Issue 9, 2023

Noncovalent induced circular dichroism sensors based on a chiral metal–organic framework: chiral induction synthesis, quantitative enantioselective sensing and noncovalent sensing mechanism

Abstract

As an important class of chiral optical sensors, chiral induced circular dichroism (ICD) sensors have received increasing attention. Herein, a series of monometallic and bimetallic centered metal–organic frameworks (MOFs) with the same crystal structure, namely [Cu(L)(2,2′-bipy)]·H2O (LNNU-2), [Cd(L)(2,2′-bipy)(H2O)] (LNNU-3) and [ZnxCuy(L)(2,2′-bipy)]·H2O (x : y = 9.6 : 0.4–1.0 : 9.0) (H2L = HOOCC6H4CH2PO(OH)(OC2H5), 2,2′-bipy = 2,2′-bipyridine), have been successfully synthesized for studying the non-covalent ICD sensing mechanism. LNNU-2 shows excellent ICD sensing performance due to the strong metal coordination interaction between LNNU-2 and chiral tryptophan (Trp). In contrast, there is no ICD effect between LNNU-3 and chiral Trp due to the absence of metal coordination interaction. The results indicate that the metal coordination interaction plays a decisive role in generating and amplifying ICD signals in this sensing system. Compared to the previously reported LNNU-1 ([Zn(L)(2,2′-bipy)]·H2O) sensor, LNNU-2 is not only capable of quantifying the enantiomeric composition of chiral Trp samples at a lower concentration but also enables highly selective and accurate determination of L-Trp concentration in water, mixed natural amino acids and simulated blood plasma components by the circular dichroism (CD) titration method. LNNU-2 also allows the accurate determination of the absolute configuration and enantiomeric excess (ee) values of two chiral aromatic amino alcohols in pure water. Additionally, the effects of different chiral amino acids as chiral inducers on the chiral induction synthesis of enantioenriched LNNU-2 were investigated. As a result, the enantioenriched (P)-LNNU-2 and (M)-LNNU-2 were successfully obtained using L-alanine (L-Ala) and D-alanine (D-Ala) as chiral inducers, respectively.

Graphical abstract: Noncovalent induced circular dichroism sensors based on a chiral metal–organic framework: chiral induction synthesis, quantitative enantioselective sensing and noncovalent sensing mechanism

Supplementary files

Article information

Article type
Research Article
Submitted
12 Feb 2023
Accepted
02 Apr 2023
First published
03 Apr 2023

Inorg. Chem. Front., 2023,10, 2818-2828

Noncovalent induced circular dichroism sensors based on a chiral metal–organic framework: chiral induction synthesis, quantitative enantioselective sensing and noncovalent sensing mechanism

Y. Zhu, T. Ding, X. Zhang, Y. Zhou, J. Yu, X. Li, H. Zheng, Z. Sun and C. Jiao, Inorg. Chem. Front., 2023, 10, 2818 DOI: 10.1039/D3QI00251A

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements