Ludmila Scoles

Polymer nanosieve membranes for CO2-capture applications

Microporous organic polymers (MOPs) are of potential significance for gas storage, gas separation and low-dielectric applications. Among many approaches for obtaining such materials, solution-processable MOPs derived from rigid and contorted macromolecular structures are promising because of their excellent mass transport and mass exchange capability. Here we show a class of amorphous MOP, prepared by [2+3] cycloaddition modification of a polymer containing an aromatic nitrile group with an azide compound, showing super-permeable characteristics and outstanding CO(2) separation performance, even under polymer plasticization conditions such as CO(2)/light gas mixtures. This unprecedented result arises from the introduction of tetrazole groups into highly microporous polymeric frameworks, leading to more favourable CO(2) sorption with superior affinity in gas mixtures, and selective CO(2) transport by presorbed CO(2) molecules that limit access by other light gas molecules. This strategy provides a direction in the design of MOP membrane materials for economic CO(2) capture processes.

Green synthesis of tunable Cu(In1−xGax)Se2 nanoparticles using non-organic solvents

A green synthesis route of Cu(In1−xGax)Se2 nanoparticles with variable Ga content is described in this report for the first time. Only water and a minimum amount of energy input are used. Heating appropriate amounts of Cu, In, Ga and Se dispersed in an aqueous solution containing mercapto-acetic acid in a microwave oven gives rise to small and uniform nanoparticles. These new materials have been characterized to confirm composition, geometrical and structural properties. Transmission electron microcopy (TEM) confirmed size distribution around 4 nm. XRD confirmed the chalcopyrite structure with an average crystallite size of 3 nm. Atomic concentration and oxidation states of the different elements have been investigated using X-ray photoelectron spectroscopy (XPS). UV-visible absorption characterization confirmed the tunable optical properties of these materials. The proposed synthesis is scalable for commercial production with minimal environmental impact.

Precursors of quadruply bridging phosphorus monoxide ligands: synthesis and structural characterization of a new family of anionic fluoro and alkoxyphosphinidene clusters Ru5(CO)15(μ4-PR) (R = NiPr2, NCy2, F, OMe, OEt, OiPr): generation and structure of [H2NCy2][Ru5(CO)15(μ4-PO)]

A new family of phosphorus functionalized, pentanuclear ruthenium clusters Ru5(CO)15(μ4-PR) [R = NiPr2, NCy2, F, OMe, OEt, OiPr, O−] has been synthesized and representative compounds structurally characterized. The reaction of Ru4(CO)13(μ3-PNR2) (1) (R = Cy, iPr) with Ru3(CO)12 in refluxing heptane yields H2Ru3(CO)9(μ3-PNR2) (2) and Ru5(CO)15(μ4-PNR2) (3). An alternative high-yield synthesis for 3 is the reaction of 1 with Ru(CO)5 in refluxing hexane. Treatment of 3 with HBF4·Et2O produces Ru5(CO)15(μ4-PF) (4) in high yield. In contrast, refluxing 3 with HBF4·H2O in CH2Cl2 yields 4 and [R2NH2][Ru5(CO)15(μ4-PO)] (5), a cluster containing a μ4-phosphorus monoxide (PO) ligand. The reaction of 4 with alcohols affords the series of alkoxy phosphinidene cluster complexes Ru5(CO)15(μ4-POR′) (6) (R′ = Me, Et, iPR). The structures of 2a (R = NCy2), 3a (R = NCy2), 4 (R = F), and the phosphorus monoxide cluster [H2NCy2][Ru5(CO)15(μ4-PO)] (5a and 6a) (R′ = Me) have been determined by X-ray diffraction studies.

