Short Intermolecular Contacts Research Articles

Metal-Induced Enhancement of Tetrel Bonding. The Case of C⋅⋅⋅X-IrIII (X=Cl, Br) Tetrel Bond Involving a Methyl Group.

In X-ray structures of the isomorphic mer-[IrX3(THT)(CNXyl)2] (X=Cl 1, Br 2; THT=tetrahydrothiophene; Xyl=2,6-Me2C6H3-) complexes, we revealed short intermolecular contacts between the C-atom of an isocyanide methyl group and halide ligands of another molecule. Geometrical consideration of the X-ray data and analysis of appropriate DFT studies allowed the attribution of these contacts to CMe⋅⋅⋅X-IrIII (X=Cl, Br) tetrel bond. Specifically, through the application of DFT calculations and various theoretical models, the presence of tetrel bonding interactions was validated, and the contribution of the CMe⋅⋅⋅X-IrIII interaction was assessed. The reinforcement of the tetrel bond upon the isocyanide coordination to iridium(III) is substantiated by molecular electrostatic potential (MEP) surface calculations. To distinguish the tetrel bonding characteristics of CMe⋅⋅⋅X-IrIII (X=Cl, Br) interactions from conventional hydrogen bonding, we employed multiple computational methodologies, including Natural Bond Orbital (NBO) analysis and Electron Localization Function (ELF) analysis. Additionally, Energy Decomposition Analysis (EDA) was applied to selected model systems to explore the underlying physical nature of these interactions.

Dioxygen-halogen bonding exemplified by crystalline peroxosolvates of N,N'-bis(haloacetyl) bispidines.

The halogen bonding in molecular crystals and supramolecular assemblies has been widely investigated. Special attention is given to the molecular structures capable of simultaneously exhibiting different types of non-covalent interactions, including conventional hydrogen bonds and halogen bonds. This paper systematically analyzes crystalline peroxosolvates of bispidine-based bis-amide derivatives, containing haloacetic acid residues, namely previously reported 1,1'-(1,5-dimethyl-3,7-diazabicyclo[3.3.1]nonane-3,7-diyl)bis(2-iodooethanone) peroxosolvate C13H20I2N2O2·H2O2 (1) and four new crystalline compounds, 1,1'-(1,5-dimethyl-3,7-diazabicyclo[3.3.1]nonane-3,7-diyl)bis(2-bromoethanone) peroxosolvate C13H20Br2N2O2·H2O2 (2), 1,1'-(9-hydroperoxy-9-hydroxy-1,5-dimethyl-3,7-diazabicyclo[3.3.1]nonane-3,7-diyl)bis(2-iodoethanone) peroxosolvate C13H20I2N2O5·0.5H2O2 (3), 1,1'-(9-hydroperoxy-9-hydroxy-1,5-dimethyl-3,7-diazabicyclo[3.3.1]nonane-3,7-diyl)bis(2-bromoethanone) peroxosolvate C13H20Br2N2O5·H2O2 (4), and 1,1'-(9-hydroperoxy-9-hydroxy-1,5-dimethyl-3,7-diazabicyclo[3.3.1]nonane-3,7-diyl)bis(2-chloroethanone) peroxosolvate C13H20Cl2N2O5·H2O2 (5). Compounds 2-5 were synthesized for the first time and their crystal structures were determined by single-crystal X-ray diffractometry (SCXRD). To the best of our knowledge, 3-5 are unprecedented crystalline hydrogen peroxide adducts of organic hydroperoxides (R-OOH). Short intermolecular contacts between halogen and hydroperoxo oxygen atoms were found in 1-3. The halogen bonding of C-I(Br) fragments with dioxygen species in compounds 1-3 as well as in the previously reported cocrystal of diacetone diperoxide with triodotrinitrobenzene (6) was identified through reduced density gradient analysis, Hirshfeld surface analysis, and Bader analysis of crystalline electron density. The interactions were quantified using the electron density topological properties acquired from the periodic DFT calculations and evaluated to lie in the range of 9-19 kJ mol-1. A distinctive spectral feature was revealed for this type of interaction, involving a red shift of the characteristic O-O stretching vibration by about 6 cm-1, which appeared in IR spectra as a narrow low-intensity band in the region 837-872 cm-1.

