Molecular and vibrational structure of 2,2′-dihydroxybenzophenone: infrared linear dichroism and quantum chemical calculations

Design of Isoindigo-Based Small-Molecule Donors for Bulk Heterojunction Organic Solar Cell Applications in Combination with Nonfullerene Acceptors

The development of small-molecule organic solar cells with the required efficiency depends on the information obtained from molecular-level studies. In this context, 39 small-molecule donors featuring isoindigo as an acceptor moiety have been meticulously crafted for potential applications in bulk heterojunction organic solar cells. These molecules follow the D2-A-D1-A-D2 and D2-A-π-D1-π-A-D2 framework. Similar molecules considered in the previous experimental study (molecules R1 ((3E,3″E)-6,6″-(benzo[1,2-b:4,5-b']dithiophene-2,6-diyl)bis(1,1'-dimethyl-[3,3'-biindolinylidene]-2,2'-dione)) and R2 ((3E,3″E)-6,6″-(4,8-dimethoxybenzo[1,2-b:4,5-b']dithiophene-2,6-diyl)bis(1,1'-dimethyl-[3,3'-biindolinylidene]-2,2'-dione))) have been chosen as reference molecules. Molecules with and without π-spacers have been considered to understand the impact of the length of the π-spacer on intramolecular charge-transfer transitions and absorption properties. A detailed investigation is carried out to establish the relationship between the structure and photovoltaic parameters using density functional theory and time-dependent density functional theory methods. The newly developed molecules exhibit better electronic, excited-state, and charge transport properties than the reference molecules. Additionally, model donor-acceptor interfaces are constructed by integrating the designed donor molecules with fullerene/nonfullerene acceptors. The electronic and excited-state properties of these interfaces are rigorously evaluated. Results elucidate that the donor comprising of isoindigo-bithiophene-pyrroloindacenodithiophene (IIG-T2-PIDT) emerges as a promising candidate for bulk heterojunction solar cells based on nonfullerene acceptors. This research provides systematic design strategies for the development of small-molecule donors for organic solar cells.

New Approaches to Stretched Film Sample Alignment and Data Collection for Vibrational Linear Dichroism

Rapid measurements of vibrational linear dichroism (VLD) infrared spectra are shown to be possible by using stretched polymer films and an extension of existing instrumentation designed for vibrational circular dichroism spectroscopy. Earlier techniques can be extended using additional inexpensive polymer substrates to record good-quality VLD spectra of a significantly wider range of compounds with comparatively short sample-preparation times. The polymer substrates used, polyethylene and polytetrafluoroethylene, are commonly available and inexpensive, and samples are more easily prepared than that for many earlier stretched-film and crystal studies. Data are presented for neutral hydrophobic organic molecules on hydrophobic films including acridine, anthracene, fluorene, and recently synthesized S-(4-((4-cyanophenyl)ethynyl)phenyl)ethanethioate. We extend the approach to polar or ionic species, including 2,2'-bipyridine, 1,10-phenanthroline, and sodium dodecyl sulfate, by oxidizing polyethylene films to change their wetting properties. The combination of new instrumentation and modified sample preparation methods is useful in basic spectroscopy for untangling and assigning complicated infrared spectra. Nevertheless, it is not a panacea as surface-adsorbed molecules are often not monodispersed, and higher analyte concentrations can lead to aggregation and resonance phenomena that have previously been observed for infrared spectra on surfaces. These effects can be assessed by varying the sample concentration. The focus of this paper is experimental, and detailed analysis of most of the spectra lies outside its scope, including some well-studied compounds such as acridine and anthracene that allow comparisons with earlier research.

Ab initio Hartree-Fock and density functional theory investigations on the conformational stability, molecular structure and vibrational spectra of 5-chloro-3-(2-(4-methylpiperazin-1-yl)-2-oxoethyl)benzo[d]thiazol-2(3H)-one drug molecule

In this work, the experimental and theoretical spectra of 5-chloro-3-(2-(4-methylpiperazin-1-yl)-2-oxoethyl)benzo[d]thiazol-2(3H)-one molecule (abbreviated as 5CMOT) are studied. The molecular geometry and vibrational frequencies are calculated in the ground state of molecule using ab initio Hartree-Fock (HF) and Density Function Theory (DFT) methods with 6-311++G(d,p), 6-31G++(d,p), 6-31G(d,p), 6-31G(d) and 6-31G basis sets. Three staggered stable conformers were observed on the torsional potential energy surfaces. The complete assignments were performed on the basis of the total energy distribution (TED) of the vibrational modes calculated. The comparison of the theoretical and experimental geometries of the title compound indicated that the X-ray parameters fairly well agree with the theoretically obtained values for the most stable conformer. The theoretical results showed an excellent agreement with the experimental values. The calculated HOMO and LUMO energies show that the charge transfer occurs within the molecule.

Investigation of structure, vibrational and NMR spectra of oxycodone and naltrexone: a combined experimental and theoretical study

In this work, two important opioid antagonists, naltrexone and oxycodone, were prepared from thebaine and were characterized by IR, (1)H NMR and (13)C NMR spectroscopy. Moreover, computational NMR and IR parameters were obtained using density functional theory (DFT) at B3LYP/6-311++G** level of theory. Complete NMR and vibrational assignment were carried out using the observed and calculated spectra. The IR frequencies and NMR chemical shifts, determined experimentally, were compared with those obtained theoretically from DFT calculations, showed good agreements. The RMS errors observed between experimental and calculated data for the IR absorptions are 85 and 105 cm(-1), for the (1)H NMR peaks are 0.87 and 0.17 ppm and for those of (13)C NMR are 5.6 and 5.3 ppm, respectively for naltrexone and oxycodone.

