Direct synthesis of the 1,2,3-[C6H4P...P...P]- anion, isoelectronic with the indenyl anion [C6H4CH...CH...CH]-

The two products obtained from the reaction of 1,2-(PH(2))(2)C(6)H(4) with the mixed-metal base (n)BuLi-Sb(NMe(2))(3) in the presence of 12-crown-4, [Li(12-crown-4)(2)]+[C(6)H(4)P(3)]- (1) and {[Li(12-crown-4)(2)]+}3[Sb(11)]3- (2), represent thermodynamic sinks in which P-P and Sb-Sb bonding are maximized at the expense of P-Sb bonding, providing access to the 1,2,3-[C(6)H(4)P(3)]- phospholide anion.     

Fabrication of ferrocene functionalised ionic liquid/carbon nanotube nanocomposite modified carbon-ceramic electrode: application to the determination of hydrazine

A novel ionic liquid, 1-(ferrocenyl butyl)-3-methylimidazolium tetrafluoroborate (Fc-IL), was synthesised. The nanocomposite of Fc-IL and multi-walled carbon nanotubes (MWCNTs) was constructed and used for surface modification of carbon-ceramic electrode. The modified electrode was applied to the determination of hydrazine. Operational parameters such as pH of the solution, ionic liquid volume and amount of carbon nanotubes, which affect the analytical performance of the modified electrode, were optimised. The linear range of the modified electrode toward hydrazine concentration was 0.96–106.10 μg L^–1 with a detection limit of 0.64 μg L^–1 (S/N = 3). The modified electrode displayed high repeatability, reproducibility, long-term life time and low response time (<3 s). The applicability of this method was further tested by analysing the hydrazine content in boiler-feed water samples containing different concentrations of hydrazine and the results were in good agreement with the spectrophotometry method.     

Penta-P<Subscript>2</Subscript>X (X=C,Si) monolayers as wide-bandgap semiconductors: A first principles prediction

By means of density functional theory computations, we predicted two novel two-dimensional (2D) nanomaterials, namely P₂X (X=C, Si) monolayers with pentagonal configurations. Their structures, stabilities, intrinsic electronic, and optical properties as well as the effect of external strain to the electronic properties have been systematically examined. Our computations showed that these P₂C and P₂Si monolayers have rather high thermodynamic, kinetic, and thermal stabilities, and are indirect semiconductors with wide bandgaps (2.76 eV and 2.69 eV, respectively) which can be tuned by an external strain. These monolayers exhibit high absorptions in the UV region, but behave as almost transparent layers for visible light in the electromagnetic spectrum. Their high stabilities and exceptional electronic and optical properties suggest them as promising candidates for future applications in UV-light shielding and antireflection layers in solar cells.     

Modeling and optimization of simultaneous photocatalysis of three dyes on ceramic-coated TiO2 nanoparticles using chemometrics methods: phytotoxicological assessment during degradation process

In this paper, ceramic plates were used as a support of TiO₂ nanoparticles for photocatalytic decolorization of a mixture of three dyes. The three textile dyes (C.I. Basic Red 46, C.I. Basic Blue 3 and Malachite Green) were quantified simultaneously during the photocatalytic degradation process. The partial least squares modeling was successfully applied for the multivariate calibration of the spectrophotometric data. Also, the central composite design has been applied to the optimization of photocatalytic decolorization of the dye solution containing three dyes using an immobilized UV/TiO₂ process. The optimum initial concentration of three dyes, reaction time, and UV light intensity were found to be 5 mg/L, 240 min, and 47.2 W/m², respectively. The chronic phytotoxicity of mixture of dyes was evaluated using aquatic species Spirodela polyrhiza (S. polyrhiza) prior to and after photocatalysis. The phytotoxicity results revealed that the photocatalysis process could effectively reduce the phytotoxicity of the dyes from their aqueous solutions.     

Metal Template Synthesis of ‘Broken’ Aromatic Preorganized Terdentate Hosts for the Recognition of Lanthanide Tris-β-Diketonate Guests

The binding of the terdentate precursor 2,2′-(4-methyl-3,5-divinylpyridine-2,6-diyl)bis(1-allyl-5-bromo-1H-benzo[d]imidazole) ( 1 ) to the lanthanide container [Ln(hfac)₃] (Ln=La, Eu, Gd, Y, Er; H-hfac=1,1,1,5,5,5-hexafluoropentane-2,4-dione) ensures the cis-cis orientation of the two adjacent α,α′-diimine units that is required for the successful intramolecular Grubb ring-closing metathesis generating the target rigid 6-methyl-9,11-dihydro-1H,3H-2λ²,10λ²-pyrido[2,3-c:6,5-c′]bis(azepine) scaffold decorated with two terminal 5-bromo-1H-benzo[d]imidazole in ligand L7 . The bond valence analysis of the crystal structures of the associated nine-coordinate adducts [ L7 Ln(hfac)₃] (Ln=La, Eu, Gd, Er, Y) reveals a satisfying match between the rigid terdentate cavity and the size of the bound lanthanide metal, with a pronounced preference for the largest lanthanum cation. Thermodynamic studies in dichloromethane confirm the formation of [ L7 Ln(hfac)₃] adducts with unprecedented stabilities due to the removal of the energy penalty associated with trans-trans to cis-cis reorganization. The introduction of saturated methylene groups within the polyaromatic ligand backbone breaks extended aromatic delocalization and clears the visible part of the electromagnetic spectrum from emission arising from low-energy ligand-based excited states.