Search

We systematically study the optical and nonlinear optical (NLO) properties of various cyclopentadithiophene (CPDT) derivatives using quantum chemical calculations. The designed derivatives are classified into three classes and each class have three types of derivatives as a, b and c. For example, compounds 1a, 2a, and 3a are formed by substituting nitrophenyl at the terminal positions of 2,6-diphenyl-4 H-cyclopenta[2,1-b:3,4-b′]dithiophene at the terminal positions to design V-shaped (Λ-shaped) compounds and similar pattered were adopted for other classes. The dipole moment (µ), linear isotropic and anisotropic polarizability along with second-order and third-order NLO polarizability are computed by applying density functional theory (DFT) methods at PBE1PBE/6-311G** level of theory. Among all the derivatives, 3a and 1a shows the maximum linear isotropic (αiso) and anisotropic (αaniso) polarizability of 120.4 × 10−24 and 161.4 × 10−24 esu respectively. The noteworthy effect of incorporating different electron donor and acceptor moieties to the overall NLO polarizability is observed. The largest average second-order NLO polarizability value is observed 92.59 × 10−30 esu for system 1a. The β// amplitude of 1a is ~ 1.5 to 11 times more as compared to other derivatives. Additionally, the nonlinear anisotropy of β// amplitudes is also seen significantly larger ranging from 4.96 to 129.63 which is due to the V-shaped structure of designed compounds. While on the other hand, some compounds shows the third-order NLO polarizability amplitudes which are ranging in thousands including 4107 × 10−36, 5020 × 10−36, 5857 × 10−36, 6412 × 10−36, 6700 × 10−36 and 9057 × 10−36 esu for compounds 1b, 2b, 3a, 2a, 3b and 1a, respectively. Strikingly, the β// and <γ> amplitudes of compound 1a are ~ 14 and ~ 1242 times greater than that of standard para-nitroaniline (prototype NLO molecule), respectively, as computed at same PBE1PBE/6-311G** method. The TD-DFT calculations are also performed to see origin of larger NLO polarizabilities. The molecular electrostatic potential maps and frontier molecular orbitals are drawn to get further insight into the structure-NLO property relationship of newly designed CPDT derivatives. Hence, we considered that the current investigation will interest the researchers to further explore the optical and NLO applications of these CPDT derivatives. [ABSTRACT FROM AUTHOR]

A series of new benzothiazole-derived donor–acceptor-based compounds (Comp1–4) were synthesized and characterized with the objective of tuning their multifunctional properties, i.e., charge transport, electronic, and optical. All the proposed structural formulations (Comp1–4) were commensurate using FTIR, 1H NMR, 13C NMR, ESI-mass, UV–vis, and elemental analysis techniques. The effects of the electron-donating group (-CH3) and electron-withdrawing group (-NO2) on the optoelectronic and charge transfer properties were studied. The substituent effect on absorption was calculated at the TD-B3LYP/6-31+G** level in the gas and solvent phases. The effect of solvent polarity on the absorption spectra using various polar and nonpolar solvents, i.e., ethanol, acetone, DMF, and DMSO was investigated. Light was shed on the charge transport in benzothiazole compounds by calculating electron affinity, ionization potential, and reorganization energies. Furthermore, the synthesized compounds were used to prepare thin films on the FTO substrate to evaluate the charge carrier mobility and other related device parameters with the help of I-V characteristic measurements. [ABSTRACT FROM AUTHOR]

Organic semiconductors have gained substantial interest as active materials in electronic devices due to their advantages over conventional semiconductors. We first designed four Schiff base compounds, then the effect of electron donor/acceptor groups (methyl/nitro) was studied on the compounds' electronic and transport nature. The absorption spectra (λabs) were computed by time-dependent DFT at TD-B3LYP/6-31+G** level. The effect of different solvents (ethanol, DMF, DMSO, and acetone) was investigated on the λabs. The substitution of the -NO2 group to the furan moiety at the 5th position in Compound 3 leads to a red-shift in the absorption spectrum. A smaller hole reorganization energy value in Compound 3 would be beneficial to get the hole's intrinsic mobility. In contrast, a reduced-electron reorganization energy value of Compound 4 than hole may result in enhanced electron charge transfer capabilities. The reorganization energies of compounds 1 and 2 exposed balanced hole/electron transport probability. The optical, electronic, and charge transport properties at the molecular level indicate that Compound 3 is suitable for organic electronic device applications. [ABSTRACT FROM AUTHOR]

Various optoelectronic properties of 10-(1,3-Dithiol-2-ylidene)anthracene based organic light harvesters were probe at solid state bulk surface. Effect of diverse conjugated π-donor-acceptor bridge, 3,4-ethylenedioxythiophene in Comp3 and phenyl for Comps1 and 2, along with two set of electron acceptor entity, an ester moiety for Comp1, a dicyanovinylene moiety for Comp2 and Comp3 was explored on various properties. The 3,4-ethylenedioxythiophene as conjugated π-bridge boost the dielectric constants, conductivity, refractive index and extinction coefficient values significantly. The dicyanovinylene is favorable than the ester group as prior moiety contributes to the p-orbitals from −2.0 to −4.0 eV. The solid states density, relative permittivity's, extinction coefficient, indices of refraction, reflectance, and electrical conductivity displayed that anthracene derivatives may act as proficient objects in multi-purpose organic semiconductors. [ABSTRACT FROM AUTHOR]

Azole derived products acquired significant consideration in everyday life based on their improved biological potential to the semiconducting substances. The research focused in-depth within pyrazol, and oxazole compounds 1–4 concerning charge transport, structural, optical as well as electronic properties. The density functional theory (DFT) along with time-dependent DFT were used for the optimization of their ground state geometries and excitation energies. We also investigated the molecule's electron coupling constants (|VRP|) as well as electron injection (ΔGinject) values. For better understanding, charge transport and electronic characteristics were performed through quantum chemical computations. The |VRP| and ΔGinject values of pyrazole, as well as oxazole molecules, exhibited that these compounds could be competent for dye-sensitized solar cell applications. The pyrazole higher diagonal band gap enlightening these might have enhanced fill factor (FF) along with short-circuit current density (Jsc). We have also explored the electron injection, energy level offset, dissociation of excitons, and band alignment of studied compounds to shed light on the functionality of these compounds for photovoltaic and semiconductor device applications. [ABSTRACT FROM AUTHOR]

