The reactions of Ln(NO(3))(3) (Ln = La, Er) with 1,4-phenylendiacetic acid (H(2)PDA) under hydrothermal conditions produce isostructural lanthanide coordination polymers with the empirical formula [Ln(2)(PDA)(3)(H(2)O)] x 2H(2)O. The extended structure of [Ln(2)(PDA)(3)(H(2)O)] x 2H(2)O consists of Ln-COO triple helices cross-linked through the [bond]CH(2)C(6)H(4)CH(2)[bond] spacers of the PDA anions, showing 1D open channels along the crystallographic c axis that accommodate the guest and coordinated water molecules. Evacuation of [Er(2)(PDA)(3)(H(2)O)] x 2H(2)O at room temperature and at 200 degrees C, respectively, generates [Er(2)(PDA)(3)(H(2)O)] and [Er(2)(PDA)(3)], both of which give powder X-ray diffraction patterns consistent with that of [Er(2)(PDA)(3)(H(2)O)] x 2H(2)O. The porosity of [Er(2)(PDA)(3)(H(2)O)] and [Er(2)(PDA)(3)] is further demonstrated by their ability to adsorb water vapor to form [Er(2)(PDA)(3)(H(2)O)] x 2H(2)O quantitatively. Thermogravimetric analyses show that [Er(2)(PDA)(3)] remains stable up to 450 degrees C. The effective pore window size in [Er(2)(PDA)(3)] is estimated at 3.4 A. Gas adsorption measurements indicate that [Er(2)(PDA)(3)] adsorbs CO(2) into its pores and shows nonporous behavior toward Ar or N(2). There is a general correlation between the pore size and the kinetic diameters of the adsorbates (CO(2) = 3.3 A, Ar = 3.40 A, and N(2) = 3.64 A). That the adsorption favors CO(2) over Ar is unprecedented and may arise from the combined differentiations on size and on host-guest interactions.

The design, synthesis, and structural characterization of two microporous metal–organic framework structures, [M(bdc)(ted)0.5]·2 DMF·0.2 H2O (M = Zn (1), Cu (2); H2bdc = 1,4‐benzenedicarboxylic acid; ted = triethylenediamine; DMF: N,N‐dimethylformamide) is reported. The pore characteristics and gas sorption properties of these compounds are investigated at cryogenic temperatures, room temperature, and higher temperatures by experimentally measuring argon, hydrogen, and selected hydrocarbon adsorption/desorption isotherms. These studies show that both compounds are highly porous with a pore volume of 0.65 (1) and 0.52 cm3 g– 1 (2). The amount of the hydrogen uptake, 2.1 wt % (1) and 1.8 wt % (2) at 77 K (1 atm; 1 atm = 101 325 Pa), places them among the group of metal–organic frameworks (MOFs) having the highest H2 sorption capacity. [Zn(bdc)(ted)0.5]·2 DMF·0.2 H2O adsorbs a very large amount of hydrocarbons, including methanol, ethanol, dimethylether (DME), n‐hexane, cyclohexane, and benzene, giving the highest sorption values among all metal–organic based porous materials reported to date. In addition, these materials hold great promise for gas separation.

Advancement in hydrogen storage techniques represents one of the most important areas of today's materials research. While extensive efforts have been made to the existing techniques, there is no viable storage technology capable of meeting the DOE cost and performance targets at the present time. New materials with significantly improved hydrogen adsorption capability are needed. Microporous metal coordination materials (MMOM) are promising candidates for use as sorbents in hydrogen adsorption. These materials possess physical characteristics similar to those of single-walled carbon nanotubes (SWNTs) but also exhibit a number of improved features. Here, we report a novel MMOM structure and its room-temperature hydrogen adsorption properties.

Separating the wheat from the chaff: The microporous metal–organic framework (MMOF) of [Cu(hfipbb)(H2hfipbb)0.5] is based on a bimetallic paddle‐wheel building block and comprises 1D tubular microchannels formed by the interpenetration of two identical 44 nets. The channels are hydrophobic and have the ideal size and shape to selectively adsorb C2, C3, and n‐C4 olefins and alkanes (see picture).

A novel guest-free metal organic framework (GFMMOF) is synthesized and structurally characterized. It contains one-dimensional close-packed open channels with a pore diameter of 4.5 A. It demonstrates a remarkable thermal stability, a unique ability to separate methanol from dimethyl ether or water, and is among the microporous MOFs having the highest adsorbed hydrogen density (0.054 g/cm3 at 77 K and 1 atm).

