Anthracite based activated carbon impregnated with HMTA as an effectiveness adsorbent could significantly uptake gasoline vapors

In this study, we synthesized and employed the amine impregnated activated carbon as an efficacious adsorbent for uptaking gasoline vapor. For this regard, anthracite as activated carbon source and hexamethylenetetramine (HMTA) as amine were selected and utilized. Physiochemical characterization of made sorbents were evaluated and investigated using SEM, FESEM, BET, FTIR, XRD, zeta potential, and elemental analysis. The synthesized sorbents provided an excellent textural features as compared with the literature and other activated carbon based sorbents and impregnated with amine. Our findings also suggested that in addition to high surface area (up to 2150 m² / g), the micro- meso pores created (Vmeso / V micro = 0.79 Cm ³ / g) surface chemistry may significantly affect the gasoline sorption capacity, which here the role of mesoporous is further highlighted. V meso for amine impregnated sample and free activated carbon was 0.89 and 0.31 Cm ³ / g, respectively. According to the results, the prepared sorbents have a potential capability in uptaking gasoline vapor and with line this, we report a high sorption capacity of 572.56 mg / g. After, four cycles used the sorbent had a high durability and about 99.11% of the initial uptake was maintained. Taking together the synthesized adsorbents as an activated carbon provided an excellent and unique features and enhanced gasoline uptake, therefore its applicability in uptaking gasoline vapor can be substantially considered.

Short X···N Halogen Bonds With Hexamethylenetetraamine as the Acceptor

Hexamethylenetetramine (HMTA) and N-haloimides form two types of short (imide)X···N and X-X···N (X = Br, I) halogen bonds. Nucleophilic substitution or ligand-exchange reaction on the peripheral X of X-X···N with the chloride of N-chlorosuccinimide lead to Cl-X···N halogen-bonded complexes. The 1:1 complexation of HMTA and ICl manifests the shortest I···N halogen bond [2.272(5) Å] yet reported for an HMTA acceptor. Two halogen-bonded organic frameworks are prepared using 1:4 molar ratio of HMTA and N-bromosuccinimide, each with a distinct channel shape, one possessing oval and the other square grid. The variations in channel shapes are due to tridentate and tetradentate (imide)Br···N coordination modes of HMTA. Density Functional Theory (DFT) studies are performed to gain insights into (imide)X···N interaction strengths (ΔE_int). The calculated ΔE_int values for (imide)Br···N (-11.2 to -12.5 kcal/mol) are smaller than the values for (imide)I···N (-8.4 to -29.0 kcal/mol). The DFT additivity analysis of (imide)Br···N motifs demonstrates Br···N interaction strength gradually decreasing from 1:1 to 1:3 HMTA:N-bromosuccinimide complexes. Exceptionally similar charge density values ρ(r) for N-I covalent bond and I···N non-covalent bond of a (saccharin)N-I···N motif signify the covalent character for I···N halogen bonding.

Mechanochemical synthesis and X-ray structural characterization of three 3-nitrophenol cocrystals with three aminal cage azaadamantanes: the role of the stereoelectronic effect on intermolecular hydrogen-bonding patterns

The structures of the cocrystalline adducts of 3-nitrophenol (3-NP) with 1,3,5,7-tetraazatricyclo[3.3.1.1^3,7]decane [HMTA, (1)] as the 2:1:1 hydrate, 2C₆H₅NO₃·C₆H₁₂N₄·H₂O, (1a), with 1,3,6,8-tetraazatricyclo[4.3.1.1^3,8]undecane [TATU (2)] as the 2:1 cocrystal, 2C₆H₅NO₃·C₇H₁₄N₄, (2a), and with 1,3,6,8-tetraazatricyclo[4.4.1.1^3,8]dodecane [TATD, (3)] as the 2:1 cocrystal, 2C₆H₅NO₃·C₈H₁₆N₄, (3a), are reported. In the binary crystals (2a) and (3a), the 3-nitrophenol molecules are linked via O-H...N hydrogen bonds into aminal cage azaadamantanes. In (1a), the structure is stabilized by O-H...N and O-H...O hydrogen bonds, and generates ternary cocrystals. There are C-H...O hydrogen bonds present in all three cocrystals, and in (1a), there are also C-H...O and C-H...π interactions present. The presence of an ethylene bridge in the structures of (2) and (3) defines the formation of a hydrogen-bonded motif in the supramolecular architectures of (2a) and (3a). The differences in the C-N bond lengths of the aminal cage structures, as a result of hyperconjugative interactions and electron delocalization, were analysed. These three cocrystals were obtained by the solvent-free assisted grinding method. Crystals suitable for single-crystal X-ray diffraction were grown by slow evaporation from a mixture of hexanes.

Efficient One-Pot Synthesis of a Hexamethylenetetramine-Doped Cu-BDC Metal-Organic Framework with Enhanced CO2 Adsorption

Herein we report a facile, efficient, low cost, and easily scalable route for an amine-functionalized MOF (metal organic framework) synthesis. Cu-BDC⊃HMTA (HMTA = hexamethylenetetramine) has high nitrogen content and improved thermal stability when compared with the previously reported and well-studied parent Cu-BDC MOF (BDC = 1,4-benzenedicarboxylate). Cu-BDC⊃HMTA was obtained via the same synthetic method, but with the addition of HMTA in a single step synthesis. Thermogravimetric studies reveal that Cu-BDC⊃HMTA is more thermally stable than Cu-BDC MOF. Cu-BDC⊃HMTA exhibited a CO₂ uptake of 21.2 wt % at 273 K and 1 bar, which compares favorably to other nitrogen-containing MOF materials.

Quinazoline-based multi-tyrosine kinase inhibitors: synthesis, modeling, antitumor and antiangiogenic properties

In this work the synthesis and the biological evaluation of some novel anilinoquinazoline derivatives carrying modifications in the quinazoline scaffold and in the aniline moiety were reported. Preliminary cytotoxicity studies identified three derivatives, carrying dioxygenated rings fused on the quinazoline portion and the biphenylamino substituent as aniline portion, as the most effective compounds. Further investigations revealed that these compounds exhibited antiproliferative activity on a wide panel of human tumor cell lines through the inhibition of both receptor and nonreceptor TKs. Furthermore, the compound bearing the dioxolane nucleus was also able to inhibit in vivo tumor growth. Molecular modeling of these compounds into kinase domain suggested that the phenyl group allows favorable interaction energies with the target proteins: this feature is favored by fused dioxygenated ring at the 6,7 positions, whereas free rotating functions do not allow the correct placement of the molecule, thus impairing the inhibitory potency. Finally, the biphenylamino derivatives, at noncytotoxic concentrations, acted as antiangiogenic agents both in in vitro and in vivo assays.