Eight new oxadiazole derivatives were designed then geometries for ground state were optimized through Density Functional Theory (DFT) at B3LYP/6-31G** level. Single electron transfer mechanism has been studied to understand the antioxidant ability of the oxadiazole derivatives. Then molecular electrostatic potential and quantitative structure–activity relationship (QSAR) was probed. Additionally, we shed light on different molecular descriptors, e.g., electrophilicity(ω), electronegativity(χ), electrophilicity indices(ωi), hardness(η), softness(S) and chemical potential(μ).The smaller value of ionization potential for 5a is showing that it might be efficient antioxidant candidate. The electrophilic reactive sites in 2a, 3a, 4a , 5a and 7a derivatives might be a good choice for reactivity that would be advantageous to improve the biological activity. The polar surface area of 3a , 4a and 5a derivatives was found < 60 A2 which is enlightening that these drugs might be suitable as orally active and for brain penetration. First-principles calculations and molecular docking results revealed that 5a would lead to superior antioxidant activity. [ABSTRACT FROM AUTHOR]

Ten coumarin class of compounds, including new fused coumarinolignoids namely, mucronin-C (1) were isolated from the methanol extract from whole plant of Daphne mucronata Royle. The structures of mucronin-C (1) and its configurations were determined by chemical and spectroscopic methods including 1DNMR, 2D-NMR and HR-FAB-MS. The isolated compounds 1-10 were evaluated for in-vitro biological activities. The anti-inflammatory (lipoxygenase) activities of compound 1, 4, 8, 9 and 10 (IC50 = 21.7, 23.7, 25.1, 27.3 and 26.0 µg/mL, respectively) were higher compared with standard Quercetin (IC50 = 22.5 µg/mL). The antioxidant property of coumarin as evaluated by DPPH scavenging bioassay was significantly greater in compounds 1-5, 9 and 10 (IC50 = 0.7, 0.8, 1.9, 2.3, 2.8, 0.5 and 2.1 µg/mL respectively) as standard Trolox (IC50 = 0.3 µg/mL). The density functional descriptors in the progress of quantitative structure-activity relationship (QSAR) are significant to analyze the reactive sites and antioxidant ability of compounds. We have explored the reactive sites and radical scavenging activity of studied coumarin derivatives by shedding light on electron affinity, ionization potential, molecular electrostatic potential, frontier molecular orbitals and molecular descriptors analysis. First-principles calculations about one-electron transfer mechanism revealed that smaller ionization potential value of Compounds 1-5, 9 and 10 are leading to superior antioxidant activity, which is in good agreement with the experimental data. [ABSTRACT FROM AUTHOR]

The Aerva plants are exceptionally rich in phytochemicals and possess therapeutics potential. Phytochemical screening shows that Aerva persica (Burm.f.) Merr. contains highest contents i.e., total phenolics, flavonoids, flavonols, tannins, alkaloids, carbohydrates, anthraquinones and glycosides. In-vitro antibacterial and enzymatic (carbonic anhydrase) inhibition studies on methanol extracts of A. persica indicated the presence of biological active constituents within chloroform soluble portions. Investigation in the pure constituents on the chloroform portions of A. persica accomplished by column chromatography, NMR and MS analysis. The bioguided isolation yields four chemical constituents of coumaronochromone family, namely aervin (1-4). These pure chemical entities (1-4) showed significant antibacterial activity in the range of 60.05–79.21 µg/ml against various bacterial strains using ampicillin and ciprofloxacin as standard drugs. The compounds 1-4 showed promising carbonic anhydrase inhibition with IC50 values of 19.01, 18.24, 18.65 and 12.92 µM, respectively, using standard inhibitor acetazolamide. First-principles calculations revealed comprehensive intramolecular charge transfer in the studied compounds 1-4. The spatial distribution of highest occupied and lowest unoccupied molecular orbitals, ionization potential, molecular electrostatic potential and Hirshfeld analysis revealed that these coumaronochromone compounds would be proficient biological active compounds. These pure constituents may be used as a new pharmacophore to treat leaukomia, epilepsy, glaucoma and cystic fibrosis. [ABSTRACT FROM AUTHOR]

The synthesis of 1-benzyl-2-((2-Aminoethyl) amino)-5-oxopyrrolidine-3,4-diyl diacetate (boad), an oxopyrrolidine type ligand; designed to coordinate lanthanides (Eu3+ and Tb3+) to get luminescent material. The target complexes showed good photoluminescence properties, which indicate that this type of compound can be used as sensitizers having luminescence for the green (Tb3+) and red (Eu3+) emission. The obtained results revealed that sensitizer efficiency can be improved by adding ligands like acac (Eu(acac)3, which has also enhanced the luminescence quantum output and period for Eu3+ ions. The ground state geometries were developed by using density functional theory at B3LYP/6-31G** level. The charge transfer analysis and electronic properties were performed. The Europium and Terbium complexes formation with boad ligand was explored based on molecular electrostatic potential, MDC-q charges, and frontier molecular orbitals (FMOs) analysis. [ABSTRACT FROM AUTHOR]

Present investigation deals with an in depth study of three compounds including 4-(4-chlorophenyl)-8-methyl-2-oxo- 1,2,5,6,7,8-hexahydroquinoline-3-carbonitrile (1), 4-(4-bromophenyl)-8-methyl-2-oxo-1,2,3,4,4a,5,6,7-octahydroquinoline-3- carbonitrile (2) and 8-methyl-2-oxo-4-(thiophen-2-yl)-1,2,5,6,7,8-hexahydroquinoline-3-carbonitrile (3) with respect to their structural, electronic, optical and charge transport properties. The ground and excited states geometries were optimized by density functional theory (DFT) and time dependent DFT, respectively. To rationalize the adopted methodology, the calculated geometrical parameters at ground state were compared with the experimental crystal structures. Several quantum chemical insights including the analysis of frontier molecular orbitals (FMOs), total/partial density of states (T/PDOS), molecular electrostatic potentials (MEP), local and global reactivity descriptors revealed that the studied compounds would be efficient multifunctional materials. The absorption wavelengths as well as their major transitions were thoroughly studied at TD-B3LYP/6-31G** level of theory. The smaller hole reorganization energies indicate that all these compounds might show better hole transport tendency. The anionic geometry relaxation of compound 2 is larger than the cationic form which leads to higher electron reorganization energy revealing the reduction of electron charge transport as compared to the hole. [ABSTRACT FROM AUTHOR]

The current work is to spotlight the key structure-property features of a novel thiourea complex bis(thiourea) silver(I) nitrate (BTSN) for future applications in nonlinear optical devices through dual approach involving experimental and theoretical techniques. The synthesis and growth of good quality single crystals of a relatively new material BTSN have been done. The crystal structure, quantitative and qualitative, vibrational, optical and dielectric analysis of the grown single crystals was carried out. The optical transparency of the grown crystals is found to be more than 80% confirms its colorless nature and applications in optoelectronic devices. Further, the state-of-art computational methods have been applied to obtain the ground state molecular geometry at B3LYP/6-31G∗, MP2/6-31G∗ and M06/6-31G∗ levels of theory. Various key electro-optical properties (complementary to experimental results) such as IR, Raman, and polarizabilities have been determined at the same levels of theory. The static and dynamic polarizability and first hyperpolarizability both were calculated to comprehend the potential applications of BTSN in nonlinear optics. In addition to the above, numerous novel molecular level insights have been achieved in the form of total and partial density of states, HOMO-LUMO gap and molecular electrostatic potential map. The calculated values of static and frequency dependent dynamic first hyperpolarizability are found to be 8.46 × 10−30 and 2.30 × 10−30 esu which are about 23 times and 13 times greater than those of prototype urea molecule, respectively, calculated at the same B3LYP/6-31G∗ level of theory. From the analyzed results it is clear that the titled compound possesses excellent electro-optic properties that make it a decent contestant for photonic devices. [ABSTRACT FROM AUTHOR]