Synthesis, crystal structure, structural and spectroscopic analysis of (2E)-1-(4-chlorophenyl)-3-(4-methoxyphenyl)prop-2-en-1-one

Chalcones are privileged structures in chemistry because they present a variety of possibilities for the construction of new molecules, which can be obtained from natural sources or by synthesis. In the solid-state, chalcones can crystalize into various space groups, and their molecular arrangements are directly associated with their chemical and physical properties. The aim of the present work was to investigate the structural, vibrational, electronic and non-linear optical (NLO) properties of a novel chalcone crystal (2E)-1-(4-chlorophenyl)-3-(4-methoxyphenyl)prop‑2-en-1-one (C16H13ClO3, hereafter named CLPMP). This chalcone was synthesized and characterized by single-crystal X-ray Diffraction (XRD), Fourier Transform Raman (FT-Raman), Attenuated Total Reflection Fourier Transform Infrared (ATR-FTIR), and Ultraviolet-visible (UV–Vis) spectroscopy. The thermal stability of CLPMP was also evaluated by thermogravimetric analysis (TGA) and differential thermogravimetric (DTG). Theoretical quantum chemistry calculations were performed to obtain information about their chemical and physical properties. Our crystallographic data show that at room temperature, CLPMP has a monoclinic structure with P21/c space group, and four molecules per unit cell, with the following cell lengths: a = 15.5924 (4) Å, b = 14.5537 (4) Å, c = 5.90980 (10) Å, and β = 90.046(2)°. A comparison between the experimental and theoretical Raman spectra allowed us to assign all normal modes of this crystal. Through the experimental and theoretical UV absorption spectra of chalcone CLPMP, it was possible to identify the electronic transitions of its first six singlet states. From the Hirshfeld surfaces analysis it was verified that short intermolecular contacts are responsible for stabilizing the packing of the CLPMP crystal. Our NLO study and thermal analysis showed that the chalcone CLPMP can be a good material for optical applications.

Insights into non-covalent interactions, molecular and electronic structures of 3-monosubstituted and 3,5-disubstituted 1,2-dithiolylium salts: Crystallographic visualization, Hirshfeld surface analysis and DFT Calculations

Compounds based on 3-monosubstituted and 3,5-disubstituted-1,2-dithiolylium salts are subjects of conventional visualization and Hirshfield surface (HS) analyses to investigate the structure and stability-directing effects of functional groups of substituents and counterions in controlling their solid-state behaviour. Both tools show the qualitative and quantitative interplay respectively of the rich network of interactions and short intermolecular contacts that culminate in important packing and geometrically aligned patterns in these compounds and the hierarchies that exist within such interplay. The hierarchies are attributed to the induction of secondary interactions and conformational variations. In addition, quantum chemical calculations of the M06/def2-TZVP model comprising the Minnesota 06 (M06) functional and Ahlrichs/Karlsruhe valence triple-zeta (with) polarization (def2-TZVP) basis set are further used to explore the structure-property relationship in these compounds. The optimization of their molecular geometries showed reasonable correlation with their respective experimental structures. Frontier molecular orbital (FMO) and natural bond orbital (NBO) investigations on the 3-D structures are used to identify intra- and intermolecular charge transfer potentials via cation→anion (donor/acceptor) interactions and their significant roles in stabilizing molecular moieties.

Gold Polyiodide Hybrid Perovskite Solar Cells

In this work, we present the ionic liquid (IL) synthesis of two novel pseudo-2D perovskite-type gold(III)polyiodide compounds, [DodMe2S][AuI4][I3] (1) and [Et3S][AuI4][I5] (2), and their application as active layers in monolithic solar cells. The compounds are composed of tetraiodoaurate anions and polyiodide entities, infinite polyiodide chains in 1 and pentaiodides in 2, which display short intermolecular contacts resulting in relatively small electronic bandgaps. This work represents the first demonstration of film deposition of gold iodide/polyiodide compounds onto porous monolithic substrates with subsequent solar cell characterization. The devices show promising photovoltaic performance and could unlock new materials design possibilities, ultimately moving away from lead-based photovoltaic materials. These findings further highlight the use of simple polyiodide entities to increase the structural and electronic dimensionality of gold perovskite-type anions.

