The reactivity of carbonic acid diesters in the presence of the amidine base DBU (1,8-diazabicyclo[5.4.0]undec-7-ene) has been investigated for the first time. Organic carbonates can be activated by DBU through the formation of N-alkoxycarbonyl ketene aminal 2 as the ultimate product. The latter species may form through deprotonation of the corresponding N-alkoxycarbonyl-amidinium cation 1 + by the amidine base. We have for the first time isolated and characterized,

No abstract

Indolenine-based croconaines are synthesized, their structure and solid state organization are investigated together with their electronic properties in thin-film transistors.

No abstract

No abstract

Fluorocarbon films using a monomer, 1H, 1H, 2H‐perfluoro–1‐dodecene were deposited in a continuous radio frequency (RF) glow discharge, the process was carried out in a parallel‐plate RF discharge onto stainless steel reactor in order to produce coating with a water‐and oil–repellent surface. Fourier‐Transform Infrared spectroscopy (FT‐IR) and X‐ray Photoelectron Spectroscopy (XPS) revealed that the films obtained contain mainly perfluoromethylene (CF2) species. Film wettability was tested using water and hydrocarbon liquids for contact angle measurements, furthermore surface energy was also calculated. Oil‐repellency was found to increase as the amount of CF2 species increases in the film structure. Film morphology was studied by Atomic Force Microscopy (AFM), films showing an usual morphology from that typical of Plasma Polymerised Fluorocarbon (PPFC) films. The combination of the low surface energy coating and the surface morphology produces materials which are both water and oil repellency.

No abstract

The crystal chemistry of Ti-rich trioctahedral micas of plutonic origin, cropping out at Black Hill (South Australia) has been investigated by combining electron microprobe analysis, single crystal X-ray diffraction, Mössbauer spectroscopy and X-ray photoelectron spectroscopy. Chemical analyses have shown the samples taken to be quite homogeneous and Ti-rich (TiO2 ≈ 7 wt.%). Mössbauer investigation yielded Fe2+/Fe3+ ≈ 30. X-ray photoelectron spectroscopy analysis seems to suggest the occurrence of three Ti species: octahedral Tr4+(60%), octahedral Ti3+(26%), and tetrahedral Ti4+(14%). The analyzed sample belongs to the 1M polytype and the relevant crystal data from structure analysis are: a = 5.347(1) Å, b = 9.261(2) Å, c = 10.195(2) Å, β = 100.29°(1). Anisotropic structure refinement was performed in space group C2/m, and converged at R = 2.62, Rw = 2.80. Structural details (the c cell parameter, the off-center shift of the M2 cation towards 04, the bond-length distortions of the cis-M2 octahedron, the interlayer sheet thickness, the projection of K−O4 distance along c*, the difference <K−O>outer-<K−O>inner) support the occurrence of the Ti-oxy substitution (VIR2+ + 2(OH)− ⇌ Ti4+ + 202− + H2) in the sample. Analysis of structural distortions as a function of the Ti content revealed that the positions of the oxygens 03 and 04 are displaced in opposite senses along [100]. This produces an enlargement of the M1 site with respect to the M2 site and a shortening of the interlayer distance. This trend seems to be in common with other Ti-rich 1M micas of plutonic origin.