Zur nomenklatur der phane—II

The new term “Phanes” has been clearly defined and a nomenclature system tentatively developed. This system is comprehensible and of general application and at the same time relatively simple. The notations “nucleus”, “bridge”, “number of bridge members” and “number of ring members” are defined. In order to get a definite characterisation of the phanes which contain a carbocyclic nucleus, a carbocyclic and heterocyclic bridge the following terms: “carbophanes”, “carba-phanes” and “hetera-phanes” have been newly introduced. The prefix “hetera-” has been proposed as a general expression and as a representative term for the syllables “aza-”, “oxa-”, “thia-” and so on. The so called “a-nomenclature” is clearly called “hetera-nomenclature”. The new expressions “heteralogous” and “substitulogous” are explained. As the various examples will show, the “Phane-Nomenclature” can also be applied to the naming of complicated metallocenophanes.     

Intermolecular vibrational energy transfer of highly excited CF3I molecules observed from transient UV absorption spectra

Intermolecular vibrational energy transfer of highly excited CF₃I molecules by probing of the UV absorption band has been studied. The value of the rate constant of V---V exchange between ensembles of “hot” and “cold” molecules has been found to be 2 ± 0.4 μs⁻¹ Torr⁻¹. Consideration has been given to the effect of this process on isotopic selectivity loss in isotope separation by the method of successive IR-UV molecular photodissociation.     

“Hole-burning spectra”. A new method for obtaining fine structure in absorption spectra of organic molecules

A new method is proposed for obtaining fine structure in broad-band absorption spectra of organic molecules in solid solutions at low temperature. This method is based on the laser burning of a series of narrow gaps in inhomogeneously broadened absorption spectra. A special spectral set-up has been developed for the measurement of the differential spectrum (a “hole-burning spectrum”) of “burnt” and “unburnt” samples. As an example the hole-burning spectrum of Zn-tetraphenylporphine in ethanol has been considered.     

Reply to “Comments on the paper entitled ‘The formulation and modelling of the anodic dissolution of zinc through adsorbed intermediates’ ” by C. Cachet et al.

The points raised in the paper entitled “Comments on the paper entitled ‘The formulation and modelling of the anodic dissolution of zinc through adsorbed intermediates”’ have been discussed. It has been shown that, in contrast to the statements in the “Comments”, most of the papers concerning the reaction schemes suggested for the interpretation of the dissolution or deposition of metals, which were considered as a support for the opinion of the Authors of the “Comments”, support the views expressed in our original paper [J. Electroanal. Chem. 583 (2005) 148]. On the other hand, it has been stressed again that the criticism expressed in the original paper refers to dubious conclusions drawn on the basis of transient measurements.     

Chemistry of the podocarpaceae—V The identification of miropinic acid and isomiropinic acid from Podocarpus ferrugineus D. Don

By reinvestigation of “isomiropinic” and “miropinic” acids from the bled resin of Podocarpus ferrugineus, the compounds have been identified as sugiol and isopimaric acid respectively. The identity of the resin acid from Dacrydium biforme has been confirmed as isopimaric acid.     

Capillary electrophoresis—matrix-assisted laser-desorption ionization mass spectrometry of proteins

An “off-line” combination of capillary electrophoresis (CE) with matrix-assisted laser-desorption mass spectrometry (MALDI-MS) has been developed for the structural characterization of CE-separated peptides and proteins. Using a sheath flow interface, similar to that developed for “on-line” CE—fast atom bombardment MS and CE—electrospray MS, an efficient sample isolation procedure has been developed which is applicable to bioorganic compounds in aqueous buffer solutions. This isolation procedure, with subsequent transfer to the MALDI-MS sample target, has been successfully used for the direct analysis of CE-separated proteins of M _r up to 67 000, and a mixture of apolipoprotein AII monomer and homodimer, using sample amounts of less than 1 pmol.     

Sythesis and crystal structure of a new nickel(II)-terpyridine complex: [Ni(terpy)(NO2)(ONO)(H2O)]

The compounds Ni(terpy)Cl₂ · 3H₂O and NaNO₂ react readily in aqueous solution to give the complex [Ni(terpy)(NO₂)(ONO)(H₂O)], which has been structurally characterized by an X-ray diffraction study. The hexacoordinate nickel atom bonds to three nitrogen atoms of the terpyridine ligand, to a “nitro” group, to a “nitrite” group and to a water molecule. Distortion from an octahedron to a trigonal prism, for the complex, has been evaluated. An infrared study of the complex has been carried out and shows bands of nitro and nitrite coordination. Magnetic study reveals a Curie-Weiss behavior, giving an effective magnetic moment at room temperature 3.12 B.M.     