Trans-9,10-Dihydro-9,10-ethanoanthracene-11,12-dicarboxylic Acid: Remarkable Host Selectivities in the Presence of Mixtures of Anisole and Bromoanisole Isomers

In this work, trans-9,10-dihydro-9,10-ethanoanthracene-11,12-dicarboxylic acid (DED), a host compound that formed complexes with anisole (ANI), 2-bromoanisole (2-BA), and 4-bromoanisole (4-BA), was revealed to possess a remarkable affinity (93.1–98.6%) for 4-BA when recrystallized from any mixtures containing this guest species, be these binary (ANI/4-BA, 2-BA/4-BA, or 3-BA/4-BA), ternary (ANI/2-BA/4-BA, ANI/3-BA/4-BA, or 2-BA/3-BA/4-BA), or quaternary (ANI/2-BA/3-BA/4-BA) in nature. Furthermore, this striking host selectivity persisted even in binary solutions containing low concentrations of 4-BA (18–25%); near-complete selectivities in favor of 4-BA were observed here too. Single crystal X-ray diffraction analyses showed that the favored guest species, 4-BA, was the only one to experience short intermolecular contacts, through its phenyl ring, with the host molecule’s carbonyl oxygen atom and the host hydrogen atom on the carbon bearing the second carboxylic acid group. Furthermore, ANI and 2-BA were accommodated in wide open channels, while the guest accommodation type for 4-BA was significantly more constricted. Thermal analyses confirmed that 2(DED)·3(ANI) and DED·2-BA, having the disfavored guests in open channels, were unstable at room temperature, while the preferred guest species, 4-BA, in its decidedly constricted channels, was only released at significantly higher temperatures (116.8 °C). Therefore, by employing host–guest chemistry strategies, DED has the ability to purify and separate any of these 4-BA-containing mixtures, a distinct advantage over fractional distillations which are cumbersome owing to physical property similarities of 2-, 3-, and 4-BA.

Crystallographic, DFT, Lattice Energy and Hirshfeld Surface Analysis of Some CSD-Based 6-Chloropurines

A comparative crystallographic and detailed computational analysis of four known 6-chloropurine X-ray structures, accessed from the CSD repository, has been reported in this paper. The quantum chemical analysis of each structure, including the optimized geometry, lattice energy, Hirshfeld surface, HOMO-LUMO energies, has been made to account for the properties of this class of biologically important organic materials. The lattice energy contribution in terms of intermolecular interactions, responsible for the packing stability, has been estimated by PIXEL procedure. Three-dimensional Hirshfeld surfaces and the corresponding 2D-fingerprint plots include the analysis of short intermolecular contacts. The π…π interactions and stacking features of molecules in the packing, have been analyzed using shape index and curvedness plots.

Synthesis, structural, spectral and molecular docking of Ni(II) and Pd(II) complexes with isatin moiety and their DNA cleavage activity

New complexes of Ni(II) and Pd(II) with Schiff base ligand derived from 5-nitro isatin with 4-phenyl-3-thiosemicarbazide have been synthesized in absolute ethanol. The isolated solid compounds have been characterized by elemental analyses and spectral (FT-IR, 1 H NMR and UV-Vis.) measurements. The Schiff base ligand has been further characterized by single-crystal XRD. It has been found that the Schiff base ligand behaves as a tridentate ligand forming chelates with 1:2 (metal:ligand) in the case of Ni-complex and 1:1 (metal:ligand) in the case of Pd-complex. Octahedral-geometry has been suggested for the Ni(II) chelate while square-planar geometry has been suggested for the Pd(II) chelate. The supramolecular structure of the thiosemicarbazide is controlled by large number of short intermolecular contacts such as O…H, H…H, C…C, S…C, S…H, S…N, H…C, N…O and C…O interactions where the most dominant contacts are H…H, H…C, C…C, O…H and S…H interactions. The optimized molecular geometry calculated at B3LYP/6-31G(d,p) level agreed very well with the reported X-ray structure. The two bands observed at 434 and 250 nm in the UV-Vis. spectrum of the compound in DMSO as solvent have been calculated using TD-DFT method at 430.9 nm (f = 0.1178) and 257.2 nm (f = 0.387), respectively. These bands have been assigned to HOMO→LUMO (96%) and HOMO→LUMO+2 (90%) excitations which belong to n-π* and π-π* transitions, respectively. All the synthesized compounds have been tested against supercoiled pBR322 DNA. These compounds have been found to promote the cleavage of plasmid DNA in the presence of H 2 O 2 . The molecular docking of the ligand and its metal complexes refer to groove binding toward the DNA with high docking score of Ni(II) complex rather than the corresponding ligand and Pd(II) complex.

