Jump to main content
Jump to site search

Issue 32, 2013
Previous Article Next Article

Copper-induced fluorescence enhancement and particle-size decrease of a C-6 unsubstituted tetrahydropyrimidine racemate

Author affiliations

Abstract

Fluorescence enhancement and particle-size control of organic fluorophores are of general interest owing to their wide applications. We recently developed a convenient five-component reaction (5CR) for the synthesis of a novel class of racemates, C-6 unsubstituted tetrahydropyrimidines with strong aggregation-induced emission (AIE) properties. The copper-induced fluorescence enhancement and particle-size decrease of the racemate dimethyl 2-(4-hydroxy-3-methoxyphenyl)-1,3-diphenyl-1,2,3,6-tetrahydropyrimidine-4,5-dicarboxylate (THP-1), one of the 5CR products, were investigated in this paper. THP-1 shows useful AIE properties, which have attracted great attention recently, and the unusual size-independent emission (SIE) properties reported in our previous work. The fluorescence intensity of THP-1 increased upon adding Cu2+ and a good linear relationship between the fluorescence intensity at the peak position and the Cu2+ concentration was observed in the range of 0–80 μM of Cu2+. The fluorescence response to Cu2+ is highly selective over other common transition metal ions. Most importantly, the suspension particle sizes of THP-1 were found to gradually decrease upon adding Cu2+. This method for controlling organic particle-size is completely different from conventional ones. The investigation results of the influences of Cu2+ on the optical properties and particle sizes of THP-1 in ethanol–water suspensions as well as the molecular stacking mode in the single-crystal of THP-1 indicate that the copper-induced fluorescence enhancement and particle-size decrease are expected to result from the coordination-induced dissociation of intermolecular O–H⋯O bonds connecting non-emissive groups. In addition, THP-1 shows no cytotoxicity in EC109 cells at concentrations below 30 μM. These useful and interesting properties of THP-1 are expected to be very helpful for new probe design, theoretical research on the relationship between intermolecular hydrogen bonds and optical properties, as well as practical applications in organic particle-size control and chemical/biological fluorescence probes.

Graphical abstract: Copper-induced fluorescence enhancement and particle-size decrease of a C-6 unsubstituted tetrahydropyrimidine racemate

Back to tab navigation
Please wait while Download options loads

Supplementary files

Publication details

The article was received on 07 Mar 2013, accepted on 22 Apr 2013 and first published on 10 May 2013


Article type: Paper
DOI: 10.1039/C3RA41121D
Citation: RSC Adv., 2013,3, 13286-13292
  •   Request permissions

    Copper-induced fluorescence enhancement and particle-size decrease of a C-6 unsubstituted tetrahydropyrimidine racemate

    L. Huang, J. Su, D. Zhong, H. Wang, R. Liu, L. Yu, Q. Zhu and S. Liu, RSC Adv., 2013, 3, 13286
    DOI: 10.1039/C3RA41121D

Search articles by author