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

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.

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Influence of Fluorine Substitution on the Optical, Thermal, Electrochemical and Structural Properties of Carbazole-Benzothiadiazole Dicarboxylic Imide Alternate Copolymers

Polymers ◽

10.3390/polym12122910 ◽

2020 ◽

Vol 12 (12) ◽

pp. 2910 ◽

Cited By ~ 2

Author(s):

Ary R. Murad ◽

Ahmed Iraqi ◽

Shujahadeen B. Aziz ◽

Hunan Hi ◽

Sozan N. Abdullah ◽

...

Keyword(s):

Thermal Stability ◽

Molecular Orbital ◽

Energy Levels ◽

Average Molecular Weight ◽

Band Gaps ◽

Hydrogen Atoms ◽

Good Thermal Stability ◽

Optical Band Gaps ◽

Fluorinated Copolymers ◽

The Impact

In this work four novel donor-acceptor copolymers, PCDTBTDI-DMO, PCDTBTDI-8, P2F-CDTBTDI-DMO and P2F-CDTBTDI-8, were designed and synthesised via Suzuki polymerisation. The first two copolymers consist of 2,7-carbazole flanked by thienyl moieties as the electron donor unit and benzothiadiazole dicarboxylic imide (BTDI) as electron acceptor units. In the structures of P2F-CDTBTDI-DMO and P2F-CDTBTDI-8 copolymers, two fluorine atoms were incorporated at 3,6-positions of 2,7-carbazole to investigate the impact of fluorine upon the optoelectronic, structural and thermal properties of the resulting polymers. P2F-CDTBTDI-8 possesses the highest number average molecular weight (Mn = 24,200 g mol−1) among all the polymers synthesised. PCDTBTDI-DMO and PCDTBTDI-8 show identical optical band gaps of 1.76 eV. However, the optical band gaps of fluorinated copolymers are slightly higher than non-fluorinated counterparts. All polymers have deep-lying highest occupied molecular orbital (HOMO) levels. Changing the alkyl chain substituents on BTDI moieties from linear n-octyl to branched 3,7-dimethyloctyl groups as well as substituting the two hydrogen atoms at 3,6-positions of carbazole unit by fluorine atoms has negligible impact on the HOMO levels of the polymers. Similarly, the lowest unoccupied molecular orbital (LUMO) energy levels are almost comparable for all polymers. Thermogravimetric analysis (TGA) has shown that all polymers have good thermal stability and also confirmed that the fluorinated copolymers have higher thermal stability relative to those non-fluorinated analogues. Powder X-ray diffraction (XRD) studies proved that all polymers have an amorphous nature in the solid state.

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

MRS Proceedings ◽

10.1557/opl.2014.793 ◽

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.

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

Acta Crystallographica Section C Structural Chemistry ◽

10.1107/s2053229617008257 ◽

2017 ◽

Vol 73 (8) ◽

pp. 609-612 ◽

Cited By ~ 1

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.

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Preparation of C60 Thin Film and Investigation of its Optical Properties

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.194-196.2317 ◽

2011 ◽

Vol 194-196 ◽

pp. 2317-2321 ◽

Cited By ~ 1

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.

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Correlation between the Photocatalytic Degradability of PAHs over Pt/TiO2-SiO2in Water and Their Quantitative Molecular Structure

Journal of Nanomaterials ◽

10.1155/2015/284834 ◽

2015 ◽

Vol 2015 ◽

pp. 1-11 ◽

Cited By ~ 4

Author(s):

Zhao-hui Luo ◽

Chuan-ling Wei ◽

Nan-nan He ◽

Zhi-guo Sun ◽

Hui-xin Li ◽

...

