1
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Ahn M, Lee S, Kim MJ, Chae M, Cho DW, Wee KR. Systematic radical species control by electron push-pull substitution in the perylene-based D-π-A compounds. RSC Adv 2023; 13:2283-2293. [PMID: 36741181 PMCID: PMC9837613 DOI: 10.1039/d2ra06460j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Accepted: 12/31/2022] [Indexed: 01/15/2023] Open
Abstract
Organic radical materials have been mainly reported on the stabilization of radical species because of their high energy and reactivity, while design strategies for controlling radical species beyond stabilization have remained challenging. Here, we report the electronic push-pull control spanning the neutral to the radical state of a series of perylene-based donor-π-acceptors (D-π-A). By introducing electron-withdrawing and -donating R groups to the donor of D-π-A, the observed intramolecular interactions controllable at the HOMO level led to the exploration of radical species. D-π-A with redox-active sites was transformed to (D-π-A)˙+ and (D-π-A)˙- in response to an external electrical stimulus under stabilization by perylene, resulting in new absorption peaks. In particular, the increasing absorption peaks of (D-π-A)˙+ showed a spectral shift and intensity change according to the R group, unlike those of (D-π-A)˙-. These experimental results support that the DFT/TD-DFT data suggests the radical cationic SOMO level variability. As a result, we provide a strategy for controlling the systematic radical species using the electron push-pull effect.
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Affiliation(s)
- Mina Ahn
- Department of Chemistry and Institute of Natural Science, Daegu UniversityGyeongsan 38453Republic of Korea
| | - Soyoon Lee
- Department of Chemistry and Institute of Natural Science, Daegu UniversityGyeongsan 38453Republic of Korea
| | - Min-Ji Kim
- Department of Chemistry and Institute of Natural Science, Daegu UniversityGyeongsan 38453Republic of Korea
| | - Minjung Chae
- Department of Chemistry and Institute of Natural Science, Daegu UniversityGyeongsan 38453Republic of Korea
| | - Dae Won Cho
- Department of Chemistry, Yeungnam UniversityGyeongsanGyeongbuk 38541Republic of Korea
| | - Kyung-Ryang Wee
- Department of Chemistry and Institute of Natural Science, Daegu UniversityGyeongsan 38453Republic of Korea
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2
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Relationship between the Molecular Geometry and the Radiative Efficiency in Naphthyl-Based Bis-Ortho-Carboranyl Luminophores. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27196565. [PMID: 36235102 PMCID: PMC9572229 DOI: 10.3390/molecules27196565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 09/26/2022] [Accepted: 09/28/2022] [Indexed: 11/05/2022]
Abstract
The efficiency of intramolecular charge transfer (ICT)-based emission on π-aromatic-group-appended closo-ortho-carboranyl luminophores is known to be affected by structural fluctuations and molecular geometry, but investigation of this relationship has been in progress to date. In this study, four naphthyl-based bis-o-carboranyl compounds, in which hydrogen (15CH and 26CH) or trimethysilyl groups (15CS and 26CS) were appended at the o-carborane cage, were synthesized and fully characterized. All the compounds barely displayed an emissive trace in solution at 298 K; however, 15CH and 26CH distinctly exhibited a dual emissive pattern in rigid states (in solution at 77 K and in films), attributed to locally excited (LE) and ICT-based emission, while 15CS and 26CS showed strong ICT-based greenish emission. Intriguingly, the molecular structures of the four compounds, analyzed by single X-ray crystallography, showed that the C-C bond axis of the o-carborane cage in the trimethysilyl group-appended compounds 15CS and 26CS were more orthogonal to the plane of the appended naphthyl group than those in 15CH and 26CH. These features indicate that 15CS and 26CS present an efficient ICT transition based on strong exo-π-interaction, resulting in a higher quantum efficiency (Φem) for ICT-based radiative decay than those of 15CH and 26CH. Moreover, the 26CS structure revealed most orthogonal geometry, resulting in the highest Φem and lowest knr values for the ICT-based emission. Consequently, all the findings verified that efficient ICT-based radiative decay of aromatic group-appended o-carboranyl luminophores could be achieved by the formation of a specific geometry between the o-carborane cage and the aromatic plane.
