Exploration of the synergistic effect of chrysene-based core and benzothiophene acceptors on photovoltaic properties of organic solar cells.

To improve the efficacy of organic solar cells (OSCs), novel small acceptor molecules (CTD1-CTD7) were designed by modification at the terminal acceptors of reference compound CTR. The optoelectronic properties of the investigated compounds (CTD1-CTD7) were accomplished by employing density functional theory (DFT) in combination with time-dependent density functional theory (TD-DFT). The M06 functional along with a 6-311G(d,p) basis set was utilized for calculating various parameters such as: frontier molecular orbitals (FMO), absorption maxima (λmax), binding energy (Eb), transition density matrix (TDM), density of states (DOS), and open circuit voltage (Voc) of entitled chromophores. A red shift in the absorption spectra of all designed chromophores (CTD1-CTD7) was observed as compared to CTR, accompanied by low excitation energy. Particularly, CTD4 was characterized by the highest λmax value of 685.791 nm and the lowest transition energy value of 1.801 eV which might be ascribed to the robust electron-withdrawing end-capped acceptor group. The observed reduced binding energy (Eb) was linked to an elevated rate of exciton dissociation and substantial charge transfer from central core in HOMO towards terminal acceptors in LUMO. These results were further supported by the outcomes from TDM and DOS analyses. Among all entitled chromophores, CTD4 exhibited bathochromic shift (685.791 nm), minimum HOMO/LUMO band gap of 2.347 eV with greater CT. Thus, it can be concluded that by employing molecular engineering with efficient acceptor moieties, the efficiency of photovoltaic materials could be improved.

Synergistic reductive catalytic effects of an organic and inorganic hybrid covalent organic framework for hydrogen fuel production.

Electrocatalytic hydrogen generation in alkaline medium has become widely used in a variety of sectors. However, the possibility for additional performance improvement is hampered by slow kinetics. Because of this restriction, careful control over processes such as water dissociation, hydroxyl desorption and hydrogen recombination is required. Covalent organic frameworks (COFs) based on porphyrin and polyoxometalates (POMs) show encouraging electrocatalytic performance, offering a viable route for effective and sustainable hydrogen generation. Their specific architectures lead to increased electrocatalytic activity, which makes them excellent choices for developing water electrolysis as a clean energy conversion method in the alkaline medium. In this regard, TTris@ZnPor and Lindqvist POM were coordinated to create a new eco-friendly and highly active covalent organic framework (TP@VL-COF). In order to describe TP@VL-COF, extensive structural and morphological investigations were carried out through FTIR, 1H NMR, elemental analysis, SEM, fluorescence, UV-visible, PXRD, CV, N2-adsorption isotherm, TGA and DSC analyses. In an alkaline medium, the electrocatalytic capability of 20%C/Pt, TTris@ZnPor, Lindqvist POM and TP@VL-COF was explored and compared for the hydrogen evolution reaction (HER). The TP@VL-COF showed the best catalytic efficiency for HER in an alkaline electrolyte, requiring just a 75 mV overpotential to drive 10 mA cm-2 and outperforming 20%C/Pt, TTris@ZnPor, Lindqvist POM and other reported catalysts. The Tafel slope value also indicates faster kinetics for TP@VL-COF (114 mV dec-1) than for 20%C/Pt (182 mV dec-1) TTris@ZnPor (116 mV dec-1) and Lindqvist POM (125 mV dec-1).

Pyridine-2,6-Dicarboxylic Acid As a Facile and Highly Selective "Turn-Off" Fluorimetric Chemosensor for Detection of Cu (II) Ions in Aqueous Media.

