Stable CI3+ salts and attempts to prepare CHI2+ and CH2I+

The room-temperature stable CI3+ salts [CI3+[pftb](-)1 and [CI3]+[al-f-al](-) 2([pftb](-) = [Al(OC(CF3)3)4](-); [al-f-al](-) = [((CF3)3CO)3Al-F-Al(OC(CF3)3)3](-)) were prepared in quantitative yields from purified CI4 and the corresponding silver aluminates with total exclusion of light (NMR, IR, UV-VIS, X-ray diffraction). The isolated CI(3)(+) cation is trigonal planar with a sum of <(I-C-I) = 360.0 degrees (1) and 359.9 degrees (2). Attempts to prepare CHI2+ and CH2I+ salts from CHI3 or CH2I2/Ag[pftb] mixtures remained unsuccessful; the reaction with CH2I2 leads to the formation of the adduct [Ag(CH2I2)3]+[pftb](-)3, while for HCI3, dismutation with formation of 1 as well as 3 was observed. All particles were also calculated at the MP2/TZVPP level to predict the vibrational and electronic spectra as well as to calculate the Gibbs free energies of all reactions (DeltaG degrees , gas phase and CH2Cl2 solution). Quantum chemical calculations were also used to investigate the stability of the [pftb](-) anion against the electrophilic attack of the CX3+ and CHnX3-n+ cations (X = F-I, n = 1-3). The strength of the Lewis acidity of these cations and of the isoelectronic boron halides BX()and BHnX3-n have been established on the basis of their fluoride ion affinities (FIAs). The FIAs of the carbon and the boron containing compounds show opposite trends, with fluorinated halomethyl cations being stronger acids than their heavier congeners but iodinated holoboranes being stronger acids than their lighter homologues.     

Mutagenic, antimutagenic and antioxidant activities of a new polyphenolic and a flavonoid substances isolated from Anagallis monelli

A new polyphenolic natural substance: 2,5-dihydroxy-benzoic acid 3'-formyl-5'-hydroxy-phenyl ester (1), Anamighrinal and 3-(O-alpha-L-rhamnosyl) quercetin (2) have been isolated from the methanolic aerial part extract of the plant Anagallis monelli by chromatographic separation. Their structures have been deduced essentially by one and two NMR spectroscopic procedures and mass spectrometry. Antioxidant, mutagenic, antimutagenic activities, of the natural products were realised and positive results were recorded.     

Soft lithography using acryloxy perfluoropolyether composite stamps

This paper describes composite patterning elements that use a commercially available acryloxy perfluoropolyether (a-PFPE) in various soft lithographic techniques, including microcontact printing, nanotransfer printing, phase-shift optical lithography, proximity field nanopatterning, molecular scale soft nanoimprinting, and solvent assisted micromolding. The a-PFPE material, which is similar to a methacryloxy PFPE (PFPE-DMA) reported recently, offers a combination of high modulus (10.5 MPa), low surface energy (18.5 mNm(-1)), chemical inertness, and resistance to solvent induced swelling that make it useful for producing high fidelity patterns with these soft lithographic methods. The results are comparable to, and in some cases even better than, those obtained with the more widely explored material, high modulus poly(dimethylsiloxane) (h-PDMS).     

On the essential spectra of coupled operators matrix and application

We define an abstract setting to treat essential spectra of unbounded coupled operator matrix. We prove a well‐posedness result and develop a spectral theory which also allows us to prove an amelioration to many earlier works. We point out that a concrete example from integro‐differential equation fit into this abstract framework involving a general class of regular operator in L₁ spaces.     

On level-transitivity and exponential growth

We prove that if the group generated by an invertible and reversible Mealy automaton acts level-transitively on a regular rooted tree, then the semigroup generated by the dual automaton has exponential growth, hence giving a decision procedure of exponential growth for a restricted family of automaton (semi)groups.     

Microwave‐Assisted Direct Amidation of Ethyl 1‐Phenyl‐5‐hydroxy‐1H‐pyrazole‐4‐carboxylate

Microwave‐assisted treatment of ethyl 5‐hydroxy‐1‐phenyl‐1H‐pyrazole‐4‐carboxylate with excess primary aliphatic amines in 1‐propanol at 140°C and with excess pyrrolidine or piperidine in 2‐methoxyethanol at 180°C produced the corresponding carboxamides in good yields.     

Fiber optic probes for linear and nonlinear Raman applications – Current trends and future development

This review focuses on fiber optic probes for linear and nonlinear Raman spectroscopy, especially for medical applications. It aims at providing an overview over contemporary technology, recent first clinical trials, and helps identifying future developments necessary to bring the emerging technology to clinical end users. After a short introduction to linear and nonlinear Raman spectroscopic modalities, general design considerations will be discussed and compared to common fiber probe setups. Subsequently, examples for medical applications of fiber optic Raman probes will be given concentrating on probes for linear Raman spectroscopy as these devices are technologically more mature compared to their counterparts based on nonlinear Raman spectroscopy. The review also includes a brief summary of first multimodal fiber optic probes and highlights their benefits for clinical applications. Finally, probes are introduced which employ either nonlinear Raman spectroscopy or surface enhanced spectroscopy.