N,N′-dichloro-p-nitrobenzenesulfonamide (dichloramine-N) as a new oxidimetric reagent: Synthesis and analytical application

A new oxidimetric reagent, dichloramine-N (N,N′-dichloro-p-nitrobenzenesulfonamide; DCN) has been synthesized and its structure elucidated from the spectral data and elemental analyses. The ultraviolet, infrared, nuclear magnetic resonance, and mass spectral data have been presented. Analytical applications of DCN as a potential redox titrant in the determination of diverse reductants such as ascorbic acid, methionine, sulfite, arsenite, glutathione, and indigocarmine have been described.     

Approaching the basis set limit for transition metal compounds with highly polar bonds: a benchmark coupled-cluster study of the ScF3 and FeF3 molecular structures and spectra

The molecular equilibrium geometries, quadratic and cubic force constants, vibrational frequencies, and infrared intensities of scandium and iron trifluorides are determined ab initio with a sequence of atomic natural orbital basis sets using the CCSD(T) treatment of electron correlation. The largest basis set of spdf ghi quality contains 462 contracted Gaussian functions. Relativistic corrections are applied to compute the equilibrium geometries and vibrational frequencies. The cubic force constants are used to estimate vibrational corrections to the effective r(g) internuclear distances determined in the gas electron diffraction experiments. The computed molecular properties are extrapolated to the complete basis-set limit. The predicted values are compared to the available experimental data; uncertainties and inconsistencies in these data are then discussed.     

Combinatorial library design: maximizing model-fitting compounds within matrix synthesis constraints

The use of combinatorial chemistry has become commonplace within the pharmaceutical industry. Less widespread but gaining in popularity is the derivation of activity models from the high-throughput assays of these libraries. Such models are then used as filters during the design of refined daughter libraries. The design of these second generation libraries, which efficiently test and conform to the derived activity model from the large space of virtual possibilities, remains an area of considerable research. We present here a computationally efficient method for the design of optimally dense (in model matching compounds) synthetic matrices from in silico virtual libraries.     

2,7-DIIODO-9-DIAZOFLUORENE: A POTENTIAL REAGENT FOR PHOTOLABELING

Abstract— The photochemistry of 2,7-diiodo-9-diazofiuorene was studied to examine its suitability as a photolabeling agent of hydrophobic sites in biological assemblies. Irradiation of the diazo compound generates 2,7-diiodofluorenylidene. The carbene was detected by laser transient absorption spectroscopy and characterized by its chemical and physical properties. Like fluorenylidene, the triplet is the ground state of 2,7-diiodofluorenylidene. However, the substituted triplet carbene does not reform its higher energy, electrophilic singlet state fast enough for reactions of the upper state to compete with the irreversible consumption of the triplet. Thus, the products from the reactions of diiodofluorenylidene contain a higher proportion of those characteristic of the triplet carbene than occurs in the reactions of fluorenylidene. This will limit the utility of this diazocompound as a photolabeling agent.     

Metallic Conductivity and Magnetic Interactions in Nickel and Copper Phthalocyanine Iodides

We discuss the charge transport and magnetic properties of the titled molecular metals. Replacement of the diamagnetic Ni(+2) by paramagnetic Cu(+2) introduces a novel coupling between local Cu(+2) spins the mobile charge carriers, and produces a coupled transition at 8 K.     

The value of information to decision makers: an experimental approach using card-based decision gaming

This paper describes a novel experimental method for determining the value of different types of information to military decision makers. The experimental method used a simple scenario and a set of serials constructed from cards, each presenting a single piece of information and presented sequentially. Each of a number of pairs of players were taken through the scenario and asked to judge when they would make each of a pair of escalating responses to the situation. The data proved well suited to analysis using a probit model and is consistent with the hypothesis of a Bayesian decision mechanism with normally distributed ‘action points’. The methodology allowed the determination of weights for each of a number of different classes of information, together with estimates of the human and situational elements of variation, including estimates of the ‘prior belief’ of the different pairs of players.