Copper metal is third most abundant trace element in human body. Determination of Cu (II) ions is a burning topic in field of environment protection and food safety because of its significant impact on ecosystem. In this study, 2,6-pyridine dicarboxylic acid (PDA) has been explored as "turn-off" florescent probe for florescent detection of Cu (II) ions. This sensor showed highly selective complexing ability towards Cu (II) ions. Addition of aqueous solution of Cu (II) ions remarkably quenched the fluorescence intensity of PDA while, on contrary, there was no any prominent fluorescence quenching interference on addition of various metal ions. The binding mode of PDA and Cu (II) ions was determined as stoichiometry of 1:1 and it was further confirmed by single crystal XRD analysis. Mechanisms of static and dynamic quenching were confirmed by stern-volmer plot. Limit of detection (LOD) and limit of quantification (LOQ) for Cu (II) ions was calculated as 3.6 µM and 1.23 µM respectively, which is far below the acceptable value (31.5µM) according to the World Health Organization. The use of the sensor for detection of Cu (II) ions in real samples in aqueous media was also performed.

Quantum chemical framework for tailoring N/B doped phenalene derivatives to achieve high performance nonlinear optical materials.

Nonlinear optical (NLO) response materials are among the smartest materials of the era and are employed to modulate the phase and frequency of the laser. The present study presents a quantum chemical framework for tailoring nitrogen/boron doped derivatives of Dihydrodibenzo [de,op]pentacene through terminal and central core modifications. The derivatives of these compounds have been designed by introducing various π-conjugated connectors as well as B/N heteroatoms in the phenalene rings. Density functional theory (DFT) methods are used to optimize the ground state molecular geometries of designed compounds, represented as 1 to 4 (phenalene derivatives) and 1-BN to 4-BN (B/N doped phenalene derivatives) at the M06-2X/6-311G* level of theory. The highest value of 116.9 × 10-24 esu and 240.2 × 10-24 esu for isotropic and anisotropic linear polarizability is shown by compound 4. Among the designed compounds, 4-BN has achieved the highest γ amplitude of 1858 × 10-36 esu owing to its unique molecular structural design. Further analysis of electronic parameters, such as electron density difference (EDD) maps, the density of states, electrostatic potentials, transition density matrix (TDM) analysis, and frontier molecular orbitals analysis (FMOs), demonstrated the more effective intramolecular charge transfer (ICT) for the best compounds, resulting in a good NLO response. The compounds were also analyzed for their potential in photovoltaic applications based on factors such as open circuit voltage values determined to be between (0.14 eV and 1.82 eV), and light harvesting efficiency (0.425-0.909).

Synthesis, Characterizations, Hirshfeld Surface Analysis, DFT, and NLO Study of a Schiff Base Derived from Trifluoromethyl Amine.

We synthesized an imine-based (Schiff base) crystalline organic chromophore, i.e., (E)-2-ethoxy-6-(((3-(trifluoromethyl)phenyl)imino)methyl)phenol (ETPMP), and explored its nonlinear optical (NLO) properties. The crystalline structure of ETPMP was determined by the XRD technique and equated with the associated structures utilizing a Cambridge Structural Database search. The supramolecular assembly of ETPMP was investigated regarding intermolecular interactions and short contacts by Hirshfeld surface analysis. Void analysis was performed to check the mechanical response of the crystal. Supramolecular assembly was further inspected by interaction energy calculations that were performed with the B3LYP/6-31G(d,p) functional. Besides this, the NLO properties of ETPMP and other already reported crystal TFMOS were explored utilizing the M06/6-31G(d,p) functional of the DFT approach. An excellent agreement was observed between XRD and DFT results of geometric parameters of the above-mentioned crystals. Narrow band gap along with bathochromic shift (3.489 eV and 317.225 nm, respectively) were investigated in TFMOS than that of ETPMP. Owing to these unique properties, TFMOS possesses higher linear (⟨a⟩ = 3.835 × 10-23 esu) and nonlinear (γtot. = 1.346 × 10-34 esu) response as compared to ETPMP. The outcomes explicitly show the higher nonlinearity in TFMOS, highlighting its importance in potential NLO applications.

Visible light-driven photocatalytic bacterial inactivation on PPE, supported by the DFT and bactericidal study.

