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The current study reports tailoring the electronic donor structures of organic dyes to modify their optical and nonlinear optical (NLO) response properties. Five (5) tri‐phenyl amine (TPA) based Donor‐π‐Acceptor (D‐π‐A) organic dyes with the codes ICAA1, ICAA2, ICAA3, ICAA4, and ICAA5 were designed and investigated for their optical and NLO properties using quantum chemical methods. Optical and NLO properties of these dyes were studied by CAM‐B3LYP method and 6‐311G* basis set. The focus has been on the impact of adding secondary donors and shifting their substitutions at ortho (o), meta (m) and para (p) positions. Among all designed compounds, ICAA4 showed the highest amplitude of average third‐order NLO polarizability <γ>, which is calculated to be 1316 × 10−36 esu. Time‐dependent Density Functional Theory (TD‐DFT) method was used to determine how a change in the position of the donor affected the excitation energy (Eg) and NLO response properties. The findings showed that changing the position of the secondary donor results in a red shift among absorption spectra as well as the increase in their NLO responses. Complete process of intramolecular charge transfer (ICT) has been investigated in terms of different optical parameters such as frontier molecular orbitals (FMOs), molecular electrostatic potentials (MEPs), transition density matrix (TDMs), density of states (DOS), electron density difference (EDD), and natural bond orbital (NBO) analysis. Our calculations for study of ICT process indicate that p‐position of methoxy group performs better among all other positions and even it has better NLO response properties than the compound with three collective methoxy groups. The calculated Voc values of all designed molecules range from 1.09 to 1.30, all of them are positive while their ΔGinject is found to be in the range of −0.87 to −1.79 eV indicating their decent potential for photovoltaic applications. The studied optical, NLO and photovoltaic parameters illustrated that ICAA1 to ICAA5 are appropriate molecules not only for NLO applications but also for efficient photovoltaic purposes. [ABSTRACT FROM AUTHOR]

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]

For energy‐efficient and high‐power illumination systems, phosphor materials have attracted huge research attention over the recent decades. Herein, applying the first‐principles method, we investigate and predict the optoelectronic and structural properties of light‐harvesting phosphors Z2SiF6 (Z = K, Li, Na, Rb) as promising candidates for weight‐light‐emitting diodes w‐LEDs. The calculated direct energy band gaps are of order 1.56, 1.461, 1.479, and 1.585 eV for Z2SiF6 (Z = K, Li, Na, Rb), respectively, thus rendering the compound's semiconducting nature suitable for optoelectronic applications. Calculated structural properties show that Rb2SiF6 is the most stable compound among Z2SiF6 (Z = K, Li, Na, Rb). The optical properties in the energy range of 0–14 eV have been investigated using the well‐known (GGA) formulism available in the literature. Studied compounds are active optical materials as the value of their refractive index nω is between 1.0 and 2.0. Based on investigated optical parameters, we can say that Z2SiF6 (Z = K, Li, Na, Rb) are potential candidates for optoelectronic device applications like white LEDs (w‐LEDs). Thermodynamic parameters of Z2SiF6 (Z = K, Li, Na, Rb) are provided to establish the thermodynamic stability of these compounds. [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]

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]

The present investigation highlights the two-dimensional design of several interesting superalkali-doped borophene derivatives for efficient nonlinear optics (NLO). The combination effects and resulting NLO responses of borophene (B36) and superalkali units (Li3O) were evaluated by orienting superalkali clusters at various sites, such as the hub, rim, and bridge, around an B36 molecule. The charge analysis was characterized by frontier and natural bond orbital analyses, a narrowed HOMO–LUMO bandgap and greater intramolecular charge transfers. Molecular electrostatic potential surfaces demonstrated enhanced optoelectronic features of these complexes that are viable due to Li3O adsorption. Singly doped and doubly doped complexes were considered, and their NLO properties were calculated. Bandgap energy was reduced approximately threefold when doped with two Li3O. As a considerably high figure of merit, first hyperpolarizability (βo) values of up to five digits (including 10,611 au for complex A) prove that these systems can be utilized as promising candidates in various NLO applications. [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]

Different grads of magnetic nano-scaled cobalt ferrites (CoFe 2 O 4 ) photocatalysts were synthesized by modified Solvothermal (MST) process with and without polysaccharide. The indigenously synthesized photocatalysts were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), thermo gravimetric analysis (TGA), Fourier transform infrared (FT-IR), UV–visible (UV–vis) spectroscopy and N 2 adsorption–desorption isotherm method. The Fourier transform infrared spectroscopy study showed the Fe-O stretching vibration 590–619 cm −1 , confirming the formation of metal oxide. The crystallite size of the synthesized photocatalysts was found in the range between 20.0 and 30.0 nm. The surface area of obtained magnetic nanoparticles is found to be reasonably high in the range of 63.0–76.0 m 2 /g. The results shown that only MST-2 is the most active catalyst for photo-Fenton like scheme for fast photodegradation action of methylene blue dye, this is possible due to optical band gap estimated of 2.65 eV. Captivatingly the percentage of degradation efficiency increases up to 80% after 140 min by using MST-2 photocatalyst. Photocatalytic degradation of methylene blue (MB) dye under visible light irradiation with cobalt ferrite magnetic nanoparticles followed first order kinetic constant and rate constant of MST-2 is almost 2.0 times greater than MST-1 photocatalyst. [ABSTRACT FROM AUTHOR]

