2,2′-[(Disulfanediyl)bis{5-[(1E)-(2-hydroxybenzylidene)amino]-1,3-thiazole-4,2-diyl}]diphenol: synthesis, crystal structure and calculation of molecular hyperpolarizability

2017 ◽  
Vol 73 (8) ◽  
pp. 609-612 ◽  
Author(s):  
Seyed Amir Zarei ◽  
Mohammad Piltan ◽  
Asmar Mashhun ◽  
Hadi Amiri Rudbari ◽  
Giuseppe Bruno
Keyword(s):  
Molecular Orbital ◽  
Condensation Reaction ◽  
X Ray Diffraction ◽  
One Dimensional ◽  
X Ray ◽  
Highest Occupied Molecular Orbital ◽  
Molecular Hyperpolarizability ◽  
Lowest Unoccupied Molecular Orbital ◽  
Ir Spectroscopic ◽  
Base Compound

The title Schiff base compound {systematic name: 2-[5-[(E)-(2-hydroxybenzylidene)amino]-4-(2-{5-[(E)-(2-hydroxybenzylidene)amino]-2-(2-hydroxyphenyl)-1,3-thiazol-4-yl}disulfanyl)-1,3-thiazol-2-yl]phenol}, C32H22N4O4S4, incorporating a disulfanediyl (dithio) linkage, was obtained from the condensation reaction between two equivalents of salicylaldehyde and one equivalent of dithiooxamide in dimethylformamide, and was characterized by elemental analysis, IR spectroscopic analysis and single-crystal X-ray diffraction. A one-dimensional chain is formed along the b axis via double intermolecular C—H...S hydrogen bonds. The HOMO (highest occupied molecular orbital) and LUMO (lowest unoccupied molecular orbital) energies and some related molecular parameters were calculated at the B3LYP/6-311G(d,p) level of theory. The molecular hyperpolarizability was also calculated.

scholarly journals Preparation and Characterization of Quinoxaline-Pyrene-Based Conjugated Copolymers for Organic Photovoltaic Devices

Coatings ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1098
Author(s):  
Bakhet A. Alqurashy ◽  
Bader M. Altayeb ◽  
Sulaiman Y. Alfaifi ◽  
Majed Alawad ◽  
Ahmed Iraqi ◽  
...  
Keyword(s):  
Molecular Orbital ◽  
Powder Diffraction ◽  
Bulk Heterojunction ◽  
Gel Permeation Chromatography ◽  
Band Gap Energy ◽  
Slight Reduction ◽  
X Ray ◽  
Highest Occupied Molecular Orbital ◽  
Lowest Unoccupied Molecular Orbital

In this study, two novel conjugated polymers, poly(4,5,9,10-tetrakis((2-ethylhexyl)oxy]pyrene-alt-2,3-bis(3-(octyloxy)phenyl)-5,8-di(2-thienyl)-6,7-difluoroquinoxaline) (PPyQxff) and poly(4,5,9,10-tetrakis((2-ethylhexyl)oxy)pyren-alt-2,3-bis(3-(octyloxy)phenyl)-5,8-di(2-thienyl)quinoxaline) (PPyQx), consisting of quinoxaline units with and without fluorine substituents, as electron-accepting moieties and pyrene flanked with dithienyl units as electron-donating moieties were prepared via Stille polymerization reactions for use as electron donor materials in bulk heterojunction (BHJ) solar cells. PPyQxff and PPyQx were characterized by X-ray powder diffraction (XRD), gel permeation chromatography (GPC), thermogravimetric analysis (TGA), cyclic voltammetry (CV), UV−VIS absorption, and nuclear magnetic resonance (NMR) spectroscopy. PPyQxff and PPyQx revealed excellent solution processability in common organic solvents. PPyQxff and PPyQx presented decomposition temperatures above 300 °C. The inclusion of F atoms to the quinoxaline moiety made a slight reduction in the highest occupied molecular orbital (HOMO) level, relative to the unfluorinated polymer, but had no impact on the lowest unoccupied molecular orbital (LUMO) level. PPyQxff and PPyQx exhibited similar physical properties with strong and broad absorbance from 400 to 700 nm and an optical band-gap energy of 1.77 eV. The X-ray powder diffraction study indicated that PPyQxff possessed a reduced π–π stacking distance relative to PPyQx.