A novel ZnO-MoO3-ZnMoO3@graphene GZM composite catalyst prepared by microwave hydrothermal process for personal protective equipment textiles (PPE) is presented in this study. The results indicated that the GZM with defect vacancy sites of two types as observed by EPR showed significantly superior inactivation of the E. coli bacteria compared to GZM without the lower defect vacancy sites and concomitant lower electron densities. Photocatalytic activated oxidation by the GZM composites coatings was observed to proceed in acceptable times as well as the bacterial inactivation (log bact. C/Co > 107 within 3 h). Defect sites in the GZM seem to be important leading to the bacterial inactivation process. DFT calculations on the GZM with and without catalyst defect sites were carried out. The electron densities were estimated by the Fourier mapping. The results found in this study showed the potential of GZM-PPE for practical applications.

Correction: Synthesis of an amantadine-based novel Schiff base and its transition metal complexes as potential ALP, α-amylase, and α-glucosidase inhibitors.

[This corrects the article DOI: 10.1039/D2RA07051K.].

Synthesis, Characterization, Crystal Structures, and Supramolecular Assembly of Copper Complexes Derived from Nitroterephthalic Acid along with Hirshfeld Surface Analysis and Quantum Chemical Studies.

Two new Cu(II) carboxylate complexes, Cu-NTA and Cu-DNTA, were prepared by treating 2-nitroterephthalic acid with CuSO4·5H2O at room temperature. The synthesized complexes were characterized by elemental (CHN), FT-IR, and thermogravimetric analysis. The crystal structures of both complexes were explored by single crystal X-ray diffraction analysis, which inferred that the coordination geometry is slightly distorted octahedral and square pyramidal in Cu-NTA and Cu-DNTA, respectively. The non-covalent interactions that are the main feature of the supramolecular assembly were investigated by Hirshfeld surface analysis for both complexes. The propensity of each pair of chemical moieties involved in crystal-packing interactions was determined by the enrichment ratio. Quantum chemical computations were performed to optimize the molecular geometry of complex Cu-NTA and compared it with the experimental single crystal structure, which was found to be in sensible agreement with the experimental structure of the complex. The DFT method was used to see the potential of the selected Cu-NTA complex for linear and nonlinear optical properties. The static NLO polarizability <γ> of complex Cu-NTA was calculated to be 86.28 × 10-36 esu at M06 functional and 6-31G*/LANL2DZ basis set, which was rationally large to look for NLO applications of complex Cu-NTA. Additionally, the molecular electrostatic potential and frontier molecular orbitals were also computed with the same methodology to see electronic characteristics and ground-state electronic charge distributions.

Exploring Probenecid Derived 1,3,4-Oxadiazole-Phthalimide Hybrid as α-Amylase Inhibitor: Synthesis, Structural Investigation, and Molecular Modeling.

1,3,4-Oxadiazole moiety is a crucial pharmacophore in many biologically active compounds. In a typical synthesis, probenecid was subjected to a sequence of reactions to obtain a 1,3,4-oxadiazole-phthalimide hybrid (PESMP) in high yields. The NMR (1H and 13C) spectroscopic analysis initially confirmed the structure of PESMP. Further spectral aspects were validated based on a single-crystal XRD analysis. Experimental findings were confirmed afterwards by executing a Hirshfeld surface (HS) analysis and quantum mechanical computations. The HS analysis showed the role of the π⋯π stacking interactions in PESMP. PESMP was found to have a high stability and lower reactivity in terms of global reactivity parameters. α-Amylase inhibition studies revealed that the PESMP was a good inhibitor of α-amylase with an s value of 10.60 ± 0.16 µg/mL compared with that of standard acarbose (IC50 = 8.80 ± 0.21 µg/mL). Molecular docking was also utilized to reveal the binding pose and features of PESMP against the α-amylase enzyme. Via docking computations, the high potency of PESMP and acarbose towards the α-amylase enzyme was unveiled and confirmed by docking scores of -7.4 and -9.4 kcal/mol, respectively. These findings shine a new light on the potential of PESMP compounds as α-amylase inhibitors.