Donor–bridge–acceptor (D–π–A) compounds have garnered significant attention, and have led to increased efficiency of photovoltaic devices. In this study, an effective D–π–A dye (TPA-PT) was designed that contains tri-phenyl-amine, thiophene-pyrimidine and cyanoacetic acid as donor (D), π-bridge and acceptor (A), respectively. The TPA-PT was adsorbed on the semiconductor surfaces, i.e., Ti3O6H and Ti6O12H clusters, and light was shed on the adsorption behavior by bidentate bridging @Ti3O6H and chelating @Ti6O12H modes. The frontier molecular orbitals (FMOs) and structural and optical properties are studied by applying density functional theory (DFT) and time-dependent DFT (TD-DFT). Important parameters including charge transfer mechanism, electronic coupling constants (|VRP|), band alignment, electron injection (ΔGinject), relative electron injection (ΔGrinject) and light-harvesting efficiency are comprehensively investigated. The charge transfer from TPA-PT dye to the semiconductor surface of Ti3O6H and Ti6O12H clusters is explored as well. Additionally, the computed values of open-circuit photo-voltage (Voc) are presented for two cases of TiO2 and PCBM. [ABSTRACT FROM AUTHOR]

A novel series of 2-(3-methyl-1,6-diphenyl-1H-pyrazolo[3,4-b]pyridin-4-yl)-5-aryl-1,3,4-oxadiazoles (4a–4h) has been synthesized from corresponding hydrazones (3a–3h) and evaluated their antiplatelet aggregation effect induced by arachidonic acid and collagen. Spectral data and elemental evaluation were used to confirm the structure of the compounds while molecular docking against cyclooxygenase 1 and 2 (COX1 & COX2) and quantitative structure-activity relationship (QSAR) were performed in describing their antiplatelet potential. All synthesized compound exhibited more than 50% platelet aggregation inhibition against both arachidonic acid and collagen. Antiplatelet activities results showed that 4b and 4f compounds have highest % inhibition against arachidonic acid. High Egap and ionization potential values showed that the compound 4d, 4e and 4f were supposed to be more active and good electron donor while 4b, 4c, 4d, 4e, 4g and 4h might be more active due to more electrophilic sites. Interaction with more than one residues in the binding pocket of COX-1 in comparison with aspirin and ligand efficacy (LE) consequences showed that compounds have excellent action potential for COX-1. Computational evaluations are in good agreement with antiplatelet activities of the compounds. All compounds might be promising antiplatelet agents especially 4b, 4f and helpful in the synthesis of new drugs for the treatment of cardiovascular diseases (CVDs). [ABSTRACT FROM AUTHOR]

Multifunctional pyrazole derivative, i.e. 3-amino-1-(5-hydroxy-3-methyl-1H-pyrazol-4-yl)-1H-benzo[f]chromene-2-carbonitrile (PBCC) has been synthesized and characterized. To shed light on various properties of interests, the ground state geometry was optimized by adopting Density Functional Theory (PBE/TZ2P). The effect of different functionals on the absorption wavelengths was studied by using Time-Domain DFT (TDDFT), e.g. GGA functional PBE, hybrid functionals B3LYP and PBE0, rang separated functionals CAM-B3LYP, LCY-PBE and CAMY-B3LYP, Dispersion Corrections PBE-D3 and B3LYP-D3. Among all these functionals PBE and PBE-D3 were found to be good choices which reproduced the absorption spectra of the PBCC. With the aim to enhance the electro-optical, charge transfer and photovoltaic properties, five new derivatives were designed by di-substituting the –F, –Cl, –Br, –COOH and –CN at benzochromene moiety. The electron injection barrier, band gap alignment and related calculated photovoltaic parameters revealed that PBCC and its newly designed derivatives would be proficient to be used in photovoltaic devices. These compounds can be used as donor materials in dye-sensitized solar cells (DSSCs) with favorable type-II band alignment. Moreover, PBCC and most of its derivatives might also be good choice as efficient acceptors with poly(dithieno[3,2-b:2,3-d]pyrrole thiophene) (PDTPr-T) and donor materials with Phenyl-C61-butyric acid methyl ester (PC61BM) in organic solar cells. [ABSTRACT FROM AUTHOR]

A novel aggregation induced emission (AIE) active anthracene based dihydroquinazolinone derivative (probe 1) has been synthesized and characterized by means of spectroscopic methods. The photophysical properties of this probe have been investigated in solvents of different polarity display that fluorescence states are of intramolecular charge transfer (ICT) character. Probe 1 show clear AIE behavior in water/THF mixture on reaching water fraction 95%. The AIE behavior of probe 1 have been exploited for the detection of metal ions in aqueous solution which reveals high selectivity and sensitivity towards Cu2+ ions by colorimetrically and function as a chemosensor in a remarkable turn-off fluorescence manner. Further, the experimental results were investigated by computational means by optimizing the ground state geometries of probe 1 and probe 1-Cu complex using density functional theory (DFT) at B3LYP/6-31G** and B3LYP/6-31G**(LANL2DZ) levels of theory. Intra-molecular charge transfer was observed in probe 1 while ligand to metal charge transfer (LMCT) for probe 1-Cu complex. [ABSTRACT FROM AUTHOR]