Semiempirical molecular orbital studies on p-quinodimethane. Electronic structure assignments based on total energies and comparisons with photoelectron and absorption spectra

The electronic structure of p-quinodimethane has been investigated using both CNDO/S and INDO molecular orbital approximations. It is found that the energetically favorable configuration is a “quinoid” construction leading to a spin-paired singlet ground state. Comparisons of the calculated excitation energies and orbital orderings with optical and photoemission measurements are consistent with this assignment. The “quinoid” configuration is found to be energetically unfavorable toward the formation of a low-lying triplet or “biradical”-like state. Charge density distributions, however, suggest a high ground state chemical reactivity.     

On the nature of so-called "Khimdu"

The reagent called “Khimdu” has been investigated and evidence found to show that it is not a pure compound but a mixture of several reaction products.     

Nanogram detection of m-dinitroaromatics and their derivatives A re-evaluation of the spot-test based on the janovsky reaction

The spot-test for m-dinitroaromatics and their derivatives, based on the Janovsky reaction, is re-investigated. The sensitivity of the spot-test has been much enhanced by changing the solvent and using the novel “pellet” spot-test. With the “pellet” spot-test and dimethylsulphoxide, 4–50 ng of m-dinitroaromatic compounds and their derivatives can be detected. The change from acetone (used in the original spot-test) to dimethylsulphoxide changes the reaction product in most cases.     

Determinations cinetiques par microcalorimetrie differentielle en programmation de temperature. II. Influence de la variation de la sensibilite du calorimetre avec la temperature sur les valeurs trouvees pour les constantes de vitesse et les enthalpies de reaction

The variation with temperature of the sensitivity of a “Thermanalyse” microcalorimeter has been determined using the electrical calibration system of the apparatus. From the results, a method for the correction of the differential scanning microcalorimetric diagrams has been developed. The influence on the determination of the rate constants during kinetic studies of the decompositions of free radical initiators and on enthalpy measurements has been studied.     

The seeded growth of calcium phosphates. Surface characterization and the effect of seed material

The kinetics of growth of calcium phosphate on seed materials hydroxyapatite, “amorphous” calcium phosphate, enamel, and dentine has been studied at 25°C and at constant physiological pH in stable supersaturated solutions of calcium phosphate. The grown material was characterized chemically, by x-ray powder diffraction and specific surface area measurements and by scanning electron microscopy. In addition, dissolution kinetic studies have been made of the material grown at different times in the crystal growth experiments and of “amorphous” calcium phosphate. The crystallization experiments were made over a range of initial supersaturation to obtain information about the nature of the calcium phosphate phases formed. The specific surface area of the grown phases show marked changes during the growth experiments. The results of the dissolution experiments indicate that the solid material formed in the early stages of crystallization has a stoichiometry corresponding to OCP.     

A stereospecific synthesis of (±)-ferruginol

A stereospecific synthesis of (±)-ferruginol following the Robinson “ring extension” method has been described. The infra-red spectra of the benzoates of the synthetic and natural ferruginol are found to be identical.     

Tautomeric equilibrium of ketonic and cis- and trans-enolic forms of β-dicarbonyl compounds in solution

In this paper the tautomeric equilibrium of ketonic and cis- and trans-enolic forms of β-dicarbonyl compounds is considered as an acid-base protolytic one. The application of the Brønsted-Izmaylov theory has enabled to suggest a general equation K_TS = for keto-enol equilibrium constant, depending on the solvent, the well known Meyer's equation being included in it as a particular case. Equilibrium constants have been bromometrically determined in a number of solvents of keto-enols of three types, i.e. “cis-fixed”, “trans-fixed” and that involving both stereo-isomeric forms. A method for quantitative determination of cis-trans-enol equilibrium had been proposed.     

