53348-05-3Relevant academic research and scientific papers
Dynamic extension-contraction motion in supramolecular springs
Kim, Ho-Joong,Lee, Eunji,Park, Hye-Seo,Lee, Myongsoo
, p. 10994 - 10995 (2007)
We have prepared coordination polymers with bent conformations that adopt a helical structure with reversible extension-contraction motions, triggered by temperature. Furthermore, this dynamic conformational change leads to a fluorescence switching between the fluorescent stretched and nonfluorescent compressed states of the supramolecular springs. Copyright
Steering power of perfluoroalkyl substituents in crystal engineering: Tuning the π-π Distance while maintaining the lamellar packing motif for aromatics with various sizes of π-conjugation
Banikhaled, Mohammad O.,Mottishaw, Jeffery D.,Sun, Haoran
, p. 2235 - 2242 (2015)
Previously, we reported that introducing perfluoroalkyl substituents onto aromatics promotes the formation of lamellar π-π stacked crystalline materials with short interplanar distances. In this report, we developed a new synthetic route that effectively prepares perfluoroalkylated N-containing aromatics by eliminating a side perfluoroalkylation reaction occurring on nonsubstituted Csp2-H sites of the corresponding bromoaromatics without regioselectivity. This results in a significant improvement of the yield of target perfluoroalkylated aromatics and facilitates the purification and scale-up processes. X-ray single crystal structural analyses show that lamellar π-π stacked structures with tunable interplanar distances are achieved with fused N-containing aromatics with varying sizes of π-conjugation. Both crystal structures and theoretical calculations demonstrated that the interplanar distance can be fine-tuned with the size of π-conjugation, with larger π-conjugation favoring shorter interplanar distances while still maintaining a lamellar π-π stacked packing motif. Compared to our previous results, we find that simply changing the perfluoroalkyl substituent positions and patterns can change molecular topology to exclusively form lamellar π-π stacked packing motifs through prioritization of specific steric effects. Electrochemical results and absorption spectra confirm that the band gap is reduced due to increasing π-conjugation, and the first reduction potential exhibits a significant positive shift due to both increasing π-conjugation and perfluoroalkylation.
Blue-orange emitting carbazole based donor-acceptor derivatives: Synthesis and studies of modulating acceptor unit on opto-electrochemical and theoretical properties
Badani, Purav M.,Kamble, Rajesh M.,Singh, Pooja S.
, (2021)
In order to demonstrate an effect of varying acceptor unit on optoelectronic properties of Donor–Acceptor (D–A) assembly, we herein designed and synthesized C–N coupled, carbazole based dyes 1–8 by employing Buchwald–Hartwig coupling amination reaction and fully characterized by spectroscopic methods. Presence of intramolecular charge transfer (ICT) transitions (λmax = 403–467 nm) in absorption spectra of all dyes reminiscent D–A assembly in it and emit in blue–yellow region (λemm = 467–565 nm) in solution state with marked positive solvatochromism. The photophysical studies of some of the dyes in different THF/water mixtures revealed aggregation-induced emission (AIE) feature with the nanoparticles formation, as confirmed by dynamic light scattering (DLS) technique. The HOMO (?5.42 to ?5.74 eV) and LUMO (?3.03 to ?3.50 eV) energy level of these molecules measured by cyclic voltammetry suggest electron transporting property in it. Further, DFT/TDDFT calculation of dyes, indicate quite comparable theoretical and experimental photophysical and electrochemical data. Moreover, calculated singlet (S1) and triplet (T1) excitation energy levels by DFT/B3LYP/6–311 G+(d,p) shows small ΔEST value for some dyes and hence called as TADF emitters. Thus obtained all optoelectrochemical properties of dyes propose its potential use in optoelectronic devices and in biosensing.