Graphical abstract Various new derivatives of 2,5-Di(pyrimidin-5-yl)thieno[3,2- b ]thiophene (Comp.1) were designed by oligocene end core strategy and bridge elongation technique. Optoelectronic and charge transport properties were tailored by di-substitution of phenyl, naphthyl, anthracenyl, tetracenyl, pentacenyl and hexacenyl at end cores of Comp. 1. The quantum chemical approach exposed that designed oligocene derivatives would be talented light emitters and charge transport materials to be utilized for multifunctional purposes in organic field effect transistors, organic light emitting diodes and other semiconductor devices. Abstract With the focus on tuning the charge transport and optoelectronic properties, various new derivatives were designed by substituting the oligocene moieties at end cores of 2,5-di(pyrimidin-5-yl)thieno[3,2- b ]thiophene (Comp. 1). The end core substitution effect of benzene, naphthalene, anthracene, tetracene, pentacene and hexacene on Comp. 1 was comprehensively studied on the structure-property relationship, electro-optical properties, ionization potential (IP), electron affinity (EA) and hole/electron reorganization energies (λ(h)/λ(e)). The injection barrier was reduced by introducing the oligocene units at end cores. The substitution of anthracene, tetracene, pentacene and hexacene at end cores of Comp. 1 significantly minimized the polarization resulting smaller λ(h) (Comp. 1c – Comp. 1f) than the referenced compound, i.e., pentacene. The smaller λ(h) values are illuminating that newly designed derivatives might be superior/analogous to pentacene, i.e., frequently used hole transport material. The fluorescence spectra, dipole moment, IP, EA and λ(h) values showed that targeted molecules would be not only good for organic light emitters but also efficient for organic semiconductors and photovoltaic devices. [ABSTRACT FROM AUTHOR]

Using density functional theory (DFT) methods, we shed light on the structural, optical, electronic, and nonlinear optical (NLO) properties of three derivatives of 9,12-diiodo-1,2-dicarba-closo-dodecaborane(12) (C2H10B10I2). The DFT and time-dependent DFT methods are considered very precise and practical to optimize the ground and excited state geometries, respectively. A vibrant intramolecular charge transfer from highest occupied molecular orbitals (HOMOs) to the lowest unoccupied molecular orbitals (LUMOs) was observed in all compounds. The geometrical parameters of the experimental crystal structure, i.e. bond lengths/angles, have been successfully reproduced. The HOMO and LUMO energies, as well as their energy gaps (Eg), were also calculated and compared with each other for all derivatives. The effect of attached groups on electronic, optical, and NLO properties along with detailed structure-property relationship was discussed. For NLO response, the CAM-B3LYP functional along with relatively larger basis set 6-31+G** (for hydrogen, carbon, boron, and oxygen atoms) and LANL2DZ (for iodine atoms) have been used to optimize the compounds at ground states. The calculation of second-order NLO polarizabilities (βtot) shows that compounds 2 and 3 possess the βtot amplitudes of 3029 and 4069 a.u., respectively, with CAM-B3LYP method that are reasonably larger than similar prototype molecules. Owing to their unique V-shapes, the nonlinear anisotropy values are found to be 0.63, 0.34, and 0.44 for compounds 1–3, respectively, which show the significant two-dimensional character of these compounds. Thus, the NLO amplitudes as well as the nonlinear anisotropies indicate that the above-entitled compounds are good contenders for optical and NLO applications. [ABSTRACT FROM AUTHOR]

Graphical abstract Charge transport nature (p-channel/ambipolar) in heterocyclic chalcones was lime lighted with the aim that how the methoxy groups change the characteristics from p- to ambipolar performance. Electro-optical and NLO properties were tuned by comprising di-/tri-methoxy at peripheral. Mono- and di-methoxy chalcone derivatives show the ambipolar performance. Balanced λ and better hole transfer integrals result in p-channel features (tri-methoxy). Abstract Chalcone derivatives gained significant consideration from scientific community due to their potential applications ranging from better biological activity to the efficient semiconducting properties. Present investigation deals with the in-depth study of three chalcone derivatives (2E)-1-(2,5-Dimethyl-3-thienyl)-3-(2-methoxyphenyl)prop-2-en-1-one (1), (2E)-3-(3,4-Dimethoxyphenyl)-1-(2,5-dimethylthiophen-3-yl)prop-2-en-1-one (2), and (E)-1-(2,5-Dimethyl-3-thienyl)-3-(2,4,5-trimethoxyphenyl)prop-2-en-1-one (3) highlighting their optoelectronic, charge transport (CT) and nonlinear optical (NLO) response. The ground and excited state geometries are optimized by applying density functional theory (DFT) and time dependent DFT, respectively. The effect of electron donating groups on the frontier molecular orbitals, absorption and emission wavelengths are investigated and discussed thoroughly using the quantum chemical calculations. The comprehensive intra-molecular charge transfer (ICT) is perceived from the occupied orbitals to the unoccupied molecular orbitals. A novel structure-property relationship is established on the basis of their calculated electronic structures, frontier orbitals and density of states. The electro-optical and nonlinear optical (NLO) properties are finely tuned in the chalcone derivatives comprising of di- and tri-methoxy groups at peripheral. The nature of the p-type and ambipolar charge transport behavior of the compounds 1 – 3 is limelighted on the basis of their ionization potentials, electron affinities, reorganization energies, transfer integrals and intrinsic mobility. The mono- and di-substituted methoxy chalcone derivatives show the ambipolar performance owing to the better transfer integral and intrinsic mobility values for hole and electron. Whilst tri-methoxy at peripheral would lead the p-channel characteristics due to the balanced reorganization energy (hole and electron) and superior hole transfer integrals leads to higher hole intrinsic mobility. [ABSTRACT FROM AUTHOR]

A novel pyrazolyl chromene derivative (Probe 1 ) displaying aggregation induced emission (AIE) properties that capable of sensing of multiple metal ions has been designed and synthesized. The multi analyte probe exhibits selective sensing for Cu 2+ and Ni 2+ ions via fluorescence turn-off mechanism and ratiometric selectivity for Hg 2+ ions in aqueous media. The extent of binding of the probe with sensitive metal ions has been demonstrated. The experimental results were further investigated by computational means by optimizing the ground state geometries of Probe 1 and its various metal complexes for Probe 1 -Ni, Probe 1 -Hg and Probe 1 -Cu using density functional theory (DFT) at B3LYP/6-31+g(d,p) (LANL2DZ) level. On the basis of binding energies, the stability of metal complexes has been studied. In Probe 1 -Ni and Probe 1 -Cu complexes, charge transfer has been observed from Probe 1 to metal ions revealing ligand to metal charge transfer (LMCT) while in Probe1-Hg complex LMCT as well as intra-molecular charge tranfer (ICT) within Probe 1 . [ABSTRACT FROM AUTHOR]

This paper presents a facile synthetic route to synthesise two new bicyclic oxazolidine compounds 3,5-bis(4- chlorophenyl)-7a-methyldihydro-1H-[1,3]oxazolo[3,4-c][1,3] oxazole (1) and 3,5-bis(2-methoxyphenyl)-7a-methyldihydro- 1H-[1,3]oxazolo[3,4-c][1,3]oxazole (2). The condensation reaction between 2-amino-2-methylpropane-1, 3-diol (ampdH2) and choloro- and methoxy- substituted aromatic aldehyde yielded the heterocyclic bicyclic compounds (1) and (2), respectively. The compounds are characterised by FT-IR and 1HNMR spectroscopy and structures are conclusively determined by single crystal X-ray diffraction analysis. The ground state geometries are optimised by using density functional theory (DFT) at B3LYP/6-31G** level of theory to compare the geometric parameters (bond lengths, bond angles and torsion angles) with the X-ray crystallographic data. The computed geometric parameters are in good agreement with the experimental data. To shed light on the electronic and photophysical properties, DFT/B3LYP/6-31G** and time dependent DFT have been applied, respectively. Intra-molecular charge transfer has been observed in both the compounds. The absorption wavelengths are calculated with and without the solvent (acetone, acetonitrile, dimethylformamide, dimethyl sulfoxide and methanol) at TD-B3LYP/6-31G** level of theory. [ABSTRACT FROM AUTHOR]

