Dichiral [4.4.3.0^1,5]tridecane copper(II) cluster derived from a tripodal ligand having unsymmetrical podands and the linker: Synthesis, structure, surface grafting and catalytic aspects

Abstract

Pseudo-atranes have a significant role in catalysis; however, obtaining chiral pseudo-atranes for covalent functionalization of heterogeneous catalytic surfaces is very challenging. Herein, synthesis of a chiral tripodal amine [N{CH (CH 2 Ph)CH 2 OH}{CH 2 (4 Br C 6 H 3 OH)}{CH 2 (2 CHO 4 Me C 6 H 2 OH)}] (1) and a dichiral [4.4.3.0 1,5 ]tridecane copper(II) cluster, that is, (Cu[N{CH (CH 2 Ph)CH 2 OH}{CH 2 (4 Br C 6 H 3 O)}{CH 2 (2 CHO 4 Me C 6 H 2 O)}]) 2 (2) is described. The compounds are characterized by elemental analyses, Fourier transform infrared (FT-IR) spectroscopy, mass spectrometry and single-crystal X-ray crystallography (for 2). The compound 2 is the first example of chiral pseudo-copper(II)atrane in which three unsymmetrical arms (two phenolic and a chiral ethanolic arm) are fused via Cu N transannular bond. The free CHO group present in one of the tricyclic arms of the 2 is tested as a linker to load it on 3-aminopropyltriethoxysilane-functionalized magnetic nanosilica for catalytic applications. The loading of 2 on magnetic nanosilica through CHO was confirmed by FT-IR spectroscopy, and the 2-loaded magnetic nanosilica (Fe 3 O 4 @SiO 2 /2) was characterized by powder X-ray diffraction, vibrating sample magnetometry, scanning electron microscopy, energydispersive X-ray spectroscopy and elemental mapping. The Fe 3 O 4 @SiO 2 /2 was found highly efficient, retrievable, eco-friendly and green catalyst for obtaining β-amino alcohols in excellent yields in an aqueous medium. Overall, present work is the first report on synthetic, structural and catalytic aspects of dichiral cluster of copper(II)atrane possessing unsymmetrical tricyclic arms. K E Y W O R D S bisphenolate, pseudo-atrane, functionalized magnetic silica, unsymmetrical tripod, epoxide ringopening [Correction added on 4 November 2020, after first online publication: The three chemical structures in the first two rows of Table 4 were transposed and are now placed correctly.]

Biomass-Derived Core–Shell Carbon Dots with Embedded Tripodal Receptors for the Selective Recognition of Mefenamic Acid in Pharmaceutical Formulations and Urine

“…This leads to faster and more efficient removal and rebinding of the template molecules with improved binding kinetics, which saves time and the cost of analysis. Therefore, strategies to obtain core–shell structures have been developed in recent years to introduce a myriad of cores in addition to common core materials. , Biomass-derived FCDs are trending materials due to their biocompatibility and low toxicity for utilization in optoelectronics, fluorescent sensing, and bioimaging applications. , The photoluminescent properties of FCDs can be tuned by functionalization with organic–inorganic modifiers such as amino functionalities, poly­(ethylenimine), Ag and Ni doping, and biological molecules. , Among inorganic–organic linkers, alkoxysilanes are excellent linkers to introduce desirable moieties on the surface of FCDs. , Therefore, TPA is grafted on the surface of FCDs within the 3D network of mesoporous silica via the Schiff base condensation and the sol–gel process using 3-aminopropyltriethoxysilane as a linker using modified methods. − The mesopores on the surface of FCDs provide channels for the mobilization of the analyte to interact with the tripodal pockets. This interaction leads to the quenching of the contributory fluorescent signal produced due to the FCDs and TPA.…”