Twisted Push-Pull Alkenes Bearing Geminal Cyclicdiamino and Difluoroaryl Substituents

The systematic combination of N-heterocyclic olefins (NHOs) with fluoroarenes resulted in twisted push-pull alkenes. These alkenes carry electron-donating cyclicdiamino substituents and two electron-withdrawing fluoroaryl substituents in the geminal positions. The synthetic method can be extended to a variety of substituted push-pull alkenes by varying the NHO as well as the fluoroarenes. Solid-state molecular structures of these molecules reveal a notable elongation of the central C-C bond and a twisted geometry in the alkene motif. Absorption properties were investigated with UV-vis spectroscopy. The redox properties of the twisted push-pull alkenes were probed with electrochemistry as well as UV-vis/NIR and EPR spectroelectrochemistry, while the electronic structures were computationally evaluated and validated.Fil: Kundu, Abhinanda. International Centre Of Theoretical Science. Tata Institute Of Fundamental Research; EspañaFil: Chandra, Shubhadeep. Universitat Stuttgart; AlemaniaFil: Mandal, Debdeep. International Centre Of Theoretical Science. Tata Institute Of Fundamental Research; EspañaFil: Neuman, Nicolás Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Mahata, Alok. International Centre Of Theoretical Science. Tata Institute Of Fundamental Research; EspañaFil: Anga, Srinivas. International Centre Of Theoretical Science. Tata Institute Of Fundamental Research; EspañaFil: Rawat, Hemant. International Centre Of Theoretical Science. Tata Institute Of Fundamental Research; EspañaFil: Pal, Sudip. International Centre Of Theoretical Science. Tata Institute Of Fundamental Research; EspañaFil: Schulzke, Carola. ERNST MORITZ ARNDT UNIVERSITÄT GREIFSWALD (UG);Fil: Sarkar, Biprajit. Universität Stuttgart; AlemaniaFil: Chandrasekhar, Vadapalli. Indian Institute Of Technology Kanpur; IndiaFil: Jana, Anukul. Tata Institute Of Fundamental Research, Hyderabad; Indi

Trisubstituted Geminal Diazaalkenes Derived Transient 1,2-Carbodications

Coulombic repulsion between two adjacent cation centres of 1,2-carbodications are known to decrease with π- and/or n-donor substituents by the positive charge delocalization. Here we report the delocalization of positive charge of transient 1,2-carbodications having one H-substituent by an intramolecular base-coordination. N-heterocyclic olefin (NHO) derived 2-pyrrolidinyl appended trisubstituted geminal diazaalkenes were employed for the generation of transient 1,2-carbodications through a 2-e chemical oxidation process. We have also studied the 1-e oxidation reaction of trisubstituted geminal diazaalkenes (electrochemically and chemically) and also studied them by in situ EPR spectroscopy.Fil: Mandal, Debdeep. Indian Institute of Technology; IndiaFil: Stein, Felix. Freie Universität Berlin; AlemaniaFil: Chandra, Shubhadeep. Universitat Stuttgart;Fil: Neuman, Nicolás Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Sarkar, Pallavi. Indian Institute of Technology; IndiaFil: Das, Shubhajit. Indian Institute of Technology; IndiaFil: Kundu, Abhinanda. Indian Institute of Technology; IndiaFil: Sarkar, Arighna. Indian Institute of Technology; IndiaFil: Rawat, Hemant. Indian Institute of Technology; IndiaFil: Pati, Swapan. Indian Institute of Technology; IndiaFil: Chandrasekhar, Vadapalli. Indian Institute of Technology; IndiaFil: Sarkar, Biprajit. Universität Stuttgart;Fil: Jana, Anukul. Indian Institute of Technology; Indi

Activation of Aromatic C‐F Bonds by a N‐Heterocyclic Olefin (NHO)

A N-heterocyclic olefin (NHO), a terminal alkeneselectively activates aromatic C-F bonds without the need of anyadditional catalyst. As a result, a straightforward methodology wasdeveloped for the formation of different fluoroaryl substituted alkenesin which the central carbon-carbon double bond is in a twistedgeometry.Fil: Mandal, Debdeep. International Centre Of Theoretical Science. Tata Institute Of Fundamental Research; EspañaFil: Chandra, Shubhadeep. Freie Universität Berlin.; AlemaniaFil: Neuman, Nicolás Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Mahata, Alok. International Centre Of Theoretical Science. Tata Institute Of Fundamental Research; EspañaFil: Sarkar, Arighna. International Centre Of Theoretical Science. Tata Institute Of Fundamental Research; EspañaFil: Kundu, Abhinanda. International Centre Of Theoretical Science. Tata Institute Of Fundamental Research; EspañaFil: Anga, Srinivas. International Centre Of Theoretical Science. Tata Institute Of Fundamental Research; EspañaFil: Rawat, Hemant. International Centre Of Theoretical Science. Tata Institute Of Fundamental Research; EspañaFil: Schulzke, Carola. ERNST MORITZ ARNDT UNIVERSITÄT GREIFSWALD (UG);Fil: Sarkar, Biprajit. Freie Universität Berlin.; AlemaniaFil: Mote, Kaustubh R.. International Centre Of Theoretical Science. Tata Institute Of Fundamental Research; EspañaFil: Chandrasekhar, Vadapalli. International Centre Of Theoretical Science. Tata Institute Of Fundamental Research; EspañaFil: Jana, Anukul. International Centre Of Theoretical Science. Tata Institute Of Fundamental Research; Españ

Molecular enneanuclear CuII phosphates containing planar hexanuclear and trinuclear sub-units: syntheses, structures, and magnetism

