Browse
Submit Data
Databases
API
Help

Dataset Information

10 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Effect of Planarity of Aromatic Rings Appended to o-Carborane on Photophysical Properties: A Series of o-Carboranyl Compounds Based on 2-Phenylpyridine- and 2-(Benzo[b]thiophen-2-yl)pyridine.

ABSTRACT: Herein, we investigated the effect of ring planarity by fully characterizing four pyridine-based o-carboranyl compounds. o-Carborane was introduced to the C4 position of the pyridine rings of 2-phenylpyridine and 2-(benzo[b]thiophen-2-yl)pyridine (CB1 and CB2, respectively), and the compounds were subsequently borylated to obtain the corresponding CN-chelated compounds CB1B and CB2B. Single-crystal X-ray diffraction analysis of the molecular structures of CB2 and CB2B confirmed that o-carborane is appended to the aryl moiety. In photoluminescence experiments, CB2, but not CB1, showed an intense emission, assignable to intramolecular charge transfer (ICT) transition between the aryl and o-carborane moieties, in both solution and film states. On the other hand, in both solution and film states, CB1B and CB2B demonstrated a strong emission, originating from π-π * transition in the aryl groups, that tailed off to 650 nm owing to the ICT transition. All intramolecular electronic transitions in these o-carboranyl compounds were verified by theoretical calculations. These results distinctly suggest that the planarity of the aryl groups have a decisive effect on the efficiency of the radiative decay due to the ICT transition.

SUBMITTER: Jin H

PROVIDER: S-EPMC6337515 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Photophysical Properties of Spirobifluorene-Based o-Carboranyl Compounds Altered by Structurally Rotating the Carborane Cages.

Project description:9,9'-Spirobifluorene-based o-carboranyl compounds C1 and C2 were prepared and fully characterized by multinuclear nuclear magnetic resonance (NMR) spectroscopy and elemental analysis. The solid-state structure of C1 was also determined by single-crystal X-ray diffractometry. The two carboranyl compounds display major absorption bands that are assigned to π-π* transitions involving their spirobifluorene groups, as well as weak intramolecular charge-transfer (ICT) transitions between the o-carboranes and their spirobifluorene groups. While C1 only exhibited high-energy emissions (λem = ca. 350 nm) in THF at 298 K due to locally excited (LE) states assignable to π-π* transitions involving the spirobifluorene group alone, a remarkable emission in the low-energy region was observed in the rigid state, such as in THF at 77 K or the film state. Furthermore, C2 displays intense dual emissive patterns in both high- and low-energy regions in all states. Electronic transitions that were calculated by time-dependent-DFT (TD-DFT) for each compound based on ground (S0) and first-excited (S1) state optimized structures clearly verify that the low-energy emissions are due to ICT-based radiative decays. Calculated energy barriers that are based on the relative energies associated with changes in the dihedral angle around the o-carborane cages in C1 and C2 clearly reveal that the o-carborane cage in C1 rotates more freely than that in C2. All of the molecular features indicate that ICT-based radiative decay is only available to the rigid state in the absence of structural fluctuations, in particular the free-rotation of the o-carborane cage.

| S-EPMC6891568 | biostudies-literature

Crucial Factors Regulating Intramolecular Charge-Transfer-Based Radiative Efficiency in <i>ortho</i>-Carboranyl Luminophores: Planarity between Substituted Biphenyl Rings.

Project description:o-Carboranyl compounds contain specific geometries, ranging from planar to orthogonally distorted biphenyl rings. Herein, 13 o-carboranyl compounds, 1HF-13PP, were synthesized and fully characterized to determine the impact of structural formation of the aromatic group appended with the o-carborane to estimate the efficiency of their radiative decay process. All the compounds exhibited significant intramolecular charge transfer (ICT)-based emission in the crystalline state at 298 K. Remarkably, increasing the distorted dihedral angles between biphenyl rings gradually decreased the emission efficiencies. Furthermore, their radiative decay constants decreased linearly with increasing dihedral angles, which demonstrated the inversely proportional relationship between these two factors. These findings distinctly suggest that the planar or distorted geometry of substituted aryl groups can strongly affect the efficiency of the ICT-based radiative process in o-carboranyl luminophores.

| S-EPMC9281304 | biostudies-literature

Novel 5-(Benzo[b]thiophen-3-yl)pyridine-3-carbaldehyde (BTPA) Functionalization Framework For Modulating Fullerene Electronics.