The present study spotlights the hybrid chalcone derivatives consisting of coumarin moieties conjugated systematically with different heterocyclic rings. The heterocyclic rings including bifuran, bicyclopentane, bipyrrole and bithiophenes groups are used to design compounds 1 , 2 , 3 and 4 , respectively. Different density functional theory (DFT) methods are used for optimization of designed compounds. The M06 functional shows reasonably good accuracy for calculations of geometrical and absorption spectra as compared with other methods and/or available experimental data. The calculated average third-order NLO polarizabilities ( γ ) for compounds 1 , 2 , 3 and 4 are found to be 526.22 × 10 −36 , 675.40 × 10 −36 , 939.58 × 10 −36 and 1109.30 × 10 −36 esu., respectively, at M06/6-311G** level of theory. The γ amplitudes of compounds 1 , 2 , 3 and 4 are reasonably enhanced, which are about 25, 27, 30 and 32 times larger to the γ amplitude of para nitroaniline (a prototype NLO molecule) at same M06/6-311G** level of theory. Furthermore, we highlight the structure-property relationship using TD-DFT calculations for absorption and emission spectra, frontier molecular orbitals and molecular electrostatic potential maps. Thus, the present study will evoke the interest of scientific community to develop the above title materials for efficient NLO applications. [ABSTRACT FROM AUTHOR]

Abstract: A series of novel N′-arylmethylidene-3-methyl-1-phenyl-6-p-chlorophenyl-1H-pyrazolo[3,4-b]pyridine-4-carbohydrazide (2a–2t) has been synthesized from hydrazide (1). The structures of newly synthesized compounds were confirmed by FT-IR, EI-MS, 1H NMR and 13C NMR techniques. The title compounds were evaluated for antioxidant and antiplatelet aggregation effect induced by arachidonic acid (AA) and collagen. All the compounds have exhibited high antioxidant potential and antiplatelet activity but (2c, 2e, 2f, 2g, 2i, 2m, 2o and 2q) have revealed superlative antiplatelet activity. The molecular docking against cyclooxygenase-1 and 2 (COX-1 and COX-2) and quantitative structure-activity relationship (QSAR) were performed in describing their antiplatelet potential against AA and collagen along with antioxidant potential determined by ABTS, DPPH and iron chelating methods. The molecular docking study exhibited that compounds (2c, 2e, 2f, 2g, 2i, 2l, 2m, 2o and 2q) were found to be active against COX-1 while 2o compound also showed activity against COX-2. Compounds 2g and 2l were found to have higher energy stabilization values in comparison to Aspirin. Computational evaluations both molecular docking and QSAR are in good agreement with antiplatelet and antioxidant activities of the compounds (2a–2t). All the compounds especially 2g, 2l, 2m might be promising antiplatelet agents and might be helpful in the synthesis of new drugs for the treatment of cardiovascular and anti-inflammatory diseases.Graphical Abstract: [ABSTRACT FROM AUTHOR]

Two new anthracene derivatives donor–π–acceptor (Compound 1 ) and acceptor–π–acceptor (Compound 2 ) have been designed with the aim to understand the effect of donor and acceptor on the electronic, optical and charge transfer properties of sensitizers and sensitizers@TiO 2 cluster. The electron donating group (–OH) and acceptor (–COOH) have been substituted at periphery and the effect was studied thoroughly. The ground state geometries of both the compounds were optimized by using density functional theory (DFT) at B3LYP/6-31G**, CAM-B3LYP/6-31G** LC-BLYP/6-31G**, BHandHLYP/6-31G** and PBE1PBE/6-31G** levels of theory. Moreover, ground state geometries of sensitizers@TiO 2 cluster were optimized by adopting the same methods along with LANL2DZ pseudopotential for Ti while 6-31G** basis set for all other atoms. The electro-optical properties and charge transfer nature of dye adsorbed at TiO 2 cluster were also systematically investigated. The absorption spectra of anthracene derivatives before and after adsorption at TiO 2 cluster were limelighted by adopting time dependent DFT. [ABSTRACT FROM AUTHOR]

Using first-principle methods, several key electronic, optical and nonlinear optical properties are calculated for two recently synthesized chalcone derivatives i.e. (2E)-3-(4-methylphenyl)-1-(3-nitrophenyl)prop-2-en-1-one (comp. 1 ) and (2E)-3-[4-(dimethylamino)phenyl]-1-(3-nitrophenyl)prop-2-en-1-one (comp. 2 ). The calculation of dipole moment, polarizability <α>, anisotropy of polarizability as well as second hyperpolarizability (usually considered as a signature for two photon absorption phenomenon) are performed using density functional theory methods at PBE0/6-311G** level of theory. The linear average polarizability <α> for comp. 1 and comp. 2 are found to be 32.15 × 10 −24 and 38.76 × 10 −24 esu, respectively. Similarly, the second hyperpolarizability <γ> amplitudes of comp. 1 and comp. 2 are found to be reasonably larger mounting to 79.31 × 10 −36 and 181.36 × 10 −36 esu, respectively. The importance of donor end is determined by comparing p -methylphenyl group of comp. 1 with that of N , N -dimethylaniline group of comp. 2 that results a remarkable increase in its <γ> amplitude, which is ∼2 times larger as compared with that of comp. 1 owing to the stronger donor-acceptor configuration of comp. 2 . Interestingly, a comparison of average static third-order nonlinear polarizabilities <γ> shows that <γ> amplitudes of comp. 1 and comp. 2 are ∼13 times and ∼29 times larger than that of para -nitroaniline (a typical standard push-pull NLO-phore) at the same PBE0/6-311G** level of theory, which indicates a real time NLO application of our titled compounds. Time dependent density functional theory (TD-DFT) calculations along with frontier molecular orbitals, density of states (DOS), second hyperpolarizability density analysis and molecular electrostatic potential (MEP) diagrams are used to trace the origin of electro-optical as well as structure property relationships. [ABSTRACT FROM AUTHOR]