Cross-conjugation as a Motif for Organic Non-Linear Optical Molecules

2014 ◽  
Vol 1698 ◽  
Author(s):  
Meghana Rawal ◽  
Kerry Garrett ◽  
Andreas F. Tillack ◽  
Werner Kaminsky ◽  
Evgheni Jucov ◽  
...  
Keyword(s):  
Molecular Orbital ◽  
Density Functional ◽  
Dipole Moments ◽  
X Ray Diffraction ◽  
Conjugated Molecules ◽  
Functional Theory ◽  
Highest Occupied Molecular Orbital ◽  
Donor And Acceptor ◽  
Vis Spectroscopy ◽  
Lowest Unoccupied Molecular Orbital

ABSTRACTWe studied the effect of a cross-conjugated bridging group (χC) on charge-transfer in a push-pull chromophore system. The hyperpolarizability of such molecules was found to be comparable to that of a fully π-conjugated molecule (πC) with the same donor and acceptor. The cross-conjugated moiety was then applied as a pendant to a fully π-conjugated chromophore containing a tricyanopyrroline acceptor (TCP). The addition of a χC moiety did not alter the intrinsic hyperpolarizability and provides an avenue for extending and aiding πC systems. The molecules were examined by X-ray diffraction (XRD), hyper-Raleigh scattering (HRS) and UV-visible (UV-vis) spectroscopy. Experimental results were compared with the predictions of density functional theory (DFT). Cross-conjugated molecules have comparable β values, relative to πC molecules, due to reduced spatial overlap between the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO). Thus, the χC architecture could facilitate independent modification of donor and acceptor strengths while minimizing unfavorable effects on electronic transitions and dipole moments.

scholarly journals Theoretical and X-ray diffraction studies of organic photovoltaic compounds

2014 ◽  
Vol 70 (a1) ◽  
pp. C996-C996
Author(s):  
Abdelkader Chouaih ◽  
Salem Yahiaoui ◽  
Nadia Benhalima ◽  
Manel Boulakoud ◽  
Rachida Rahmani ◽  
...  
Keyword(s):  
Molecular Orbital ◽  
Organic Semiconductor ◽  
Density Functional ◽  
Energy Gap ◽  
Three Dimensional ◽  
Basis Set ◽  
X Ray Diffraction ◽  
Hybrid Functional ◽  
X Ray ◽  
Lowest Unoccupied Molecular Orbital

The electronic and structural properties of thiazolic ring derivatives were studied using density functional theory (DFT) and X-ray diffraction in terms of their application as organic semiconductor materials in photovoltaic devices. The B3LYP hybrid functional in combination with Pople type 6-31G(d) basis set with a polarization function was used in order to determine the optimized geometries and the electronic properties of the ground state, while transition energies and excited state properties were obtained from DFT with B3LYP/6-31G(d) calculation. The investigation of thiazolic derivatives formed by the arrangement of several monomeric units revealed that three-dimensional (3D) conjugated architectures present the best geometric and electronic characteristics for use as an organic semiconductor material. The highest occupied molecular orbital (HOMO) . lowest unoccupied molecular orbital (LUMO) energy gap was decreased in 3D structures that extend the absorption spectrum toward longer wavelengths, revealing a feasible intramolecular charge transfer process in these systems. All calculations in this work were performed using the Gaussian 03 W software package.

scholarly journals A Cooperative Photoactive Class-I Hybrid Polyoxometalate With Benzothiadiazole–Imidazolium Cations