Consumer attitudes to radiation and irradiated potatoes at “radiation fair” in Osaka, Japan

“Radiation Fair” has been held in summer vacation season in August for more than 10 years in Osaka, the largest city of western Japan, for the purpose of public education and information transfer of radiation and radiation-related technology. We distributed questionnaires to the visitors for recent 3 years to inquire their status toward radiation and irradiated products including irradiated potatoes as well as impression toward the displays. According to the survey results, more than 60% of the kids visitors were satisfied with this exhibition as informative, more than half of the older visitors (16 years old and upward) indicated that they recognized the word of “radiation” when they were at elementary school and the most significant sources of this information were school lessons and the mass media. Consumer's image toward radiation seems to shift to more “positive” when correct knowledge about radiation is given. More than half of consumers did not know “irradiated potatoes” but the percentage indicating that irradiated potatoes was definitely hazardous was less than 10%.     

Individuation of characteristic parameters of “glass paste” of Meridional Etruria by the use of scientific methodologies

The individuation of parameters that characterize decorations in “glass paste” of Etruscan jewels in Meridional Etruria area, by the use of scientific methodologies, has the aim to collocate this typology of manufacts in a historical and geographical context and to improve the knowledge of the technology connected with their realization. The term “glass paste” is widely used in humanistic literature to describe different materials, all based on a “glass like” composition, but its definition is lacking or confusing if the term is not referred to a scientific meaning.The glass analysis is difficult owing to the complexity of the elements that compose the various classes of vitreous materials. For this reason the interpretation of the composition table containing the values of the numerous glass elements, induces the use of statistical methods for the elaboration of the results. The multivariate analysis can be a valid tool for an immediate lecture of the common characteristics of the different typologies of vitreous materials.In this work, the application of the Principal Component Analysis (PCA), has been applied for the elaboration of chemical composition data obtained by electronic microanalysis (SEM-EDS) on findings coming from Etruscan archaeological sites of Nepi and Cerveteri, and on pearls of a necklace from Castellani's Collection. Besides, an attempt has been made to compare the chemical elements found in the vitreous materials of the jewelry with the elements of sands from probable sites along the rivers present in the Etruscan sites by following the indications reported by historical fonts.The obtained results furnished information in various directions, either for the characterization of each historical sample analyzed or the validation of the applied statistical methodology for the composition data elaboration, besides it has been possible to contribute in the knowledge of the possible existence of glass production sites in the Meridional Etruria, more specifically for the realization of decoration in glass paste.     

The influence of a self-assembled monolayer on the activity of rough gold for glucose oxidation

Gold surface has been roughened by amalgamation and tested for self-assembled monolayer (SAM) formation and glucose oxidation. The rough gold undergoes structural changes at elevated temperatures, which lead to loss of activity for glucose oxidation and lower affinity for the self-assembly. The transformation of “active” into “inactive” surface can be prevented by SAM formation. The SAM modified gold exhibits high activity for glucose oxidation. These results are important especially for those studies, which use rough gold modified by SAM for enzyme immobilisation and further glucose oxidation, since the gold activity itself was so far neglected.     

Inversion of states in two conformers of 1,8-bis(dimethylamino) naphthalene—the proton sponge

The S₁↔S₀ transitions of two conformers of 1,8-bis(dimethylamino) naphthalene, the “proton sponge”, have been studied by semiempirical AM1 calculations. They reveal that “inversion of states” occurs in the asymmetric conformer DMAN-2, which in the gas phase may be emitted from the ¹L_a state in comparison to the ¹L_b state in symmetric DMAN-1. It was also concluded that because of the mixed character of the HOMO-1 orbital in both conformers, a certain CT contribution to the S₀↔S₁ transition has to be taken into account. The calculated maxima of absorption and emission have been compared to those experimentally obtained in supersonic expansion.     

Nucleation and growtn of polythiophene films on gold electrodes

The nucleation and growth of polythiophene films on gold electrodes has been studied using potentiostatic steps. The mechanism has been deduced and estimates made of the kinetic parameters. Dissolution of the gold substrate at potentials where thiophene polymerisation occurs is suppressed by the initial rapid formation of a monolayer of polymer. The data indicate that formation of bulk film occurs by the instantaneous nucleation and three-dimensional growth of polymer on top of this monolayer. Rate constants for growth parallel to the surface on the bare gold substrate and the covering polymer layer are surprisingly very similar. Growth perpendicular to the surface is slightly more rapid, typically by a factor of 1.5–3, although it is less dependent on potential. The high density of nuclei results in their overlap at an early stage, after which growth is only possible perpendicular to the surface. Within a narrow potential range, the observation of maxima and minima in current-time transients is interpreted in terms of the “death” and “rebirth” of growing centres.