Synthesis of an amantadine-based novel Schiff base and its transition metal complexes as potential ALP, α-amylase, and α-glucosidase inhibitors.

A Schiff base ligand HL, (E)-2-((adamantan-1-ylimino)methyl)-6-allylphenol, was synthesized by condensation of amantadine with 3-allyl-2-hydroxybenzaldehyde, followed by the synthesis of its Zn(ii), Co(ii), Cr(iii), and VO(iv) complexes under reflux conditions. The synthesized compounds were comprehensively elucidated by using different spectroscopic and analytical techniques: UV-Vis, 1H and 13C-NMR, FT-IR, ESI-MS, thermal, and single-crystal XRD analysis. The chemical composition of the synthesized compounds was also verified by molar conductance and elemental analysis. An octahedral geometry for Cr(iii) and Co(ii) complexes, tetrahedral for Zn(ii) complex, and square pyramidal geometry have been proposed for VO(iv) complexes. The antidiabetic activities of the synthesized compounds were also evaluated by performing in vitro α-amylase and α-glucosidase inhibition studies. The Co(ii) complex exhibited the highest α-glucosidase inhibitory activity, whereas oxovanadium(iv) and zinc(ii) complexes were also found to be effective against α-amylase. In alkaline phosphatase (ALP) inhibition studies, the HL was found to be inactive, while the complexes showed remarkable enzyme inhibition in the following order: VO > Zn > Co, in a concentration-dependent manner.

First theoretical framework for highly efficient photovoltaic parameters by structural modification with benzothiophene-incorporated acceptors in dithiophene based chromophores.

Now a days, researchers are constantly doing efforts to upgrade the performance of solar based devices with the aim of increasing the role of photovoltaic materials in modern hi-tech optoelectronic applications. Realizing the recent energy conditions across the globe, research is diverted from fullerene to non-fullerene electron acceptor moieties in this era, considering their remarkable contribution in organic solar cells (OSCs). Therefore, we designed seven novel non-fullerene fused ring electron acceptor chromophores (MD2-MD8) from DOC2C6-2F by structural tailoring with different acceptors at end-capped units. DFT study was performed at B3LYP functional to discover the opto-electronic characteristics of the newly tailored chromophores. Various analysis such as frontier molecular orbitals (FMOs), transition density matrix (TDM), density of states (DOS), binding energy (Eb), reorganization energy, open circuit voltage (Voc) was carried out to comprehend the photovoltaic response of MD2-MD8. Decrease in band gaps (1.940-1.571 eV) with wider absorption spectrum (725.690-939.844 nm in chloroform) along with greater charge transfer rate from HOMO towards LUMO were examined in derivatives as compared to MR1 (Egap = 1.976 eV, λmax = 738.221 nm) except MD7. Further, in all derivatives, smaller values of Eb (0.252-0.279 eV) were examined than that of reference (0.296 eV). These lower binding energy values of MD2-MD8 indicated the higher rate of excitation dissociation with lager charger transfer rate than MR1, which further supported by DOS and TDM analyses. Additionally, least reorganization energy in the aforesaid compounds for hole with electron was also inspected. Moreover, Voc a good photovoltaic response was noted for all studied compounds which indicated that these compounds are suitable to synthesize OSCs in future.

Exploring Highly Functionalized Tetrahydropyridine as a Dual Inhibitor of Monoamine Oxidase A and B: Synthesis, Structural Analysis, Single Crystal XRD, Supramolecular Assembly Exploration by Hirshfeld Surface Analysis, and Computational Studies.