Project description:Through a cycloaddition reaction, fullerene (C60) was derivatized with a novel organic compound 5-(benzo[b]thiophen-3-yl)pyridine-3-carbaldehyde to form the processable and stable 3-(benzo[b]thiophene-3yl)-5-fullero-1-methylpyrrolidinepyridine (BTFP) compound. BTFP exhibits close similarities to phenyl-C61-butyric-acid-methyl-ester (PCBM) in terms of first reduction potential values (-0.62 and -0.61 V vs. Ag/AgCl, for BTFP and PCBM, respectively) and lowest occupied molecular orbital (LUMO) energy level values (3.93 eV in both cases). In chloroform, BTFP exhibits a bathochromic shift in the λmax of BTFP (λmax,BTFP=290 nm and λmax,PCBM=260 nm), owing to the grafted benzo[b]thiophene-3-yl)pyridine moiety. Despite the similarity in LUMO (3.93 eV) energy values, BTFP and PCBM differ in their luminescence-quenching ability. The bathochromic shift in the λmax of BTFP (relative to PCMB) is likely to contribute to improved light absorption of a suitable donor for photovoltaic applications.

| S-EPMC5474664 | biostudies-literature

Carborane-Induced Excimer Emission of Severely Twisted Bis-o-Carboranyl Chrysene.

Project description:The synthesis of a highly twisted chrysene derivative incorporating two electron deficient o-carboranyl groups is reported. The molecule exhibits a complex, excitation-dependent photoluminescence, including aggregation-induced emission (AIE) with good quantum efficiency and an exceptionally long singlet excited state lifetime. Through a combination of detailed optical studies and theoretical calculations, the excited state species are identified, including an unusual excimer induced by the presence of o-carborane. This is the first time that o-carborane has been shown to induce excimer formation ab initio, as well as the first observation of excimer emission by a chrysene-based small molecule in solution. Bis-o-carboranyl chrysene is thus an initial member of a new family of o-carboranyl phenacenes exhibiting a novel architecture for highly-efficient multi-luminescent fluorophores.

| S-EPMC6099267 | biostudies-literature

β,β-Directly Linked Porphyrin Rings: Synthesis, Photophysical Properties, and Fullerene Binding.

Project description:Cyclic porphyrin oligomers have been studied as models for photosynthetic light-harvesting antenna complexes and as potential receptors for supramolecular chemistry. Here, we report the synthesis of unprecedented β,β-directly linked cyclic zinc porphyrin oligomers, the trimer (CP3) and tetramer (CP4), by Yamamoto coupling of a 2,3-dibromoporphyrin precursor. Their three-dimensional structures were confirmed by nuclear magnetic resonance (NMR) spectroscopy, mass spectrometry, and single-crystal X-ray diffraction analyses. The minimum-energy geometries of CP3 and CP4 have propeller and saddle shapes, respectively, as calculated using density functional theory. Their different geometries result in distinct photophysical and electrochemical properties. The smaller dihedral angles between the porphyrin units in CP3, compared with CP4, result in stronger π-conjugation, splitting the ultraviolet-vis absorption bands and shifting them to longer wavelengths. Analysis of the crystallographic bond lengths indicates that the central benzene ring of the CP3 is partially aromatic [harmonic oscillator model of aromaticity (HOMA) 0.52], whereas the central cyclooctatetraene ring of the CP4 is non-aromatic (HOMA -0.02). The saddle-shaped structure of CP4 makes it a ditopic receptor for fullerenes, with affinity constants of (1.1 ± 0.4) × 105 M-1 for C70 and (2.2 ± 0.1) × 104 M-1 for C60, respectively, in toluene solution at 298 K. The formation of a 1:2 complex with C60 is confirmed by NMR titration and single-crystal X-ray diffraction.

| S-EPMC10236496 | biostudies-literature

Comparison of Photophysical Properties of Lanthanide(III) Complexes of DTTA- or DO3A-Appended Aryl-2,2'-Bipyridines.

