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Two new cadmium-containing Wells-Dawson polyoxometalates K8[α1-P2W17Cd(OH2)O61]•16H2O (α1-P2W17Cd) and K8[α2-P2W17Cd(OH2) O61]•16H2O (α2-P2W17Cd) were synthesized as aqueous soluble potassium salts. The cadmium-substituted complexes have been characterized by IR, 31P NMR, 113Cd NMR spectroscopy and cyclic voltametry (CV). Redox activities for the tungsten and cadmium centers have been observed by using cyclic voltammetry. It was found that the presence of cadmium decreases the electrocatalytic activity of the [α1-LiP2W17O61]9- and α2-[P2W17O61]10-heteropolyanions.

The synthesis of a new organic-inorganic nano-hybrid material [H 5 O 2 ][pip] 2.5 [SiMoV 2 W 9 O 40 ]. 7H 2 O (pip = Piperazine) (1) , in which piperazine is connected to a mixed-addenda Keggin structure of polyoxometalate by hydrogen bonding interaction, is reported. This nano-hybrid is characterized by single-crystal X-ray diffraction, fourier transform infrared (FT-IR), proton nuclear magnetic resonance ( 1 H NMR), powder X-ray diffraction (XRD), thermogravimetric analysis (TGA-DTA), field emission scanning electron microscopy (FESEM) and cyclic voltammetry (CV). Single crystal X-ray analysis reveals that compound 1 has been assembled by hydrogen bonding among polyoxometalate, piperazine and crystallization water units. In this compound, polyoxometalates are located in the cavities which are created by piperazine groups in the zigzag form. In addition, based on XRD and FESEM analyzes, the nano composition of compound 1 can be verified. Moreover, the electrochemical properties of 1 were perused, which represent that 1 has an appropriate electrocatalytic activity towards reduction of nitrate (NO 2 − ) ion attributed to the metal-center and piperazine units. [ABSTRACT FROM AUTHOR]

The article presents the study on the synthesis of symmetrical N,N′-alkylidene bis-amides which was catalyzed by a heteropolyacid. The study reportedly involved catalysts under mild and environmentally friendly conditions, condensation of benzaldehyde with benzamide. The results led to the development of a simple synthesis protocol for the compound.

Two new cadmium-containing Wells-Dawson polyoxometalates K8[α1-P2W17Cd(H2O)O61]⋅14H2O (α1-P2W17Cd) and K8[α2-P2W17Cd(H2O)- O61]⋅16H2O (α2-P2W17Cd) were synthesized as water-soluble potassium salts. The cadmium-substituted complexes were characterized by IR, 31P-NMR, 1113Cd-NMR spectroscopy and cyclic voltammetry (CV). Redox activities for the tungsten and cadmium centers were observed by cyclic voltammetry. It was found that the presence of cadmium decreased the electrocatalytic activity of the [α1-LiP2W17O61] and α2-[P2W17O61]10- heteropolyanions. [ABSTRACT FROM AUTHOR]

A convenient synthesis of sulfonamides and sulfonyl azides from thiols is described. In situ preparation of sulfonyl chlorides from thiols was accomplished by oxidation with chloramine-T (= N-chlorotosylamide= N-chloro-4-methylbenzenesulfonamide), tetrabutylammonium chloride (Bu4NCl), and H2O. The sulfonyl chlorides were then further allowed to react with excess amine or NaN3 in the same pot. [ABSTRACT FROM AUTHOR]

A new organic-inorganic hybrid consisting of Keggin-type polyoxometalate ([BW 12 O 40 5-) and imidazole, namely [H 5 O 2 [imi] 4 [BW 12 O 40 ·nH 2 O (imi = Imidazole) (1) , has been created under reflux state and identified through material identification devices like single crystal crystallography, FT-IR and 1H NMR spectroscopies, powder XRD, TG-DT Analysis, field emission SEM, elemental-analysis and cyclic voltammetry. Crystallography investigation exhibits that two main factors which are the numerous number of hydrogen bonding between organic and inorganic species and π-π stacking interaction between two adjacent imidazole rings a have crucial role in 1 formation. In addition, three types of imidazole exist in 1 structure in terms of different kind of hydrogen bonding among [BW 12 O 40 5- clusters and imidazole cations. Furthermore, the electrochemical and photochemical attributes of 1 have been considered, and the outcomes present that compound owns privileged electrocatalytic activity against the reduction of nitrite ions as well as an appropriate photochemical effect on methylene blue (MB) dye depredation. Because of the use of catalyst 1 in the form of modified carbon paste electrode (MCPE) to reduce nitrite ions, and of course its ability to recover and reuse repeatedly in the degradation of MB, this catalyst can be classified in green chemistry domain. Image 1 • This compound is a new organic-inorganic nano-hybrid. • Hydrogen bonding and π-π stacking interaction are two main factors in the formation of 1. • Compound 1 exhibits remarkable electrocatalytical activity on the nitrite reduction. • Hybrid 1 shows notable photocatalytical property on the methylene blue degradation. [ABSTRACT FROM AUTHOR]

