scholarly journals Aryl substitution of pentacenes

2014 ◽  
Vol 10 ◽  
pp. 1692-1705 ◽  
Author(s):  
Andreas R Waterloo ◽  
Anna-Chiara Sale ◽  
Dan Lehnherr ◽  
Frank Hampel ◽  
Rik R Tykwinski
Keyword(s):  
Thin Films ◽  
Cyclic Voltammetry ◽  
Solid State ◽  
Physical Properties ◽  
X Ray ◽  
X Ray Crystallography ◽  
Vis Spectroscopy ◽  
Solid State Devices ◽  
Pentacene Derivatives

A series of 11 new pentacene derivatives has been synthesized, with unsymmetrical substitution based on a trialkylsilylethynyl group at the 6-position and various aryl groups appended to the 13-position. The electronic and physical properties of the new pentacene chromophores have been analyzed by UV–vis spectroscopy (solution and thin films), thermoanalytical methods (DSC and TGA), cyclic voltammetry, as well as X-ray crystallography (for 8 derivatives). X-ray crystallography has been specifically used to study the influence of unsymmetrical substitution on the solid-state packing of the pentacene derivatives. The obtained results add to our ability to better predict substitution patterns that might be helpful for designing new semiconductors for use in solid-state devices.

scholarly journals Crystal Structures and Optical Properties of Two Novel 1,3,5-Trisubstituted Pyrazoline Derivatives

Crystals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 467
Author(s):  
Qi Feng ◽  
Wenhui Huan ◽  
Jiali Wang ◽  
Jiadan Lu ◽  
Guowang Diao ◽  
...  
Keyword(s):  
Optical Properties ◽  
Charge Transfer ◽  
Solid State ◽  
Physical Properties ◽  
Intramolecular Charge Transfer ◽  
Solvent Polarity ◽  
Dihedral Angles ◽  
Polar Solvents ◽  
X Ray ◽  
X Ray Crystallography

Two novel 1,3,5-trisubstituted pyrazoline derivatives—1-acetyl-3-(4-methoxyphenyl)-5-(6-methoxy-2-naphthyl)-pyrazoline (2a) and 1-(4-nitrophenyl)-3-(4-methoxyphenyl)-5-(6-methoxy-2-naphtyl)-pyrazoline (2b)—were synthesized and their structures were determined by single crystal X-ray crystallography. Both of the two crystals exhibit twisted structures due to the large dihedral angles between the pyrazolinyl ring and the aromatic ring at the 5-position (88.09° for 2a and 71.26° for 2b). The optical–physical properties of the two compounds were investigated. The fluorescent emission of 2b arises from the 1,3-disubstituted pyrazoline chromophores and exhibits a red shift in polar solvents and solid-state, which could be attributed to photo-induced intramolecular charge transfer (ICT) from N1 to C3 in the pyrazoline moiety and the intermolecular interactions within the crystal. The fluorescent emissions of 2a (λmax 358–364 nm) in solvents and solid-state both come from 6-methoxy-2-naphthyl chromophores, which are fairly insensitive to the solvent polarity.

TEM studies of solid-state reactions in sputter-deposited Nb/Al multilayer thin films

1996 ◽  
Vol 54 ◽  
pp. 1020-1021
Author(s):  
F. Ma ◽  
S. Vivekanand ◽  
K. Barmak ◽  
C. Michaelsen
Keyword(s):  
Thin Films ◽  
Solid State ◽  
Stoichiometric Composition ◽  
Analytical Electron Microscopy ◽  
Grain Structure ◽  
Solid State Reactions ◽  
Multilayer Thin Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sputter Deposited

Solid state reactions in sputter-deposited Nb/Al multilayer thin films have been studied by transmission and analytical electron microscopy (TEM/AEM), differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The Nb/Al multilayer thin films for TEM studies were sputter-deposited on (1102)sapphire substrates. The periodicity of the films is in the range 10-500 nm. The overall composition of the films are 1/3, 2/1, and 3/1 Nb/Al, corresponding to the stoichiometric composition of the three intermetallic phases in this system.Figure 1 is a TEM micrograph of an as-deposited film with periodicity A = dA1 + dNb = 72 nm, where d's are layer thicknesses. The polycrystalline nature of the Al and Nb layers with their columnar grain structure is evident in the figure. Both Nb and Al layers exhibit crystallographic texture, with the electron diffraction pattern for this film showing stronger diffraction spots in the direction normal to the multilayer. The X-ray diffraction patterns of all films are dominated by the Al(l 11) and Nb(l 10) peaks and show a merging of these two peaks with decreasing periodicity.

scholarly journals A Mixed-metal Mixed-halide Complex Prepared from Zerovalent Copper and Lead Salts: Solution and Solid-state Chemistry

1999 ◽  
Vol 23 (11) ◽  
pp. 670-671
Author(s):  
Larisa A. Kovbasyuk ◽  
Olga Yu. Vassilyeva ◽  
Vladimir N. Kokozay ◽  
Wolfgang Linert ◽  
Paul R. Raithby
Keyword(s):  
Solid State ◽  
Direct Interaction ◽  
Solid State Chemistry ◽  
X Ray ◽  
Mixed Metal ◽  
X Ray Crystallography ◽  
Halide Complex ◽  
Layer Arrangement ◽  
Lead Salts