Fully Conjugated [4]Chrysaorene. Redox-Coupled Anion Binding in a Tetraradicaloid Macrocycle
Gregolińska, Hanna,Majewski, Marcin,Chmielewski, Piotr J.,Gregoliński, Janusz,Chien, Alan,Zhou, Jiawang,Wu, Yi-Lin,Bae, Youn Jue,Wasielewski, Michael R.,Zimmerman, Paul M.,Stepień, Marcin
, p. 14474 - 14480 (2018)
[4]Chrysaorene, a fully conjugated carbocyclic coronoid, is shown to be a low-bandgap π-conjugated system with a distinct open-shell character. The system shows good chemical stability and can be oxidized to well-defined radical cation and dication states. The cavity of [4]chrysaorene acts as an anion receptor toward halide ions with a particular selectivity toward iodides (Ka = 207 ± 6 M-1). The interplay between anion binding and redox chemistry is demonstrated using a 1H NMR analysis in solution. In particular, a well-resolved, paramagnetically shifted spectrum of the [4]chrysaorene radical cation is observed, providing evidence for the inner binding of the iodide. The radical cation-iodide adduct can be generated in thin solid films of [4] chrysaorene by simple exposure to diiodine vapor.
Synthesis and investigation of the photophysical, electrochemical and theoretical properties of phenazine-Amine based cyan blue-red fluorescent materials for organic electronics
Chacko, Sajeev,Kanekar, Deepali N.,Kamble, Rajesh M.
, p. 3278 - 3293 (2020)
To understand the structure-property relationship, we have designed and synthesized seven novel donor-Acceptor based phenazine-Amines, 2-8, by the Buchwald-Hartwig coupling amination reaction in moderate yield. The synthesized molecules were fully characterized and the influence of modulating the donor and phenazine core on the optoelectrochemical properties was studied. The absorption spectra of 2-8 display intramolecular charge transfer (ICT) transitions in the range of 431-501 nm. Dyes 2-8 exhibit positive solvatofluorochromism and emit in the cyan blue-red region with emission maxima at 498-641 nm on excitation at their respective ICT maxima in toluene, chloroform, DCM and neat solid film. The photophysical studies of the dyes in different THF/water mixtures revealed aggregation induced emission (AIE) features in dyes 2, 3 and 5. The HOMO and LUMO energy levels were found to be in the ranges of-5.39 to-5.68 eV and-3.59 to-3.71 eV, respectively, with electrochemical band gaps within the range 1.73-2.04 eV. Theoretical studies of the molecules were also carried out by using TD-DFT calculations. The comparable electrochemical energy levels to ambipolar materials, solid state luminescence with AIE characteristics and good thermal stability of the synthesized dyes signify their potential to be used as solid state emitters and ambipolar materials in optoelectronics.
A soluble ladder-conjugated star-shaped oligomer composed of four perylene diimide branches and a fluorene core: Synthesis and properties
Zhang, Youdi,Chen, Lingcheng,Zhang, Kaichen,Wang, Helin,Xiao, Yi
, p. 10170 - 10178 (2014)
A new ladder-conjugated star-shaped oligomer electron-transporting material TetraPDI-PF, with four perylene diimide (PDI) branches and a fluorene core, was efficiently synthesized. The oligomer is highly soluble in dichlorobenzene with a solubility of 155 mg mL-1, which is higher than those of PDI (35 mg mL-1) and PDI-Phen (70 mg mL-1). Demonstrated by thermogravimetric analysis (TGA), the oligomer exhibits excellent thermal stability with the decomposition temperature (Td) of 291.2 °C, which is 65 °C higher than that of PDI. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were employed to investigate the electrochemical properties. Although the CV curves of TetraPDI-PF are successively scanned for 15 cycles, they still remain invariable reduction potentials. The oligomer also shows outstanding photostability, even better than PDI, which maintains 99 % fluorescence intensity after irradiation for 10 min using maximum laser intensity. In the steady-state space-charge-limited current (SCLC) devices, TetraPDI-PF exhibits higher intrinsic electron mobility of 2.22×10-5 cm2 V-1 s-1, three orders of magnitude over that of PDI (3.52×10-8 cm2 V-1 s-1). The bulk heterojunction (BHJ) organic solar cells (OSCs) using TetraPDI-PF as non-fullerene acceptors and P3HT as donors give optimum power conversion efficiency (PCE) of 0.64 %, which is 64 times that of the PDI:P3HT BHJ cells.
