The Resource Utilization of Poplar Leaves for CO Adsorption.

Every late autumn, fluttering poplar leaves scatter throughout the campus and city streets. In this work, poplar leaves were used as the raw material, while HPO and KOH were used as activators and urea was used as the nitrogen source to prepare biomass based-activated carbons (ACs) to capture CO. The pore structures, functional groups and morphology, and desorption performance of the prepared ACs were characterized; the CO adsorption, regeneration, and kinetics were also evaluated.

Crystal Structure, Photophysical Study, Hirshfeld Surface Analysis, and Nonlinear Optical Properties of a New Hydroxyphenylamino Meldrum's Acid Derivative.

The structural, photophysical, and vibrational properties of a new hydroxyphenylamino Meldrum's acid derivative, 3-((2-hydroxyphenylamino)methylene)-1,5-dioxaspiro[5.5]undecane-2,4-dione (HMD), were studied. The comparison of experimental and theoretical vibrational spectra can help understand basic vibration patterns and provides a better interpretation of IR spectra.

The development of activated carbon from corncob for CO capture.

The accumulation and incineration of crop waste pollutes the environment and releases a large amount of CO. In this study, corncob crop waste was directly activated using solid KOH in an inert atmosphere to prepare porous activated carbon (AC) to capture CO, and to introduce N-containing functional groups that favour CO adsorption, urea was mixed with corncob and KOH to prepare N-doped AC. The physical and chemical properties of the AC were characterized, and the effects of the mass ratio of KOH and urea to corncob, the activation temperature and time as well as regeneration were investigated to explore the optimal preparation process.

Synthesis, Crystal Structures, and Density Functional Theory Studies of Two Salt Cocrystals Containing Meldrum's Acid Group.

Two salt cocrystals, CHNO () and CHNO (), were synthesized and their structures were determined by single-crystal X-ray diffraction. is made up of one (CHO) anion, one (CHN) cation, and one 5,6-dimethyl-1-benzo[]imidazole molecule. consists of one (CHN) cation and one (CHO) anion.

The dynamic CO adsorption of polyethylene polyamine-loaded MCM-41 before and after methoxypolyethylene glycol codispersion.

To reduce the cost of CO capture, polyethylene polyamine (PEPA), with a high amino density and relatively low price, was loaded into MCM-41 to prepare solid sorbents for CO capture from flue gases. In addition, methoxypolyethylene glycol (MPEG) was codispersed and coimpregnated with PEPA to prepare composite sorbents. The pore structures, surface functional groups, adsorption and regeneration properties for the sorbents were measured and characterized.

The further activation and functionalization of semicoke for CO capture from flue gases.

To systematically study CO adsorption performance, semicoke from the low-rank lignite was further activated and functionalized for CO capture from flue gases. The effect of the activation conditions, such as the activation temperature, activation time and HCl washing, and the tetraethylenepentamine (TEPA)-functionalization on CO adsorption were investigated; the pore structure and surface morphology of the semicoke under different activation conditions were characterized. Both the surface structure and adsorption performance of the activated semicoke could be improved under appropriate activation and acid-treatment conditions.

2,2-Dimethyl-5-(2,3,4-trimeth-oxy-benzyl-idene)-1,3-dioxane-4,6-dione.

The title compound, C(16)H(18)O(7), was prepared by the reaction of 2,2-dimethyl-1,3-dioxane-4,6-dione and 2,3,4-trimeth-oxy-benzaldehyde. The 1,3-dioxane ring is in a slightly distorted boat conformation. The crystal structure is stabilized by weak inter-molecular C-H⋯O hydrogen bonds.

5,5'-[(2,4-Dichloro-phen-yl)methyl-ene]bis-(2,2-dimethyl-1,3-dioxane-4,6-dione).

The title compound, C(19)H(18)Cl(2)O(8), was prepared by the reaction of 2,2-dimethyl-1,3-dioxane-4,6-dione and 2,4-dichloro-benzaldehyde in ethanol. The two 1,3-dioxane rings exhibit boat conformations. In the crystal, mol-ecules are linked by weak inter-molecular C-H⋯O and C-H⋯Cl hydrogen bonds, forming chains parallel to the a axis.

3-(2,4-Dichloro-benzyl-idene)-1,5-dioxa-spiro-[5.5]undecane-2,4-dione.

In the title mol-ecule, C(16)H(14)Cl(2)O(4), the 1,3-dioxane and cyclo-hexane rings exhibit distorted boat and chair conformations, respectively. In the crystal, a pair of weak inter-molecular C-H⋯O hydrogen bonds link the mol-ecules into an inversion dimer.

5-(3,4-Dimethyl-benzyl-idene)-2,2-dimethyl-1,3-dioxane-4,6-dione.

The title compound, C(15)H(16)O(4), was prepared by the reaction of 2,2-dimethyl-1,3-dioxane-4,6-dione and 3,4-dimethyl-benzaldehyde in ethanol. The 1,3-dioxane ring exhibits an envelope conformation. In the crystal, mol-ecules are linked by weak inter-molecular C-H⋯O hydrogen bonds, forming chains parallel to the b axis.

2,2-Dimethyl-5-[(5-methyl-furan-2-yl)methyl-idene]-1,3-dioxane-4,6-dione.

The asymmetric unit of the title compound, C(12)H(12)O(5), contains two independent mol-ecules. In each, the 1,3-dioxane ring adopts an envelope conformation with the dimethyl-substituted C atom forming the flap. The crystal structure is stabilized by weak inter-molecular C-H⋯O hydrogen bonds.

3-(4-Bromo-benzyl-idene)-1,5-dioxaspiro-[5.5]undecane-2,4-dione.