Ethyl 4-(4-fluorophenylamino)-2,6-bis(4-(trifluoromethyl)phenyl)-1-(4-fluoro-phenyl)-1,2,5,6-tetrahydropyridine-3-carboxylate (FTEAA) has been synthesized efficiently in an iodine-catalyzed five-component reaction of 4-fluoroaniline, 4-trifluoromethyl benzaldehyde, and ethyl acetoacetate in methanol at 55 °C for 12 h. Various spectro-analytical techniques such as 1H and 13C NMR and Fourier-transform infrared spectroscopy have validated the structure of FTEAA. Further confirmation of the structure of FTEAA has been established on the basis of single-crystal X-ray diffraction analysis. The supramolecular assembly of FTEAA in terms of strong and comparatively weak noncovalent interactions is fully investigated by Hirshfeld surface analysis, the interaction energy between pairs of molecules, and energy frameworks. The void analysis is conducted to explore the strength and stability of the crystal structure. Furthermore, molecular docking analysis was computationally performed to see the potential intermolecular interactions between the selected proteins and FTEAA. The binding interaction energies are found to be -8.8 and -9.6 kcal/mol for the proteins MAO-B (PDB ID: 2V5Z) and MAO-A (PDB ID: 2Z5X), respectively. These reasonably good binding energies (more negative values) indicate the efficient associations between the FTEAA and target proteins. The proteins and FTEAA were also analyzed for intermolecular interactions. FTEAA and proteins interact in a variety of ways, like conventional hydrogen bonds, carbon-hydrogen bonds, alkyl, π-alkyl, and halide interactions.

Exploration of Nonlinear Optical Properties for the First Theoretical Framework of Non-Fullerene DTS(FBTTh2)2-Based Derivatives.

Organic compounds having significant nonlinear optical (NLO) applications are being employed in the optoelectronics field. In the current work, a series of non-fullerene acceptor (NFA) based compounds are designed by modifying the acceptors with different substituents using DTS(FBTTh 2 ) 2 R1 as a reference compound. To study the NLO responses to the tuning of various acceptors, DFT and TD-DFT based parameters were calculated at the M06 level along with the 6-31G(d,p) basis set. The designed compounds (MSTD2-MSTD7) showed smaller values of the energy gap in comparison to the reference compound. The energy gaps of the title compounds were linked to global reactivity insights; MSTD7 provided a lower band gap, with smaller and larger quantities for hardness and softness characteristics, respectively. Further, UV-vis analyses were performed for all of the designed compounds, displaying wavelengths red-shifted from that of DTS(FBTTh 2 ) 2 R1 . The intraelectron transfer (ICT) process and stability of the title compounds were explored via frontier molecular orbital (FMO) and natural bond orbital (NBO) studies, respectively. Out of all the designed compounds, the highest value of linear polarizability ⟨α⟩ of 3.485 × 10-22 esu, first hyperpolarizability (ßtotal) of 13.44 × 10-27 esu and second-order hyperpolarizability ⟨γ⟩ of 3.66 × 10-31 esu were exhibited by MSTD7. In short, all of the designed compounds exhibited promising NLO properties because of their low charge transport resistance. These NLO properties may be useful for experimental researchers to uncover NLO materials for modern applications.

Synthesis, crystal structure, Hirshfeld surface and void analysis of bis-(µ2-4-amino-benzoato-κ2 O:O')bis-[bis-(4-amino-benzoato-κ2 O,O')di-aquathulium(III)] dihydrate.

The asymmetric unit of the title compound, [Tm2(C7H6NO2)6(H2O)4]·2H2O, contains three 4-amino-benzoate (4ABA) ligands, two coordinated water mol-ecules, a thulium metal ion, and a water mol-ecule of crystallization. The overall structure of the complex (4ABA-Tm) is in the form of a dimer. In the dinuclear thulium complex, symmetry-relevant TmO8 coordination polyhedra are formed by the O atoms of two chelating 4-amino-benzoate ligands, the O atoms of two non-chelating 4-amino-benzoate ligands, and two water mol-ecules. The Tm-O bond lengths range from 2.216 (3) to 2.471 (3) Šwith the Tm⋯Tm separation in the dinuclear complex being 4.7863 (5) Å. The crystal structure features O-H⋯N, N-H⋯O, and O-H⋯O hydrogen-bonding inter-actions. Further stabilization of the crystal packing is due to C-H⋯π and off-set π-π stacking inter-actions. Hirshfeld surface analysis indicates that H⋯H contacts are the most significant contributors to the crystal packing (45.9%). In addition, a void analysis was performed to check the strength of the crystal packing.