2021 ◽  
Vol 8 ◽  
Author(s):  
Alexander J. Kibler ◽  
Virginia S. Souza ◽  
Jesum Alves Fernandes ◽  
William Lewis ◽  
Stephen P. Argent ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Molecular Orbital ◽  
Crystallographic Analysis ◽  
Hybrid Species ◽  
X Ray ◽  
Imidazolium Cations ◽  
Organic Components ◽  
Highest Occupied Molecular Orbital ◽  
Lowest Unoccupied Molecular Orbital ◽  
Inorganic And Organic

An organic–inorganic hybrid species based on the Wells–Dawson polyoxotungstate [P2W18O62]6− and novel fluorescent benzothiadiazole–imidazolium cations, [BTD-4,7-ImH]2+, has been synthesized. X-ray crystallographic analysis shows that the inorganic and organic components form a hydrogen-bonded superstructure and that the cations are revealed to be non-equivalent with varying degrees of rotation between the BTD and imidazolium rings due to competition between weak intra- and intermolecular interactions. The UV–vis diffuse reflectance spectra indicate that the hybrid has a band gap of 3.13 eV, while the solid-state fluorescence properties of the cation are quenched in the hybrid material, suggesting the existence of electron transfer between the inorganic and organic components. The highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energies of the polyoxometalate (POM) and BTD-4,7-ImH precursors, estimated through UV–vis absorption spectroscopy and cyclic voltammetry, indicate that electron transfer from the BTD cations to the POM may occur in the excited state.

scholarly journals Isolation and structure determination of missing fullerenes Gd@C 74 (CF 3 ) n through in situ trifluoromethylation

2018 ◽  
Vol 5 (9) ◽  
pp. 181015 ◽  
Author(s):  
Ayano Nakagawa ◽  
Shinobu Aoyagi ◽  
Haruka Omachi ◽  
Katsuma Ishino ◽  
Makiko Nishino ◽  
...  
Keyword(s):  
Molecular Orbital ◽  
High Performance ◽  
Density Functional ◽  
Crystallographic Analysis ◽  
X Ray ◽  
Multi Stage ◽  
Highest Occupied Molecular Orbital ◽  
Lowest Unoccupied Molecular Orbital

Our trifluoromethyl functionalization method enables the dissolution and isolation of missing metallofullerenes of Gd@C 74 (CF 3 ) n . After multi-stage high-performance liquid chromatography purification, Gd@C 74 (CF 3 ) 3 and two regioisomers of Gd@C 74 (CF 3 ) are isolated. X-ray crystallographic analysis reveals that all of the isolated metallofullerenes react with CF 3 groups on pentagons of the D 3 h -symmetry C 74 cages. Highest occupied molecular orbital-lowest unoccupied molecular orbital gaps of these trifluoromethylated derivatives, estimated by absorption spectra, are in the range 0.71–1.06 eV, consistent with density functional calculations.

scholarly journals Synthesis of Amorphous Conjugated Copolymers Based on Dithienosilole-Benzothiadiazole Dicarboxylic Imide with Tuned Optical Band Gaps and High Thermal Stability

2021 ◽  
Vol 11 (11) ◽  
pp. 4866
Author(s):  
Ary R. Murad ◽  
Elham M. A. Dannoun ◽  
Shujahadeen B. Aziz ◽  
Ahmed Iraqi ◽  
Sozan N. Abdullah ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Molecular Weight ◽  
Molecular Orbital ◽  
Structural Characteristics ◽  
Average Molecular Weight ◽  
Band Gaps ◽  
X Ray Diffraction ◽  
Optical Band Gaps ◽  
Highest Occupied Molecular Orbital ◽  
Lowest Unoccupied Molecular Orbital

