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41.
Samir Kumar Sarkar Meenakshi Pegu Santosh Kumar Behera Siva Krishna Narra Pakkirisamy Thilagar 《化学:亚洲杂志》2019,14(24):4588-4593
Typically, molecules with a twisted donor–acceptor (D‐A) architecture have been exploited for constructing thermally activated delayed fluorescence (TADF) materials. Herein, we report the first example of a thiophene‐based thermally activated delayed fluorescent molecule without a D‐A architecture. Compound 1 (2,5‐bis(2,2‐di(thiophen‐2‐yl)vinyl)thiophene) is conformationally flexible and shows weak fluorescence in the solution state but displays bright TADFin both condensed and solid states. Compound 1 crystallized in two different polymorphs ( 1 a and 1 b ). Interestingly, both polymorphs show distinctly different TADF features. The broad spectral features and the TADF characteristics of 1 have been explored for the time‐dependent multicolor (green, yellow and red) imaging of living cells. 相似文献
42.
Samir Kumar Sarkar Meenakshi Pegu Santosh Kumar Behera Siva Krishna Narra Pakkirisamy Thilagar 《化学:亚洲杂志》2019,14(24):4431-4431
43.
The interaction of four moderately reactive molecules (MRMs), benzene (BZ), water, ammonia and silicon dioxide, with three aromatic organic superhalogens (OSHs) has been investigated at the density functional theory (DFT) level. The strength of the interaction is analysed from the distortions in the structures of both the MRMs and OSHs after complexation and the calculated binding energy (BE) values between the two interacting moieties. The interaction becomes stronger as we move from BZ to H2O to NH3 and strongest for SiO2 molecule. Contributions from different terms in total interaction energy have been examined by energy decomposition analysis (EDA). The charge flow values between MRMs and OSHs, and Mulliken spin density localised on the moderately reactive molecules have been evaluated to ensure whether the interaction is ionic or not. Atoms in Molecules (AIM) analysis has been performed to characterise the bonds formed between the two. Overall, our study gives a comprehensive account of the interaction between the moderately reactive molecules and three theoretically designed aromatic organic superhalogens, which will further motivate researchers in the field of superhalogen chemistry. 相似文献
44.
Prof. Vladimir I. Bregadze Prof. Igor B. Sivaev Ravindra Dhar Dubey Prof. Andrey Semioshkin Dr. Akim V. Shmal'ko Dr. Irina D. Kosenko Kseniya V. Lebedeva Prof. Swadhin Mandal Prasannakumar Sreejyothi Arindam Sarkar Prof. Zheyu Shen Prof. Aiguo Wu Prof. Narayan S. Hosmane 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(61):13832-13841
A series of boron-containing lipids were prepared by reactions of cyclic oxonium derivatives of polyhedron boranes and metallacarboranes (closo-dodecaborate anion, cobalt and iron bis(dicarbollides)) with amine and carboxylic acids which are derived from cholesterol. Stable liposomal formulations, on the basis of synthesized boron-containing lipids, hydrogenated soybean l -α-phosphatidylcholine and (HSPC) 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)-2000] (DSPE-PEG) as excipients, were prepared and then characterized by dynamic light scattering (DLS) that revealed the formation of particles to be smaller than 200 nm in diameter. The resulting liposomal formulations showed moderate to excellent loading and entrapment efficiency, thus justifying the design of the compounds to fit in the lipid bilayer and ensuring ease of in vivo use for future application. The liposomal formulations based on cobalt and iron bis(dicarbollide)-based lipids were found to be nontoxic against both human breast normal epithelial cells MCF-10A and human breast cancer cells MCF-7. 相似文献
45.
Mithilesh Kumar Nayak Jessica Stubbe Dr. Nicolás I. Neuman Dr. Ramakirushnan Suriya Narayanan Sandipan Maji Prof. Dr. Carola Schulzke Prof. Vadapalli Chandrasekhar Prof. Dr. Biprajit Sarkar Dr. Anukul Jana 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(19):4425-4431
This work presents a stepwise reversible two-electron transfer induced hydrogen shift leading to the conversion of a bis-pyrrolinium cation to an E-diaminoalkene and vice versa. Remarkably, the forward and the reverse reaction, which are both reversible, follow two completely different reaction pathways. Establishing such unprecedented property in this type of processes was possible by developing a novel synthetic route towards the starting dication. All intermediates involved in both the forward and the backward reactions were comprehensively characterized by a combination of spectroscopic, crystallographic, electrochemical, spectroelectrochemical, and theoretical methods. The presented synthetic route opens up new possibilities for the generation of multi-pyrrolinium cation scaffold-based organic redox systems, which constitute decidedly sought-after molecules in contemporary chemistry. 相似文献
46.