The ground state neutral geometries of some natural tropolones, i.e. stipitatonic acid (AF1), stipitalide (AF2), stipitaldehydic acid (AF3) and methyl stipitate (AF4) have been optimized by using Density Functional Theory (DFT) at B3LYP/6-31G*, B3LYP/6-31G**, B3LYP/6-31+G* and B3LYP/6-31+G** levels of theory. The excited state geometries of AF1-AF4 were optimized by adopting the Time Dependent Density Functional Theory (TDDFT) at the same levels of theory. The frequencies and cation species of AF1-AF4 were also computed at all the above mentioned levels of theory. We shed light on the electro-optical and molecular properties, e.g. energy gaps, highest occupied molecular orbitals, lowest unoccupied molecular orbitals, absorption wavelengths, electronegativity (χ), hardness (η), electrophilicity (ω), softness (S), electrophilicity index (ωi) and the radical scavenging activity (RSA). Hydrogen atom transfer (HAT) and one-electron transfer mechanisms have been discussed to shed light on the RSA. The smallest ionization potential and bond dissociation energy of AF4 are revealing that this compound would have more RSA than those of other counterparts. [ABSTRACT FROM AUTHOR]

The isoxazole derivatives gained significant attention in our daily life from better biological activity to the semiconducting materials. This study deals in depth investigation of two isoxazole derivatives, i.e. 2-[(E)-(3,4-Dimethylisoxazol-5-yl)iminomethyl]phenol ( 1) and 1-[(E)-(3,4-Dimethylisoxazol-5-yl)iminomethyl]-2-naphthol ( 2) with respect to the geometric, charge transport, optoelectronic and nonlinear optical properties by density functional theory (DFT) and time-dependent DFT. The comprehensible intra-molecular charge transfer (ICT) was conceived from HOMOs to LUMOs. Strength of the electron donor groups was investigated on the absorption wavelengths, emission wavelengths, ionization potentials (IPs), electron affinities (EAs), total/partial densities of states and structure-property relationship. The smaller hole reorganization energies and superior transfer integrals of isoxazole derivatives ( 1 and 2) than the electron ones are leading to higher hole intrinsic mobility values as compared to the electron mobility exhibit that these systems would be good hole transport contenders. The first hyperpolarizability values are about 19 and 21 times larger than that of urea suggesting that 1 and 2 can also be considered as potential contestants for NLO applications as well. The FMO, MEP, IP, EA, NLO and SAR of isoxazole derivatives were studied by DFT and TDDFT. The effect of donor strength was discussed on optoelectronic and charge transport properties. The smaller hole reorganization energies and superior transfer integrals of both the derivatives is leading to higher hole intrinsic mobility values as compared to the electron mobility exhibit that these systems would be good hole transport contenders. [ABSTRACT FROM AUTHOR]

Using the density functional theory methods, we effectively tune the second-order nonlinear optical (NLO) properties in some chalcone derivatives. Various unique push–pull configurations are used to efficiently enhance the intramolecular charge transfer process over the designed derivatives, which result in significantly larger amplitudes of the first hyperpolarizability as compared to their parent molecule. The ground state molecular geometries have been optimized using B3LYP/6-311G** level of theory. A variety of methods including B3LYP, CAM-B3LYP, PBE0, M06, BHandHLYP and MP2 are tested with 6-311G** basis set to calculate the first hyperpolarizability of parent system 1 . The results of M06 are found closer to highly correlated MP2 method, which has been selected to calculate static and frequency dependent first hyperpolarizability amplitudes of all selected systems. At M06/6-311G** level of theory, the permanent electronic dipole moment (μ tot ), polarizability (α 0 ) and static first hyperpolarizability (β tot ) amplitudes for parent system 1 are found to be 5.139 Debye, 274 a. u. and 24.22 × 10 −30 esu, respectively. These amplitudes have been significantly enhanced in designed derivatives 2 and 3 . More importantly, the (β tot ) amplitudes of systems 2 and 3 mount to 75.78 × 10 −30 and 128.51 × 10 −30 esu, respectively, which are about 3 times and 5 times larger than that of their parent system 1 . Additionally, we have extended the structure-NLO property relationship to several newly synthesized chalcone derivatives. Interestingly, the amplitudes of dynamic frequency dependent hyperpolarizability μβ ω (SHG) are also significantly larger having values of 366.72 × 10 −48 , 856.32 × 10 −48 and 1913.46 × 10 −48 esu for systems 1 – 3 , respectively, at 1400 nm of incident laser wavelength. The dispersion behavior over a wide range of change in wavelength has also been studied adopting a range of wavelength from 1907 to 544 nm. Thus, the present work realizes the potential of designed derivatives as efficient NLO-phores for modern NLO applications. [ABSTRACT FROM AUTHOR]

The quinazolinone compounds (1 and 2) in this work were examined for their in vitro antibacterial activities against gram-positive (Staphylococcus aureus) and gram-negative bacteria (Klebsiella pneumonia, Proteus bacilli and Shigella flexneri). Compared to the reference antibiotic chloramphenicol, these compounds showed high antibacterial activities against studied strains with inhibition zones observation. The ground state geometries have been optimized by using density functional theory (DFT) at B3LYP/6-31G* level of theory. The absorption spectra have been calculated by using time dependent density functional theory (TDDFT) with and without solvent. The effect of different functionals (B3LYP, MPW1PW91, and PBE1PBE) on the absorption wavelengths has been studied. The ionization potential (IP), electron affinity (EA), energy gap (Egap), electronegativity (χ), hardness (η), electrophilicity (ε), softness (S) and electrophilicity index (εi) were computed and discussed. The nonlinear optical (NLO) properties vary by changing the theory (DFT to HF) or functional (B3LYP to CAM-B3LYP). The physicochemical parameters have been studied by quantitative structure-activity relationship (QSAR). The computed properties of investigated compounds have been compared with the Chloramphenicol as well as available experimental data. [ABSTRACT FROM AUTHOR]

The structural, electro-optical and charge-transport properties of compound trans -3-(3,4-dimethoxyphenyl)-2-(4-nitrophenyl)prop-2-enenitrile (DMNPN) were studied using quantum chemical methods. The neutral, cation and anion molecular geometries were optimized in the ground state using density functional theory (DFT) at the restricted and unrestricted B3LYP/6-31G** level of theory. The excited state geometries were optimized by applying time-dependent DFT at the TD-B3LYP/6-31G** level of theory. The absorption and fluorescence wavelengths were calculated at the TD-CAM-B3LYP/6-31G** and TD-LC-BLYP/6-31G** levels of theory. The distribution pattern of the charge densities on the highest occupied molecular orbitals (HOMOs) and lowest unoccupied molecular orbitals (LUMOs) are discussed. Intramolecular charge transfer was observed from the dimethoxyphenyl to (nitrophenyl)prop-2-enenitrile moieties. The detailed charge-transport behavior of the DMNPN molecule is investigated based on its ionization potential, electron affinity, hole and electron reorganization energies, hole and electron-transfer integrals, and hole and electron intrinsic mobilities. The total/partial densities of states and structure–property relationship are discussed in detail. The higher computed hole intrinsic mobility than electron intrinsic mobility reveals that DMNPN is an efficient hole-transport material. [ABSTRACT FROM AUTHOR]

