 mmol/g (37 mg/g), which is the maximum among the adsorbents studied to date.