Inverse Triphenylmethylium-Farbstoffe / Inverse Triphenylmethylium Dyes

1986 ◽  
Vol 41 (8) ◽  
pp. 1045-1060 ◽  
Author(s):  
Dieter Hellwinkel ◽  
Heinrich Georg Gaa ◽  
Reiner Gottfried
Keyword(s):  
Crystal Violet ◽  
Molecular Orbitals ◽  
Experimental Results ◽  
Equal Energy ◽  
Wavelength Absorption ◽  
Stable Models ◽  
Visual Observations

Keywords When in the conventional triphenylmethylium dye systems of the crystal violet and malachit green type, 6 and 7, the N̈ -donor and C⊕ -acceptor centers are interchanged , the “Inverse Triphenylmethylium Dye Types” 4 and 5 are obtained , showing very similar colors. The stable models with R = phenyl (8-10) and R = p-tolyl (11-13) were investigated in more detail. The visual observations were supported by the VIS spectra which show ed nearly the same longest wavelength absorption maxim a for corresponding pairs of inverse and conventional dye representatives. The experimental results can be interpreted with a simple HMO -model according to which the longest wavelength absorptions correspond here to transitions of equal energy from weakly bonding to nonbonding and from nonbonding to weakly antibonding molecular orbitals, respectively. On the same basis numerous isoelectronic variants of that dye type can be envisaged. In the N M R -spectra of the new dyes, characteristically increasing deshieldings of nearly all positions are observed in going from the mono- (10+, 13+) through the di- (9++, 12++) to the trications (8+++, 11+++).

Effect of Ligands on the Photoluminescence Performance of Ir(III) Complexes: A Theoretical Exploration

2013 ◽  
Vol 798-799 ◽  
pp. 219-222
Author(s):  
Jian Po Zhang ◽  
Li Jin ◽  
Xing Jin ◽  
Xiu Yun Sun ◽  
Fu Quan Bai
Keyword(s):  
Charge Transfer ◽  
Ground State ◽  
Electronic Structures ◽  
Spectroscopic Properties ◽  
Molecular Orbitals ◽  
Experimental Results ◽  
Frontier Molecular Orbitals ◽  
Bond Lengths ◽  
Td Dft

A series of iridium (III) complexes (C^N)2Ir (Pic) (C^N = Phi (1), Ppi (2), Mpfpi (3), and Cpfpi (4) have been investigated theoretically to explore their electronic structures and spectroscopic properties. The calculate bond lengths of Ir-N and Ir-O in the ground state agree well with the corresponding experimental results. At the TD-DFT and PCM levels, 1-4 give rise to absorptions at 359, 360, 348, and 335 nm and phosphorescent emissions at 454 , 469, 441, and 425 nm, respectively. The transitions of 1-4 are all attributed to {[d (Ir)+π (C^N)][π*(C^N) or π*(Pic)]} charge transfer. It is shown that the emissions are significantly dominated by the metal participating in the frontier molecular orbitals and affected by the C^N ligands.

scholarly journals Generation of Electromagnetic Field by Microtubules

2021 ◽  
Vol 22 (15) ◽  
pp. 8215
Author(s):  
Jan Pokorný ◽  
Jiří Pokorný ◽  
Jan Vrba
Keyword(s):  
Electromagnetic Field ◽  
Energy Distribution ◽  
Biological Systems ◽  
Molecular Orbitals ◽  
General Mechanism ◽  
General Phenomenon ◽  
Coherent Signals ◽  
Equal Energy ◽  
Conduction Bands ◽  
Electric Dipoles

The general mechanism of controlling, information and organization in biological systems is based on the internal coherent electromagnetic field. The electromagnetic field is supposed to be generated by microtubules composed of identical tubulin heterodimers with periodic organization and containing electric dipoles. We used a classical dipole theory of generation of the electromagnetic field to analyze the space–time coherence. The structure of microtubules with the helical and axial periodicity enables the interaction of the field in time shifted by one or more periods of oscillation and generation of coherent signals. Inner cavity excitation should provide equal energy distribution in a microtubule. The supplied energy coherently excites oscillators with a high electrical quality, microtubule inner cavity, and electrons at molecular orbitals and in ‘semiconduction’ and ‘conduction’ bands. The suggested mechanism is supposed to be a general phenomenon for a large group of helical systems.

Study of a Port Design for Silo Blenders

1991 ◽  
Vol 113 (3) ◽  
pp. 343-349 ◽  
Author(s):  
B. G. Scrivens ◽  
E. E. Michaelides ◽  
F. M. Thomson
Keyword(s):  
Velocity Distribution ◽  
Response Surface ◽  
Average Velocity ◽  
Experimental Results ◽  
Angle Of Repose ◽  
Particle Properties ◽  
Geometric Characteristics ◽  
Port Design ◽  
Active Channel ◽  
Visual Observations

Experimental results are reported on two silo-blenders equipped with a new design of ports in their downcomers. None of the mixing streams was falling freely. The mixing of pellets within the ports is determined as a function of the port geometric characteristics such as awning angle, height of port, width of awning and width of the downcomer, and of the particle properties such as the angle of repose. It was observed that two dimensionless quantities are sufficient to describe the mixing fraction at the port. Visual observations on the flow near the port were made and the port’s mixing response surface was estimated. When the new port design was fitted in a cylindrical blender the active channel of the port was recorded as well as the average velocity distribution in the channel.

scholarly journals Pressure Distribution and Bubble Formation Induced by Longitudinal Vibration of a Flexible Liquid-Filled Cylinder

1967 ◽  
Vol 89 (4) ◽  
pp. 737-747 ◽  
Author(s):  
R. J. Schoenhals ◽  
T. J. Overcamp
Keyword(s):  
Pressure Distribution ◽  
Longitudinal Vibration ◽  
Bubble Formation ◽  
Experimental Results ◽  
Experimental Measurements ◽  
Visual Observations

Analytical and experimental results are presented for a flexible liquid-filled cylinder subjected to forced longitudinal vibration. Analytical predictions are correlated with experimental measurements of pressure amplitudes and threshold acceleration levels required to produce bubble formation, as well as visual observations of the regions in which formations occur.