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3
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Sinha S, Kelemen Z, Hümpfner E, Ratera I, Malval JP, Jurado JP, Viñas C, Teixidor F, Núñez R. o-Carborane-based fluorophores as efficient luminescent systems both as solids and as water-dispersible nanoparticles. Chem Commun (Camb) 2022; 58:4016-4019. [PMID: 35266927 DOI: 10.1039/d1cc07211k] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
A set of o-carborane-appended π-conjugated fluorophores and their light-emitting properties in the solid state are reported. The aggregation-induced emission enhancement (AIEE) exhibited for one of the fluorenyl derivatives paved the way to successfully preparing o-carborane-containing organic nanoparticles (NPs) homogeneously dispersed in aqueous media that maintain their luminescence properties. Notably, NPs processed as thin films also show high fluorescence efficiency, suggesting potential optical and optoelectronic applications.
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Affiliation(s)
- Sohini Sinha
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus U.A.B., 08193, Bellaterra, Barcelona, Spain.
| | - Zsolt Kelemen
- Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, Mũegyetem Rkp 3, H-1111 Budapest, Hungary
| | - Evelyn Hümpfner
- Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, Mũegyetem Rkp 3, H-1111 Budapest, Hungary
| | - Imma Ratera
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus U.A.B., 08193, Bellaterra, Barcelona, Spain. .,CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), 28029 Madrid, Spain
| | - Jean-Pierre Malval
- Université de Haute-Alsace, Institut de Science des Matériaux de Mulhouse (CNRS-UMR7361), 15 rue Jean Starcky BP 2488, 68057 Mulhouse, France
| | - José Piers Jurado
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus U.A.B., 08193, Bellaterra, Barcelona, Spain.
| | - Clara Viñas
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus U.A.B., 08193, Bellaterra, Barcelona, Spain.
| | - Francesc Teixidor
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus U.A.B., 08193, Bellaterra, Barcelona, Spain.
| | - Rosario Núñez
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus U.A.B., 08193, Bellaterra, Barcelona, Spain.
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Krebs J, Haehnel M, Krummenacher I, Friedrich A, Braunschweig H, Finze M, Ji L, Marder TB. Synthesis and Structure of an o-Carboranyl-Substituted Three-Coordinate Borane Radical Anion. Chemistry 2021; 27:8159-8167. [PMID: 33769625 PMCID: PMC8252506 DOI: 10.1002/chem.202100938] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Indexed: 12/14/2022]
Abstract
Bis(1-(4-tolyl)-carboran-2-yl)-(4-tolyl)-borane [(1-(4-MeC6 H4 )-closo-1,2-C2 B10 H10 -2-)2 (4-MeC6 H4 )B] (1), a new bis(o-carboranyl)-(R)-borane was synthesised by lithiation of the o-carboranyl precursor and subsequent salt metathesis reaction with (4-tolyl)BBr2 . Cyclic voltammetry experiments on 1 show multiple distinct reduction events with a one-electron first reduction. In a selective reduction experiment the corresponding paramagnetic radical anion 1.- was isolated and characterized. Single-crystal structure analyses allow an in-depth comparison of 1, 1.- , their calculated geometries, and the S1 excited state of 1. Photophysical studies of 1 show a charge transfer (CT) emission with low quantum yield in solution but a strong increase in the solid state. TD-DFT calculations were used to identify transition-relevant orbitals.
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Affiliation(s)
- Johannes Krebs
- Institute for Inorganic ChemistryInstitute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Martin Haehnel
- Institute for Inorganic ChemistryInstitute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Ivo Krummenacher
- Institute for Inorganic ChemistryInstitute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Alexandra Friedrich
- Institute for Inorganic ChemistryInstitute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Holger Braunschweig
- Institute for Inorganic ChemistryInstitute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Maik Finze
- Institute for Inorganic ChemistryInstitute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Lei Ji
- Frontiers Science Center for Flexible Electronics (FSCFE)Shaanxi Institute of Flexible Electronics (SIFE)Northwestern Polytechnical University127 West Youyi Road710072Xi'anP. R. China
| | - Todd B. Marder
- Institute for Inorganic ChemistryInstitute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
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Marsh AV, Little M, Cheetham NJ, Dyson MJ, Bidwell M, White AJP, Warriner CN, Swain AC, McCulloch I, Stavrinou PN, Heeney M. Highly Deformed o-Carborane Functionalised Non-linear Polycyclic Aromatics with Exceptionally Long C-C Bonds. Chemistry 2021; 27:1970-1975. [PMID: 33044792 PMCID: PMC7898797 DOI: 10.1002/chem.202004517] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Indexed: 11/16/2022]
Abstract
The effect of substituting o-carborane into the most sterically hindered positions of phenanthrene and benzo(k)tetraphene is reported. Synthesised via a Bull-Hutchings-Quayle benzannulation, the crystal structures of these non-linear acenes exhibited the highest aromatic deformation parameters observed for any reported carborane compound to date, and among the largest carboranyl C-C bond length of all organo-substituted o-carboranes. Photoluminescence studies of these compounds demonstrated efficient intramolecular charge-transfer, leading to aggregation induced emission properties. Additionally, an unusual low-energy excimer was observed for the phenanthryl compound. These are two new members of the family of carborane-functionalised non-linear acenes, notable for their peculiar structures and multi-luminescent properties.