The oxazole compounds are being used for multifunctional purposes ranging from organic light emitting diodes, organic thin film transistors, and photovoltaic to the nonlinear optical materials. In this study, several structural, electro-optical, charge transport and nonlinear optical properties of (4 Z )-4-Benzylidene-2-(4-methylphenyl)-1,3-oxazol-5(4 H )-one ( BMPO ) have been investigated. Density functional theory (DFT) and time dependent DFT are very accurate and reasonable approaches to optimize the ground and excited state geometries, respectively. Thus, in the present study DFT and TDDFT methods with the B3LYP/6-31G ∗∗ levels of theory have been applied to shed some light on the structure-property relationship, frontier molecular orbitals (FMOs), optical properties. A clear intra-molecular charge transfer (ICT) from the highest occupied molecular orbitals (HOMOs) to the lowest unoccupied molecular orbitals (LUMOs) has been observed. The ionization potentials (IP), electron affinities (EA), total and partial densities of states have been discussed intensively. The electron reorganization energy of oxazole compound ( BMPO ) is smaller than the hole reorganization energy revealing that it might be good electron transport contender in OLED. The electron reorganization energy of BMPO is calculated to be 0.223 eV that is smaller than the perfluoropentacene (value is 0.250 eV), which is famous n -type semiconductor material. The first pathway of BMPO has almost comparable hole and electron transfer integral values whereas the calculated electron reorganization energy (0.223 eV) is considerably lower than the hole reorganization energy (0.381 eV) which leads to superior electron intrinsic mobility of the studied oxazole derivative as compared to the hole one. It is expected that BMPO might be excellent electron transport material. [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]

Pyrazole compounds are gaining noteworthy attention in our daily life from better biological active to the semiconducting materials. Present work deals in depth study of indigenously synthesized pyrazole compound, i.e., 2-[(3,5-dimethyl-1-phenyl-1H-pyrazol-4-yl)methylidene]indan-1,3-dione ( DMPI ) with respect to the structural, electronic, optical and charge transport properties. The ground and excited state geometries were optimized by applying density functional theory (DFT) and time dependent DFT, respectively. The frontier molecular orbitals (FMOs) have been spotlighted. The comprehensible intra-molecular charge transfer (ICT) from the highest occupied molecular orbital (HOMO) to the lowest unoccupied molecular orbital (LUMO) was observed. The absorption and emission wavelengths were studied at the TD-B3LYP/6-31G** level of theory. The total and partial density of states (T/PDOS) has been studied to understanding the contribution of different states in the electronic properties. The ionization potentials (IP), electron affinities (EA), reorganization energies, transfer integrals, intrinsic mobility and structure-property relationship have been discussed intensively. The smaller hole reorganization energy and superior transfer integral values resulting improved hole intrinsic mobility than the electron ones is revealing that DMPI would be better hole transport material. [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]

Imidazolidin derivatives gained significant attention in our daily life from better biological activity to the semiconducting materials. The present investigation deals with the in depth study of (Z)-2-sulfanylidene-5-(thiophen-2-ylmethylidene)imidazolidin-4-one (STMI) with respect to their structural, electronic, optical and charge transport properties as semiconducting material. The ground and first excited state geometries were optimized by applying density functional theory (DFT) and time dependent DFT, respectively. The light has been shed on the frontier molecular orbitals (FMOs) and observed comprehensible intramolecular charge transfer (ICT) from the highest occupied molecular orbitals (HOMOs) to the lowest unoccupied molecular orbitals (LUMOs). The absorption, emission, ionization potentials (IP), electron affinities (EA), total and partial densities of states and structure-property relationship have been discussed. Finally, hole as well as electron reorganization energies, transfer integrals and intrinsic mobilities have been calculated then charge transport behavior of STMI was discussed, intensively. [ABSTRACT FROM AUTHOR]

The ground state structures of 5,5″-diperfluorophenyl-2,2′:5′,2″:5″,2‴-quaterthiophene ( 1 ), 5,5′-bis{1-[4-(thien-2-yl)perfluorophenyl]}-2,2′-dithiophene ( 2 ), 4,4′-bis[5-(2,2′-dithiophenyl)]-perfluorobiphenyl ( 3 ), 5,5″-diperfluorophenyl-2,2′:5′,2″-tertthiophene ( 4 ), 5,5′-diperfluorophenyl-2,2′-dihiophene ( 5 ), and 5,5-diperfluorophenylthiophene ( 6 ) have been optimized at the B3LYP/6-31G(d), B3LYP/6-31G(d,p), PBE0/6-31G(d), and PBE0/6-31G(d,p) level of theories. The B3LYP/6-31+G(d) and PBE0/6-31+G(d) level of theories have been applied to investigate the absorption spectra. The PBE0 functional is good to predict the C–S bond lengths while the C–F bond lengths are good envisaged with B3LYP functional. The increment of thiophene rings between two perfluoroarene rings leads to red shift in absorption spectra. The electron affinities are energetically destabilized while energetic stabilization of the radical-cation increases by decreasing the thiophene rings from four to one. The perfluoroarene rings leads to enhance the electron injection. [ABSTRACT FROM AUTHOR]

Abstract In the present study, the number and position of sulfur atoms on naphthalene diimide (NDI) is systematically investigated to tune its nonlinear optical (NLO) response properties. Our DFT calculations for third-order polarizability (γ) show that the thionation significantly influences the nonlinear optical property of NDI as it is seen among its several designed derivatives (NDI-1 to NDI-10). The smallest and the largest γ zzzz amplitudes are 503.49 × 10−36 and 1299.5 × 10−36 esu for NDI-1 (having tetraone group) and NDI-10 (having tetrathione group), respectively. The increase in γ zzzz amplitude for NDI-10 is 796 × 10−36 esu, which is ∼150% from the γ zzzz amplitude of NDI-1. A comparison of the γ zzzz amplitudes of our designed derivatives are made with para -nitroaniline i.e. a prototype NLO molecule. The γ zzzz amplitude of p NA is found to be 42.64 × 10−36 esu at the same B3LYP/DZVP2 level of theory. Using two-level model, the origin of larger γ zzzz amplitudes is traced in lower transition energy of NDI-10. Furthermore, the calculation of vertical ionization potentials (VIPs) shows that the thionation does not affect the stability of designed derivatives, where a slight difference of 0.06 eV is seen between the VIPs of NDI-1 (6.63 eV) and NDI-10 (6.57 eV). Thus, a systematic comparison of the third-order polarizability and other electro-optical properties of our designed derivatives shows that our derivative systems possess good potential for their practical realization in the field of optical and NLO materials. Graphical abstract Image 1 Highlights • The number and position of sulfur atoms play a crucial role to modulate the NLO response of naphthalene diimide derivatives. • The thionation influences significantly the NLO response of naphthalene diimide derivatives • The naphthalene diimide derivatives possess reasonably larger γ zzzz amplitudes and are good contender for NLO applications. [ABSTRACT FROM AUTHOR]