PREPARATION AND CHARACTERIZATION OF A NEW SERIES OF TI(III) HYDROBORATES SUPPORTED BY SILAZANATE LIGANDS

Abstract The synthesis and characterization of a new series of mono- and bis-borohydride Ti(III) complexes supported by amide ligands are described. The reaction of [(Me3Si)2N]2Ti(THF)Cl (1) with NaBH4 afforded the corresponding [(Me3Si)2N]2Ti(BH4)(THF) (3) complex in good yield. Attempts to form terminal hydride species by abstracting the BH3 group by treatment with a Lewis base,such as pyridine, led to ligand redistribution and formation of [(Me3Si)2N]Ti(py)2(BH4)2 (4). Complex 1 gave a desulfurization reaction with CS2 forming the diamagnetic dinuclear complex {[(Me3Si)2N]2Ti}2(μ-S) (5). The structures of 1, 3, 4 and 5 were elucidated by X-ray analysis. Crystal data are as follows. 1: C16H44Si4TiN2ClO, triclinic, P - 1 , a = 11.682(2), b = 15.991(3), c = 8.501(2) A , α = 94.25(2), β = 108.42(2), γ = 106.19(2)°, Z = 2, R = 0.054, R w = 0.045 ; 3: C16H48Si4TiN2BO, triclinic, P - 1 , a = 9.920(1), b = 17.847(2), c = 8.442(1) A , α = 90.283(9), β = 108.552(9), γ = 100.540(9)°, Z = 2, R = 0.042, R w = 0.053 ; 4: C16H36Si2N3B2, monoclinic, P2 1 /c, a = 11.569(2), b = 15.299(3), c = 13.486(4) A , β = 103.02(21)°, Z = 4, R = 0.042, R w = 0.046 ; 5: C30H86S2Ti2N4, monoclinic, C2/c, a = 16.895(1), b = 27.697(1), c = 11.6940(9) A , β = 105.457(9)°, Z = 4, R = 0.065, R w = 0.085 .

Superhydrophobic surfaces fabricated by spray-coating micelle solutions of comb copolymers

A series of comb copolymers (poly(arylene alkylene ether) (FPAE)-polystyrene (PS)) with a highly fluorinated FPAE main chain and narrow dispersed PS-grafted chains have been prepared. They are used to prepare micelle solutions in methanol/acetone (M/A) mixed solvents which are good for the FPAE main chains and poor for the PS-grafted chains. In these solutions, the PS-grafted chains form the cores and the FPAE main chains form the corona layers of micelle particles. Uniform micelle particles are achieved because of the narrow molecular weight dispersion of the PS chain length. The micelle solutions are spray-coated onto glass substrates to fabricate hydrophobic surfaces. It is found that the stability of the micelle particles increases with the length of the PS-grafted chains, which further influences the morphology and hydrophobicity of the spray-coated films. The effects of the M/A ratio and the copolymer concentration on the morphology and hydrophobicity of the coating surfaces are also studied. The results prove that a binary nano/microsurface structure is important to achieve a superhydrophobic surface with a low contact angle hysteresis. This binary structure is formed from conglomeration of micelle particles by spray coating the micelle solutions. The best sample reported in this paper has a static contact angle of 163° and a sliding angle of 5.9°. This fabrication procedure is facile, less time consuming, and easily applicable for large-scale surface treatment.

Synthesis, structure, bonding and reactivity in clusters of the lower phosphorus oxides

The chemistry of transition metal complexes of the lower phosphorus oxides has been reviewed with emphasis on cluster complexes of phosphorus monoxide (PO). Synthetic routes to complexes containing PO and related ligands are described, and spectroscopic and structural data for known PO complexes are reported and discussed.

Mixed nitrosyl/phosphinidene and nitrene/phosphinidene clusters of rutheniumElectronic supplementary information (ESI) available: experimental, preparation of compounds. See http://www.rsc.org/suppdata/cc/b1/b110927h

Reaction of the aminophosphinidene complex [Ru5(CO)15(mu 4-PNPri2)] 1 with [PPN][NO2] (PPN = Ph3P=N=PPh3) led to the mixed nitrosyl/phosphinidene cluster complex [PPN][Ru5(CO)13(mu-NO)(mu 4-PNPri2)] 2 which is transformed into the novel nitrene/phosphinidene cluster [Ru5(CO)10(mu-CO)2(mu 3-CO)(mu 4-NH)(mu 3-PNPri2)] 3 via treatment with triflic acid.