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Affiliation(s)
- Adam V. Marsh
- Department of Chemistry and Centre for Processable ElectronicsImperial College LondonLondonSW7 2AZUK
| | - Mark Little
- Department of Chemistry and Centre for Processable ElectronicsImperial College LondonLondonSW7 2AZUK
| | - Nathan J. Cheetham
- Department of Physics and Centre for Processable ElectronicsImperial College LondonLondonSW7 2AZUK
| | - Matthew J. Dyson
- Molecular Materials and Nanosystems and Institute for Complex Molecular SystemsEindhoven University of Technology5600 MBEindhovenNetherlands
| | - Matthew Bidwell
- Department of Chemistry and Centre for Processable ElectronicsImperial College LondonLondonSW7 2AZUK
| | - Andrew J. P. White
- Department of Chemistry and Centre for Processable ElectronicsImperial College LondonLondonSW7 2AZUK
| | | | | | - Iain McCulloch
- Department of ChemistryChemistry Research LaboratoryUniversity of OxfordOxfordOX1 3TAUK
| | - Paul N. Stavrinou
- Department of Engineering ScienceUniversity of OxfordOxfordOX1 3PJUK
| | - Martin Heeney
- Department of Chemistry and Centre for Processable ElectronicsImperial College LondonLondonSW7 2AZUK
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6
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Prakash S, Mishra AK. Stercobilin and Urobilin in Aqueous Media: Existence of Specific H-Aggregates and Nonspecific Higher Aggregates at Different Concentrations. J Phys Chem A 2020; 124:10053-10065. [PMID: 33211965 DOI: 10.1021/acs.jpca.0c08642] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Fecal matter is considered to be one of the primary sources of water pollution. Understanding the aggregation behavior of the fecal pigments (FPs) could play a critical role in their detection and analysis. This work shows that in aqueous media, the fluorescence of FPs indicates the presence of multiple emitting species, which have been assigned to monomers, lower-order H-aggregates (dimers), and higher-order H-aggregates. Steady-state absorbance, fluorescence and time-resolved fluorescence decay studies conclude that the emission of FPs in aqueous medium indicates H-type of aggregation, even up to nanomolar and sub-nanomolar concentrations. Four sets of independent experiments involving the variation of (i) concentration of FPs, (ii) temperature, (iii) pH, and (iv) ethanol/water composition as solvent media suggest the presence of monomer (540 nm), dimer (516 nm), and higher-order aggregates (500 nm) of FPs in aqueous solutions. The dimeric FP species appear to be present in the entire concentration range of 1 pM to 1 μM. Fluorescence lifetimes of H-aggregates are relatively longer as compared to the corresponding monomers. Hydrogen bonding appears to play an important role in forming H-aggregates in the aqueous phase of FPs as observed in the IR spectra of the FPs in dichloromethane. Density functional theory (DFT) calculations using the B3LYP functional and the LANL2DZ basis set show the contributions of π-π stacking and hydrogen-bonding interactions toward the formation of H-aggregated dimer of FPs in aqueous media.
