Studies on nessler's reagent part I

The nature of the reaction between [HgI₄]^-2 and OH^- ions, which are the components of the Nessler's reagent, has been. studied and established as

, by determining the concentration of iodide ions formed in the solution, potentiometrically from the concentration cells of iodide-hypoiodite system. The equilibrium constant has also been calculated and found to be lo^-3.26.     

Approach to geminally alkylated azaphthalans via a consecutive double desilylation-alkylation reaction: application to a synthesis of cerpegin

A new approach to geminally alkylated azaphthalans and an application of this chemistry to the synthesis of the pyridone alkaloid, cerpegin, is reported.     

Oxoanionic or sulfur lone pair attack? The difference in reactivity of hydrogensulfite anion and neutral dimethylsulfite towards [Bu4N]2[MoO2(S2C2)CN)2)2] in the model reductive half reaction of sulfite oxidase

pH dependent reactivity differences of dimethylsulfite towards the title complex 1 demonstrate the crucial need of oxo-anionic coordination of sulfite to the molybdenum centre of 1 in the model reductive half reaction of sulfite oxidase.     

Archimedean Synthesis and Magic Numbers: "Sizing" Giant Molybdenum-Oxide-Based Molecular Spheres of the Keplerate Type

Pythagorean harmony can be found in the spherical polyoxometalate clusters described here (see illustration for an example of a structure), since there are interesting relationships between the so-called magic numbers (12, 32, 42, 72, 132) relevant for spherical viruses and the number of the building blocks in the cluster. The size of these Keplerate clusters can be tailored by varying the type of connections between the pentagons by means of different spacers.     

K X-ray emission spectra from ν-Al2O3

Summary η-Al₂O₃ sample was bombarded with 12.5 keV electron.K X-ray spectra of this sample were compared with those of pure Al and α-Al₂O₃.     

Isovalent and mixed-valent diruthenium complexes [(acac)2RuII (-bpytz)RuII(acac)2] and [(acac)2RuII(-bpytz)RuIII(acac)2](ClO4) (acac = acetylacetonate and bpytz = 3,6-bis(3,5-dimethylpyrazolyl)-1,2,4,5-tetrazine): synthesis, spectroelectrochemical, and epr investigation

The title compounds involving the structurally characterized bridging ligand bpytz were characterized, showing very strong electrochemical stabilization of the mixed-valent RuIIRuIII state (Kc = 10(13.9)) but no detectable (epsilon < 20 M(-1) cm(-1)) intervalence charge-transfer band in the infrared region. In situ reduction of the neutral precursor produces a diruthenium(II) complex of the bpytz radical anion according to EPR spectroscopy, whereas oxidation of the mixed-valent form leads to a diruthenium(III) species.     

A linear worst-case lower bound on the number of holes inside regions visible due to multiple diffuse reflections

It is known that the region V(s) of a simple polygon P, directly visible (illuminable) from an internal point s, is simply connected. Aronov et al. [2] established that the region V₁(s) of a simple polygon visible from an internal point s due to at most one diffuse reflection on the boundary of the polygon P, is also simply connected. In this paper we establish that the region V₂(s), visible from s due to at most two diffuse reflections may be multiply connected; we demonstrate the construction of an n-sided simple polygon with a point s inside it so that the region of P visible from s after at most two diffuse reflections is multiply connected. We also show that V₃(s), the region of P visible from s after at most three diffuse reflections, can have (n) holes.A part of this work was done when this author was visiting the University of Miami, Coral Gables, Florida, USA.     

On the nucleon self-energy in nuclear matter

We consider the nucleon self-energy in nuclear matter in the absence of Pauli blocking. It is evaluated using the partial-wave analysis of scattering data. Our results are compared with that of a realistic calculation to estimate the effect of this blocking. It is also possible to use our results as a check on the realistic calculations.PACS: 21.30.-x Nuclear forces - 21.65. + f Nuclear matter