Two alternating copolymers of dithienosilole (DTS) were designed and synthesized with small optical band gaps, flanked by thienyl units as electron-donor moieties and benzothiadiazole dicarboxylic imide (BTDI) as electron-acceptor moieties. The BTDI moieties were anchored to two different solubilizing side chains, namely 3,7-dimethyloctyl and n-octyl chains. An analysis of the effect of the electrochemical, optical, thermal, and structural characteristics of the resulting polymers along with their solubility and molecular weight is the subject of this paper. The Stille polymerization was used to synthesize PDTSDTBTDI-DMO and PDTSDTBTDI-8. The average molecular weight of PDTSDTBTDI-DMO and PDTSDTBTDI-8 is 14,600 and 5700 g mol−1, respectively. Both polymers have shown equivalent optical band gaps around 1.4 eV. The highest occupied molecular orbital (HOMO) levels of the polymers were comparable, around −5.2 eV. The lowest unoccupied molecular orbital (LUMO) values were −3.56 and −3.45 eV for PDTSDTBTDI-DMO and PDTSDTBTDI-8, respectively. At decomposition temperatures above 350 °C, both copolymers showed strong thermal stability. The studies of powder X-ray diffraction (XRD) have shown that they are amorphous in a solid-state.

Photoluminescence and Electroluminescence Quenching in 8-Hydroxyquinoline Aluminum Chelates

1995 ◽  
Vol 413 ◽  
Author(s):  
Xian-man Zhang ◽  
Keith A. Higginson ◽  
Fotios Papadimitrakopoulos
Keyword(s):  
Molecular Orbital ◽  
Elevated Temperatures ◽  
Light Emitting Diode ◽  
Condensation Reaction ◽  
Energy Levels ◽  
Polymeric Compound ◽  
Light Emitting ◽  
Highest Occupied Molecular Orbital ◽  
Lowest Unoccupied Molecular Orbital ◽  
Pl Quenching

ABSTRACTThe present communication proposes a mechanism for photoluminescence (PL) and electroluminescence (EL) quenching in aluminum(III) 8-hydroxyquinoline (Alq3) chelates. Our experiments indicate that in the presence of moisture, ligand exchange of 8-hydroxyquinoline with water can occur. At elevated temperatures, the liberated 8-hydroxyquinoline undergoes a condensation reaction in the presence of traces of oxygen, generating a dark, non-emissive polymeric compound. Spectroscopic and electrochemical methods were used to determine the band gap and energy levels (highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO)) of this byproduct. Steady state PL experiments indicate that (0.5 to 1%) concentration of this byproduct, evenly dispersed in Alq3 films, results in dramatic PL quenching. Deliberate insertion of an approximately 50 Å thick film of this byproduct into the interface of a poly(p-phenylenevinylene)/Alq3 light emitting diode (LED) completely quenches the EL as well. Initial data suggest an energy transfer quenching mechanism.

scholarly journals Electrochemical trapping of metastable Mn3+ ions for activation of MnO2 oxygen evolution catalysts

2018 ◽  
Vol 115 (23) ◽  
pp. E5261-E5268 ◽  
Author(s):  
Zamyla Morgan Chan ◽  
Daniil A. Kitchaev ◽  
Johanna Nelson Weker ◽  
Christoph Schnedermann ◽  
Kipil Lim ◽  
...  
Keyword(s):  
Coordination Number ◽  
Oxygen Evolution ◽  
Molecular Orbital ◽  
Local Strain ◽  
Spectroscopic Studies ◽  
X Ray ◽  
Highest Occupied Molecular Orbital ◽  
Lowest Unoccupied Molecular Orbital ◽  
X Ray Absorption

Electrodeposited manganese oxide films are promising catalysts for promoting the oxygen evolution reaction (OER), especially in acidic solutions. The activity of these catalysts is known to be enhanced by the introduction of Mn3+. We present in situ electrochemical and X-ray absorption spectroscopic studies, which reveal that Mn3+ may be introduced into MnO2 by an electrochemically induced comproportionation reaction with Mn2+ and that Mn3+ persists in OER active films. Extended X-ray absorption fine structure (EXAFS) spectra of the Mn3+-activated films indicate a decrease in the Mn–O coordination number, and Raman microspectroscopy reveals the presence of distorted Mn–O environments. Computational studies show that Mn3+ is kinetically trapped in tetrahedral sites and in a fully oxidized structure, consistent with the reduction of coordination number observed in EXAFS. Although in a reduced state, computation shows that Mn3+ states are stabilized relative to those of oxygen and that the highest occupied molecular orbital (HOMO) is thus dominated by oxygen states. Furthermore, the Mn3+(Td) induces local strain on the oxide sublattice as observed in Raman spectra and results in a reduced gap between the HOMO and the lowest unoccupied molecular orbital (LUMO). The confluence of a reduced HOMO–LUMO gap and oxygen-based HOMO results in the facilitation of OER on the application of anodic potentials to the δ-MnO2 polymorph incorporating Mn3+ ions.