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Affiliation(s)
- Swayam Prakash
- Department of Chemistry, IIT Madras, 600036 Chennai, India
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7
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Deboronation-Induced Ratiometric Emission Variations of Terphenyl-Based Closo- o-Carboranyl Compounds: Applications to Fluoride-Sensing. Molecules 2020; 25:molecules25102413. [PMID: 32455846 PMCID: PMC7287808 DOI: 10.3390/molecules25102413] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Revised: 05/20/2020] [Accepted: 05/21/2020] [Indexed: 01/02/2023] Open
Abstract
Closo-o-carboranyl compounds bearing the ortho-type perfectly distorted or planar terphenyl rings (closo-DT and closo-PT, respectively) and their nido-derivatives (nido-DT and nido-PT, respectively) were synthesized and fully characterized using multinuclear NMR spectroscopy and elemental analysis. Although the emission spectra of both closo-compounds exhibited intriguing emission patterns in solution at 298 and 77 K, in the film state, closo-DT mainly exhibited a π-π* local excitation (LE)-based emission in the high-energy region, whereas closo-PT produced an intense emission in the low-energy region corresponding to an intramolecular charge transfer (ICT) transition. In particular, the positive solvatochromic effect of closo-PT and theoretical calculation results at the first excited (S1) optimized structure of both closo-compounds strongly suggest that these dual-emissive bands at the high- and low-energy can be assigned to each π-π* LE and ICT transition. Interestingly, both the nido-compounds, nido-DT and nido-PT, exhibited the only LE-based emission in solution at 298 K due to the anionic character of the nido-o-carborane cages, which cannot cause the ICT transitions. The specific emissive features of nido-compounds indicate that the emissive color of closo-PT in solution at 298 K is completely different from that of nido-PT. As a result, the deboronation of closo-PT upon exposure to increasing concentrations of fluoride anion exhibits a dramatic ratiometric color change from orange to deep blue via turn-off of the ICT-based emission. Consequently, the color change response of the luminescence by the alternation of the intrinsic electronic transitions via deboronation as well as the structural feature of terphenyl rings indicates the potential of the developed closo-o-carboranyl compounds that exhibit the intense ICT-based emission, as naked-eye-detectable chemodosimeters for fluoride ion sensing.
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8
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Recent Progress in the Development of Solid‐State Luminescent
o
‐Carboranes with Stimuli Responsivity. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.201916666] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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9
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Ochi J, Tanaka K, Chujo Y. Recent Progress in the Development of Solid-State Luminescent o-Carboranes with Stimuli Responsivity. Angew Chem Int Ed Engl 2020; 59:9841-9855. [PMID: 32009291 DOI: 10.1002/anie.201916666] [Citation(s) in RCA: 122] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2019] [Indexed: 12/20/2022]
Abstract
o-Carborane, a cluster compound containing boron and adjacent carbon atoms, displays intriguing luminescent properties. Recently, compounds containing o-carborane units were found to show suppressed aggregation-induced quenching and intense solid-state emission; they also show potential for the development of stimuli-responsive luminochromic materials. In this Minireview, we introduce three kinds of fundamental photochemical properties: aggregation-induced emission, twisted intramolecular charge transfer in crystals, and environment-sensitive excimer formation in solids. Based on these properties, several types of luminochromism, such as thermos-, vapo-, and mechanochromism, have been discovered. Based mainly on results from recent studies, we illustrate these mechanisms as well as unique luminescent behaviors of o-carborane derivatives.
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Affiliation(s)
- Junki Ochi
- Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto, 615-8510, Japan
| | - Kazuo Tanaka
- Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto, 615-8510, Japan
| | - Yoshiki Chujo
- Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto, 615-8510, Japan
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10
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Kim MJ, Ahn M, Shim JH, Wee KR. Terphenyl backbone-based donor–π–acceptor dyads: geometric isomer effects on intramolecular charge transfer. Phys Chem Chem Phys 2020; 22:3370-3378. [DOI: 10.1039/c9cp06466d] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The molecular geometry effects of ortho, meta, and para-terphenyl based donor–π–acceptor (D–π–A) dyads on intramolecular charge transfer (ICT) were studied to investigate structure-ICT relationships.
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Affiliation(s)
- Min-Ji Kim
- Department of Chemistry
- Daegu University
- Gyeongsan
- Republic of Korea
| | - Mina Ahn
- Department of Chemistry
- Daegu University
- Gyeongsan
- Republic of Korea
| | - Jun Ho Shim
- Department of Chemistry
- Daegu University
- Gyeongsan
- Republic of Korea
| | - Kyung-Ryang Wee
- Department of Chemistry
- Daegu University
- Gyeongsan
- Republic of Korea
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11
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Photophysical Properties of Spirobifluorene-Based o-Carboranyl Compounds Altered by Structurally Rotating the Carborane Cages. Molecules 2019; 24:molecules24224135. [PMID: 31731632 PMCID: PMC6891568 DOI: 10.3390/molecules24224135] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 11/11/2019] [Accepted: 11/13/2019] [Indexed: 11/25/2022] Open
Abstract
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.
