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NaNO3 -promoted MgO composite materials have been prepared and their ability to sorb CO2 at a concentration relevant to CO2 capture from flue gas is explored. The uptake kinetics and capacities of sorbents of different NaNO3 /MgO ratios are measured at intermediate temperatures of 230-300 °C. The sorbent with a NaNO3 /MgO ratio of 0.10 has the highest 12 h sorption capacity among sorbents with different NaNO3 loadings, and the highest sorption capacity of 11.2 mmol CO2 g-1 is observed at 260 °C. Intriguingly, an induction period is observed in the initial stage of CO2 sorption. In situ XRD analysis, in situ FTIR spectroscopy, and a comparison of the CO2 sorption behavior under simulated flue gas conditions in comparison to prior studies employing pure CO2 indicated that the sorption of CO2 occurred through nucleation of MgCO3 crystallites in the material. The data indicate that the concentration of CO2 within the molten medium of NaNO3 , which is affected by both the solubility of CO2 in molten NaNO3 and the partial pressure of CO2 in the surrounding atmosphere, has a critical impact on the length of the induction period. A partially desorbed sample after sorption of CO2 displays much-improved sorption kinetics in the next cycle and was able to sorb and desorb CO2 over multiple cycles at isothermal conditions by simply switching the feed gas from CO2 to inert gas.

9,9'-Spirobifluorene-based closo-o-carboranyl (SFC1 and SFC2) compounds and their nido-derivatives (nido-SFC1 and nido-SFC2) were prepared and characterized. The two closo-compounds displayed major absorption bands assignable to π-π* transitions involving the spirobifluorene group, as well as weak intramolecular charge-transfer (ICT) transitions between the o-carboranes and their spirobifluorene moieties. The nido-compounds exhibited slightly blueshifted absorption bands resulting from the absence of the ICT transitions corresponding to the o-carborane moieties due to the anionic character of the nido-o-carboranes. While SFC1 exhibited only high-energy emissions in THF at 298 K (only from locally excited (LE) states assignable to π-π* transitions on the spirobifluorene group), remarkable emissions in the low-energy region were observed in the rigid state such as in THF at 77 K and in the film state. SFC2 displayed intense emissions in the low-energy region in all states. The fact that neither of the nido-derivatives of SFC1 and SFC2 exhibited low-energy emissions and the TD-DFT calculation results of each closo-compound clearly verified that the low-energy emission was based on ICT-based radiative decay. The conformational barriers from each relative energy calculation upon changing the dihedral angles around the o-carborane cages for both compounds confirmed that the rotation of the o-carborane cages and terminal phenyl rings for SFC1 is freer than that for SFC2.

The effect of metal on the degree of flexibility upon evacuation of metal-organic frameworks (MOFs) has been revealed with positional control of the organic functionalities. Although Co-, Cu-, and Zn-based DMOFs (DMOF = DABCO MOF, DABCO = 1,4-diazabicyclo[2.2.2]octane) with ortho-ligands (2,3-NH2 Cl) have frameworks that are inflexible upon evacuation, MOFs with para-ligands (2,5-NH2 Cl) showed different N2 uptake amounts after evacuation by metal exchange. Considering that the structural analyses were not fully sufficiently different to explain the drastic changes in N2 adsorption after evacuation, quantum chemical simulation was explored. A new index (η) was defined to quantify the regularity around the metal based on differences in the oxygen-metal-oxygen angles. Within 2,5-NH2 Cl, the η value becomes larger as the metal are varied from Co to Zn. A large η value means that the structures around the metal center are less ordered. These results can be used to explain flexibility changes upon evacuation by altering the metal cation in this regioisomeric system.

A series of dimeric aluminum compounds [Al(OCMe2 CH2 N(R)CH2 X)]2 [X=pyridin-2-yl, R=H (PyrH ); X= pyridin-2-yl, R=Me (PyrMe ); X=furan-2-yl, R=H (FurH ); X= furan-2-yl, R=Me (FurMe ); X=thiophen-2-yl, R=H (ThioH ); X= thiophen-2-yl, R=Me (ThioMe )] containing heterocyclic pendant group attached to the nitrogen catalyze the coupling of CO2 with epoxides under ambient conditions. In a comparison of their catalytic activities with those of aluminum complexes without pendant groups at N [X=H, R=H (HH ); X=H, R=Me (HMe )] or with non-heterocyclic pendant groups [X=CH2 CH2 OMe, R=H (OMeH ); X=CH2 CH2 NMe2 , R=H (NMe2H ); X=CH2 CH2 NMe2 , R=Me (NMe2Me )], complexes containing heterocycles, in conjunction with (nBu)4 NBr as a cocatalyst, show higher catalytic activities for the synthesis of cyclic carbonates under the same ambient conditions. The best catalyst system for this reaction is PyrH /(nBu)4 NBr system, which gives a turnover number of 99 and a turnover frequency of 4.1 h-1 , making it 14- and 20-times more effective than HH /(nBu)4 NBr and HMe /(nBu)4 NBr, respectively. Although there are no direct interactions between the aluminum and the heteroatoms in the heterocyclic pendants, electronic effects combined with the increased local concentration of CO2 around the active centers influences the catalytic activity in the coupling of CO2 with epoxides. In addition, PyrH /(nBu)4 NBr shows broad epoxide substrate scope and seven terminal epoxides and two internal epoxides undergo the designed reaction.