The mixed-metal mixed-halide complex [CuPbBrlL2]2 has been prepared by the direct interaction of zerovalent copper with lead halides and 2-dimethylaminoethanol (HL) in dmso and has been characterized by X-ray crystallography; the structure shows a layer arrangement of the tetranuclear metal units through the μ3-halogen bridging.

scholarly journals Vacuum-Free and Highly Dense Nanoparticle Based Low-Band-Gap CuInSe2 Thin-Films Manufactured by Face-to-Face Annealing with Application of Uniaxial Mechanical Pressure

Coatings ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 484
Author(s):  
Matthias Schuster ◽  
Dominik Stapf ◽  
Tobias Osterrieder ◽  
Vincent Barthel ◽  
Peter J. Wellmann
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Coarse Grained ◽  
High Porosity ◽  
Low Band Gap ◽  
Seeding Layer ◽  
X Ray ◽  
Face To Face ◽  
Copper Indium ◽  
Vis Spectroscopy

Copper indium gallium sulfo-selenide (CIGS) based solar cells show the highest conversion efficiencies among all thin-film photovoltaic competition. However, the absorber material manufacturing is in most cases dependent on vacuum-technology like sputtering and evaporation, and the use of toxic and environmentally harmful substances like H2Se. In this work, the goal to fabricate dense, coarse grained CuInSe2 (CISe) thin-films with vacuum-free processing based on nanoparticle (NP) precursors was achieved. Bimetallic copper-indium, elemental selenium and binary selenide (Cu2−xSe and In2Se3) NPs were synthesized by wet-chemical methods and dispersed in nontoxic solvents. Layer-stacks from these inks were printed on molybdenum coated float-glass-substrates via doctor-blading. During the temperature treatment, a face-to-face technique and mechanically applied pressure were used to transform the precursor-stacks into dense CuInSe2 films. By combining liquid phase sintering and pressure sintering, and using a seeding layer later on, issues like high porosity, oxidation, or selenium- and indium-depletion were overcome. There was no need for external Se atmosphere or H2Se gas, as all of the Se was directly in the precursor and could not leave the face-to-face sandwich. All thin-films were characterized with scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and UV/vis spectroscopy. Dense CISe layers with a thickness of about 2–3 µm and low band gap energies of 0.93–0.97 eV were formed in this work, which show potential to be used as a solar cell absorber.

Bis(1-phenyl-1-propyne) complexes of tungsten(II): crystal structures of [WI2(CO)(NCR)(η2-MeC2Ph)2] (R = Me, Et, or Ph)

2001 ◽  
Vol 79 (3) ◽  
pp. 263-271
Author(s):  
Paul K Baker ◽  
Michael GB Drew ◽  
Deborah S Evans
Keyword(s):  
Carbon Monoxide ◽  
Solid State ◽  
Crystal Structures ◽  
Octahedral Geometry ◽  
X Ray ◽  
X Ray Crystallography ◽  
Alkyne Complexes ◽  
First Time

Reaction of [WI2(CO)3(NCMe)2] with two equivalents of 1-phenyl-1-propyne (MeC2Ph) in CH2Cl2, and in the absence of light, gave the bis(1-phenyl-1-propyne) complex [WI2(CO)(NCMe)(η2-MeC2Ph)2] (1) in 77% yield. Treatment of equimolar quantities of 1 and NCR (R = Et, i-Pr, t-Bu, Ph) in CH2Cl2 afforded the nitrile-exchanged products, [WI2(CO)(NCR)(η2-MeC2Ph)2] (2-5) (R = Et (2), i-Pr (3), t-Bu (4), Ph (5)). Complexes 1, 2, and 5 were structurally characterized by X-ray crystallography. All three structures have the same pseudo-octahedral geometry, with the equatorial sites being occupied by cis and parallel alkyne groups, which are trans to the cis-iodo groups. The trans carbon monoxide and acetonitrile ligands occupy the axial sites. In structures 1 and 2, the methyl and phenyl substituents of the 1-phenyl-1-propyne ligands are cis to each other, whereas for the bulkier NCPh complex (5), the methyl and phenyl groups are trans to one another. This is the first time that this arrangement has been observed in the solid state in bis(alkyne) complexes of this type.Key words: bis(1-phenyl-1-propyne), carbonyl, nitrile, diiodo, tungsten(II), crystal structures.