In this work, it is shown that choosing an organic-on-inorganic Schottky diode for photoconductive sensing by a using a power law exponent (PLE or γ ) determined at a single bias point is a limited approach. The standard literature approach does not highlight any bias voltage effects on the distribution of interface state density and other operationally important parameters. In this paper we suggest a new empirical method that holistically highlights the variation of γ with voltage, irradiance and temperature to reach a more informed choice of photosensor for real applications. We obtain a simple, plausible relation of the variation of barrier height, Φ, with voltage, irradiance and temperature. The method is evaluated with data collected previously for Schottky diodes of structure Al/p-Si/organic-semiconductor (OSC)/Au, where OSC is Coumarin-doped with graphene oxide (GO), Cobalt Phthacyanine (CoPC) doped with GO or PCBM doped with GO, respectively. The method reproduces published data for the three diodes reported at specific bias and provides for the first time some qualitative evidence of barrier height variation with light intensity, for which a possible physical basis is also given. Typically, Schottky barrier height is characterized using dark current leading to an under reporting of the effect of illumination on barrier height. Finally, since recombination mechanisms are gauged on the basis of the magnitude of PLE, the method facilitates the identification of the recombination mechanism at a given bias. [ABSTRACT FROM AUTHOR]

• Confirmation and preparation of new funcional single-chain polymer. • Summarizes electro-optic properties of single-chain polymer composites doped nanographene. • Discusses optic properties of single-chain polymer composites doped Sudan III. • Reveals thermal behaviors of both composites doped nanographene and Sudan III. The synthesis of poly[4-(4-vinylbenzyl)oxy)phthalonitrile-co-styrene] [P(VBOPN5 %-co-St)] was carried out by free radical polymerisation at 60 °C. The successful formation of a green coloured single-chain polymer molecule with the formation of cobalt phthalocyanine (SCP-CoPc) was performed at 140–150 °C in the presence of dilute cyclohexanol. The characterization of SCP-CoPc was confirmed by FT-IR and UV/vis spectroscopic techniques. The absorption filtration process of the SCP-CoPc polymer/Sudan III composite was investigated. The introduction of Sudan III into the SCP-CoPc polymer matric strongly affected the optical transmission spectrum of the composite films. The optical transmission measurements of the SCP-CoPc/Sudan III thin film show a high absorption in the visible region (400–800 nm). In the SCP-CoPc/Sudan III composites, the optical band gaps (Eg1 and Eg2) of each of its components has changed significantly. The Eg1 and Eg2 were found to be between 1.90 and 2.83 eV, respectively. Depending on the sudan III content, a wide range from 600 nm to 730 nm indicates complete absorption filtration. The dc electrical conductivity and dielectric behavior of the SCP-CoPc/Nanografene (NG) 6 wt% nanocomposite increased with increasing temperature. From the dc conductivity plot, the Ea values of I. and II. regions were found to be 0.75 eV and 0.27 eV, respectively and it was found that the calculated activation energy obeyed the Arrhenius relationship. The refractive index and the optical permittivity of SCP-CoPc/NG 6 wt% have been estimated. [Display omitted] [ABSTRACT FROM AUTHOR]

The benzoxadiazole class of organic compounds demonstrates exceptional versatility, particularly in the realm of nonlinear optical (NLO) materials, where their unique properties find impactful applications. In the present study, we have focused on systematically designed six benzoxadiazole (BDZ) derivatives named as BDZ-1 to BDZ-6 by using 2,3,1-benzoxadiazole as a central core/π-spacer between the donor and acceptor. Triphenylamine and triphenylborane are used as donor and acceptor in all derivatives with addition of nitro and methoxy group as substitutions. B3LYP/6-311G* method of density functional theory (DFT) is employed for optimization of purposed systems while M06/6-311G* is used to check the NLO properties. The isotropic polarizability (α iso) and anisotropic polarizability (α aniso) of BDZ-6 , were found to be 110.1 × 10−24 esu and 106.3 × 10−24 esu, respectively. Among our designed compounds, the BDZ-6 exhibits the highest third-order NLO polarizability, which was found to be 5954.8 × 10−36 esu corresponding to lowest transition energy of 2.00 eV. Additionally, frontier molecular orbitals (FMOs), molecular electrostatic potential maps (MEPs), electron difference density maps (EDD) and UV–Vis analysis were performed. BDZ-6 shows minimum energy gap of 2.24 eV, while it shows maximum absorption at 620 nm. The density of states (DOS) analysis reveals distinct electronic contributions of various fragments in the formation of HOMO and LUMO orbitals resulting in efficient intramolecular charge transfer (ICT). Photovoltaic findings revealed that BDZ-4 have maximum open circuit voltage of 1.70 eV with minimum dye regeneration value (0.30 eV). Our findings shed light on the design and development of novel NLO materials with BDZ derivatives. [Display omitted] • Enhancement of ICT by electron withdrawing substitution on acceptor and electron donating on donor. • Minimum band gap (2.24eV) between HOMO and LUMO for BDZ-6. • BDZ-6 shows ∼817 times larger value (5954.8 × 10−36 esu) for <γ> than p-NA (prototype NLOphore). • EDD, MEPs, TDM and DOS calculations also illustrates intramolecular charge transfer. • BDZ-4 had the highest V oc value of 1.70 and the lowest ΔG reg value of 0.30 eV. [ABSTRACT FROM AUTHOR]