Keyword(s):

Molecular Structure ◽

Molecular Weight ◽

Molecular Orbital ◽

Molecular Descriptors ◽

Order Equation ◽

First Order ◽

Highest Occupied Molecular Orbital ◽

Polycyclic Aromatic ◽

Lowest Unoccupied Molecular Orbital ◽

The Difference

The correlation between the photocatalytic degradability of polycyclic aromatic hydrocarbons (PAHs) over Pt/TiO2-SiO2in water and their quantitative molecular structure was studied. Six PAHs, namely, naphthalene, fluorene, phenanthrene, pyrene, benzo[a]pyrene, and dibenzo[a,h]anthracene, were tested in Pt/TiO2-SiO2suspension under UV irradiation. The results showed that the degradation efficiencies of the higher molecular weight PAHs were enhanced significantly in the presence of Pt/TiO2-SiO2, while the degradation efficiencies of the lower molecular weight PAHs were decreased in the presence of Pt/TiO2-SiO2. Both the photolysis and photocatalysis of all PAHs fit the pseudo-first-order equation very well, except FL. Quantitative analysis of molecular descriptors of energy of the highest occupied molecular orbital (Ehomo), energy of the lowest unoccupied molecular orbital (Elumo), and the difference betweenElumoandEhomo, GAP (GAP=Elumo-Ehomo), suggested that the GAP was significant for predicting a PAHs’ photocatalytic degradability. Through comparison against the maximum GAP (7.4529 eV) of PAHs (dibenzo[a,h]anthracene) that could be photocatalytically degraded and the minimum GAP (8.2086 eV) of PAHs (pyrene) that could not be photocatalytically degraded in this study, the photocatalytic degradability of 67 PAHs was predicted. The predictions were partly verified by experimental photocatalytic degradation of anthracene and Indeno[1.2.3.cd]pyrene.

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Fabrication of Alternating Copolymers Based on Cyclopentadithiophene-Benzothiadiazole Dicarboxylic Imide with Reduced Optical Band Gap: Synthesis, Optical, Electrochemical, Thermal, and Structural Properties

Polymers ◽

10.3390/polym13010063 ◽

2020 ◽

Vol 13 (1) ◽

pp. 63

Author(s):

Ary R. Murad ◽

Ahmed Iraqi ◽

Shujahadeen B. Aziz ◽

Sozan N. Abdullah ◽

Mohamad A. Brza ◽

...

Keyword(s):

Structural Properties ◽

Molecular Orbital ◽

Average Molecular Weight ◽

Good Thermal Stability ◽

Molecular Weights ◽

Alternating Copolymers ◽

Highest Occupied Molecular Orbital ◽

Lowest Unoccupied Molecular Orbital ◽

Direct Arylation Polymerization ◽

The Impact

A series of alternating copolymers containing cyclopentadithiophene (CPDT) flanked by thienyl moieties as electron-donor units and benzothiadiazole dicarboxylic imide (BTDI) as electron-acceptor units were designed and synthesized for solar cell applications. Different solubilizing side chains, including 2-ethylhexyl chains and n-octyl chains were attached to CPDT units, whereas 3,7-dimethyloctyl chains and n-octyl chains were anchored to the BTDI moieties. The impact of these substituents on the solubilities, molecular weights, optical and electrochemical properties, and thermal and structural properties of the resulting polymers was investigated. PCPDTDTBTDI-EH, DMO was synthesized via Suzuki polymerization, whereas PCPDTDTBTDI-8, DMO, and PCPDTDTBTDI-EH, 8 were prepared through direct arylation polymerization. PCPDTDTBTDI-8, DMO has the highest number average molecular weight (Mn = 17,400 g mol−1) among all polymers prepared. The PCPDTDTBTDI-8, DMO and PCPDTDTBTDI-8, 8 which have n-octyl substituents on their CPDT units have comparable optical band gaps (Eg ~ 1.3 eV), which are around 0.1 eV lower than PCPDTDTBTDI-EH, DMO analogues that have 2-ethylhexyl substituents on their CPDT units. The polymers have their HOMO levels between −5.10 and −5.22 eV with PCPDTDTBTDI-EH, DMO having the deepest highest occupied molecular orbital (HOMO) energy level. The lowest unoccupied molecular orbital (LUMO) levels of the polymers are between −3.4 and −3.5 eV. All polymers exhibit good thermal stability with decomposition temperatures surpassing 350 °C. Powder X-ray diffraction (XRD) studies have shown that all polymers have the amorphous nature in solid state.