Ajay Gupta Fillip Kumar Sarkar Rajib Sarkar Ramen Jamatia Chang Yeon Lee Gajendra Gupta Amarta Kumar Pal 《应用有机金属化学》2020,34(9):e5782
Magnetically retrieval CuFe2O4@MIL-101(Cr) metal–organic framework was successfully prepared from easily available starting materials and characterized using various spectroscopic and analytical techniques such as powder X-ray diffraction, scanning electron microscopy, energy dispersive X-ray, transmission electron microscopy, elemental mapping, Fourier transform infrared spectroscopy, thermogravimetric analysis, X-ray photoelectron spectroscopy, Brunauer–Emmett–Teller, vibrating sample magnetometer, and inductively coupled plasma optical emission spectroscopy. The catalyst was then used in the synthesis of benzodiazepines containing a triazole moiety in water. The advantages of this protocol include high yields, reusability of the catalyst, and gram-scale synthesis. 相似文献
47.
Dr. Ashok Yadav Meghamala Sarkar Dr. Sappati Subrahmanyam Atul Chaudhary Prof. Dr. Evamarie Hey-Hawkins Prof. Dr. Ramamoorthy Boomishankar 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(19):4209-4213
The design of porous materials for the recognition of multiple hydrocarbons is highly desirable for the energy-efficient separation and recognition of chemical feedstock. Herein, three new iso-structural porous discrete metal–organic cages of formula {[Pd3(NiPr)3PO]4(R-AN)6} (R-AN=anilate linkers) for the selective recognition of substituted aromatic hydrocarbons are reported. The tetrahedral cages 1 , 2 , and 3 containing anilate, chloranilate, and bromanilate linkers exhibited selective encapsulation of mesitylene, o-xylene, and p-xylene, respectively, over other analogous aromatic hydrocarbons. These selective encapsulations were driven by the variations in the portal diameters present at each of these cages and their interactions with the hydrocarbon guests. These observations are supported by mass spectrometry, NMR studies, and theoretical binding-energy calculations. 相似文献
48.
Dr. V. Arun Dr. Lisa Roy Dr. Suman De Sarkar 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(70):16649-16654
An acceptorless dehydrogenative strategy for the synthesis of polyfluoroalkylated bis-indoles is described by employing an earth-abundant nickel-based catalytic system under air. The notable feature of the present transformation is the use of bench stable and easily affordable polyfluorinated alcohols without any pre-functionalization for the introduction of precious polyfluoroalkyl groups. The developed straightforward protocol accomplished biologically relevant fluoroalkyl bis-indoles in a sustainable fashion. Extensive DFT study predicts the unique role of indole molecules which stabilizes the transition states during the dehydrogenation process of polyfluorinated alcohols, presumably through non-covalent π⋅⋅⋅π and H-bonding interactions. 相似文献
49.
Philipp Rietsch Dr. Sebastian Sobottka Dr. Katrin Hoffmann Dr. Alexey A. Popov Pascal Hildebrandt Prof. Dr. Biprajit Sarkar Dr. Ute Resch-Genger Prof. Dr. Siegfried Eigler 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(72):17361-17365
Reversibly switching the light absorption of organic molecules by redox processes is of interest for applications in sensors, light harvesting, smart materials, and medical diagnostics. This work presents a symmetrical benzothiadiazole (BTD) derivative with a high fluorescence quantum yield in solution and in the crystalline state and shows by spectroelectrochemical analysis that reversible switching of UV absorption in the neutral state, to broadband Vis/NIR absorption in the 1st oxidized state, to sharp band Vis absorption in the 2nd oxidized state, is possible. For the one-electron oxidized species, formation of a delocalized radical is confirmed by electron paramagnetic resonance spectroelectrochemistry. Furthermore, our results reveal an increasing quinoidal distortion upon the 1st and 2nd oxidation, which can be used as the leitmotif for the development of BTD based redox switches. 相似文献
50.
Narayan Das Soumen De Nantu Sarkar 《Mathematical Methods in the Applied Sciences》2020,43(3):1313-1336
The generalized thermoelasticity theory based upon the Green and Naghdi model III of thermoelasticity as well as the Eringen's nonlocal elasticity model is used to study the propagation of harmonic plane waves in a nonlocal thermoelastic medium. We found two sets of coupled longitudinal waves, which are dispersive in nature and experience attenuation. In addition to the coupled waves, there also exists one independent vertically shear-type wave, which is dispersive but experiences no attenuation. All these waves are found to be influenced by the elastic nonlocality parameter. Furthermore, the shear-type wave is found to face a critical frequency, while the coupled longitudinal waves may face critical frequencies conditionally. The problem of reflection of the thermoelastic waves at the stress-free insulated and isothermal boundary of a homogeneous, isotropic nonlocal thermoelastic half-space has also been investigated. The formulae for various reflection coefficients and their respective energy ratios are determined in various cases. For a particular material, the effects of the angular frequency and the elastic nonlocal parameter have been shown on phase speeds and the attenuation coefficients of the propagating waves. The effect of the elastic nonlocality on the reflection coefficients and the energy ratios has been observed and depicted graphically. Finally, analysis of the various results has been interpreted. 相似文献