The molybdenum heteropolyacid used in the presented protocol has the advantage to be non-corrosive, environmentally benign, and thermally stable. [ABSTRACT FROM AUTHOR]

Among the important needs of human societies is the elimination of environmental pollution and also the construction of high-performance and inexpensive biosensors. In this regard, the construction of multi-functional composites has been considered. A novel magnetic graphite carbon nitride decorated by tri-vanadium substituted Dawson-type heteropolytungstate nanocomposite (C 3 N 4 /Fe 3 O 4 @P 2 W 15 V 3) effectively synthesized and characterized by prevalent functional analysis. The prepared nano-catalyst presents bi-functional usage involving photocatalytic removal of dyes (methylene blue, congo red and phenyl red) (around 98%) under visible light radiation and greatly sensitive colorimetric sensing of cysteine in an aqueous media. Moreover, synthesized nano-catalyst successfully recovered five times without any considerable deficiency on its photocatalytic ability. Further, Moreover, we propose a novel method for cysteine detection based on the C 3 N 4 /Fe 3 O 4 @P 2 W 15 V 3 nanocomposite. This nanocomposite displayed a privileged catalytic feature for cysteine oxidation to extend a clock reaction of methylene blue as an indicator in the presence of NaBH 4 in acidic solution. More importantly, this colorimetric sensing method of cysteine presents an easy, low-cost, selective, and rapid colorimetric assay with a detection limit value of 7.2 μM in the acceptable linear range of 5–600 μM. [Display omitted] • The Preparation and characterization of a novel and green photocatalyst abbreviated g-C 3 N 4 /Fe 3 O 4 @P 2 W 15 V 3. • The g-C 3 N 4 /Fe 3 O 4 @P 2 W 15 V 3 has been used for the degradation of organic dyes. • The g-C 3 N 4 /Fe 3 O 4 @P 2 W 15 V 3 photocatalyst exhibits great recovery ability and photodegradation activity than pristine g-C 3 N 4. • Efficient colorimetric sensing of Cys with g-C 3 N 4 /Fe 3 O 4 @P 2 W 15 V 3 system. [ABSTRACT FROM AUTHOR]

Understanding the properties of ionic liquids confined into nano-pores is required to use ionic liquids for many applications such as electrolytes for energy storage in capacitors and solar cells. Recently, polyoxometalate ionic liquids have attracted much attention for their potential applications in electrochemistry, catalysis, and nanotechnology. In this work, we have performed MD simulations on 1-ethyl-3-methylimidazolium Keggin ([emim] 3 [PW 12 O 40 ]) confined into armchair (20,20) CNTs to study the thermal properties and melting process. Changes in the simulated results of configurational energy of confined polyoxometallate IL indicated that the melting range of the confined polyoxometalate IL is about 650-750 K. Heat capacity at constant volume of the confined IL is about 2 (cal K -1 mol -1 ) which shows sharp changes around the melting range. The average number of hydrogen bonds (〈HB〉) of the confined IL is about 2.8 which also presents sharp changes around the melting range. The ion conductivity and self-diffusion coefficient of [emim] 3 [PW 12 O 40 ] IL also present a sharp maximum of 25 (S m -1 ) and 6 × 10 -10 (m 2 s -1 ) at the melting point. Our results did not show a significant hysteresis in the melting process and therefore, the process is reversible. Our simulation also indicated that the confinement of the polyoxometallate IL into the CNT increases its thermal stability and melting point. Our simulations also indicated that the type of CNT configuration has a small effect on the melting point of the confined polyoxometallate IL., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)