Synthesis, crystal structure, ATR-FTIR, FT-Raman and UV spectra, structural and spectroscopic analysis of (3E)‐4‐[4‐(dimethylamine)phenyl]but‐3‐en‐2‐one

Chalcones are a large and promising source of molecules that can be used for drug development, as they have a wide variety of pharmacological activities associated with their structural diversity. In this work, the chalcone named (3E)‐4‐[4‐(dimethylamine)phenyl]but‐3‐en‐2‐one (DMAP) was synthesized, crystallized, and characterized by single-crystal X-Ray Diffraction (XRD), Fourier Transform Raman (FT-Raman), Attenuated Total Reflection Fourier Transform Infrared (ATR-FTIR), and Ultraviolet-visible (UV–Vis) spectroscopy. Theoretical calculations of quantum chemistry were performed to obtain data regarding normal vibration modes, dipole moment, frontier molecular orbitals, quantum chemical parameters, molecular electrostatic potential map, Hirshfeld surfaces, and theoretical UV–vis spectrum. In contrast to most chalcones which are formed by two aromatic rings, the DMAP is formed by only one aromatic ring. The crystal of DMAP at 300 K has orthorhombic symmetry with space group P212121 with four molecules per unit cell. The crystalline structure is stabilized by two intermolecular short contacts, both involving the dimethylamine group. In the direction of the crystallographic a-axis, the molecules are arranged to form layers.

A photo-reversible, sensitive, and selective sensor for copper ions in an aqueous medium

A naphthopyran derivative 3, 3-diphenyl-3H-benzo[f]chromen-5-ol having a suitably positioned hydroxyl group has been synthesized via condensation of naphthalene-2,3-diol with 1,1-diphenylprop-2-yn-1-ol. The naphthopyran derivative has been characterized by various techniques such as NMR, IR, HRMS, and single-crystal X-ray crystallography. The intermolecular short contacts have been quantitatively investigated. The suitably positioned OH group allowed complexation of metal ions with an optical signal. The screening of metal ions with naphthopyran derivative led to selective and sensitive binding of Cu2+ ions with a perceptible color change (colorless to light yellow). The metal binding by naphthopyran derivative was analyzed by using UV-vis spectrophotometry. The detection was also accomplished using digital colorimetry based on a paper-based device and solution method. Furthermore, calculations based on density functional theory were performed to inspect the formation of a complex and find a suitable complex geometry. The time-dependent theory was also used to compare the observed changes in the absorption spectra for a solution containing naphthopyran derivative and copper ions with the calculated excitation parameter, which provided further evidence of complex formation.

Experimental and computational tuning of metalla-N-heterocyclic carbenes at palladium(II) and platinum(II) centers.

Palladium(II) and platinum(II) complexes featuring metalla-N-heterocyclic carbenes (7-12) were synthesised via metal-mediated coupling between equimolar cis-[MCl2(CNR)2] (R = 2,6-Me2C6H3 (Xyl), 2,4,6-Me3C6H3 (Mes)) and 2-aminopyridine or 2-aminopyrazine. Thiocyanate complexes 13-18 with two thiocyanate ligands were obtained through the ligand exchange in the parent compounds 7-12 with NH4CNS in acetone/CH2Cl2. Complexes 7-18 were isolated and characterised by HRESI+-MS, IR, 1H and 13C{1H} NMR spectroscopy and single-crystal X-ray diffraction (in the case of 11, 16, and 18). The UV-vis properties of 7-18 and the electrochemical properties of 7-12 were also evaluated. To study the electronic structure and bonding nature in the new compounds, the quantum theory of atoms in molecules (QTAIM) and Mayer bond order analysis together with the extended transition state with the natural orbitals for chemical valence (ETS-NOCV) method, were used. X-ray diffraction studies and theoretical considerations indicate that the thiocyanate derivatives 16 and 18 form supramolecular dimers by two symmetrical pairs M1⋯C5 and S1⋯C2 with short intermolecular contacts between an electron-rich MII-center and thiocyanate ligand on the one side and the electron-poor π-system of an azaheterocyclic ring on the other side. Representative carbenes 8, 11 and 12 were evaluated as photocatalysts for the hydrosilylation of diphenylacetylene with triethylsilane giving 1,2-(diphenylvinyl)triethylsilane in 98% yield under visible light irradiation (blue light, 445 nm).