The first-principles based DFT calculations were used to investigate the effect of transition metal (TM) doping on structural, electronic, optical and thermoelectric properties of Sn 1-x A x Se (A = Au and Ag). The PBE-GGA approximation is used to calculate ground state properties of TM doped SnSe. These compounds show the presence of type-II intermediate band (IB) at Fermi level. A considerable energy bandgap is present between IB and conduction band. Significant contributions from Ag/Au and Se-atom in valence bands of Sn 1-x A x Se (A = Au and Ag) are evident from presented DOS spectra. The calculated Fermi surfaces and Seebeck coefficient (S) confirms p-type nature of these semiconductors. From ε 2 (ω) spectra, it is evident that Sn 1-x A x Se (A = Au and Ag) absorbs maximum number of incident photons in infrared (at ∼0.5 eV) and visible (at ∼2.2 eV) regions. The calculated values of n (ω) are 2.27 and 2.58 for Sn 1-x Ag x Se and Sn 1-x Au x Se, respectively. We can confirm that Sn 1-x A x Se (A = Au and Ag) are promising candidates for energy applications (especially solar cells) based on their optoelectronic and thermoelectric properties. [Display omitted] • Electronic, optical and thermoelectric properties of Sn 1-x A x Se (A = Ag and Au) are investigated ab-initio. • Sn 1-x A x Se (A = Ag and Au) show type-II intermediate band in their band structures. • These compounds are p-type materials based on Fermi surface and Seebeck coefficient. • Optical spectra show major absorption peaks in visible region around 2.2 eV. • Among the considered compounds, Sn 1-x Au x Se shows the highest absorption. [ABSTRACT FROM AUTHOR]

Unlike the previous several investigations on planar donor-π-acceptor chromophores, the present investigation highlights the importance of twisted molecular configurations to effectively tune the optical and nonlinear optical (NLO) response properties. A variety of substitutions are made to design several twisted molecular compounds (1 – 7). These compounds are designed using pyrenyl and naphthalimide moieties, which are twisted with each other in their molecular configurations. The calculated versus experimental highest intensity absorption energy peaks (3.482 V. 3.444 eV) and experimental ionization potentials (6.07 V. 5.93 eV) of parent compound 1 reproduced reasonably well at M06/6-311G∗∗ methodology. The twisted chromophores show significantly larger amplitudes of third-order NLO polarizabilities (<γ>), which are found to be as large as 778.31 × 10−36 esu for compound 7 at the M06/6-311G∗∗ methodology. The <γ> amplitudes were also compared with planar donor-π-acceptor prototype para -nitroaniline (p -NA) molecule to provide the semi-quantitative assessment. For instance, the <γ> amplitudes of all compounds are about ∼7–∼39 times bigger from the amplitude of p -NA at the same computational level. The origin of larger amplitudes has been traced though three-level model using the TD-DFT results. The larger oscillator strengths, lower transitions energies and larger change between the electronic dipole moment between the ground and the excited states. We believe the present study will not only put these compounds under the spotlight of material science but also provide structure-property relationships in designed compounds. Image 1 • The twisted molecular configurations are explored for NLO. • Origin of larger NLO amplitudes traced is in better ICT process. • The hyperpolarizability density (ρ z z z (3) (r)) analysis is performed. • Effects of donor and acceptor substitutions have been studied. • The FMO and MEPs are drawn to see charge distributions. [ABSTRACT FROM AUTHOR]

• Optoelectronic properties of phenylimidazo-pyridine derivatives are analysed at molecular and bulk scales. • Effect of indol, phenyl and anthracenyl on properties of interests was examined. • Hybrid functionals are accurate to reproduce experimental λ abs and λ emi than LC. • The n- or p-type charge transport nature has been explored. • FMOs, IP, EA, intrinsic mobility, DOS, dielectric constant displayed them as multifunctional materials. Various optoelectronic and charge transfer properties of 3-(1H-indol-3-yl)-1-phenylimidazo[1,5-a]pyridine (Comp 1), 1,3-diphenylimidazo[1,5-a]pyridine (Comp 2), and 3-(Anthracen-9-yl)-1-phenylimidazo[1,5-a]pyridine (Comp 3) have been explored at the molecular and solid state bulk level. The absorption and emission spectra (λ abs and λ emi) were calculated by time domain B3LYP/6-311G*, CAM-B3LYP/6-311G*, LC-BLYP/6-311G* and PBE0/6-311G* levels. The hybrid functionals B3LYP and PBE0 successfully reproduced experimental λ abs and λ emi more accurately than the long-range corrected functionals. Effect of indol, phenyl and anthracenyl moieties on various properties of interests has been explored. The indol and phenyl units lead to smaller hole reorganization energies and greater transfer integrals resulting superior hole intrinsic mobility for Comps 1 and 2. The substitution of anthracenyl moiety at phenylimidazo[1,5-a]pyridine core increase the electron affinity and electron transfer integrals while decrease the electron reorganization energy. The n- or p-type charge transfer nature of Comp 3 or Comps 1 and 2 has been explored, respectively. The frontier molecular orbitals, ionization potential, electron affinity, reorganization energy, transfer integral, intrinsic mobility, density of states, dielectric constant, extinction coefficient, refractive indices, reflectivity and conductivity shown that imidazo[1,5-a]pyridine derivatives would be efficient materials to be used in multifunctional organic semiconductor devices. [ABSTRACT FROM AUTHOR]

