The physico-and electrochemical behaviors of a series of [WZn 3 (H 2 O) 2 (ZnW 9 O 34 ) 2 ] 12− (Zn−WZn 3 ) and its first-row transition-metalsubstituted analogues [WZn(TM) 2 (H 2 O) 2 (ZnW 9 O 34 ) 2 ] 12− (Zn−WZn(TM) 2 ; TM = Mn II , Co II , Fe III , Ni II and Cu II ) are reported. Various spectroscopic studies, including Fourier transform infrared (FTIR) spectroscopy, UV−visible spectroscopy, electrospray ionization (ESI)−mass spectrometry, and Raman spectroscopy, show similar spectral patterns in all sandwich polyoxometalates (POMs) because of their isostructural geometry and constancy of the overall negative charge (−12). However, the electronic properties highly depend on the transition metals at the "sandwich core" and correlate well with the density functional theory (DFT) study. Further, depending on the substituted TM atoms, there is a decrease in the highest occupied molecular orbital−lowest unoccupied molecular orbital (HOMO−LUMO) bandgap energy in these transition-metal-substituted POM (TMSP) complexes wrt Zn−WZn 3 , as confirmed by diffuse reflectance spectroscopy and DFT study. Cyclic voltammetry reveals that the electrochemistry of these sandwich POMs (Zn−WZn 3 and TMSPs) is highly dependent on the pH of the solution. Moreover, the dioxygen binding/activation studies of these polyoxometalates show that Zn−WZn 3 and Zn−WZnFe 2 have better efficiency toward dioxygen binding, as confirmed by FTIR spectroscopy, Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA), which is also reflected in their catalytic activity toward imine synthesis.

Sandwich polyoxometalate [WCo3(H2O)2(CoW9O34)2]12- (Co-WCo3) heterogenized with poly(vinyl butyl imidazolium) cation (PVIM+) acts as stable electrochemical water oxidation catalyst in 1 M KOH with 0.28 V@10 mA/cm2 overpotential and TOF of...

A well marked low resulting in active to vigorous monsoon conditions in Rajasthan during 15 to 17 July 1979 resulted in devastating flood in Luni Basin, western Rajasthan. Favourable antecedent moisture condition, geomorphological characteristics of this basin and breaches in the earthen dams worsened the flood situation.

In the current trends every organization manages work and its data online. Even though e-Commerce website maintaining data online in a distributed form. Online approach is very useful to collaborate with consumer and seller without any dependency of place and time. Every consumer can select product with any brand without wait for a time and produce the order for purchasing. Most of purchasing the product is done by using the website that produce some navigational or access pattern. This access pattern is utilized to produce some access rules. The projected Constraint based Closed Sequential Pattern Mining by using Self-Organizing Map Clustering (CBCSPMSC)approach principal comprises specific profile and GRC constraints for filtration of data among the duration and occurrence of article gap. Now applying closed pattern method for underrates the number of rules generation and execution time. At last SOM clustering method is implemented so that each item belongs the cluster for partial database scan not whole data with fewer execution time.