Project description:New Tb(III) and Eu(III) complexes based on aryl-2,2'-bipyridine ligands with a cyclic DO3A chelating unit appended in the alpha position of the bipyridine core were synthesized. The photophysical properties of these complexes were compared with those of complexes of ligands with identical aryl-2,2'-bipyridine chromophores, but with an acyclic DTTA residue as an additional chelating site in the alpha position of the bipyridine core. The nature of the polyaminocarboxylic acid fragments was found to have a significant influence on the luminescence. For some of the Eu(III) complexes, upon the transition from acyclic DTTA- to the cyclic DO3A-appended ligands, a noticeable increase in the intensity of Eu(III) luminescence was observed, with an increase in the quantum yield of up to 2.55 times. In contrast, for most of the Tb(III) complexes, a similar transition resulted in a noticeable decrease in the luminescence intensity of the Tb(III) cation.

| S-EPMC9864760 | biostudies-literature

N'-(4-Methoxy-benzo-yl)pyridine-2-carbohydrazide.

Project description:The crystal structure of the title compound, C(14)H(13)N(3)O(3), exhibits two inter-molecular N-H?O hydrogen bonds.

| S-EPMC2979049 | biostudies-literature

Benzo-Fused Perylene Oligomers with up to 13 Linearly Annulated Rings.

Project description:The longer acenes with more than six linearly fused six-membered rings are still fascinating chemists and physicists because of their unique photophysical properties and their high potential for organic electronics applications. Unfortunately, with increasing size (seven and more rings) these compounds rapidly lose chemical stability. Besides kinetic and chemical stabilization approaches introducing either bulky or electron-withdrawing groups or both, such systems also have been stabilized by peri-annulation. Although strictly spoken, these peri-annulated compounds are no longer real acenes, they have fascinating properties as well. Herein, we describe the first synthesis of a new series of peri-annulated acenes with up to 13 linearly fused rings, which is unprecedented till date. Furthermore, this new series contains perylene units connected through benzene rings along their [b,k]edges, responsible for unique absorption and emission properties.

| S-EPMC8048933 | biostudies-literature

Free-radical cyclization approach to polyheterocycles containing pyrrole and pyridine rings.

Project description:A wide range of derivatives with new pyrido[2,1-a]pyrrolo[3,4-c]isoquinoline skeleton was synthesized by free-radical intramolecular cyclization of o-bromophenyl-substituted pyrrolylpyridinium salts using the (TMS)3SiH/AIBN system. The cyclization provides generally good yields of pyrido[2,1-a]pyrrolo[3,4-c]isoquinoline hydrobromides having no additional radical-sensitive substituents. The free bases can be obtained from the synthesized hydrobromides in quantitative yield by basification at room temperature. The selectivity control of intramolecular arylation was achieved by replacing the halogen: the use of 1-(2-(ortho-bromophenyl)-4-(ortho-iodophenyl)pyrrol-3-yl)pyridinium bromide makes it possible to obtain a monocyclization product, and the bicyclization product from the dibromo derivative. The procedure is also applicable to obtain 3-arylpyrido[2,1-a]pyrrolo[3,2-c]isoquinoline derivatives including 2-unsubstituted skeletons that are inaccessible via Pd-catalyzed cyclization.

| S-EPMC8239278 | biostudies-literature

The efficient synthesis of dibenzo[d,d']benzo[1,2-b:4,3-b']dithiophene and cyclopenta[1,2-b:4,3-b']bis(benzo[d]thiophen)-6-one.

Project description:With 3,3'-bi[benzo[b]thiophenyl] as starting material, dibenzo[d,d']benzo[1,2-b:4,3-b']dithiophene, a [5]heterohelicene, was synthesized efficiently in 60% yield via formylation and McMurry reaction. Cyclopenta[1,2-b:4,3-b']bis(benzo[d]thiophen)-6-one, another interesting helical ketone, was also prepared in 79% yield via deprotonation and ketonization of 3,3'-bi[benzo[b]thiophenyl]. In addition, the single-crystal structure of dibenzo[d,d']benzo[1,2-b:4,3-b']dithiophene and UV-vis spectra of both title compounds are described.

| S-EPMC2814327 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data