Qigang Deng

Synthesis and physiochemical properties of novel gemini surfactants with phenyl-1,4-bis(carbamoylmethyl) spacer

A series of novel gemini surfactants, namely, phenyl-1,4-bis[(carbamoylmethyl) N,N-dimethylalkyl ammonium chloride)] (a, b and c), was synthesized systematically and characterized by FTIR, 1H NMR, 13C NMR and MS. The surface and bulk properties were evaluated by surface tension, conductivity, viscosity, dynamic light scattering (DLS) and transmission electron microscopy (TEM) measurements. These surfactants have been found to have low surface tension (γCMC) values as compared to other categories of gemini cationic surfactants, and they form vesicles in solutions at low concentrations. The DLS and TEM studies showed that the aggregations of the above mentioned surfactants changed from larger globular vesicles and smaller globular micelles to network aggregates and then to globular vesicles with an increase in the surfactant concentration. It is assumed that this unusual aggregation behavior is related to the transformation of the molecular conformation of phenyl-1,4-bis(carbamoylmethyl) spacer, along with its rigidity and hydrogen-bonding capability. The thermodynamic parameters of micellization process, namely, standard Gibbs free energy (ΔG0m), enthalpy (ΔH0m) and entropy (ΔS0m), were derived from conductivity measurements at different temperatures. The Krafft points of three gemini surfactants are very low.

4,4′,5,5′-Tetra­phenyl-3,3′-[methyl­idene­bis(sulfanedi­yl)]bis­(4H-1,2,4-triazole)

The asymmetric unit of the title compound, C29H22N6S2, contains one half-molecule situated on a twofold rotational axis. The two triazole rings form a dihedral angle of 27.6 (2)°. In the crystal, weak intermolecular C—H⋯N hydrogen bonds link the molecules into ribbons extending along [001].

A selective fluorescence probe for copper(II) ion in aqueous solution based on 4-(1,4,5-triphenyl-1H-imidazol-2-yl)anilinyl acetates

A novel fluorescent probe potassium 4-(1,4,5-triphenyl-1H-imidazol-2-yl)anilinyl acetate (PPIA) was designed and synthesized. It exhibited very strong sensitive, selective, and irreversible for Cu2+ over other commonly coexistent metal ions (Ca2+, Mg2+, Ni2+, Co2+, Cu+, Hg2+, Zn2+, Ba2+, Ag+, and Cd2+) in aqueous environment (pH 7.4). Moreover, according to the Job plot, 2:1 stoichiometry between PPIA and Cu2+ was deduced in aqueous media. A B3LYP/6-31 G(d) basis set was employed for optimization of PPIA and PPIA·Cu2+ complex.

A new on-fluorescent sensor for Ag+ based on benzimidazole bearing bis(ethoxycarbonylmethyl)amino groups

Abstract A new fluorescent sensor based on a benzimidazole unit bearing bis(ethoxycarbonylmethyl)amino groups was designed and synthesized. The ligand exhibits strong sensitivity and selectivity for Ag+ by enhanced fluorescent intensity in the presence of a wide range of other tested metal ions in methanol. The colorimetric and fluorescent response to Ag+ can be conveniently detected even by the naked eye, which offers a facile method for visual detection of Ag+.

Synthesis of Ni/Co/Al-layered triple hydroxide@brominated graphene hybrid on nickel foam as electrode material for high-performance supercapacitors

The determined need for a sustainable energy economy has evoked the increasing interest of researchers concerning the discovery of smart material designs of layered double hydroxide (LDH) nanocomposites for energy-based applications. This paper presents a novel method for the direct growth of brominated graphene and layered triple hydroxide (LTH) on 3D nickel foam (NF) as a supercapacitor electrode by a facile one-step in situ crystallization hydrothermal method. Subsequently, the as-synthesized NCA-L@BG-NF hybrids were characterized by TEM, SEM, HRTEM, XRD, FT-IR, RAMAN, XPS, and EDS. Moreover, the electrochemical performance disclosed that by fine-tuning the Ni/Co/Al mole ratios, it was possible to obtain optimized ratio of NCA-L@BG-NF-3 to display the maximum specific capacity of 1998 C g−1 at 6 A g−1, excellent rate capability of 75.3% at 20 A g−1, and excellent cyclic stability of ∼91% capacitance retention after 2000 cycles at 20 A g−1 with 100% coulombic efficiency. Furthermore, the greater electrochemical performance of LTH was achieved and synergistically strengthened with a high surface area provided by the conducting brominated graphene oxide framework directly grown on a 3D porous NF to form a binder-free electrode, which could improve the electrochemical performance in terms of charge transport and storage. Accordingly, these remarkable properties show that NCA-L@BG-NF-3 may be considered as a promising candidate for high-performance supercapacitor applications.

Microwave-assisted Michael addition of 2-amino pyridine to chalcones under catalyst-free conditions

A microwave-assisted, convenient, efficient, and catalyst-free procedure is described for the synthesis of 1,3-diphenyl-3-(pyridin-2-ylamino)propan-1-one derivatives by Michael addition of 2-aminopyridine to the chalcones. Short reaction times, simple reaction, easy of product isolation, high yields, and clean work-up are the advantages of this method.

Synthesis and characterization of heteroarylthio derivatives of 5,17-di-tert-butyl-11,23-diamido-25, 27-diprotected calix[4]arene

Abstract A series of 2-pyridylthio and 2-pyrimidinylthio derivatives of calix[4]arene have been synthesized and characterized by IR, 1H NMR, 13C NMR and MS.

Reformatsky reaction promoted by an ionic liquid ([Bmim]Cl) in the synthesis of β -hydroxyl ketone derivatives bearing a coumarin unit

A number of β-hydroxy-ketone derivatives bearing a coumarin unit have been synthesised by the Reformatsky reaction of formyl coumarin and α-bromoacetophenone in an ionic liquid (1-butyl-3-methylimidazolium chloride, [Bmim]Cl). The recovered ionic liquid can be reused at least five times without a significant reduction in yield. This procedure is green, mild and environmentally benign.