A method for obtaining in situ external reflectance infrared spectra in strongly acidic solutions using fluorite windows

We report a simple method that allows to obtain external reflectance infrared spectra in strongly acidic solutions using a fluorite window without damaging it. The method is demonstrated by measuring the infrared spectra of carbon monoxide adsorbed on a nickel electrode in 7.5% and 28% aqueous HCl solutions.     

Pentagrams and Paradoxes

Klyachko and coworkers consider an orthogonality graph in the form of a pentagram, and in this way derive a Kochen-Specker inequality for spin 1 systems. In some low-dimensional situations Hilbert spaces are naturally organised, by a magical choice of basis, into SO(N) orbits. Combining these ideas some very elegant results emerge. We give a careful discussion of the pentagram operator, and then show how the pentagram underlies a number of other quantum “paradoxes”, such as that of Hardy.     

Zr(IV) and Hf(IV) β-diketonate complexes as precursors for the photochemical deposition of ZrO2 and HfO2 thin films

In this paper amorphous ZrO₂ and HfO₂ thin films were obtained by direct UV irradiation of Zr(IV) and Hf(IV) β-diketonate precursor complexes on Si(1 0 0) and fused silica substrates. The precursors, Zr(CH₃COCHCOCH₃)₄ and Hf(C₆H₅COCHCOCH₃)₄ were deposited as amorphous thin films by spin coating. The photochemistry of these films was monitored by FT-IR spectroscopy. The photolysis with 254 nm light led to the loss of the ligands from the coordination complexes, and the production of metallic oxides. The thin films products were characterized by X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). These analyses revealed that as-deposited films are amorphous and that the presence of carbon is thought to arise from the ligands. However, post-annealing of the photodeposited films favors the stoichiometric and optical properties of ZrO₂ and HfO₂ thin films.     

Pointwise tensor products of function spaces

By means of a mixture of linear and nonlinear techniques, the paper treats quasi-Banach function spaces as _L∞$L_{\infty }$-modules and studies the basic algebraical constructions and their interactions, placing the emphasis on tensor products. Sample result: if 0→Y→X→Z→0$0\to Y\to X\to Z\to 0$ is an exact sequence of _L∞$L_{\infty }$-modules and homomorphisms, where Y and Z are function spaces, and V   is another function space, then the tensorized sequence 0→Y⊗V→X⊗V→Z⊗V→0$0\to Y\otimes V\to X\otimes V\to Z\otimes V\to 0$ is exact too.     

Selective detection of specific protein-ligand complexes by electrosonic spray-precursor ion scan tandem mass spectrometry

A novel mass spectrometric method for the selective detection of specific protein-ligand complexes is presented. The new method is based on electrosonic spray ionization of samples containing protein and ligand molecules, and mass spectrometric detection using the precursor ion scanning function on a triple quadrupole instrument. Mass-selected intact protein-ligand complex ions are subjected to fragmentation by means of collision-induced dissociation in the collision cell of the instrument, while the second mass analyzer is set to the m/z of protonated ligand ions or their alkali metal adducts. The method allows for the detection of only those ions which yield ions characteristic of the ligand molecules upon fragmentation. Since the scan range of first analyzer is set well above the m/z of the ligand ion, and the CID conditions are established to permit fragmentation of only loosely bound, noncovalent complexes, the method is specific to the detection of protein-ligand complexes under described conditions. Behavior of biologically specific and nonspecific complexes was compared under various instrumental settings. Parameters were optimized to obtain maximal selectivity for specific complexes. Specific and nonspecific complexes were found to show markedly different fragmentation characteristics, which can be a basis for selective detection of complexes with biological relevance. Preparation of specific and nonspecific complexes containing identical building blocks was attempted. Complex ions with identical stoichiometry but different origin showed the expected difference in fragmentation characteristics, which gives direct evidence for the different mechanism of specific versus nonspecific complex ion formation.