Shedding Light on the Synthesis, Crystal Structure, Characterization, and Computational Study of Optoelectronic Properties and Bioactivity of Imine derivatives.

Two imine compounds named as (E)-2-(((3,4-dichlorophenyl)imino)methyl)phenol (DC2H) and (E)-4-(((2,4-dimethylphenyl)imino)methyl)phenol (DM4H) are synthesized, and their crystal structures are verified using the single-crystal X-ray diffraction (XRD) technique. The crystal structures of the compounds are compared with the closely related crystal structures using the Cambridge Structural Database (CSD). The crystal packing in terms of intermolecular interactions is fully explored by Hirshfeld surface analysis. Void analysis is carried out for both compounds to check the strength of the crystal packing. Furthermore, a state-of-the-art dual computational technique consisting of quantum chemical and molecular docking methods is used to shed light on the molecular structure, optoelectronic properties, and bioactivity of indigenously synthesized compounds. The optimized molecular geometries are compared with their counterpart experimental values. Based on previous reports of biofunctions of the indigenously synthesized imine derivatives, they are explored for their potential inhibition properties against two very crucial proteins (main protease (Mpro) and nonstructural protein 9 (NSP9)) of SARS-CoV-2. The calculated interaction energy values of DC2H and DM4H with Mpro are found to be -6.3 and -6.6 kcal/mol, respectively, and for NSP9, the calculated interaction energy value is found to be -6.5 kcal/mol. We believe that the current combined study through experiments and computational techniques will not only pique the interest of the broad scientific community but also evoke interest in their further in vitro and in vivo investigations.

Single-Crystal Investigation, Hirshfeld Surface Analysis, and DFT Study of Third-Order NLO Properties of Unsymmetrical Acyl Thiourea Derivatives.

In the current research work, unsymmetrical acyl thiourea derivatives, 4-((3-benzoylthioureido)methyl)cyclohexane-1-carboxylic acid (BTCC) and methyl 2-(3-benzoylthioureido)benzoate (MBTB), have been synthesized efficiently. The structures of these crystalline thioureas were unambiguously confirmed by single-crystal diffractional analysis. The crystallographic investigation showed that the molecular configuration of both compounds is stabilized by intramolecular N-H···O bonding. The crystal packing of BTCC is stabilized by strong N-H···O bonding and comparatively weak O-H···S, C-H···O, C-H···π, and C-O···π interactions, whereas strong N-H···O bonding and comparatively weak C-H···O, C-H···S, and C-H···π interactions are responsible for the crystal packing of MBTB. The noncovalent interactions that are responsible for the crystal packing are explored by the Hirshfeld surface analysis for both compounds. The void analysis is performed to find the quantitative strength of crystal packing in both compounds. Additionally, state-of-the-art applied quantum chemical techniques are used to further explore the structure-property relationship in the above-entitled molecules. The optimization of molecular geometries showed a reasonably good correlation with their respective experimental structures. Third-order nonlinear optical (NLO) polarizability calculations were performed to see the advanced functional application of entitled compounds as efficient NLO materials. The average static γ amplitudes are found to be 27.30 × 10-36 and 102.91 × 10-36 esu for the compounds BTCC and MBTB, respectively. The γ amplitude of MBTB is calculated to be 3.77 times larger, which is probably due to better charge-transfer characteristics in MBTB. The quantum chemical analysis in the form of 3-D plots was also performed for their frontier molecular orbitals and molecular electrostatic potentials for understanding charge-transfer characteristics. We believe that the current investigation will not only report the new BTCC and MBTB compounds but also evoke the interest of the materials science community in their potential use in NLO applications.

Synthesis, Crystal Structure, Hirshfeld Surface Analysis, and Computational Study of a Novel Organic Salt Obtained from Benzylamine and an Acidic Component.