Novel electroluminescent donor-acceptors based on dibenzo[a,c]phenazine as hole-transporting materials for organic electronics
Shaikh, Azam M.,Sharma, Bharat K.,Chacko, Sajeev,Kamble, Rajesh M.
, p. 628 - 638 (2017)
A series of novel donor-acceptor type of molecules (2-6) based on dibenzo[a,c]phenazine were synthesized by employing a palladium = catalyzed C-N bond forming amination reaction in a good yield and were then fully characterized, whereby the optical properties of 2-6 were determined by UV-vis absorption, fluorescence spectroscopy, and the electrochemical properties by cyclic voltammetry. The absorption spectra of 2-6 showed intramolecular charge transfer (ICT) transitions in the range of 447-513 nm in solution. The HOMO and LUMO energy levels of 2-6 were in the range from ?5.03 to ?5.29 eV and ?2.75 to ?2.87 eV, respectively, with an electrochemical band gap within 2.26-2.45 eV. The HOMO energy levels of 2-6 are comparable with those of the most commonly used hole-transporting materials, which makes them potential candidates for hole-transporting materials in organic electronics.
A triangular macrocycle altering planar and bulky sections in its molecular backbone
Kaleta, Jiri,Mazal, Ctibor
, p. 1326 - 1329 (2011)
A triangular macrocyclic molecule has been synthesized which consists of substituted phenanthrene vertices interconnected by 1,3-diethynylbicyclo[1.1.1] pentane sides. The molecule is the very first example of exploiting the bicyclopentane motif in the construction of a shape persistent macrocycle's backbone. It carries new features such as bulkiness, nonconjugated σ-bonding, and a certain conformational flexibility due to its easy longitudinal rotation. We have used some of the features in order to rationalize the observed tendency of the compound to form films on various surfaces.
Study of modulating opto-electrochemical properties in Suzuki coupled phenazine derivatives for organic electronics
Kanekar, Deepali N.,Badani, Purav M.,Kamble, Rajesh M.
, p. 5945 - 5961 (2021)
In this work, five 3,6,11-trisubstituted-dibenzo[a,c]phenazine (2–6) derivatives were synthesized by employing Palladium-catalyzed Suzuki–Miyaura ‘C–C bond’ coupling reaction and characterized. Absorption spectra of 2–6 show the formation of charge-transfer complexes. Dyes exhibit blue-green fluorescence with emission maxima 434–506?nm in various solvents and neat solid film. To elucidate AIE phenomenon, photophysical properties of dye 2 and 3 in different THF/water mixture were studied. The HOMO and LUMO energy level were found in the range of ? 6.38 to ? 6.82?eV and ? 3.67 to ? 3.75?eV with an electrochemical bandgap of 2.71–3.08?eV. The HOMO and LUMO distribution in molecules were further studied by DFT/TD–DFT calculations. Herein, characteristic blue emission, comparable energy levels with n-type materials, and good thermal stability of derivatives make them a potential candidate for their application in optoelectronics. Graphic abstract: [Figure not available: see fulltext.].
Concentration dependent halogen-bond density in the 2D self-assembly of a thienophenanthrene derivative at the aliphatic acid/graphite interface
Zha, Bao,Miao, Xinrui,Liu, Pei,Wu, Yumeng,Deng, Wenli
, p. 9003 - 9006 (2014)
The supramolecular patterns of a thienophenanthrene derivative could be switched among dissimilar polymorphs with different halogen-bond densities by solution concentration, which is demonstrated through a combination of STM and density functional theory (DFT) calculations. This journal is the Partner Organisations 2014.