The review includes scientific literatures published in the year of 2017 regarding the uses of biofilm and bioreactor to treat wastewater. Topics considered are: biofilm formation and factors that impact biofilm formation; extracellular polymeric substance from biofilms; biofilm consortia and quorum sensing; biofilm associated phage; biofilm reactors; and biofilm in bioelectrochemical systems.

A novel aluminum complex, [(naph)salen]AlMe [(naph)salen = N,N'-(2,3-naphthalene)bis(3,5-dimethylsalicylideneiminato)], has been synthesized and fully characterized by NMR spectroscopy, high-resolution mass spectrometry, elemental analysis, and single-crystal X-ray diffraction. The complex exhibits square pyramidal geometry around the aluminum center in the solid-state structure, and it has a trigonality parameter (τ) of 0.13. Comparison of the catalytic activity of [(naph)salen]AlMe with that of four related aluminum complexes containing tetradentate salen ligands with different bridging groups revealed that the naphthyl bridged salen-based aluminum complex, in conjunction with tetra(n-butyl)ammonium iodide as a cocatalyst, showed higher catalytic activity than the other complexes for the coupling of CO2 with epoxides under the mild conditions of room temperature and 5 bar of CO2 in 12 h. In addition, the new salen complex [(naph)salen]AlMe showed favorable features, such as requiring low catalyst loading (0.5 mol%) and broad epoxide substrate scope, including six terminal epoxides and three internal epoxides.

Homoleptic BAr3 (1) and heteroleptic Ar2BAr’ (2) (Ar=4-OMe-2,6-Me2-C6H2-, Ar′=3-Br-6-OMe-2,4-Me2-C6H-) have been selectively synthesized by the reaction between 4-bromo-3,5-dimethylanisole and BF3⋅OEt2 in the presence of n-BuLi. The selectivity of 1 and 2 was controlled by the sequential or in-situ reaction, respectively. The use of stronger base such as t-BuLi than n-BuLi gave only homoleptic 1 even in in-situ reaction. The solid state structure for 2 was confirmed by single crystal X-ray analysis. Especially, the emission of compound 2 showed a bathochromic shift of ca. 50 nm compared with that of compound 1. Both 1 and 2 exhibited significant solvatochromism of fluorescence.

A wide range of carboxylic acid derivatives including aldoximes, aldehydes, nitriles, primary amides, and carboxylic acid esters were reacted with various amines to form secondary and tertiary amides from a single cobalt catalyst. CoCl2/PPh3 was revealed as a universal, efficient catalyst for secondary or tertiary amide synthesis from a variety of starting materials. A two-step mechanism for the secondary amide synthesis from aldoximes was proposed and the substrate scope was intensively investigated. This study informs us about the reactivity of the cobalt catalyst with regards to carboxylic acid derivatives, along with the functional group tolerance of the substrates.

A monomeric aluminum complex containing aliphatic tetradentate ligand L1 (HOCMe2CH2NMeCH2CH2NMeCH2CMe2OH) was synthesized and used as a catalyst for cycloaddition between CO2 and epoxides in the presence of PPNCl as a cocatalyst. To check the effect of ligand L1, coordinated to the aluminum center, on the activity of cycloaddition, the new ligand HOCMe2CH2NMe2, which corresponds to half of L1, was systematically designed to make monomeric or dimeric aluminum complexes. Comparison of the catalytic properties of the aluminum complex containing the tetradentate ligand with those of the two related aluminum complexes containing the bidentate ligand under the same conditions revealed that the first system showed higher activity than the other two for cycloaddition between CO2 and epoxides in the presence of PPNCl, which was the best cocatalyst out of the six compounds nBu4PBr, nBu4NCl, nBu4NBr, nBu4NI, DMAP, and PPNCl.

The N-arylation of various amines with aryl chlorides proceeded in good-to-excellent yields in the presence of P[N{(p-NMe2)C6H4CH2}CH2CH2]3N (1e, a new electron-rich proazaphosphatrane ligand) and small amounts of Pd2(dba)3 (dba = dibenzylideneacetone). This catalytic system was also very effective for the synthesis of carbazoles.