Highly symmetric enneanuclear copper(II) phosphates [Cu9(Pz)6(μ-OH)3(μ3-OH)(ArOPO3)4(DMF)3] (PzH =pyrazole, Ar = 2,6-(CHPh2)2-4-R-C6H2; R = Me, 2MeAr; Et, 2EtAr; iPr, 2iPrAr; and Ar = 2,6-iPr2C6H3, 2Dip) comprising nine copper(II) centers and pyrazole, hydroxide and DMF as ancillary ligands were synthesized by a reaction involving the arylphosphate monoester, 1, copper(I)chloride, pyrazole, and triethylamine in a 4 : 9 : 6 : 14 ratio. All four complexes were characterized by single crystal structural analysis. The complexes contain two distinct structural motifs within the multinuclear copper scaffold: a hexanuclear unit and a trinuclear unit. In the latter, the three Cu(II) centres are bridged by a µ3-OH. Each pair of Cu(II) centers in the trinuclear unit are bridged by a pyrazole ligand. The hexanuclear unit is made up of three dinuclear Cu(II) motifs where the two Cu(II) centres are bridged by an -OH and a pyrazole ligand. The three dinuclear units are connected to each other by phosphate ligands. The latter also aid the fusion of the trinuclear and the hexanuclear motifs. Magnetic studies reveal a strong antiferromagnetic exchange between the Cu(II) centres of the dinuclear units in the hexanuclear part and a strong spin frustration in the trinuclear part leading to a degenerate ground state

A conceptual framework for the adoption of big data analytics by e-commerce startups: a case-based approach

E-commerce start-ups have ventured into emerging economies and are growing at a significantly faster pace. Big data has acted like a catalyst in their growth story. Big data analytics (BDA) has attracted e-commerce firms to invest in the tools and gain cutting edge over their competitors. The process of adoption of these BDA tools by e-commerce start-ups has been an area of interest as successful adoption would lead to better results. The present study aims to develop an interpretive structural model (ISM) which would act as a framework for efficient implementation of BDA. The study uses hybrid multi criteria decision making processes to develop the framework and test the same using a real-life case study. Systematic review of literature and discussion with experts resulted in exploring 11 enablers of adoption of BDA tools. Primary data collection was done from industry experts to develop an ISM framework and fuzzy MICMAC analysis is used to categorize the enablers of the adoption process. The framework is then tested by using a case study. Thematic clustering is performed to develop a simple ISM framework followed by fuzzy analytical network process (ANP) to discuss the association and ranking of enablers. The results indicate that access to relevant data forms the base of the framework and would act as the strongest enabler in the adoption process while the company rates technical skillset of employees as the most important enabler. It was also found that there is a positive correlation between the ranking of enablers emerging out of ISM and ANP. The framework helps in simplifying the strategies any e-commerce company would follow to adopt BDA in future. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature

Analysis for Mapping of Built-Up Area Using Remotely Sensed Indices – A Case Study of Rajarhat Block in Barasat Sadar Sub-Division in West Bengal (India)

Present study investigated mapping and monitoring urban land areas from Landsat8 satellite data using remotely sensed indices. The normalized difference built-up index (NDBI), Enhanced Built-Up and Bareness Index (EBBI), Index-based built-up index (IBI), urban index (UI), normalized difference bareness index (NDBaI) were used to extract the built-up area. The NDBI was more effective at discriminating built-up areas and at increasing accuracy (overall accuracy of 76.45 % and kappa accuracy of 57 %) of the built-up density percentage than other remotely sensed indices. Evidence on built-up area change geographically would permit urban planner and decision makers to comprehend and appraise urban growth pattern in regards to land cover dynamics

Assembly of NHC-stabilized 2-hydrophosphasilenes from Si(iv) precursors: a Lewis acid-base complex

NHC-stabilized 2-hydrophosphasilenes are obtained from 1,2-dihydro-2-chlorophosphasilanes as Si(iv) precursors by a NHC-assisted 1,2-elimination of HCl. The NHC-exchange of these compounds is demonstrated as a proof of donor acceptor bonding between NHC and the silicon centre of the “P” moiety. We have also explored the possibility of similar exchanges in NHC-stabilized Si2 and P2 compounds. Theoretical DFT calculations were performed to address the nature of Si-P bonding in the NHC-stabilized 2-hydrophosphasilenes. © The Royal Society of Chemistry

Reduction of 2-H-substituted pyrrolinium cations: the carbon-carbon single bond in air stable 2,2′-bipyrrolidines as a two-electron-source

Reduction of 2-H-substituted pyrrolinium cations via initially formed secondary radicals results in either dimerisation or H-abstracted products, while the outcome depends on the N-substituents. The resultant central carbon-carbon single bond in the dimerised 2,2′-bipyrrolidine derivatives can be oxidised chemically and electrochemically. The notably air and moisture-stable dimers were subsequently utilised as a source of two electrons in various chemical transformations

Facile One‐Pot Assembly of Push–Pull Imines by a Selective C–F Substitution Process in Aryl Fluorides

Herein, we report the synthesis of a series of push–pull imines by considering cyclic diamino substituent at the C‐centre and fluoroaryl substituent at the N‐centre. This has been achieved by a selective aromatic nucleophilic substitution of different fluoroarenes by N‐H‐substituted N‐heterocyclic imines (NHIs) at ambient conditions without any additional reagent. Solid‐state molecular structure analysis reveals the elongation of the central C–N bond of the imine functionality, which is consistent with the push–pull nature of these imines. The push–pull nature of these imines is further validated by computational studies