Effect of axial ligands on the spectroelectrochemical properties of zinc phthalocyanine films. In situ Raman and electroreflection spectra

Electroreflection and Raman spectra (in situ and ex situ) of zinc phthalocyanine (ZnPc) films (80 nm thick) have been studied. Raman spectra were resonantly and preresonantly enhanced. Both electroreflection and Raman experiments reveal the homogeneous inclusion of electrolyte anions upon oxidation of the film. The anions coordinate preferentially axial positions of the ZnPc molecule. This process is accompanied by an out-of-plane deformation of the phthalocyanine macrocycle, which results in the change of both electroreflection and Raman spectra. The ZnPc molecule remains deformed when the film is saturated with anions. The detailed analysis of new bands and altered intensities in the Raman spectrum indicates that the molecular symmetry point group changes from the D4h point group to C2v. The influence of ZnPc oxidation on the Raman excitation mechanism has been also studied. Effects of axial ligands on the molecular geometry have been studied by quantum chemical calculations for the ZnPc+, ZnPc+Cl¿ and ZnPc+(Cl¿)2 species using the unrestricted Hartree¿Fock variant of the MNDO method. Calculation results show that the ZnPc molecule undergoes an out-of-plane deformation when one axial position is coordinated by the anion

The photoelectron spectra of the diazanaphthalenes

The high-resolution He 584 Å photoelectron spectra of ten diazanaphthalenes are presented. The ordering of the π orbitals and the nitrogen “lone-pair” orbitals is discussed. Several semi-empirical quantum-chemical calculation methods have been screened against the experimental evidence

Perfluoro effect in the photoelectron spectra of quinoline and isoquinoline

The high-resolution He 584Aophotoelectron spectra of heptafluoroquinoline and heptafluoroisoquinoline are compared with those of the parent compounds. Shifts in π ionisation potentials, due to the fluorine substitution, can be described with an inductive and a combined inductive-conjugative Hu¨ckel model

The crystal and molecular structure of 2,7-diazanaphthalene

X-ray diffraction data were collected at 20°C on a computer-controlled Philips diffractometer (PW 1100). The structure was solved by direct methods and refined by the full-matrix least-squares method to an R of 0.065 (weighted R 0.046). The molecule in the crystal is of lower symmetry than C2,.. The geometry of the molecule has been compared with NMR results obtained by Danieli, Lunazzi & Veracini [J. Chem. Soc. Perkin II, (1976), pp. 19-201. As a result a C-H bond-length correction of 0.09 (2) A was found

Milieu en economie kunnen goed samengaan

Milieu en economie kunnen op bedrijfsniveau goed samengaan. Dat blijkt uit de resultaten van het Landelijk Meetnet effecten Mestbeleid (LMM). Er zijn melkveehouder-deelnemers die zowel goede economische resultaten als goede milieuresultaten halen. Bovendien blijkt dat zo’n combinatie niet aan één bepaalde bedrijfsstrategie is gebonden. Wel blijven er grote verschillen tussen bedrijven met een vergelijkbare strategie, zowel qua economische resultaten als qua milieuresultaten. Al houden melkveehouders zich in grote lijnen allen aan dezelfde wettelijke gebruiksnormen, ze doen dat dus toch niet allen op dezelfde wijze

Individueel en gericht stimuleren zorgt voor lager melkureumgehalte

Als agrarische ondernemers individueel gestimuleerd worden om bedrijf en milieu te combineren levert dat goede resultaten op voor beide doeleinden. Een voorbeeld is het melkureumgehalte. Het kan vaak en gemakkelijk worden gemeten en kan dienen als snelle signalering, waardoor de melkveehouder beter bij kan sturen

Melkveehouders zijn via bedrijfsdoelen te motiveren tot milieubewust handelen

Onderzoek naar de mogelijkheid om ammoniakemissie te verminderen door gedeeltelijk zelfregulering toe te passen. Ook werd gekeken naar de wijze waarop dit dan het beste kon gebeuren. Het blijkt dat zelfregulering het beste te realiseren is via bedrijfsplanne

The organization of 2,3-iron-naphthalocyanine molecules on substrate as revealed by scanning tunneling microscopy

Surface morphology of thin molecular layer of 2,3-Iron-naphthalocyanine (2,3 FeNPc) was studied by scanning tunneling microscopy (STM) at the ambient conditions. Organic layer with thickness of 40 nm was vapour phase deposited on amorphous carbon substrate. The STM images have revealed the pecularities of surface molecular organization from large range (hundreds of nm) down to atomic scale. Arrays of locally ordered linear stuctures have been distinguished as the main morphological features of the examined surface. At several places the well-ordered STM patterns have been distinguished at the atomic scale. They can be described as stacks of periodicity approximatelly 0.4 nm in a row and 1.5 nm between stacks. These results can be explained by arrangement of 2,3-FeNPh molecules in stacks with a main plane being perpendicular to the substrate surface

Overview geotechnical model tests on dike safety at Deltares

Three on-going dike safety studies (on: macro stability, piping and flow slides) in the Netherlands make use of geotechnical physical models. A short outline of these projects is presented; the physical models chosen are described and discussed. The three studies use different physical models, depending on the research questions at the beginning of the model test series, the heterogeneity that is anticipated in the field, the scaling laws and the knowledge level. The paper describes why a certain model was chosen