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Characteristics of Low Band Gap Copolymers Containing Anthracene-Benzothiadiazole Dicarboxylic Imide: Synthesis, Optical, Electrochemical, Thermal and Structural Studies

Polymers ◽

10.3390/polym13010062 ◽

2020 ◽

Vol 13 (1) ◽

pp. 62

Author(s):

Ary R. Murad ◽

Ahmed Iraqi ◽

Shujahadeen B. Aziz ◽

Mohammed S. Almeataq ◽

Sozan N. Abdullah ◽

...

Keyword(s):

Band Gap ◽

Molecular Orbital ◽

Energy Levels ◽

X Ray Diffraction ◽

Low Band Gap ◽

Molecular Weights ◽

Highest Occupied Molecular Orbital ◽

Donor Acceptor ◽

Lowest Unoccupied Molecular Orbital ◽

The Impact

Two novel low band gap donor–acceptor (D–A) copolymers, poly[9,10-bis(4-(dodecyloxy)phenyl)-2,6-anthracene-alt-5,5-(4′,7′-bis(2-thienyl)-2′,1′,3′-benzothiadiazole-N-5,6-(3,7-dimethyloctyl)dicarboxylic imide)] (PPADTBTDI-DMO) and poly[9,10-bis(4-(dodecyloxy)phenyl)-2,6-anthracene-alt-5,5-(4′,7′-bis(2-thienyl)-2′,1′,3′-benzothiadiazole-5,6-N-octyl-dicarboxylic imide)] (PPADTBTDI-8) were synthesized in the present work by copolymerising the bis-boronate ester of 9,10-phenylsubstituted anthracene flanked by thienyl groups as electron–donor units with benzothiadiazole dicarboxylic imide (BTDI) as electron–acceptor units. Both polymers were synthesized in good yields via Suzuki polymerisation. Two different solubilizing alkyl chains were anchored to the BTDI units in order to investigate the impact upon their solubilities, molecular weights, optical and electrochemical properties, structural properties and thermal stability of the resulting polymers. Both polymers have comparable molecular weights and have a low optical band gap (Eg) of 1.66 eV. The polymers have low-lying highest occupied molecular orbital (HOMO) levels of about −5.5 eV as well as the similar lowest unoccupied molecular orbital (LUMO) energy levels of −3.56 eV. Thermogravimetric analyses (TGA) of PPADTBTDI-DMO and PPADTBTDI-8 did not prove instability with decomposition temperatures at 354 and 313 °C, respectively. Powder X-ray diffraction (XRD) studies have shown that both polymers have an amorphous nature in the solid state, which could be used as electrolytes in optoelectronic devices.

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Synthesis and Characterization of Fluorene-Based Polymers Having Azine Unit for Blue Light Emission

International Letters of Chemistry Physics and Astronomy ◽

10.18052/www.scipress.com/ilcpa.62.21 ◽

2015 ◽

Vol 62 ◽

pp. 21-28

Author(s):

Zhong Min Geng ◽

Masashi Kijima

Keyword(s):

Molecular Orbital ◽

Light Emission ◽

Energy Levels ◽

Average Molecular Weight ◽

Orbital Energy ◽

Good Thermal Stability ◽

Highest Occupied Molecular Orbital ◽

Donor Acceptor ◽

Lowest Unoccupied Molecular Orbital

Two types of donor-acceptor copolymers were designed and synthesized by combination of an electron donor unit of fluorene sequences and an electron acceptor azine unit such as 1,2,4,5-tetrazine and 1,3,5-triazine. They were well soluble in common organic solvents with the number average molecular weight (Mn) of 7.0 and 14.5 kg mol-1, respectively, and have good thermal stability showing about at 360 °C with 5 wt% loss in TGA. Two copolymers exhibited intense blue photoluminescence with emission peak maxima at 437 and 421 nm in CHCl3, and 451 and 422 nm in the film state, respectively. These polymers exhibited good fluorescence quantum efficiencies in CHCl3 (φfl = 0.63, 0.97). Energy levels of the highest occupied molecular orbital and lowest unoccupied molecular orbital energy levels estimated by cyclic voltammetry were to be –5.83, –6.0 eV and –2.85, –2.88 eV, respectively.

