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651.
A. Kundu 《Theoretical and Mathematical Physics》1999,118(3):333-340
Integrable inhomogenous or impurity models are usually constructed by either shifting the spectral parameter in the Lax operator or using another representation of the spin algebra. We propose a more involved general method for such construction in which the Lax operator contains generators of a novel quadratic algebra, a generalization of the known quantum algebra. In forming the monodromy matrix, we can replace any number of the local Lax operators with different realizations of the underlying algebra, which can result in spin chains with nonspin impurities causing changed coupling across the impurity sites, as well as with impurities in the form of bosonic operators. Following the same idea, we can also generate integrable inhomogeneous versions of the generalized lattice sine-Gordon model, nonlinear Schrödinger equation, Liouville model, relativistic and nonrelativistic Toda chains, etc. 相似文献
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Dibenzyltin bis(2‐ethylhexanoate) 1 (4‐Y C6H4CH2)2Sn(OC(O)R1)2 [Y = H, 1a; MeO, 1b; Cl, 1c; Me, 1d; and R1 = MeCH2CH2CH2CH(Et) ] were synthesized either from the reaction of corresponding dibenzyltin dichlorides with silver 2‐ethylhexanoate or from the reaction of dibenzyltin oxides with 2‐ethylhexanoic acid. Compound 1a was further utilized as a catalyst for the reaction of mono‐ and di‐isocyanates [PhNCO, CH3C6H3‐2,4‐(NCO)2 and OCN(CH2)6NCO] with alcohols (primary, secondary, tertiary, cyclohexcyl, alkyl, allyl, benzyl and aryl) leading to the formation of the corresponding urethanes. The catalytic efficiencies of 1 vis‐à‐vis industrially known organotin catalysts have been determined through kinetic studies for the reaction of PhNCO and n‐BuOH at various temperatures. Compounds 1a, 1c and 1d show higher efficiency than dibutyltin bis(2‐ethylhexanoate). FTIR studies further provide mechanistic insights into the catalytic cycle, which comprises pre‐coordination of isocyanate to tin(IV), formation of stannyl carbamate and generation of dibenzyl(alkoxy)carboxylate as the active catalyst. Copyright © 2000 John Wiley & Sons, Ltd. 相似文献
656.
Dr. Yanbang Li Rohin Biswas William P. Kopcha Dr. Thierry Dubroca Dr. Laura Abella Yue Sun Ryan A. Crichton Dr. Christopher Rathnam Dr. Letao Yang Dr. Yao-Wen Yeh Dr. Krishnendu Kundu Dr. Antonio Rodríguez-Fortea Prof. Josep M. Poblet Prof. Ki-Bum Lee Prof. Stephen Hill Dr. Jianyuan Zhang 《Angewandte Chemie (International ed. in English)》2023,62(3):e202380362
657.
Dr. Yanbang Li Rohin Biswas William P. Kopcha Dr. Thierry Dubroca Dr. Laura Abella Yue Sun Ryan A. Crichton Dr. Christopher Rathnam Dr. Letao Yang Dr. Yao-Wen Yeh Dr. Krishnendu Kundu Dr. Antonio Rodríguez-Fortea Prof. Josep M. Poblet Prof. Ki-Bum Lee Prof. Stephen Hill Dr. Jianyuan Zhang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2023,135(3):e202211704
Endohedral metallofullerenes (EMFs) are excellent carriers of rare-earth element (REE) ions in biomedical applications because they preclude the release of toxic metal ions. However, existing approaches to synthesize water-soluble EMF derivatives yield mixtures that inhibit precise drug design. Here we report the synthesis of metallobuckytrio (MBT), a three-buckyball system, as a modular platform to develop structurally defined water-soluble EMF derivatives with ligands by choice. Demonstrated with PEG ligands, the resulting water-soluble MBTs show superb biocompatibility. The Gd MBTs exhibit superior T1 relaxivity than typical Gd complexes, potentially superseding current clinical MRI contrast agents in both safety and efficiency. The Lu MBTs generated reactive oxygen species upon light irradiation, showing promise as photosensitizers. With their modular nature to incorporate other ligands, we anticipate the MBT platform to open new paths towards bio-specific REE drugs. 相似文献