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Hydrothermal reactions of simple alkaline salts or their hydroxides with 3,5-pyrazoledicarboxylic acid (H(3)pdc) yielded seven new compounds. At a lower pH level three one-dimensional structures [Ca(Hpdc)(H(2)O)(4)].2H(2)O (1), [Ca(Hpdc)(H(2)O)(4)].H(2)O (2), and [Ba(H(2)pdc)(2)(H(2)O)(4)].2H(2)O (6) were obtained by evaporation of the solutions resulting from hydro(solvo)thermal reactions of MCl(2) (M = Ca, Ba) with H(3)pdc in water (1, 6) or in water/Et(3)N (2) at 150 degrees C for 3 days. Crystal structures of 1 and 2 contain zigzag chains of metal centers bridged by a single Hpdc(2-) ligand, whereas structure 6 consists of linear chains of metal centers bridged by two H(2)pdc(-) ligands. A dimer molecule [Sr(H(3)pdc)(H(2)pdc)(2)(H(2)O)(3)](2).2(H(3)pdc).4H(2)O (4) was obtained from a similar hydrothermal reaction using Sr(ClO(4))(2).6H(2)O instead of MCl(2). This compound contains [2+2] metallomacrocycles. At higher pH levels (pH = 4-6), the three-dimensional polymers [M(Hpdc)(H(2)O)] (Ca 3, Sr 5, Ba 7 ) were isolated by reactions of MCl(2) (M = Ca, Sr, Ba) with H(3)pdc in water/Et(3)N or in M(OH)(2) (M = Ca, Sr, Ba) with H(3)pdc in water under hydro(solvo)thermal conditions (150 degrees C, 3 days). Calcium and strontium are seven- and nine-coordinated in 3 and 5, respectively; barium is nine- and ten-coordinated in 7. It was observed that the increase in pH resulted in a higher connectivity level of ligands, which in turn leads to a higher dimensionality of the crystal structures. The correlation between the structures and pH values will be discussed. Crystal data: for 1, monoclinic, space group P2(1)/n (No. 14), with a = 8.382(2), b = 12.621(3), c = 11.767(2) A, beta = 98.91(3) degrees, Z = 4; for 2, 3, and 5, monoclinic, space group P2(1)/c (No. 14), Z = 4, a = 7.711(2), b = 15.574(3), c = 9.341(2) A, beta = 96.73(3) degrees, Z = 4 (2), a = 6.616(1), b = 12.654(3), c = 8.782(2) A, beta = 103.65(3) degrees, Z = 4 (3), a = 9.213(2), b = 12.088(3), c = 6.196(2) A, beta = 98.96(3) degrees (5); for 4 and 7, triclinic, space group P1 (No. 2), with a = 11.263(2), b = 11.460(3), c = 12.904(2) A, alpha = 71.54(3), beta = 98.96(3), gamma = 89.03(3) degrees, Z = 1 (4), a = 7.107(1), b = 9.780(2), c = 11.431(2) A, alpha = 74.69(3), beta = 73.39(3), gamma = 85.29(3) degrees, Z = 2 (7); for 6, monoclinic, space group C2/c (No. 15), with a = 20.493(4), b = 6.708(1), c = 15.939(3) A, beta = 123.56(3) degrees, Z = 4.

Simple inorganic salts are used to tune N‐containing conjugated microporous polymers (CMPs) synthesized by Buchwald–Hartwig (BH) cross‐coupling reactions. Poly(triphenylamine), PTPA, initially shows a broad distribution of micropores, mesopores, and macropores. However, the addition of inorganic salts affects all porous network properties significantly: the pore size distribution is narrowed to the microporous range only, mimicking COFs and MOFs; the BET surface area is radically improved from 58 m2 g−1 to 1152 m2 g−1; and variations of the anion and cation sizes are used to fine‐tune the surface area of PTPA, with the surface area showing a gradual decrease with an increase in the ionic radius of salts. The effect of the salt on the physical properties of the polymer is attributed to adjusting and optimizing the Hansen solubility parameters (HSPs) of solvents for the growing polymer, and named the Beijing–Xi'an Jiaotong (BXJ) method.