Density functional theory study of the Fourier transform infrared and Raman spectra of Cu(II) bis-acetylacetone

Fourier transform infrared and Fourier transform Raman spectra of Cu(II) bis-acetylacetone have been obtained. The geometry, frequency and intensity of the vibrational bands of this compound and its 1,5-(13)C(2), 3-(13)C, 1,3,5-(13)C(3), 2,4-(13)C(2), (18)O(2) and 2,4-(13)C(2)-(18)O(2) derivatives were obtained by the density functional theory (DFT) with the B3LYP functional and using the 6-31G(*) and 3-21G(*) basis sets. The calculated frequencies are compared with the solid infrared and Raman spectra. All the measured infrared and Raman bands were interpreted in terms of the calculated vibrational modes. The percentage of deviation of the bond lengths and bond angles gives a good picture of the normal modes, and serves as a basis for the assignment of the wavenumbers. Most computed bands are predicted to be at higher wavenumbers than the experimental bands. The calculated geometrical parameters show slight differences compared with the experimental results. These differences can be explained by the different physical state of Cu(II) bis-acetylacetone. The DFT-B3LYP calculations assumed a free molecule in the gas phase. Analysis of the vibrational spectra indicates a strong coupling between the chelated ring modes.     

Chemoselective tetrahydropyranylation of alcohols and phenols using polystyrene supported aluminium chloride as a catalyst

A simple, efficient and highly chemoselective method for tetrahydropyranylation of alcohols and phenols has been developed by their reaction with 3,4-dihydro-2H-pyran at room temperature in the presence of a catalytic amount of polystyrene supported AlCl₃. The method is also highly selective for monoprotection of symmetrical diols.     

Immobilized Vanadium Histidine and Tryptophan Schiff Base Complexes on Modified Magnetite Nanoparticles as Epoxidation Catalyst

In this study, magnetically recoverable vanadium complexs designated as VO(Sal-Tryp)/AmpSCMNPs and VO(Sal-His)/AmpSCMNPs were prepared through immobilization of Schiff bases of histidine or tryptophan with salicylaldehyde on the surface of modified silica coated iron oxide magnetite nanoparticles with (3-aminopropyl) trimethoxysilane as aminopropyl (Amp) spacer followed by complexation with VOSO₄. Characterization was carried out by chemical analysis, Fourier transform infrared spectroscopy, XRD, scanning electron microscopy and vibrating sample magnetometry techniques. VO(Sal-Tryp)/AmpSCMNPs and VO(Sal-His)/AmpSCMNP were found to catalyze the epoxidation of allyl alcohols and olefins with tert-butyl hydroperoxide with excellent conversions and selectivities. Investigation of the stability and reusability revealed the heterogeneity character of the catalyst with no desorption during the course of epoxidation reactions. High yields, clean reactions, easily catalyst separation and recyclability of the solid catalyst are some advantages of this method.     

Silica gel and polystyrene supported aluminum chloride as heterogeneous catalysts for the preparation of α‐aminophosphonates

Silica gel supported aluminum chloride (SiO₂‐AlCl₃) and cross‐linked polystyrene‐supported aluminum chloride (PS‐AlCl₃) are environment‐ friendly heterogeneous catalysts for the condensation of amines and aldehydes with diethyl phosphite to afford α‐aminophosphonates. These solid acid catalysts are stable (as bench top catalysts) and can be easily recovered and reused without appreciable change in their efficiency. © 2010 Wiley Periodicals, Inc. Heteroatom Chem 21:418–422, 2010; View this article online at wileyonlinelibrary.com . DOI 10.1002/hc.20629     

Synthesis of Tetraarylethene Luminogens by C−H Vinylation of Aromatic Compounds with Triazenes

Tetraarylethenes are obtained by acid-induced coupling of vinyl triazenes with aromatic compounds. This new C−H activation route for the synthesis of aggregation-induced emission luminogens is simple, fast, and versatile. It allows the direct grafting of triarylethenyl groups onto a variety of aromatic compounds, including heterocycles, supramolecular hosts, biologically relevant molecules, and commercial polymers.     

Comparative Study of the Supercapacitive Performance of Three Ferrocene-Based Structures: Targeted Design of a Conductive Ferrocene-Functionalized Coordination Polymer as a Supercapacitor Electrode

As redox-active based supercapacitors are known as highly desirable next-generation supercapacitor electrodes, the targeted design of two ferrocene-functionalized (Fc(COOH)₂) clusters based on coinage metals, [(PPh₃)₂AgO₂CFcCO₂Ag(PPh₃)₂]₂ ⋅ 7 CH₃OH (SC₁: super capacitor) and [(PPh₃)₃CuO₂CFcCO₂Cu(PPh₃)₃] ⋅ 3 CH₃OH (SC₂), is reported. Both structures are fully characterized by various techniques. The structures are utilized as energy storage electrode materials, giving 130 F g⁻¹ and 210 F g⁻¹ specific capacitance at 1.5 A g⁻¹ in Na₂SO₄ electrolyte, respectively. The obtained results show that the presence of Cu^I instead of Ag^I improves the supercapacitive performance of the cluster. Further, to improve the conductivity, the PSC₂ ([(PPh₃)₂CuO₂CFcCO₂]_∞), a polymeric structure of SC₂, was synthesized and used as an energy storage electrode. PSC₂ displays high conductivity and gives 455 F g⁻¹ capacitance at 3 A g⁻¹. The PSC₂ as a supercapacitor electrode presents a high power density (2416 W kg⁻¹), high energy density (161 Wh kg⁻¹), and long cycle life over 4000 cycles (93 %). These results could lead to the amplification of high-performance supercapacitors in new areas to develop real applications and stimulate the use of the targeted design of coordination polymers without hybridization or compositions with additive materials.