Conjugated donor-acceptor substituted systems involving the 1,3-indandione-derived electron accepting moieties.

Conjugated donor-acceptor molecules are the focus of research owing to their unusual photo- and electro-physical properties. At the same time, several unusual features of these compounds are difficult to explain or predict. Here we present our results on the synthesis, X-ray structures and D-NMR spectra providing a deeper insight into the conjugation within the derivatives involving the 1,3-indandione-derived series of compounds with varying electron acceptor strength and conjugating bridge length. The X-ray structures show the presence of several intermolecular short contacts strongly affecting the molecular geometries. In solution, the coalescence temperatures corresponding to the rotation of the phenylamino moiety of all derivatives do not exceed 246 K indicating the unhindered rotation at room temperature. Using B3LYP/aug-cc-pVDZ, the calculated model chemistry barriers to rotation, dipole moments and first hyperpolarizabilities are within experimental error. We conclude that neglecting the electron donating properties of bridges themselves and internal rotation about the single bonds taking part in conjugation can result, for instance, in misinterpretation of their room temperature NMR spectra and overestimation of the computed molecular dipole moments by more than 5 D.

Straightforward Regio- and Diastereoselective Synthesis, Molecular Structure, Intermolecular Interactions and Mechanistic Study of Spirooxindole-Engrafted Rhodanine Analogs.

Straightforward regio- and diastereoselective synthesis of bi-spirooxindole-engrafted rhodanine analogs 5a–d were achieved by one-pot multicomponent [3 + 2] cycloaddition (32CA) reaction of stabilized azomethine ylide (AYs 3a–d) generated in situ by condensation of L-thioproline and 6-chloro-isatin with (E)-2-(5-(4-chlorobenzylidene)-2,4-dioxothiazolidin-3-yl)-N-(2-morpholinoethyl)acetamide. The bi-spirooxindole-engrafted rhodanine analogs were constructed with excellent diastereo- and regioselectivity along with high chemical yield. X-ray crystallographic investigations for hybrid 5a revealed the presence of four contiguous stereocenters related to C11, C12, C19 and C22 of the spiro structure. Hirshfeld calculations indicated the presence of many short intermolecular contacts such as Cl...C, S...S, S...H, O...H, N...H, H...C, C...C and H...H interactions. These contacts played a very important role in the crystal stability. The polar nature of the 32CA reaction was studied by analysis of the conceptual DFT reactivity indices. Theoretical study of this 32CA reaction indicated that it takes place through a non-concerted two-stage one-step mechanism associated with the nucleophilic attack of AY 3a to the electrophilic ethylene derivative.

Crystal Structure and Solid-State Packing of 4-Chloro-5H-1,2,3-dithiazol-5-one and 4-Chloro-5H-1,2,3-dithiazole-5-thione.

The crystal structure and solid-state packing of 4-chloro-5H-1,2,3-dithiazol-5-one and two polymorphs of 4-chloro-5H-1,2,3-dithiazole-5-thione were analyzed and compared to structural data of similar systems. These five-membered S,N-rich heterocycles are planar with considerable bond localization. All three structures demonstrate tight solid-state packing without voids which is attributed to a rich network of short intermolecular electrostatic contacts. These include Sδ+…Nδ−, Sδ+…Oδ−, Sδ+…Clδ− and Sδ+…Sδ− interactions that are well within the sum of their van der Waals radii (∑VDW). B3LYP, BLYP, M06, mPW1PW, PBE and MP2 were employed to calculate their intramolecular geometrical parameters, the Fukui condensed functions to probe their reactivity, the bond order, Bird Index and NICS(1) to establish their aromaticity.