• Quantum chemical calculations on performed on few oxazole compounds using. • Band gap, local softness values have been procured for different solvents. • Chemical structure and reactivity, topological analyses were carried out. • Solvation effects on UV–Visible spectrum were inspected using the TD-DFT system. • Optical properties and charge transport nature of the compounds were explored. The ground state geometries of oxazole compounds, i.e. , 3,5-Bis-(4-chloro-phenyl)-7a-methyl-dihydro-oxazolo[3,4-c]oxazole (Compound 1) and 3,5-Bis-(4-methoxy-phenyl)-7a-methyl-dihydro-oxazolo[3,4-c]oxazole (Compound 2) were optimized using Density functional theory employing B3LYP/6-31G++ level for comparing the geometric parameters (torsion angles, bond angles & bond lengths) with the X-ray crystallographic information. We explored the charge transport nature, wave functional properties, optical and electronic properties of both the oxazoles. The computed geometric parameters are rational to the experimental data. The time-domain TD - B3LYP/6-31G++ & the B3LYP/6-31G++ levels were used to reveal the electronic characteristics and absorption wavelength. Intra-molecular charge transfer was perceived in studied compounds. The IEFPCM (Integral Equation Formalism Polarizable Continuum Model) model was used to calculate the solvation UV spectrum. The effect of various solvents (acetone, acetonitrile, DMF(Dimethylformamide), DMSO (Dimethyl sulfoxide) and methanol) was examined on the excitation energies but solvent polarity has no discernible impact on the wavelengths of absorption. From HOMO-LUMO (Highest Occupied Molecular Orbital – Lowest Unoccupied Molecular Orbital) orbitals with various solvent molecules, band gap energies with the solvation effect are determined. Additionally, through the use of topological analytics like RDG (Reduced Density Gradient), ELF (Electron Localisation Function) & LOL (Localised Orbital Locator), the energy concentration of electrons was elucidated. Furthermore, the outcome of electron-donating cluster (–OCH 3) and electron-withdrawing cluster (–Cl) was studied on open-circuit voltage, bandgap alignment, electron coupling constants, excitons dissociation values, ΔGinject – electron injection, LHE-Light Harvesting Efficiency and electron coupling constants (|V RP |). [ABSTRACT FROM AUTHOR]

The transition metal complexes are playing the crucial role in advancement of modern chemical science. In the present study, we synthesized the Pd(II) complex [Pd 2 (C 5 H 5 F 3 N 2) 2 (C 5 H 4 F 3 N 2) 2 Cl 2 ]·3(C 2 H 6 O), 1 with 3-Methyl-5-(trifluoromethyl) pyrazole ligand. The complex 1 has been characterized by IR spectroscopy, elemental analysis and X-ray crystallography. The complex 1 crystallizes in triclinic space group P -1. Moreover, density functional theory (DFT) methods are successfully used not only to study the optical and nonlinear optical (NLO) properties of complex 1 but also to design its potential derivatives with Ni(II) and Pt(II) metals as complexes 2 and 3 , respectively. The interaction energies are calculated for optimized complexes that are found to be −400, −524.41 and −504.16 kcal/mol for complexes 1 , 2 and 3 , respectively. The calculations for third-order nonlinear optical polarizability (γ) show that the average γ amplitudes for compounds 1 , 2 and 3 are found to be 79.89 × 10−36, 71.24 × 10−36 and 102.09 × 10−36 esu, respectively. The γ amplitudes of compounds 1 , 2 and 3 are about 4 times, 3 times and 5 times larger than that of para -nitroaniline (p NA), which is a prototype NLO molecule, respectively. The calculations of UV–Visible spectra show that the maximum absorption wavelength for complex 3 is around 260 nm with a significantly larger oscillator strength, which is about 4 times larger than the absorption spectra of complexes 1 and 2. The analysis of FMOs shows the ligand to metal intramolecular charge transfer (LMCT) process which might be the reason of larger NLO response properties in complex 3. Additionally, the calculations of global chemical reactivity descriptors indicate that the complexes are thermally and kinetically stable. Thus, we believe the present study will intrigue the scientific community to explore the designed complexes for optical and NLO applications. [ABSTRACT FROM AUTHOR]

Abstract Nitrido silicates are emerged as highly efficient luminescent materials (phosphors) that found considerable industrial application as white light emitting diodes (LEDs) have been studied with respect to band structure and related electronic structure parameters. They have tunable optical properties, as the band gap is of indispensable because it determines both the electrical and optical features of the material, which can be varied by the material composition (by doping technique). It is found also that the nitride (alumo) silicates "Sr 2 Si 5 N 8 : Eu2+" have wide industrial application as highly efficient red-emitting phosphor materials in pc-LEDs. In this report we apply density functional theory (DFT) within the GGA+U approach to study the structural, electronic and optical properties of Eu2+ and Ce3+ doped Sr 2 Si 5 N 8. The total energy has been optimized as a function of the unit cell volume. Electronic structure including, the electronic density of state (DOS), the band structure and the linear optical susceptibility are calculated for the relaxed structure applying the optimized lattice constant. The calculated optical dispersion of dielectric susceptibility are closely related to the corresponding electronic structure and our results are in very good agreement with experimental data. Graphical abstract Image 1 Highlights • Complex studies of band structure for Sr 2 Si 5 N 8 and doped compound with Eu2+and Ce+3 have been done. • Static value of real part for pure Sr 2 Si 5 N 8 is 2.1 while for Eu2+ doped Ce+3 2.6–2.9 • Plasmonic resonances appear at 12.5 eV and for doped – at 10.5 eV. • Main perspectives of eh further improvements of the optical constants are given. [ABSTRACT FROM AUTHOR]