Nanocrystalline Solutions as Precursors to The Spray Deposition of Cdte Thin Films

1995 ◽  
Vol 382 ◽  
Author(s):  
Martin Pehnt ◽  
Douglas L. Schulz ◽  
Calvin J. Curtis ◽  
Helio R. Moutinho ◽  
Amy Swartzlander ◽  
...  
Keyword(s):  
Thin Films ◽  
Atomic Force Microscopy ◽  
Grain Size ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Cdte Nanoparticles ◽  
Atomic Force ◽  
Vis Spectroscopy ◽  
Cdte Thin Films

ABSTRACTIn this article we report the first nanoparticle-derived route to smooth, dense, phase-pure CdTe thin films. Capped CdTe nanoparticles were prepared by injection of a mixture of Cd(CH3)2, (n-C8H17)3 PTe and (n-C8H17)3P into (n-C8H17)3PO at elevated temperatures. The resultant nanoparticles 32-45 Å in diameter were characterized by x-ray diffraction, UV-Vis spectroscopy, transmission electron microscopy, thermogravimetric analysis and energy dispersive x-ray spectroscopy. CdTe thin film deposition was accomplished by dissolving CdTe nanoparticles in butanol and then spraying the solution onto SnO2-coated glass substrates at variable susceptor temperatures. Smooth and dense CdTe thin films were obtained using growth temperatures approximately 200 °C less than conventional spray pyrolysis approaches. CdTe films were characterized by x-ray diffraction, UV-Vis spectroscopy, atomic force microscopy, and Auger electron spectroscopy. An increase in crystallinity and average grain size as determined by x-ray diffraction was noted as growth temperature was increased from 240 to 300 °C. This temperature dependence of film grain size was further confirmed by atomic force microscopy with no remnant nanocrystalline morphological features detected. UV-Vis characterization of the CdTe thin films revealed a gradual decrease of the band gap (i.e., elimination of nanocrystalline CdTe phase) as the growth temperature was increased with bulk CdTe optical properties observed for films grown at 300 °C.

Structures and properties of hemiquinone-substituted oxoporphyrinogens

2009 ◽  
Vol 13 (01) ◽  
pp. 60-69 ◽  
Author(s):  
Jonathan P. Hill ◽  
Katsuhiko Ariga ◽  
Francis D'Souza
Keyword(s):  
Physical Properties ◽  
Redox Reactions ◽  
Photophysical Properties ◽  
Electron Acceptors ◽  
Substitution Pattern ◽  
X Ray ◽  
X Ray Crystallography ◽  
Guest Binding ◽  
Structures And Properties

The structure and physical properties of a series of N-substituted, hemiquinone-substituted oxoporphyrinogens is presented and discussed. Structures of the compounds are dictated by the nature of the substituent, with the substitution pattern being in turn dictated by regioselectivity of N-alkylation. X-ray crystallography and other aggregation properties of the compounds are discussed. Redox reactions are also strongly influenced by N-substitution and substituent identity. Also presented are properties related to guest binding and photophysical properties of oligochromophoric host-guest complexes, involving oxoporphyrinogen, N-substituted with porphyrins and appropriately substituted fullerene guest electron acceptors.

Synthesis and structural characterization of a magnesium phthalocyanine(3–) anion

2012 ◽  
Vol 16 (01) ◽  
pp. 154-162 ◽  
Author(s):  
Edwin W.Y. Wong ◽  
Daniel B. Leznoff
Keyword(s):  
Absorption Spectrum ◽  
Solid State ◽  
Single Crystal ◽  
Structural Characterization ◽  
Heterometallic Complex ◽  
State Structure ◽  
Solid State Structure ◽  
X Ray ◽  
X Ray Crystallography

The reduction of magnesium phthalocyanine (MgPc) with 2.2 equivalents of potassium graphite in 1,2-dimethoxyethane (DME) gives [K2(DME)4]PcMg(OH)(1) in 67% yield. Compound 1 was structurally characterized using single crystal X-ray crystallography and was found to be a monomeric, heterometallic complex consisting of a μ3-OH ligand that bridges a [MgIIPc3-]- anion to two potassium cations solvated by four DME molecules. An absorption spectrum of 1 confirms the Pc ligand is singly reduced and has a 3–charge. The solid-state structure of 1 does not indicate breaking of the aromaticity of the Pc ligand. Compound 1 is only the second Pc3- complex and the first reduced MgPc to be isolated and structurally characterized.

scholarly journals Simple Methylcadmium Alkoxides

2007 ◽  
Vol 62 (10) ◽  
pp. 1339-1342 ◽  
Author(s):  
Surajit Jana ◽  
Tania Pape ◽  
Norbert W. Mitzel
Keyword(s):  
Mass Spectrometry ◽  
Solid State ◽  
Molecular Formula ◽  
Equimolar Ratio ◽  
X Ray ◽  
X Ray Crystallography ◽  
Elemental Analyses ◽  
Solid State Structures ◽  
Structural Aspects ◽  
C Nmr

The reaction of dimethylcadmium with alcohols R-OH in equimolar ratio leads to the formation of tetrameric methylcadmium alkoxides with molecular formula [(MeCd)4 (OR)4] [R = Me (1), Et (2) and iPr (3)]. These compounds have been characterised by 1H, 13C NMR and IR spectroscopy, by mass spectrometry, elemental analyses and by X-ray crystallography (for 2 and 3). The solid state structures show distorted cubane-type aggregates with Cd4O4 cores. The structural aspects and the spectroscopic characterisations of these compounds are discussed.

Sign in / Sign up

Export Citation Format

Share Document