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181.
182.
Ruma?Karmakar Chirantan?Roy?Choudhury Andrei?S.?Batsanov Stuart?R.?Batten Samiran?MitraEmail author 《Structural chemistry》2005,16(5):535-539
Two new complexes [CuBr(C11H13N2O)] (1) and [Cu(NCO)(C11H13N2O)] (2) containing the tridentate Schiff base ligand, N-(1-acetyl-2-propylidene)(2-pyridylmethyl) amine which is the 1:1 condensation product of acetylacetone and 2-aminomethylpyridine, have been synthesised and characterised by elemental analysis, IR and electronic spectra, electrochemical study and single crystal X-ray diffraction study. Crystal structures reveal that the copper atom in both the complexes are in square geometry formed by the N2O donor set of the Schiff base and a bromine atom in 1 and one cyanate ligand in 2. Both bromide and isocyanate ligands act in a terminal monodentate fashion. 相似文献
183.
Hydrogen‐Bonded Organic Frameworks (HOFs): A New Class of Porous Crystalline Proton‐Conducting Materials
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Avishek Karmakar Rajith Illathvalappil Bihag Anothumakkool Arunabha Sen Partha Samanta Aamod V. Desai Dr. Sreekumar Kurungot Dr. Sujit K. Ghosh 《Angewandte Chemie (International ed. in English)》2016,55(36):10667-10671
Two porous hydrogen‐bonded organic frameworks (HOFs) based on arene sulfonates and guanidinium ions are reported. As a result of the presence of ionic backbones appended with protonic source, the compounds exhibit ultra‐high proton conduction values (σ) 0.75× 10?2 S cm?1 and 1.8×10?2 S cm?1 under humidified conditions. Also, they have very low activation energy values and the highest proton conductivity at ambient conditions (low humidity and at moderate temperature) among porous crystalline materials, such as metal–organic frameworks (MOFs) and covalent organic frameworks (COFs). These values are not only comparable to the conventionally used proton exchange membranes, such as Nafion used in fuel cell technologies, but is also the highest value reported in organic‐based porous architectures. Notably, this report inaugurates the usage of crystalline hydrogen‐bonded porous organic frameworks as solid‐state proton conducting materials. 相似文献
184.
Sandeep Mohanty Amrendra Kumar Roy Sandeep Reddy Kuchipudi Pavithran Vinay Kumar Arun Chandra Karmakar 《Phosphorus, sulfur, and silicon and the related elements》2016,191(6):857-866
We investigated the POCl3-mediated transformation of aromatic bisulfite adducts to the corresponding 5-arylidenethiazolidine-2,4-diones. The in situ transformation of an aromatic bisulfite adduct to the parent aldehyde in a non-aqueous non-polar solvent (toluene) was demonstrated using DoE (Design of experiment), offline 1H NMR, online ReactIR, HPLC, LC-MS, and GC-MS. By means of these analytical tools, we determined, for the first time, the structure of the intermediate species (aldehyde) prior to the carbon–carbon double-bond formation. The carbon–sulfur bond undergoes a fast cleavage, immediately after the addition of POCl3, which finally affords the corresponding 5-arylidenethiazolidine-2,4-diones. 相似文献
185.
Bimodal Functionality in a Porous Covalent Triazine Framework by Rational Integration of an Electron‐Rich and ‐Deficient Pore Surface
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Avishek Karmakar Amrit Kumar Abhijeet K. Chaudhari Partha Samanta Aamod V. Desai Rajamani Krishna Dr. Sujit K. Ghosh 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(14):4931-4937
A porous covalent triazine framework (CTF) consisting of both an electron‐deficient central triazine core and electron‐rich aromatic building blocks is reported. Taking advantage of the dual nature of the pore surface, bimodal functionality has been achieved. The electron deficiency in the central core has been utilized to address one of the pertinent problems in chemical industries, namely separation of benzene from its cyclic saturated congener, that is, cyclohexane. Also, by virtue of the electron‐rich aromatic rings with Lewis basic sites, aqueous‐phase chemical sensing of a nitroaromatic compound of highly explosive nature (2,4,6‐trinitrophenol; TNP) has been achieved. The present compound supersedes the performance of previously reported COFs in both the aspects. Notably, this reports the first example of pore‐surface engineering leading to bimodal functionality in CTFs. 相似文献
186.
Ruma?Karmakar Chirantan?Roy?Choudhury Samiran?MitraEmail author Lutz?Dahlenburg 《Structural chemistry》2005,16(6):611-616
One novel copper(II) complex [Cu(L)(4,4′-bipy)](ClO4) (1), (where L: tridentate Schiff base derived from salicylaldehyde and L-serine) has been synthesised and characterised by spectroscopic and electrochemical studies. The single-crystal structure
of the complex was determined. The crystal structure features the presence of [Cu(L)(4,4′-bipy)]+ cations and ClO4− anions aggregated by hydrogen bonding. Here, 4,4′-bipyridine functions as a monodentate ligand, which appears to be an unusual
phenomenon. 相似文献
187.
Chaudhuri P Karmakar S Dasgupta C Krishnamurthy HR Sood AK 《Physical review letters》2005,95(24):248301
The phase diagram of a polydisperse hard-sphere system is examined by numerical minimization of a discretized form of the Ramakrishnan-Yussouff free-energy functional. Crystalline and glassy local minima of the free energy are located and the phase diagram in the density-polydispersity plane is mapped out by comparing the free energies of different local minima. The crystalline phase disappears and the glass becomes the equilibrium phase beyond a "terminal" value of the polydispersity. A crystal-to-glass transition is also observed as the density is increased at high polydispersity. The phase diagram obtained in our study is qualitatively similar to that of hard spheres in a quenched random potential. 相似文献
188.
189.
Biprajit Paul Ayan Mukherjee Deepak Bhuyan Samit Guha 《Journal of heterocyclic chemistry》2021,58(10):2033-2038
Construction of synthetic macrocyclic host that can bind with neutral molecules and anions has potential applications in supramolecular chemistry. Herein, we have designed and synthesized blue light emitting an unsymmetrical neutral bis-urea macrocyclic host. This macrocycle can bind with neutral DMF molecule (1:1) as well as Cl− ion (1:1) through noncovalent interactions. X-Ray crystal structure, 1H NMR titrations with Job's Plot, HRMS with isotropic distribution pattern, FT-IR, and density functional theory analysis revealed the binding of bis-urea macrocyclic host with the guest molecule. 相似文献
190.
Ayan Dhara Joshua Weinmann Ana‐Maria Krause Dr. Florian Beuerle 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(35):12473-12478
The introduction of one alkyne moiety at the central carbon atom of the tripodal tribenzotriquinacene scaffold allows easy access to a great variety of apically functionalized derivatives. The spatially well‐separated arrangement of different functional units on the convex face and outer rim was further proven by single‐crystal X‐ray studies. Subsequent modifications that feature a general protecting group‐free strategy for the demethylation of protected catechols in the presence of a terminal alkyne group, an azide–alkyne Huisgen cycloaddition, and Sonogashira cross‐coupling reactions showcase the high synthetic potential of this modular approach for tribenzotriquinacene derivatization. 相似文献