Graphical abstract We use a dual approach comprising of experimental and computational techniques to report the syntheses and characterizations of two novel nickel (II) [Ni(L) 2 ] (1) and copper (II) [Cu(L) 2 ] (2) coordination complexes, which are made through the coordination of 1-(E -(2, 4-dibromophenylimino) methyl) naphthalene-2-ol (HL) ligand. Several modern techniques including experimental electronic spectroscopy, single crystal X-ray crystallography and quantum computational methods are used to characterize the isolated coordination compounds. Both the complexes display a square planar trans-[MN 2 O 2 ] coordination geometry (Figure 1), whose central M (II) atoms lie on the centre of symmetry. State of the art quantum computations are performed at molecular and bulk levels to get structure-property relationships from molecule to materials. The molecular nonlinear optical (NLO) response properties including third-order polarizability (γ) are calculated using density functional theory (DFT) methods. The calculated γ amplitudes for the synthesized [Ni(L) 2 ] (1) and [Cu(L) 2 ] (2) complexes are found to be 444.09 × 10−36 and 567.03 × 10−36 esu, respectively. Highlights • Design and synthesis of Schiff base (HL) ligand and its metal (II) complexes. • Single crystal X-ray crystallography analysis. • Dual approach comprising of experimental and computational techniques. • Nonlinear optical (NLO) response properties. • Optoelectronic properties. Abstract In the present study, we use a dual approach comprising of experimental and computational techniques to report the syntheses and characterizations of two novel nickel (II) [Ni(L) 2 ] (1) and copper (II) [Cu(L) 2 ] (2) coordination complexes, which are made through the coordination of 1-(E -(2, 4-dibromophenylimino) methyl) naphthalene-2-ol (HL) ligand. Several modern techniques including experimental electronic spectroscopy, single crystal X-ray crystallography and quantum computational methods are used to characterize the isolated coordination compounds. Both the complexes display a square planar trans-[MN 2 O 2 ] coordination geometry, whose central M (II) atoms lie on the centre of symmetry. Complexes [Ni(L) 2 ] (1) and [Cu(L) 2 ] (2) crystallize in the monoclinic system of the space groups P 21/ c with a = 9.307(4)Å, b = 12.242(4)Å, c = 13.823(4)Å, α = 90°, β = 105.262(10)°, γ = 90° and Z = 2 for complex (1), a = 9.171(5) Å, b = 12.507(8) Å, c = 13.666(8) Å, α = 90°, β = 103.823(15)°, γ = 90°, and Z = 2 for complex (2). The ligand (HL) is coordinated as monobasic bidentate with N and O donor groups suitably oriented for forming two six membered chelate rings. State of the art quantum computations are performed at molecular and bulk levels to get structure-property relationships from molecule to materials. The molecular nonlinear optical (NLO) response properties including third-order polarizability (γ) are calculated using density functional theory (DFT) methods. The calculated γ amplitudes for the synthesized [Ni(L) 2 ] (1) and [Cu(L) 2 ] (2) complexes are found to be 444.09 × 10−36 and 567.03 × 10−36 esu, respectively. These γ amplitudes of [Ni(L) 2 ] (1) and [Cu(L) 2 ] (2) complexes are about 21 and 27 times larger than that of standard para -nitroaniline (PNA, a prototype NLO molecule), respectively, which show the potential of these complexes as efficient NLO materials. Additionally, several important optical parameters including dielectric function, reflective index, reflectivity, conductivity and loss function are calculated at bulk level using ab initio methods within periodic boundary conditions (PBC). The obtained results indicate that both coordination complexes has good optical and NLO properties, which may render the above entitled complexes as efficient candidates for optoelectronic and NLO device fabrications. [ABSTRACT FROM AUTHOR]

Abstract Optical and magnetic features of the A 2 V 2 O 2 (A = F e and C o) compounds are explored. Density functional theory (DFT) within a framework of FPLAPW (full-potential linearized augmented plane wave) method, as well as generalized gradient approximation plus the Hubbard parameter (GGA+U) and Hubbard on-site Coulomb interaction corrections are applied. U is evaluated assuming constraint generalized gradient approximation for transition metals Fe/Co and V. The calculated band structures for the Fe doped compounds demonstrate the metallic nature while for the Co doped we observe half metallicity possessing 100% spin polarization in the vicinity of the Fermi level. The influence of Fe/Co and V magnetic moment (μ B) on the electronic, magnetic and optical features is explored in details additionally. The optical constants reveal the strong response for A 2 V 2 O 2 (A = F e and C o) in the IR (infra-red region) and UV (Ultra Violet) regions. Graphical abstract Image 1 Highlights • A 2 V 2 O 7 (A = Fe and Co) band structure was studied by functional theory based on FP-LAPW. • The spin polarized structure is more stable as that of without spin structure. • From the Fermi surface Co 2 V 2 O 7 has higher electrical conductivity as compared to Fe 2 V 2 O 7. • Spin polarized magnetic moments is 19.356 μ B (Fe 2 V 2 O 7), 14.002 μ B (Co 2 V 2 O 7). [ABSTRACT FROM AUTHOR]

• High-quality Ta 2 C MXenes were successfully synthesized by an aqueous acid etching method. • The nonlinear optical properties of Ta 2 C MXenes were measured from the visible to near-infrared regime. • A highly stable femtosecond fiber laser in communication band was obtained by employing the Ta 2 C MXenes. Broadband optical response and strong optical nonlinearity have enabled MXenes to be applied in numerous ultrafast photonic devices. Here, we explored the nonlinear optical properties of a novel MXene, Ta 2 C, and demonstrated a femtosecond fiber laser with a Ta 2 C-based saturable absorber (SA). First-principles calculations were employed to fully reveal the structural and electronic properties of the Ta 2 C MXene. The third-order nonlinear optical properties of the as-prepared Ta 2 C nanosheets were measured from the visible to near-infrared regime by the commonly used open-aperture Z-scan technique. Its maximum nonlinear absorption coefficient was fitted to be −0.42 cm/GW, implying its broad application prospects in nonlinear photonic devices. Moreover, Ta 2 C MXene-coated microfibers as SAs were integrated into erbium-doped fiber laser cavities. Long-term stable mode-locked pulses centered at 1560.1 nm were generated by the constructed laser device. The ultrashort pulse duration of about 774 fs and high signal-to-noise ratio of over 50 dB indicate that Ta 2 C MXene is a promising material for generating ultrafast pulses. [ABSTRACT FROM AUTHOR]