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12
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Huang R, Liu H, Liu K, Wang G, Liu Q, Wang Z, Liu T, Miao R, Peng H, Fang Y. Marriage of Aggregation-Induced Emission and Intramolecular Charge Transfer toward High Performance Film-Based Sensing of Phenolic Compounds in the Air. Anal Chem 2019; 91:14451-14457. [DOI: 10.1021/acs.analchem.9b03096] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Rongrong Huang
- Key Laboratory of Applied Surface and Colloid Chemistry (Ministry of Education), School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi’an 710119, P. R. China
| | - Huijing Liu
- Key Laboratory of Applied Surface and Colloid Chemistry (Ministry of Education), School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi’an 710119, P. R. China
| | - Ke Liu
- Key Laboratory of Applied Surface and Colloid Chemistry (Ministry of Education), School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi’an 710119, P. R. China
| | - Gang Wang
- Key Laboratory of Applied Surface and Colloid Chemistry (Ministry of Education), School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi’an 710119, P. R. China
| | - Quan Liu
- Key Laboratory of Applied Surface and Colloid Chemistry (Ministry of Education), School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi’an 710119, P. R. China
| | - Zhaolong Wang
- Key Laboratory of Applied Surface and Colloid Chemistry (Ministry of Education), School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi’an 710119, P. R. China
| | - Taihong Liu
- Key Laboratory of Applied Surface and Colloid Chemistry (Ministry of Education), School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi’an 710119, P. R. China
| | - Rong Miao
- Key Laboratory of Applied Surface and Colloid Chemistry (Ministry of Education), School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi’an 710119, P. R. China
| | - Haonan Peng
- Key Laboratory of Applied Surface and Colloid Chemistry (Ministry of Education), School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi’an 710119, P. R. China
| | - Yu Fang
- Key Laboratory of Applied Surface and Colloid Chemistry (Ministry of Education), School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi’an 710119, P. R. China
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13
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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. Molecules 2019; 24:molecules24010201. [PMID: 30621119 PMCID: PMC6337515 DOI: 10.3390/molecules24010201] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 12/31/2018] [Accepted: 01/03/2019] [Indexed: 11/16/2022] Open
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 C∧N-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.
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14
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Jin H, Bae HJ, Kim S, Lee JH, Hwang H, Park MH, Lee KM. 2-Phenylpyridine- and 2-(benzo[b]thiophen-2-yl)pyridine-based o-carboranyl compounds: impact of the structural formation of aromatic rings on photophysical properties. Dalton Trans 2019; 48:1467-1476. [DOI: 10.1039/c8dt04367a] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
2-Phenylpyridine and 2-(benzo[b]thiophen-2-yl)pyridine-based o-carboranyl compounds showed intriguing emission that depended on the structural formation.
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Affiliation(s)
- Hyomin Jin
- Department of Chemistry and Institute for Molecular Science and Fusion Technology
- Kangwon National University
- Gangwon 24341
- Republic of Korea
| | - Hye Jin Bae
- Department of Chemistry
- KAIST
- Daejeon 34142
- Republic of Korea
| | - Seonah Kim
- Department of Chemistry and Institute for Molecular Science and Fusion Technology
- Kangwon National University
- Gangwon 24341
- Republic of Korea
| | - Ji Hye Lee
- Department of Chemistry and Institute for Molecular Science and Fusion Technology
- Kangwon National University
- Gangwon 24341
- Republic of Korea
| | - Hyonseok Hwang
- Department of Chemistry and Institute for Molecular Science and Fusion Technology
- Kangwon National University
- Gangwon 24341
- Republic of Korea
| | - Myung Hwan Park
- Department of Chemistry Education
- Chungbuk National University
- Chungbuk 28644
- Republic of Korea
| | - Kang Mun Lee
- Department of Chemistry and Institute for Molecular Science and Fusion Technology
- Kangwon National University
- Gangwon 24341
- Republic of Korea
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