In this paper, we present the design of five new derivatives of triphenylamine dyes with variable thiophene rings (0-5) and shed light on their electrooptical and charge-injection properties. Computational techniques are used to study the effect of the thiophene moieties on the properties of interest, i.e., how the number of thiophene rings in π-conjugated systems influence the absorption spectra and electron injection of the dyes. The results show that the absorption spectra gradually became broad and red-shifted (384-542 nm) with the number of thiophene units. The effect of thiophene units on the performance of sensitizers in dye-sensitized solar cells is also determined. During theoretical examination, the electron injection efficiency (Φinject) and light harvesting efficiency ( LHE) are determined. Results indicate that the selection of appropriate lengths of conjugated bridges in the dye sensitizer is very important in designing high-efficiency dyes. [ABSTRACT FROM AUTHOR]

The corner stone of present study is to tune the electro-optical and charge transport properties of donor-bridge-acceptor (D- π -A) triphenylamine (TPA) derivatives. In the present investigation, an electron deficient moiety (pyrimidine), electron-rich moiety (thiophene) and oligocene (benzene, naphthalene, anthracene, tetracene and pentacene) have been incorporated as π -spacer between the donor TPA unit and cyanoacetic acid acceptor and anchoring group. The elongation of bridge usually affects the energy levels, i.e., higher the highest occupied molecular orbital (HOMO) while lower the lowest unoccupied molecular orbital (LUMO) thus reduces the HOMO–LUMO energy gap. The lowered LUMO energy levels of cyano-{2-[6-(4-diphenylamino-phenyl)-pyrimidin-4-yl]-tetraceno[2,3-b]thiophen-8-yl}-acetic acid (TPA-PTT4) and cyano-{2-[6-(4-diphenylamino-phenyl)-pyrimidin-4-yl]-pentaceno[2,3-b]thiophen-9-yl}-acetic acid (TPA-PPT5) dyes revealed that electron injected from dye to semiconductor surface might be auxiliary stable resulting in impediment of quenching. The broken co-planarity between the π -spacer conceiving LUMO and the TPA moiety would help to impede the recombination process. Moreover, it is expected that TPA derivatives with the tetracenothiophene and pentacenothiophene moieties as π -bridge would show better photovoltaic performance due to lowered LUMO energy level, higher electronic coupling constant, light harvesting efficiency and electron injection values. [ABSTRACT FROM AUTHOR]

This study was carried out to design heterocyclic azo dyes for dye sensitized solar cells. Quantum chemical calculations were performed to determine the open-circuit photovoltage ( V OC ), and to quantify the parameters such as the light harvesting efficiency, the electron injection efficiency associated with the short-circuit photocurrent density ( J SC ). All the dyes showed absorbance in visible region (502–521 nm) with high oscillator strength ( f ) (0.473–0.961) and light harvesting efficiency (LHE) (0.663–0.891). After binding to titanium oxide, all dye showed slightly red-shifted absorption (521–527 nm) with improved oscillator strength ( f ) (0.573–0.991) and light harvesting efficiency (LHE) (0.733–0.898). There is high probability that these dyes will show larger J SC due to high driving force for electron injection. These dyes also showed high V OC (1.037–1.128 eV). These results indicate that heterocyclic azo dyes will show better light to power conversion efficiency in DSSCs due high J SC and V OC . These theoretical criteria would be useful to design and fast screen other organic dyes, specifically for chemically fairly similar dyes. [ABSTRACT FROM AUTHOR]

The triphenylamine (TPA), thiophene and pyrimidine are being used as efficient advanced functional semiconductor materials. In the present study, some new TPA donor–π–acceptor derivatives were designed where TPA moiety acts as donor, thiophene-pyrimidine π-bridge and acetic/cyanoacetic acid as acceptor. The ground-state geometries were optimized at B3LYP/6-31G** level of theory. The excitation energies and oscillator strengths were computed at TD-CAM-B3LYP/6-31G** (polarizable continuum model (PCM), in methanol) level of theory. The electronic, photophysical and charge transport properties were calculated wherever possible the computed values were compared with the available experimental as well as computational data. The electron injection (ΔGinject), relative electron injection (ΔGinjectr), electron coupling constants (∣VRP∣) and light harvesting efficiencies (LHE) have been calculated and compared with referenced compounds. The energies of the lowest unoccupied molecular orbitals (ELUMOs), diagonal bandgaps and energy level offsets were studied to shed light on the electron transport behavior. The effect of anchoring groups (acetic acid and cyanoacetic acid) was studied on the properties of interests in the dye and dye@Ti6O12. It was observed that after interaction of dye with the TiO2 cluster intra-molecular charge transport enhanced from HOMO of the dye to LUMO of the semiconductor cluster. The cyanoacetic acid anchoring group leads the superior LHE, ΔGinject and ∣VRP∣ which might improve the solar cell performance. [ABSTRACT FROM AUTHOR]

A quantum chemical investigation has been performed to spotlight the structure–property relationship among methoxybenzeylidene-based humidity sensor and water molecules. The chemical interactions among (E)-2-(4-(2-(3,4-dimethoxybenzeylidene)hydrazinyl)phenyl) ethane-1,1,2-tricarbonitrile (DMBHPET) sensor and water molecules have been studied using density functional theory (DFT) methods. The molecular structural parameters, binding energies and Infrared (IR) spectroscopic analyses have been performed to assess the nature of intermolecular interactions. Three different positions have been identified for possible attachments of H2O molecules through hydrogen bonding interactions. These positions include NH (complex 1a), p-OCH3 (complex 1b) and N=N (complex 1c) group in sensor molecule (1) for the chemical adsorption of water molecules. While, the complex 1abc includes all three sites with simultaneously three H2O molecules attached to it through hydrogen bonding. The binding energies calculated for complex 1a(NH…H2O), complex 1b(CH3O…H2O), complex 1c(N=N…H2O) and complex 1abc are -30.97, -18.41, -13.80 and -65.36 kcal/mol, respectively. The counterpoise (CP) scheme has been used to correct the basis set superposition error (BSSE) in calculation of binding energies of sensor and H2O complexes. The higher binding energy of -65.36 kcal/mol for complex 1abc represents that the present methoxybenzeylidene-based sensor has significant potential through hydrogen bonding formation for sensing humidity as indicated in our previous experimental investigation. The evidence of hydrogen bonding interactions between sensor 1 and H2O molecules has been traced through structural parameters, red shift in IR spectra as well as molecular electrostatic maps. Thus the present investigation highlights the first computational framework for a molecular level structure-binding activity of a methoxybenzeylidene-based sensor and water molecules. [ABSTRACT FROM AUTHOR]