Six zirconocene derivatives were systematically designed; one of the cyclopentadienyl (Cp) ligands of zirconocene dichloride [Cp2ZrCl2] was silylated and this group was then incrementally increased in size; furthermore, one derivative with a 4,4′-disilylbiphenyl bridge between the two zirconocene fragments was prepared. One zirconium complex was characterized by single-crystal X-ray analysis. All zirconium complexes were effective catalysts for the cycloaddition of CO2 to propylene oxide. Two complexes containing a biphenyl group attached to a SiMe2 group showed higher activity than the other complexes. In addition, the dinuclear complex containing the biphenylenebis(dimethylsilyl) bridge showed the highest activity among all the zirconium complexes reported. Furthermore, these complexes are the first examples of zirconocene catalytic systems for the cycloaddition reaction of CO2 to propylene oxide.

Aromatic aldehydes (I), aldoximes (VI), nitriles (VII), amides (VIII), and esters (IX) are converted into benzamides by reaction with primary or secondary amines.

Depending on temperature only, either double-N-arylated o-hydroxyanilines (III) or 2-arylated benzoxazoles (IV) are accessible.

An efficient Pd-catalyzed process for the Buchwald type amination of aryl chlorides with primary and secondary aliphatic and aromatic amines is described using a new and electron-rich proazaphosphatrane (PPT) as ligand.

The effect of a bis(proazaphosphatrane) ligand on the palladium-catalyzed direct α-arylation of nitriles with various aryl chlorides under mild conditions is reported. Comparisons of the catalytic properties of this ligand with those of three related mono(proazaphosphatrane)s under the same reaction conditions revealed that bis(proazaphosphatrane) displayed a synergistically enhanced activity. In the presence of the bis(proazaphosphatrane) ligand, ethyl cyanoacetate and primary as well as secondary nitriles were efficiently coupled with a wide variety of aryl chlorides that contained electron-rich, electron-poor, and electron-neutral groups.

Several titanium isopropoxides have facilitated the ring opening polymerization of l-lactide (LA) and rac-lactide in toluene solution at various polymerization temperatures via a coordination insertion mechanism. Depending on catalysts, the controlled/living poly(l-lactide), or the heterotactic-biased poly(rac-lactide) were obtained. The stereochemical microstructure of polylactide (PLA) was determined from homonuclear decoupled 'H NMR spectral studies. Such spectra of PLA derived from rac-LA featured the characteristic five-methine resonance pattern, whereas corresponding spectra derived from l-LA exhibited only one methine peak.

The tetrameric titanium alkoxide (MeC(CH 2 -μ 3 -O)(CH 2 -μ-O) 2 ) 2 Ti 4 (O-i-Pr) 10 (1) catalyzes the ring-opening polymerization (ROP) of lactide (LA) in toluene solution at various polymerization temperatures, and its bulk ROP at 130 °C. Compound 1 facilitated reasonably controlled polymerization characteristics via a coordination/insertion mechanism in solution, whereas the bulk polymerization products displayed broad molecular-weight distributions. The stereochemical microstructure of PLA was determined from homonuclear decoupled 1 H NMR spectroscopic studies.

A new type of half-metallocene catalyst for the polymerization of ethylene and styrene Cp * M((O) 3 O 9 Si 7 (c-C 5 H 9 ) 7 ) (M= Ti (1), Zr (2)) is prepared by the reaction of (HO) 3 O 9 Si 7 (c-C 5 H 9 ) 7 with Cp * MCl 3 in the presence of triethylamine. Complex 1 is stable to heat and air but heavier congener 2 is sligtly air sensitive. The catalytic systems 1/MMAO and 2/MMAO, in which MMAO is modified methylaluminoxane show good activities in ethylene polymerization, with that of 2/MMAO greater than that of 1/MMAO. Polyethylenes with bimodal molecular weight distributions were obtained. In addition, the catalytic system 1/MMAO shows fairly good activities for the syndiospecific polymerization of styrene.

Syndiospecific silyloxy-functionalized polystyrene with high molecular weight was prepared using a (pentamethylcyclopentadienyl)titanatrane/MMAO catalyst system. The resulting polymer is soluble in polar organic solvents such as THF and shows good thermal stability. In addition, the compound Ni(acac) 2 was used as a catalyst in preparing authentic atactic polymer of 4-tert-butyldimethylsilyloxystyrene under the same conditions. The chemical transformation of syndiospecific poly(4-tert-butyldimethylsilyloxystyrene) also gave a new polar polymer namely syndiotactic poly(4-hydroxystyrene) which is unattainable by traditional synthetic methods.

The title compounds are synthesized from the elements (Nb ampule, 1075 °C, 5 h, followed by annealing at 750 °C for 2 d).

The title compound is prepared from a stoichiometric mixture of the elements (sealed Nb ampule, 1080 °C, 5 h and 750 °C, 2 d) and characterized by single crystal XRD and TB-LMTO computations.

The title compound is prepared from a stoichiometric mixture of the elements (Nb ampule, Ar, 1085 °C, 5 h) and characterized by powder and single crystal XRD.