In this work, 3% Fe doped zinc oxide (ZnO) doped by Nitrogen thin films were grown by reactive radio frequency magnetron sputtering on p -Si substrates. The structural and optical properties of the 3% Fe doped ZnO doped by Nitrogen thin films were investigated by the scanning electron microscope and spectrophotometry. The diodes with the configuration of Al/ p -Si/3% Fe-ZnO:N/Al have been fabricated and it has been observed that the diodes exhibit a good rectification. The optical band gap was found to be 3.98 ± 0.02 eV for 3% Fe doped ZnO:N thin film deposited at the N 2 flow rate of 15 sccm. The electrical parameters of the diode were determined using Cheung's and Norde's method. The capacitance–voltage and conductance–voltage characteristics of Al/ p -Si/3% Fe-ZnO:N/Al structure have been investigated in the frequency range 10 kHz–1 MHz. The increase in capacitance at lower frequency is attributed to the density of interface states. It is evaluated that the prepared diodes can be used as nanoscale electronic and optoelectronic devices. [ABSTRACT FROM AUTHOR]

Large size single crystals of Diiodo-bis(carbamide)-zinc(II) [ZnI 2 . 2[CO(NH 2 ) 2 ] were grown successfully for the first time by slow evaporation techniques at room temperature within the evaporation time of two weeks. The single phase and high crystalline nature of the grown crystals was confirmed by X-ray diffraction analysis. Quantum chemically the geometrical parameters were found in good correlation with experimental values calculated at B3LYP/6-31G* (LANL2DZ), B2LYPD/6-31G* (LANL2DZ), M062X/6-31G* (LANL2DZ) and MP2/6-31G* (LANL2DZ) level of theories. Additionally, the experimental vibrational modes also have shown a good agreement with calculated ones. The optical transparency and band gap were calculated and found to be ∼80% and 4.706 eV, respectively. The calculated value of HOMO-LUMO gap was found in correlation with experimental energy gap. The electronic properties were investigated by shedding light on the frontier molecular orbitals, partial density of states (PDOS), and total density of states (TDOS). The mechanical and dielectric studies show that the grown crystals possess quite good mechanical strength and dielectric constant. The dielectric loss revealed that the grown crystal contains low defects. The total ac electrical conductivity was increased with frequency and the frequency components confirm the sudden hoping mechanism in the grown crystal. [ABSTRACT FROM AUTHOR]

[Display omitted] • Symmetrical disubstituted compounds with D-A-D-A-D configuration was synthesized. • Exhibited excellent NLO properties with promising optical limiting threshold values under nanosecond pulse excitation. • A detailed energy level mechanism is proposed for the NLO activity of the molecules. • Formation of charge separation state by photo-induced charge transfer is discussed. Organic materials figure among the most widely investigated nonlinear optical (NLO) materials towards the realization of optical limiters. Among the organic materials, donor–acceptor systems are getting special consideration due to their excellent NLO activities arising from the intramolecular charge transfer (ICT). But NLO activities of many of these systems are restricted by photo-bleaching and limited thermal stability. This deficiency can be overcome by introducing more than one donor–acceptor groups into the framework. Herein we report NLO activities of two symmetrical disubstituted compounds with D-A-D-A-D configuration, containing bis-1,3,4-oxadiazole with phenothiazine backbone in which two different electron donor systems namely naphthalene (NOPON)/4-bromophenyl (BOPOB) were bonded with the phenothiazine-1,3,4-oxadiazole core unit. Solution phase absorption spectrum of these compounds exhibited two peaks, one located in the 300–350 nm regions and a comparatively weak and broad band located at the longer wavelength region attributed to ICT state. Photophysical, electrochemical and excited state life time analysis of the compounds were carried out. HOMO-LUMO energies of the system obtained from DFT calculation are comparable with the experimental values obtained from voltammetric study. NLO and optical limiting behaviour of the compounds were analysed by Z scan technique using a Q switched Nd: YAG laser at 532 nm. Both the compounds exhibited promising limiting threshold values (2.43 J/cm2 for NOPON and 3.80 J/cm2 for BOPOB) comparable with many of the reported values, suggesting their ability to perform as good optical limiters. [ABSTRACT FROM AUTHOR]

Cadmium sulfide has been the subject of wide studies due to its vast applications in solar cells. Bilayer system of Fe doped CdS, is used for synthesis of metal coated semiconductor nanocrystals to fabricate variety of electroluminescent and optical devices. The electronic and optical properties of Fe doped CdS nanostructures were investigated by first principles computations. The electronic properties (band structures and densities of states) have been estimated to evaluate the effect of the Fe doping on the electronic and optical properties of CdS nanostructure. Results show that the properties of CdS are changed when Fe is doped in the parent material. Calculations reveal a semiconducting nature with different behavior for both spin up and down band structures. Fe induced change in the studied properties nanostructured CdS is discussed. Absorption characteristics of Fe doped CdS may be related to the change among valence band and vacant d-orbitals of Fe. • The electronic and optical properties of Fe doped CdS nanostructures were investigated. • Via first principles studies in the framework of density functional theory (DFT). • The electronic properties have been estimated to evaluate the effect of the Fe doping. • We have discussed the Fe induced changes in these ground state properties of nanostructured CdS in details in this study. [ABSTRACT FROM AUTHOR]