This study spotlights the fundamental insights about the structure and static first hyperpolarizability ( β) of a series of 2,4-dinitrophenol derivatives (1-5), which are designed by novel bridging core modifications. The central bridging core modifications show noteworthy effects to modulate the optical and nonlinear optical properties in these derivatives. The derivative systems show significantly large amplitudes of first hyperpolarizability as compared to parent system 1, which are 4, 46, 66, and 90% larger for systems 2, 3, 4, and 5, respectively, at Moller-Plesset (MP2)/6-31G* level of theory. The static first hyperpolarizability and frequency dependent coupled-perturbed Kohn-Sham first hyperpolarizability are calculated by means of MP2 and density functional theory methods and compared with respective experimental values wherever possible. Using two-level model with full-set of parameters dependence of transition energy (Δ Ε), transition dipole moment ( μ0) as well as change in dipole moment from ground to excited state (Δ μ), the origin of increase in β amplitudes is traced from the change in dipole moment from ground to excited state. The causes of change in dipole moments are further discovered through sum of Mulliken atomic charges and intermolecular charge transfer spotted in frontier molecular orbitals analysis. Additionally, analysis of conformational isomers and UV-Visible spectra has been also performed for all designed derivatives. Thus, our present investigation provides novel and explanatory insights on the chemical nature and origin of intrinsic nonlinear optical (NLO) properties of 2,4-dinitrophenol derivatives. © 2014 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

The 2-{4-[2-benzylidenehydrazino]phenyl}ethylene-1,1,2-tricarbonitrile (System 1), 2-{4-[2-(1- naphthylmethylene)hydrazino]phenyl}ethylene-1,1,2-tricarbonitrile (System 2) and 2-{4-[2-(9-anthrylmethylene)- hydrazino]phenyl}ethylene-1,1,2-tricarbonitrile (System 3) were synthesized by direct tricyanovinylation of hydrazones. The bathochromic shift in absorption spectra has been observed by increasing the solvent polarity. The FTIR spectra of these new dyes exhibited three important absorption bands. The first band centered near 3260 cm-1 in System 1 while 3208 cm-1 and 3211 cm-1 in System 2 and System 3 for the • NH absorption, respectively. The second band is a sharp absorption band in the region of 2212-2209 cm-1, which was attributed to the cyano group absorption. The third is an absorption band in the region of 1611-1603 cm-1 ascribed for the C=N. Density functional theory (DFT) calculation of relative energies, relative enthalpies and free energies shows that E isomers are the most stable except System 3 in which the most stable is Z isomers. The conformational energy profile shows two maxima near (-90 and 90°) while three local minima observed at (-180, 0 and 180) for N1-N2-C1-C2 torsional angle. The highest occupied molecular orbitals (HOMOs) are localized on the whole molecules while lowest unoccupied molecular orbitals (LUMOs) are distributed on the tricarbonitrile. [ABSTRACT FROM AUTHOR]

The efficient organic dyes 2-{4-[2-(2-hydroxybenzylidene)hydrazino]phenyl}ethylene-1,1,2-tricarbonitrile and 2-{4-[2-(4-hydroxybenzylidene)hydrazino]phenyl}ethylene-1,1,2-tricarbonitrile have been synthesized, characterized and fabricated as hetero-junction solar cell materials. We use B3LYP/6-31G*, B3LYP/6-31G** and HF/6-31G** level of theories to optimize the ground state geometries. The absorption wavelengths have been computed by using time dependent density functional theory which is in good agreement with the experimental data. The hetero-junction solar cell devices have been fabricated by organic–inorganic heterojunction (dye/Si/TiO 2 ) and measured the efficiency by applying the incident power 30, 50 and 70 mW/cm 2 . The maximum efficiency 3.6% for dye2 has been observed. We shed light on the electronic and charge transport properties. Moreover, the stability and external quantum efficiencies have been measured. [ABSTRACT FROM AUTHOR]

A new triol-based compound, teucriol (1) and eleven others (2 – 12), were first time isolated from the ethanol extract of Teucrium stocksianum Bioss using bioassay guidelines, and their structures were established using various spectroscopic techniques. Antibacterial, antifungal, insecticidal, cytotoxic, phytotoxic, and antioxidant properties of ethanol extract fractions and a novel isolate were tested. When compared to the standard ceftriaxone, the extract, fractions, and novel isolate demonstrated good antibacterial potential against Streptococcus pneumonia , Staphylococcus aureus , Klebsiella pneumonia and Escherichia coli bacteria, while all were inert against Fusarium solani, Candida albicans, Candida glabrata, Microsporum Canis and Aspergillus flavus fungi, and Tribolium castaneum and Rhyzopertha dominica insects. All fractions showed promising antioxidant activity. Density functional theory was used to optimize the ground state geometry of teucriol (1) at the B3LYP/TZ2P level. The global molecular descriptors, electronic characteristics, molecular electrostatic potential, and Hirshfeld surface analyses were studied to investigate the biological activity of the investigated molecule. [ABSTRACT FROM AUTHOR]

Highlights: [•] DFT and TDDFT have been applied to investigate the properties of interests. [•] Intra-molecular charge transfer was observed from donor to acceptor moieties. [•] The designed materials would be good contenders for photovoltaic technology. [ABSTRACT FROM AUTHOR]

Highlights: [•] ICT has been enhanced by introducing the bridge, donor and acceptor moieties. [•] Electronic and charge transport properties have been tuned. [•] New derivatives would be good light-emitters. [•] Smaller hole λ of a and d than naphthalene revealing efficient hole transporters. [•] The modeled compounds would be efficient multipurpose semiconductor materials. [ABSTRACT FROM AUTHOR]

We synthesized a number of aniline derivatives containing acyl groups to compare their barriers of rotation around the N-CO groups. Geometry optimization for all the rotamers have been performed using density functional theory (DFT) at the B3LYP/6-31G** level of theory. For each stationary point we carried out vibrational frequency calculations at the same level to characterize their nature as minima or transition states. The methoxy group substituent on the benzene ring causes some changes in the C-C bond distances. We carried out potential energy surface scanning to find out all possible low-energy conformations, which would be used as the initial structure for further molecular calculations. There were only three kinds of conformations with local minimum potential energy and two transition states. The optimized bond lengths and bond angles are in better agreement with the experimental values. [ABSTRACT FROM AUTHOR]

Highlights: [•] ICT has been improved by introducing the bridge, donor and acceptor moieties. [•] Electronic, optical and charge transport properties have been tuned. [•] DFT and TDDFT have been applied to predict the properties. [•] The IP, EA, reorganization energies and FMOs have been discussed thoroughly. [Copyright &y& Elsevier]