Synthesis and Structure of (Nitronyl Nitroxide-2-ido)(tert-butyldiphenylphosphine)gold(I) and -(Di(tert-butyl)phenylphosphine)gold(I) Derivatives; Their Comparative Study in the Cross-Coupling Reaction

We synthesized two new organogold derivatives of a nitronyl nitroxide (NN) with phosphine ligands, namely NN-Au-PtBuPh2 and NN-Au-PtBu2Ph. They were characterized by X-ray diffraction analysis, cyclic voltammetry, and ESR, IR, and UV/Vis spectroscopy. The X-ray structural analysis revealed a tendency of the NN moiety to form a large number of short intermolecular contacts. This phenomenon is related to the anionic nature of the paramagnetic group NN, as evidenced by a significantly lower oxidation potential in comparison with purely organic derivatives of NN radicals. The cross-coupling reaction of NN-Au-PPh3, NN-Au-PtBuPh2, or NN-Au-PtBu2Ph with an activated bromoarene, namely, p-BrC6H4NO2, was investigated. It was shown that regardless of the presence of the bulky tert-butyl substituent, all gold derivatives have similar activities in the cross-coupling reaction and give a cross-coupling product, NN-C6H4NO2, with comparable yields.

A rare hetero-bimetallic Zn(II)/Ca(II) Schiff base complex: Synthesis, crystal structure, DFT, molecular docking and unveiling antimicrobial activity

A new hetero-bimetallic Zn(II)/Ca(II) complex, [Zn2(LOMe-pn)2(ƞ1-NCS)2Ca] (1) has been synthesized using a potentially hexadentate N2O4 proligand, H2LOMe-pn = N,N-bis(3-methoxysalicylidene)-2,2-dimethylpropane-1,3 diamine and structurally well characterized by different physicochemical techniques. Single crystal X-ray diffraction study of the complex revealed that, de-protonic form of the ligand utilizes two pockets, one is occupied by Zn(II) ion and other is housed by a Ca(II) ion. The Zn centres are fitted into the N2O2 compartment with distorted square pyramidal geometry while a large open O2O2′ compartment is occupied by a Ca(II) ion in a octacoordinated environment. DFT studies were successfully carried out using DFT/M06 functional level and 6–31 G * basis set (over all the atoms) to delineate the complex optimized structure, composition of the frontier molecular orbitals, global reactivity, total energy frameworks, MEP, total dipole moment, average polarizability and first hyperpolarizability. First hyperpolarizability value (59.62 × 10−31 esu) suggests that complex is a good NLO material. Hirshfeld surface revealed the presence of many short intermolecular contacts like C⋯H/S⋯H/N⋯H/O⋯H/H⋯H/C⋯C and S⋯S in the crystal structure. The experimental absorption spectra are comparable with the electronic transitions assigned from TD-DFT studies. CHEF based (π→π*) luminescence property has been measured in DMSO solvent at room temperature. Concentration dependant antibacterial efficacy was investigated against gram-negative bacterial strains viz. E. coli (ATCC 25,922) & Pseudomonas aeruginosa (ATCC 27,853) and gram-positive bacterial strains viz. Staphylococcus aureus (ATCC 25,923) & Bacillus subtilis (ATCC 6633). The bacterial killing efficiency and solvent effect of the complex was compared with that of ligand. Finally, a docking study with the active site of DNA Gyrase and DNA Polymerase III proteins has been carried out to corroborate the experimental findings.

Meta‐Stable Molecular Configuration Enables Thermally Stable and Solution Processable Organic Charge Transporting Materials

AbstractThe construction of state‐of‐the‐art charge transporting materials (CTMs) is challenging in modulating molecular configurations for simultaneously achieving high thermal stability and appreciable solution processability. Herein, N,N′‐bis(1‐indanyl)naphthalene‐1,4,5,8‐tetracarboxylic diimide (NDI‐ID) is served as a theoretical model to investigate the influence of molecular structure on the tradeoff between thermal stability and solubility. Compared with the alkyl substituted analog, the thermal stability of NDI‐ID is enhanced by the intramolecular and intermolecular short contacts, indicating the conformational rigidity dictates the morphological stability of the film phase. On the other hand, the dynamic topological transformation of material molecules occurs during the solvation process and, where the intramolecular hydrogen bonds are attenuated by the interactions with the surrounding solvent, leads to the increased solubility. The meta‐stable molecular configuration endows NDI‐ID a favorable union of superior solution processability and higher thermal stability, and this insight is also perfectly exemplified by the newly designed CTMs. Therefore, these results reveal the significant role of structural dynamics on material properties, which can provide a new train of thought to develop CTMs for highly efficient and stable perovskite solar cells.