Experimental and density functional theory and ab initio Hartree-Fock study on the vibrational spectra of 5-chloro-6-(4-chlorobenzoyl)-2-benzothiazolinone molecule

The vibrational frequencies and infrared intensities of 5-chloro-6-(4-chlorobenzoyl)-2-benzothiazolinone (abbreviated as CCB) molecule in the ground state were calculated by HF and DFT (B3LYP and BLYP) methods using different basis sets to elucidate the molecular structure. The solid-state FT-IR spectrum was measured and compared with calculated values. CCB was found to have two different stable conformations. The dihedral angles alpha and beta (i.e. C9-C8-C12-C18 and C8-C12-C18-C17, respectively) were computed as -59.6 degrees and -14.5 degrees for the most stable conformer. The comparison of the theoretical and experimental geometries of the title compound indicated that the X-ray parameters fairly well agree with the theoretically obtained values for the most stable conformer. The calculated vibrational frequencies are also in good agreement with the experimental results.

Experimental, anticancer activity and density functional theory study on the vibrational spectra of 2-(4-fluorobenzylideneamino) propanoic acid

2-(4-Fluorobenzylideneamino) propanoic acid was synthesized through the reaction of 4-fluorobenzaldehyde and alpha-alanine in refluxing EtOH. Its structure was verified by (1)H NMR, FTIR and Raman spectroscopy. The ground-state geometries were optimized at B3LYP/6-31G*, B3LYP/6-31+G** and B3LYP/6-31G** level without symmetry constrains. The vibrational wavenumbers of 4-FA were calculated at same level. The scaled theoretical spectra using B3LYP methods are in a good agreement with the experimental ones. The title compound was tested for anticancer activity of the Hela cell line (using an MTT viability assay) with an IC(50) 166.6 microg/mL.

Synthesis, crystal structure, insecticidal activity and DFT study on the geometry and vibration of O-(E)-1-{1-[(6-chloropyridin-3-yl)methyl]-5-methyl-1H-1,2,3-triazol-4-yl}ethyleneamino-O-ethyl-O-phenylphosphorothioate

The title compound, O-(E)-1-{1-[(6-chloropyridin-3-yl)methyl]-5-methyl-1H-1,2,3-triazol-4-yl}ethyleneamino-O-ethyl-O-phenylphosphorothioate, has been synthesized via the condensation reaction of 1-{1-[(6-chloropyridin-3-yl)methyl]-5-methyl-1H-1,2,3-triazol-4-yl}ethanone oxime and O-ethyl-O-phenylphosphorochloridothioate in the presence of NaOH powder in refluxing EtOH. Its structure was characterized by (1)H NMR, FTIR, Raman, elemental analysis and X-ray single crystal diffraction. The results of preliminary bioassays indicated that the title compound displays good insecticidal activity. Density functional (DFT) calculations have been carried out for the title compound by using the Becke-Lee-Yang-Parr's three-parameter hybrid functional (B3LYP) method at 6-31G and 6-31G basis sets. The calculated results show that the predicted geometry can well reproduce the structural parameters. The vibrational wave numbers of the title compound were calculated at same level. Predicted vibrational frequencies have been assigned and compared with experimental IR and Raman spectra and they are supported each other.

Experimental and density functional theory and ab initio Hartree-Fock study on the vibrational spectra of 2-(4-fluorobenzylideneamino)-3-(4-hydroxyphenyl) propanoic acid

2-(4-Fluorobenzylideneamino)-3-(4-hydroxyphenyl) propanoic acid (4-FT) was synthesized through the reaction of 4-fluorobenzaldehyde and l-tyrosine in refluxing EtOH. The structure of 4-FT was verified by measuring 1H NMR, FTIR and Raman. The ground-state geometries were optimized at B3LYP/6-31G**, B3LYP/6-31G*, HF/6-31G** and HF/6-31G* levels without symmetry constrains. The vibrational wavenumbers of 4-FT were calculated at same levels. The scaled spectra using B3LYP methods, which are in a good agreement with the measured spectra, are superior to those calculated using HF methods.

Experimental and density functional theory and ab initio Hartree-Fock study on the vibrational spectra of 2-(4-fluorobenzylideneamino)-3-mercaptopropanoic acid

2-(4-Fluorobenzylideneamino)-3-mercaptopropanoic acid (4-FC) was synthesized through the reaction of 4-fluorobenzaldehyde and l-cysteine in refluxing EtOH. Its structure was verified by (1)H NMR, FT-IR and Raman. The ground-state geometries were optimized at B3LYP/6-31G**, B3LYP/6-31G*, HF/6-31G** and HF/6-31G* levels without symmetry constrains, respectively. The vibrational wavenumbers of 4-FC were calculated at same level. The scaled theoretical spectra using B3LYP methods, which are in a good agreement with the experimental ones, are superior to those using HF methods.

Density-functional theory studies on standard electrode potentials of half reaction for l-adrenaline and adrenalinequinone

DFT (B3LY/6-31G(d) and B3PW91/6-31G(d)) calculations are performed for L-adrenaline and adrenalinequinone. The calculated IR spectrum of L-adrenaline is used for the assignment of IR frequencies that are observed in the experimental IR spectrum. Cyclic voltammetry with a platinum electrode of L-adrenaline solutions in phosphate buffers at pH 1 shows that standard electrode potential of half reaction for L-adrenaline and adrenalinequinone is 0.803 V. Standard electrode potential of half reaction for L-adrenaline and adrenalinequinone is calculated using the energies of solvation and the sum of electronic and thermal free energies of L-adrenaline and adrenalinequinone.