A new two-dimensional homochiral cadmium(II) coordination polymer: synthesis, structure determination, optical properties, and fluorescent sensing

Abstract

A new two-dimensional (2D) homochiral cadmium(II) coordination polymer, {[Cd₄(OH)₂(L)₂(pea)₄]·CH₃OH}_n (1) (pea = (S)-1-phenylethanamine), was solvothermally synthesized based on an enantiomerically pure chiral ligand (S)-5-(((1-carboxy-2-phenylethyl)amino) methyl)isophthalic acid (H₃L). Crystal structure analysis shows that 1 is a 2D homochiral framework consisting of coaxial double-helical chains where a pair of left- and right-handed 2₁ helixes shares tetranuclear Cd cluster subunits [Cd₄(μ₃-OH)₂]. Topologically, 1 is an interesting 3,6-connected network with the point symbol of (4³)₂(4⁶·6⁶·8³). The thermal stability and solid-state optical properties, including circular dichroism, and nonlinear optical and luminescent properties of 1 were systematically investigated. Furthermore, the fluorescence response of 1 to various common solvents and metal ions was preliminarily studied. Interesting enough, N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMA), acetone and Fe³⁺ ion have strong quenching effect on the fluorescence of 1, indicating that 1 has certain potential application in the visual detection of these species.

Graphical Abstract

Keywords:

• Homochiral metal-organic framework
• amino acid-functionalized isophthalic acid
• optical properties
• fluorescent probe

Supplementary material

Crystallographic information of 1 (CCDC: 2076056) for this paper can be obtained free of charge from the Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/data_request/cif. Additional structural figures, TGA curve, PXRD patterns, selected bond lengths and angles, and excitation/emission spectrum to this article can be found online.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China (21271157), the Key Scientific Research Projects of Colleges and Universities in Henan Province (20A150007), and the Key R & D and Promotion Projects in Henan Province (202102210008).