A novel Schiff base compound named as phenylmethanaminium (E)-4-((benzylimino)methyl)benzoate C7H10N+. C15H12NO2 - (A) is synthesized by the chemical reaction of benzylamine and 4-carboxybenzaldehyde in ethanol, and the structure of the titled compound is verified using the single-crystal X-ray diffraction technique. Structural investigation inferred that the crystal packing is mainly stabilized by N-H···O and comparatively weak C-H···O bonding between the cation and anion and further stabilized by weak C-H···π and C-O···π interactions. Hirshfeld surface analysis is employed to explore the noncovalent interactions that are responsible for crystal packing quantitatively. Furthermore, we have used state-of-the-art quantum chemical calculations to get comprehensive insights into the structure-optoelectronic property relationship for the entitled compound. The molecular geometry of compound A is optimized at the M06/6-311G* level of theory. The linear polarizability, third-order nonlinear optical (NLO) polarizability, total and partial density of states, and UV-visible spectrum are calculated through quantum chemical calculations. We believe that compound A is not only a new addition to crystallographic data but also possesses good optical and NLO properties for its potential use in lasers and frequency-converting applications.

Oxygen-Cluster-Modified Anatase with Graphene Leads to Efficient and Recyclable Photo-Catalytic Conversion of CO2 to CH4 Supported by the Positron Annihilation Study.

Anatase TiO2 hollow nanoboxes were synthesized and combined with the graphene oxide to get nanocomposite of TiO2/rGO (TG). Graphene oxide was used to modify the Oxygen-Clusters and bulk to surface defects. Anatase and TG composite were characterized with the positron annihilation, XPS, EPR, EIS and photocurrent response analysis. The relative affects of defects on the photocatalytic reduction (CO2 to CH4) were studied. The TG composites showed highest photo-catalytic activity after GO coupling (49 µmol g-1 h-1), 28.6 times higher photocurrent yields much higher quantum efficiency (3.17%@400 nm) when compared to the TiO2 nanoboxes. The mechanism of enhanced photo-catalytic CO2 conversion to CH4 elucidated through electrochemical and photo-catalytic experiments with traceable isotope containing carbon dioxide (13CO2). For the first time we discovered that diminishing the comparative concentration ratio of anatase from the bulk to surface defects could significantly increase the conversion of CO2 to CH4.

2-(2-Meth-oxy-phen-yl)-1H-isoindole-1,3(2H)-dione.

In the title compound, C(15)H(11)NO(3), the dihedral angle between the meth-oxy-benzene and isoindole ring systems is 70.21 (3)°. The meth-oxy C atom is close to being coplanar with its attached ring [deviation = 0.133 (2) Å] and is oriented away from the isoindole moiety. In the crystal, inversion dimers linked by pairs of C-H⋯O hydrogen bonds generate R(2) (2)(10) loops. Further C-H⋯O inter-actions lead to (010) infinite sheets and weak aromatic π-π stacking [centroid-centroid separations = 3.6990 (10) and 3.7217 (10) Å] is also observed.

Methyl (2Z)-3-[(4-nitro-phen-yl)carbamo-yl]prop-2-enoate.

In the title compound, C(11)H(10)N(2)O(5), the amide group is nearly coplanar and the ester group approximately perpendicular to the vinyl C-HC=CH-C group [dihedral angles of 5.0 (2) and 88.89 (5)°, respectively]. This results in a short intra-molecular O =C⋯O=C contact of 2.7201 (17) Šbetween the amide O atom and the ester carbonyl C atom. The prop-2-enamide fragment and the nitro group make dihedral angles of 20.42 (6) and 13.54 (17)°, respectively, with the benzene ring. An intra-molecular C-H⋯O inter-action between the benzene ring and the amide group generates an S(6) ring motif. Inter-molecular C-H⋯O and N-H⋯O hydrogen bonds complete R(2) (2)(11) ring motifs and join mol-ecules into [100] chains.