Synthesis, Crystal Structure and Computational Investigation of New 4‐Phenyl‐decahydro‐1H‐1,5‐benzodiazepin‐2‐one as Potent Inhibitor of Mu‐opioid Receptor

AbstractA novel benzodiazepine derivative was prepared and characterized by elemental analysis, FT‐IR, NMR (1H and 13C) and HR‐MS methods. Its crystal structure was also investigated by single crystal X‐ray diffraction. In the title compound, the fused 6‐ and 7‐membered rings adopt chair and “twist boat” conformations, respectively. In the crystal, the molecules form inversion dimers through N—H⋅⋅⋅O hydrogen bonds and pack with no unusually short intermolecular contacts, which is in agreement with the results of the Hirshfeld surface analysis. The Hirshfeld surface analysis showed that the H⋅⋅⋅H contact was the most important interaction for the studied compound. Based on the DFT−B3LYP study, the studied compound owned a little different geometry in the gas phase concerning the solid phase. The molecular docking was performed between the title compound and a mu‐opioid receptor. Molecular dynamics studies were also carried up to 50 ns to understand the stability for the title compound complex with the mu‐opioid receptor.

Experimental and theoretical exploration on single crystal, structural, and quantum chemical parameters of (E)‐7‐(arylidene)‐1,2,6,7‐tetrahydro‐8H‐indeno[5,4‐b]furan‐8‐one derivatives: A comparative study

AbstractIn the present research work, biologically important halogen‐substituted (E)‐7‐(arylidene)‐1,2,6,7‐tetrahydro‐8H‐indeno[5,4‐b]furan‐8‐one derivatives are studied from a structural investigation point of view. For a detailed molecular structure description, some quantum‐chemical calculations were performed by using the density functional theory method with a basis set 6–311++G(d,p). The optimized molecular geometry, bond length, atomic charges, bond angle, and harmonic vibrational frequencies have been investigated. The quantum and structural entities such as total energy, electron density distribution in highest occupied molecular orbital and lowest unoccupied molecular orbital, charge distribution, electronegativity, absolute hardness (η), softness, electrophilicity, chemical potential, and charge transfer in molecules (ΔNmax) have been computed using 6–311++G(d,p) basis set. Importantly, single‐crystal analysis study for (E)‐7‐(2‐chlorobenzylidene)‐1,2,6,7‐tetrahydro‐8H‐indeno[5,4‐b]furan‐8‐one (CBIF) has been presented. The single‐crystal examination reveals CBIF has triclinic crystal lattice with nonclassical intermolecular short contact interactions. The vibrational wavenumbers are calculated and the scaled values are compared with the experimental FT‐IR spectrum. Furthermore, the molecular electrostatic potential (MEP) and some thermodynamic functions were also explored using computational work. The theoretical geometrical parameters have been compared with the experimental results obtained from the single‐crystal examination.

Effect of Axial Ligands on Easy-Axis Anisotropy and Field-Induced Slow Magnetic Relaxation in Heptacoordinated FeII Complexes.

A rational approach to modulating easy-axis magnetic anisotropy by varying the axial donor ligand in heptacoordinated FeII complexes has been explored. In this series of complexes with formulae of [Fe(H4 L)(NCS)2 ]⋅3 DMF⋅0.5 H2 O (1), [Fe(H4 L)(NCSe)2 ]⋅3 DMF⋅0.5 H2 O (2), and [Fe(H4 L)(NCNCN)2 ]⋅DMF⋅H2 O (3) [H4 L=2,2'-{pyridine-2,6-diylbis(ethan-1-yl-1-ylidene)}bis(N-phenylhydrazinecarboxamide)], the axial positions are successively occupied by different nitrogen-based π-donor ligands. Detailed dc and ac magnetic susceptibility measurements reveal the existence of easy-axis magnetic anisotropy for all of the complexes, with 1 [Ueff =21 K, τ0 =1.72×10-6 s] and 2 [Ueff =25 K, τ0 =2.25×10-6 s] showing field-induced slow magnetic relaxation behavior. However, both experimental studies and theoretical calculations indicate the magnitude of the D value of complex 3 to be larger than those of complexes 1 and 2 due to the axial bond angle being smaller than that for an ideal geometry. Detailed analysis of the field and temperature dependences of relaxation time for 1 and 2 has revealed that multiple relaxation processes (quantum tunneling of magnetization, direct, and Raman) are involved in slow magnetic relaxation for both of these complexes. Magnetic dilution experiments support the role of intermolecular short contacts.