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Electronic Properties of Triangle Molybdenum Disulfide (MoS2) Clusters with Different Sizes and Edges

Molecules ◽

10.3390/molecules26041157 ◽

2021 ◽

Vol 26 (4) ◽

pp. 1157

Author(s):

Songsong Wang ◽

Changliang Han ◽

Liuqi Ye ◽

Guiling Zhang ◽

Yangyang Hu ◽

...

Keyword(s):

Quantum Chemistry ◽

Electronic Properties ◽

Absorption Spectra ◽

Molecular Orbital ◽

Electronic Structures ◽

Edge States ◽

Frontier Orbitals ◽

Edge Structure ◽

Highest Occupied Molecular Orbital ◽

Lowest Unoccupied Molecular Orbital

The electronic structures and transition properties of three types of triangle MoS2 clusters, A (Mo edge passivated with two S atoms), B (Mo edge passivated with one S atom), and C (S edge) have been explored using quantum chemistry methods. The highest occupied molecular orbital (HOMO)–lowest unoccupied molecular orbital (LUMO) gap of B and C is larger than that of A, due to the absence of the dangling of edge S atoms. The frontier orbitals (FMOs) of A can be divided into two categories, edge states from S3p at the edge and hybrid states of Mo4d and S3p covering the whole cluster. Due to edge/corner states appearing in the FMOs of triangle MoS2 clusters, their absorption spectra show unique characteristics along with the edge structure and size.

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Photoconductivity of Low-Bandgap Polymer and Polymer: Fullerene Bulk Heterojunction Studied by Constant Photocurrent Method

Organic Photonics and Photovoltaics ◽

10.1515/oph-2015-0011 ◽

2015 ◽

Vol 3 (1) ◽

Cited By ~ 2

Author(s):

V. V. Malov ◽

A. R. Tameev ◽

S. V. Novikov ◽

M. V. Khenkin ◽

A. G. Kazanskii ◽

...

Keyword(s):

Molecular Orbital ◽

Bulk Heterojunction ◽

Inorganic Materials ◽

Fullerene Derivative ◽

Approximation Procedure ◽

Photoelectric Properties ◽

Highest Occupied Molecular Orbital ◽

Donor Acceptor ◽

Lowest Unoccupied Molecular Orbital ◽

Doped Polymers

AbstractOptical and photoelectric properties of modern photosensitive polymers are of great interest due to their prospects for photovoltaic applications. In particular, an investigation of absorption and photoconductivity edge of these materials could provide valuable information. For these purpose we applied the constant photocurrent method which has proved its efficiency for inorganic materials. PCDTBT and PTB7 polymers were used as objects for the study as well as their blends with a fullerene derivative PC71BM. The measurements by constant photocurrent method (CPM) show that formation of bulk heterojunction (BHJ) in the blends increases photoconductivity and results in a redshift of the photocurrent edge in the doped polymers compared with that in the neat polymers. Obtained from CPM data, spectral dependences of absorption coefficient were approximated using Gaussian distribution of density-of-states within HOMO (highest occupied molecular orbital) and LUMO (lowest unoccupied molecular orbital) bands. The approximation procedure allowed us to evaluate rather optical than electrical bandgaps for the studied materials. Moreover, spectra of polymer:PC71BM blends were fitted well by the sum of two Gaussian peaks which reveal both the transitions within the polymer and the transitions involving charge transfer states at the donor-acceptor interface in the BHJ.

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