Perovskite oxynitride are of great interest due to their use as photo-catalysts. We investigated the electronic, thermoelectric and optical properties of ATaO 2 N (A = Ba, Sr, Ra) with generalized gradient plus Hubbard approximation (GGA + U). In electronic properties, we have computed, for each compound, densities of states (total and partial), band structure to extract their band gaps, nature and transition probability when the cation changes. Optical properties were explored by calculating dielectric constant ε (ω), refractive index n (ω), reflectivity R (ω), optical loss L (ω), and absorption coefficient I (ω) response against different photon energies. In order to examine the possibility of using these compounds in thermoelectric devices, we calculated their transport properties from Boltzman transport theory. We examined their thermal conductivity κ, electrical conductivity σ, seebeck coefficient S, power factor PF and dimensionless figure of merit ZT. [ABSTRACT FROM AUTHOR]

Herein, two new thiazole derivatives: ethyl2-(2-benzylidenehydrazinyl)thiazole-4-carboxylate (3) and ethyl2-(2-(2-hydroxybenzylidene)hydrazinyl)thiazole-4-carboxylate (4) were synthesized by cyclization of 1-benzylidenethiosemicarbazide with ethyl bromopyruvate. The synthesis was validated by spectroscopic techniques like FTIR, 1H- NMR, 13C-NMR and chemical structure of title compounds 3 and 4 has been determined using SC-XRD. Ancillary to experimental analysis, DFT calculations with B3LYP/6-311 + G (d,p) level were performed for comparative analysis of FT-IR spectroscopic data, optimized geometry, frontier molecular orbitals (FMOs), natural bond orbital (NBO) analysis and nonlinear optical (NLO) properties. Overall, experimental findings were supported by corresponding DFT computed results. TDDFT calculations were executed at M06/6-311 + G (d,p) level of theory to calculate the vertical electronic transition states. NBO analysis disclosed that intramolecular charge transfer and hyper-conjugative interactions among bonds provide stability to the investigated compounds 3 and 4. The global reactivity parameters calculated from energy of FMOs indicates that 3 and 4 enclose larger softness and fewer hardness values. NLO results of 3 and 4 were observed better than standard molecule recommended the NLO activity of said compounds. We hope that this joint experimental and computational insight may provide new ways for the utilization of title molecules as NLO material for optoelectronic applications. Image 1 • Two novel ethyl 2-(2-(2-substitutedbenzylidene)hydrazinyl)thiazole-4-carboxylate crystals were synthesized. • XRD, 1H NMR, 13C NMR, FT-IR and UV–Vis were performed for the characterization. • Computational study was done at B3LYP/6-311 + G (d,p) level for comparative analysis. • Comparative study reveals a good agreement between experimental and DFT results. • FMOs, NBO analysis and nonlinear optical (NLO) properties were calculated. [ABSTRACT FROM AUTHOR]

Herein we report the crystal structure geometry, optoelectronic and charge transport properties of (E)-1-(4-Bromophenyl)-3-(2-chlorophenyl)prop-2-en-1-one (1), (E)-3-(3-Bromophenyl)-1-(4-methoxyphenyl)prop-2-en-1-one (2) and (E)-3-(4-Chlorophenyl)-1-(2-furyl)prop-2-en-1-one (3) chalcone derivatives. In experimental part UV–vis-NIR, X-ray diffraction and Photoluminescence spectroscopy techniques were used. Additionally, quantum chemical density functional theory calculations were executed with a clear view to explore the linear optical, second and third-order nonlinear optical (NLO) properties as well as transfer integrals of all three systems. The experimental and theoretically calculated properties are found to be in excellent accord with each other. Comprehensible intra- and inter-molecular charge transport was observed from occupied to unoccupied molecular orbitals illuminating that these chalcones would be good choice to be used in various semiconductor devices. The compound (3) is found to have better NLO activities and thermal stability compared to (1) and (2). Larger electron transfer integral values than hole ones exposed that studied compounds would be better electron transport materials and can function as n -type in organic semiconductor devices. [ABSTRACT FROM AUTHOR]

A copper (II) malonate complex{[(C 7 H 8 O 2 N) 2 ][Cu(C 3 H 2 O 4) 2 (H 2 O) 2 ]}, 1 has been synthesized and characterized by IR spectroscopy, elemental analysis, TGA/DSC and X-ray crystallography. The X-ray analysis reveals that the complex is anionic species in which copper is coordinated by six oxygen atoms having octahedral coordination geometry that is tetragonally compressed due to Jahn Teller effect. To balance the charge on the complex ion two molecules of 4-carboxybenzeneammonium ions are present as counter ions. The density functional theory methods are applied to explore the linear and nonlinear optical (NLO) properties of 1 using M06 method and 6-31G*/LANL2DZ basis set. The calculated linear molecular polarizability and third-order NLO polarizability of 1 are found to be 43.98 × 10−24 esu and 33.93 × 10−36 esu, respectively, which interestingly better than some standard NLO molecules. To comprehend more understanding, the optical properties from molecule to material levels, we also calculated the optical properties (dielectric function, refractive index and absorption spectrum) in solid-state at bulk-level within periodic boundary conditions (PBC). The calculated optical properties show that the complex 1 possesses static dielectric function and refractive index values of 2.0 and 1.4, respectively. The absorption wavelength from 3 eV to 6 eV illustrates that the complex 1 has strong absorption and larger reflectivity values in UV region, which may be potential for using complex 1 as coating materials. It is credible that the synthesized complex 1 may possess reasonable potential for its application as optical and NLO material. Unlabelled Image • Synthesis of Copper malonate complex {[(C 7 H 8 O 2 N) 2 ][Cu(C 3 H 2 O 4) 2 (H 2 O) 2 ]} • Experimental characterization by single crystal X-ray analysis, IR, TGA/DSC and CHNS analysis • The quantum chemical study of linear and nonlinear optical properties of 1 • The reasonably large NLO polarizability of 1 is found to be 33.93 × 10−36 esu. • The optical properties of complex 1 were also determined in solid-state within PBC. [ABSTRACT FROM AUTHOR]