Diagnostics of Gold Laser Plasmas

1988 ◽  
Vol 102 ◽  
pp. 357-360
Author(s):  
J.C. Gauthier ◽  
J.P. Geindre ◽  
P. Monier ◽  
C. Chenais-Popovics ◽  
N. Tragin ◽  
...  
Keyword(s):  
Experimental Results ◽  
Pure Gold ◽  
Electronic Temperature ◽  
X Ray ◽  
Laser Plasmas ◽  
Collisional Radiative Model ◽  
Radiative Model

AbstractIn order to achieve a nickel-like X ray laser scheme we need a tool to determine the parameters which characterise the high-Z plasma. The aim of this work is to study gold laser plasmas and to compare experimental results to a collisional-radiative model which describes nickel-like ions. The electronic temperature and density are measured by the emission of an aluminium tracer. They are compared to the predictions of the nickel-like model for pure gold. The results show that the density and temperature can be estimated in a pure gold plasma.

Observation of Phase Contrast Images in STEM and CTEM Modes by Using 100 kV Field Emission Electron Gun

1974 ◽  
Vol 32 ◽  
pp. 390-391
Author(s):  
Y. Harada ◽  
T. Goto ◽  
H. Koike ◽  
T. Someya
Keyword(s):  
Field Emission ◽  
Phase Contrast ◽  
Image Formation ◽  
Fresnel Diffraction ◽  
Experimental Results ◽  
Electron Gun ◽  
Scanning Microscopy ◽  
Emission Electron ◽  
Lattice Images

Since phase contrasts of STEM images, that is, Fresnel diffraction fringes or lattice images, manifest themselves in field emission scanning microscopy, the mechanism for image formation in the STEM mode has been investigated and compared with that in CTEM mode, resulting in the theory of reciprocity. It reveals that contrast in STEM images exhibits the same properties as contrast in CTEM images. However, it appears that the validity of the reciprocity theory, especially on the details of phase contrast, has not yet been fully proven by the experiments. In this work, we shall investigate the phase contrast images obtained in both the STEM and CTEM modes of a field emission microscope (100kV), and evaluate the validity of the reciprocity theory by comparing the experimental results.

A new dissociation mode for dislocations in silicon

1978 ◽  
Vol 36 (1) ◽  
pp. 346-347
Author(s):  
A. Ourmazd ◽  
G.R. Booker ◽  
C.J. Humphreys
Keyword(s):  
Detailed Examination ◽  
Experimental Results ◽  
Dislocation Network ◽  
Weak Beam ◽  
Phosphorus Doped

A (111) phosphorus-doped Si specimen, thinned to give a TEM foil of thickness ∼ 150nm, contained a dislocation network lying on the (111) plane. The dislocation lines were along the three <211> directions and their total Burgers vectors,ḇt, were of the type , each dislocation being of edge character. TEM examination under proper weak-beam conditions seemed initially to show the standard contrast behaviour for such dislocations, indicating some dislocation segments were undissociated (contrast A), while other segments were dissociated to give two Shockley partials separated by approximately 6nm (contrast B) . A more detailed examination, however, revealed that some segments exhibited a third and anomalous contrast behaviour (contrast C), interpreted here as being due to a new dissociation not previously reported. Experimental results obtained for a dislocation along [211] with for the six <220> type reflections using (g,5g) weak-beam conditions are summarised in the table below, together with the relevant values.

Multislice calculations of RHEED patterns from vicinal Si (001)

1993 ◽  
Vol 51 ◽  
pp. 1000-1001
Author(s):  
Scott Lordi
Keyword(s):  
Misorientation Angle ◽  
Incident Angle ◽  
Incident Beam ◽  
Experimental Results ◽  
Bragg Condition ◽  
Vicinal Surfaces ◽  
Kinematic Theory ◽  
Step Edges

Vicinal Si (001) surfaces are interesting because they are good substrates for the growth of III-V semiconductors. Spots in RHEED patterns from vicinal surfaces are split due to scattering from ordered step arrays and this splitting can be used to determine the misorientation angle, using kinematic arguments. Kinematic theory is generally regarded to be inadequate for the calculation of RHEED intensities; however, only a few dynamical RHEED simulations have been attempted for vicinal surfaces. The multislice formulation of Cowley and Moodie with a recently developed edge patching method was used to calculate RHEED patterns from vicinal Si (001) surfaces. The calculated patterns are qualitatively similar to published experimental results and the positions of the split spots quantitatively agree with kinematic calculations.RHEED patterns were calculated for unreconstructed (bulk terminated) Si (001) surfaces misoriented towards [110] ,with an energy of 15 keV, at an incident angle of 36.63 mrad ([004] bragg condition), and a beam azimuth of [110] (perpendicular to the step edges) and the incident beam pointed down the step staircase.

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