The title mol-ecule, C(16)H(15)BrO(4), was prepared by the reaction of (R)-2,4-dioxo-1,5-dioxaspiro-[5.5]undecane and 4-bromo-benzaldehyde with ethanol. The 1,3-dioxane ring exhibits a distorted boat and the fused cyclo-hexane ring exhibits a chair conformation.

3-(4-Fluoro-benzyl-idene)-1,5-dioxa-spiro-[5.5]undecane-2,4-dione.

In the title mol-ecule, C(16)H(15)FO(4), the fused 1,3-dioxane and cyclo-hexane rings exhibit a bath and a chair conformation, respectively. In the crystal, weak inter-molecular C-H⋯O hydrogen bonds link the mol-ecules into centrosymmetric dimers.

Synthesis, characterization, crystal structure and DFT studies on 3-(1H-benzo[d][1,2,3]triazol-1-yl)-1-(4-ethylphenyl)-1-oxopropan-2-yl-4-ethylbenzoate.

3-(1H-benzo[d][1,2,3]triazol-1-yl)-1-(4-ethylphenyl)-1-oxopropan-2-yl-4-ethyl-benzoate (BEOE) has been synthesized and characterized by elemental analysis, IR, UV-vis and fluorescence spectroscopy. Its crystal structure has also been determined by X-ray single crystal diffraction. For the title compound, density functional theory (DFT) calculations of the structure and vibrational frequencies have been performed at B3LYP/6-31G* level of theory.

(E)-2,2-Dimethyl-5-(3-phenyl-allyl-idene)-1,3-dioxane-4,6-dione.

The title compound, C(15)H(14)O(4), was prepared by the reaction of 2,2-dimethyl-1,3-dioxane-4,6-dione and (Z)-3-phenyl-acryl-aldehyde in ethanol. The dioxane ring is in a sofa conformation with the C atom bonded to the two methyl groups forming the flap. With the exception of the flap atom and the methyl group C atoms, all other non-H atoms are essentially planar, with an r.

3-(4-Meth-oxy-benzyl-idene)-1,5-dioxa-spiro-[5.5]undecane-2,4-dione.

In the title mol-ecule, C(17)H(18)O(5), which was prepared by the reaction of (R)-1,5-dioxaspiro-[5.5]undecane-2,4-dione and 4-meth-oxy-benzaldehyde with ethanol, the 1,3-dioxane ring is in a distorted envelope conformation with the spiro C atom forming the flap. The crystal structure is stabilized by weak inter-molecular C-H⋯O hydrogen bonds.

5-(4-Fluoro-benzyl-idene)-2,2-dimethyl-1,3-dioxane-4,6-dione.

The title compound, C(13)H(11)FO(4), was prepared by the reaction of 2,2-dimethyl-1,3-dioxane-4,6-dione and 4-fluoro-benz-alde-hyde in ethanol. The 1,3-dioxane ring adopts an envelope conformation. The crystal structure is stabilized by weak inter-molecular C-H⋯O hydrogen bonds.

5-(4-Hy-droxy-benzyl-idene)-2,2-dimethyl-1,3-dioxane-4,6-dione.

The title compound, C(13)H(12)O(5), was prepared by the reaction of 2,2-dimethyl-1,3-dioxane-4,6-dione and 4-hy-droxy-benz-alde-hyde in ethanol. The 1,3-dioxane ring is in a distorted boat conformation. In the crystal, inversion dimers linked by pairs of O-H⋯O hydrogen bonds generate R(2) (2)(20) rings.

2-(1H-Benzotriazol-1-yl)-1-(2-fluoro-benzo-yl)ethyl 4-methyl-benzoate.

In the crystal structure of the title compound, C(23)H(18)FN(3)O(3), inter-molecular C-H⋯N hydrogen bonds link the mol-ecules into chains extended along the c axis. The packing is further stabilized by weak C-H⋯O and C-H⋯F inter-actions. The F atom is disordered over two equally occupied 1- and 5-positions of the benzene ring.

3-[(5-Methyl-furan-2-yl)methyl-ene]-1,5-dioxaspiro-[5.5]undecane-2,4-dione.

There are two crystallographically independent mol-ecules in the asymmetric unit of the title compound, C(15)H(16)O(5). In each, the 1,3-dioxane ring is in an envelope conformation with the C atom common to the cyclo-hexane ring forming the flap. The dihedral angles between the five essentially planar [maximum deviations from the least-squares planes of 0.

2-(1H-Benzotriazol-1-yl)-1-(3-methyl-benzo-yl)ethyl benzoate.

In the title mol-ecule, C(23)H(19)N(3)O(3), the dihedral angles between the mean plane of the benzotriazole ring system and the benzene and phenyl rings are 9.67 (9) and 86.08 (10)°, respectively.

3-(2-Furylmethyl-ene)-1,5-dioxaspiro-[5.5]undecane-2,4-dione.

In the title mol-ecule, C(14)H(14)O(5), the 1,3-dioxane ring is in an envelope conformation with the ring C atom common to the cyclo-hexane ring forming the flap. The other five atoms of the 1,3-dioxane ring are essentially planar [maximum deviation from the least-squares plane = 0.041 (3) Å] and form a dihedral angle of 13.

2-Hydroxy-benzoic acid-purin-6-amine (3/1).

In the title 3:1 adduct, 3C(7)H(6)O(3)·C(5)H(5)N(5), an intra-molecular O-H⋯O hydrogen bond occurs in each of the three 2-hydroxy-benzoic acid mol-ecules. In the crystal, the components are linked by N-H⋯O and O-H⋯N hydrogen bonds.