Preparation of C60 Thin Film and Investigation of its Optical Properties

2011 ◽  
Vol 194-196 ◽  
pp. 2317-2321 ◽  
Author(s):  
Xue Liang Yang ◽  
Jin Xiang Deng ◽  
Ting Li ◽  
Yang Qin ◽  
Le Kong
Keyword(s):  
Thin Film ◽  
Molecular Orbital ◽  
Extensive Study ◽  
X Ray Diffraction ◽  
Thermal Evaporation Method ◽  
Force Microscopy ◽  
Si Substrates ◽  
Atomic Force ◽  
Highest Occupied Molecular Orbital ◽  
Lowest Unoccupied Molecular Orbital

C60thin films were deposited on Si substrates at different evaporation temperatures using the thermal evaporation method. In this paper, an extensive study of morphology and crystallinity of the films was presented by atomic force microscopy (AFM), low angle X-ray diffraction (LA-XRD) and UV-vis spectrophotometer. It is found that a good crystalline quality along a (333) preferred orientation was observed at the 450°C evaporation temperature and an ordered sequence of fcc structure was evaluated. The 2.24eV optical energy bandgag of C60thin film corresponding to hu→ t1utransition between the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) levels was also extracted.

Effect of pH on the charge-assisted hydrogen-bonded assembly of the anionic [Cu(oxalate)2]2−building unit andN,N′-ditopic cations

2018 ◽  
Vol 74 (3) ◽  
pp. 300-306
Author(s):  
Fatima Klongdee ◽  
Jaursup Boonmak ◽  
Sujittra Youngme
Keyword(s):  
Solvothermal Reaction ◽  
Spectroscopic Techniques ◽  
X Ray Diffraction ◽  
Ionic Complex ◽  
One Dimensional ◽  
X Ray ◽  
Structural Assembly ◽  
Acidic Conditions ◽  
The One ◽  
Ir Spectroscopic

By the solvothermal reaction under acidic conditions of Cu(NO3)2·3H2O, Na2C2O4and theN,N′-ditopic organic coligands 1-(pyridin-4-yl)piperazine (ppz) and 1,2-bis(pyridin-4-yl)ethane (bpa), two novel anionic copper(II) coordination compounds were obtained, namely the one-dimensional coordination polymercatena-poly[4-(pyridin-1-ium-4-yl)piperazin-1-ium [[(oxalato-κ2O1,O2)copper(II)]-μ-oxalato-κ3O1,O2:O1′]], {(C9H15N3)[Cu(C2O4)2)]}nor {(H2ppz)[Cu(C2O4)2]}n, (I), and the discrete ionic complex 4,4′-(ethane-1,2-diyl)dipyridinium bis(oxalato-κ2O1,O2)copper(II), (C12H14N2)[Cu(C2O4)2] or (H2bpa)[Cu(C2O4)2], (II). The products were characterized by single-crystal X-ray diffraction, elemental analysis, powder X-ray diffraction, thermogravimetric analyses and UV and IR spectroscopic techniques. The [Cu(C2O4)2]2−units for (I) and (II) are stabilized by H2ppz2+and H2bpa2+cations, respectively,viacharge-assisted hydrogen bonds. Also, a study of the pH-controlled synthesis of this system shows that (I) was obtained at pH values of 2–4. When using bpa, a two-dimensional square-grid network of [Cu(C2O4)(bpa)]nwas obtained at a pH of 4. This indicates that the pH of the reaction also plays a key role in the structural assembly and coordination abilities of oxalate andN,N′-ditopic coligands.

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