Two novel six-coordinated cadmium(ii) and zinc(ii) complexes from carbazate β-diketonate: crystal structures, enhanced two-photon absorption and biological imaging application

Abstract

To explore the photophysical properties of coordination compounds with enhanced two-photon absorption, two novel six-coordinated metal complexes (ML2, M = Cd(ii), Zn(ii)) from carbazole β-diketone ligand (HL = 4,4,4-trifluoro-1-(9-butylcarbazole-3-yl)-1,3-butanedione) were prepared and fully characterized. Their crystal structures were determined by X-ray diffraction analysis. Both variable temperature (1)H NMR spectra and MALDI-TOF mass spectrometry proved that the coordination compounds exhibit good stability in solution. The results of time-dependent density functional theory (TD-DFT) calculations indicated that the complexation of the ligands with metal ion extends the electronic delocalization in the coordination compounds, leading to enhanced two-photon absorption. The photophysical properties for the coordination compounds were identified relying on both experimentally and theoretically studies. Finally, confocal microscopy and two-photon microscopy fluorescent imaging of HepG2 cells labeled with the Zn(ii) complexe revealed its potential applications as a biological fluorescent probe.

Two-photon luminescent metal complexes for bioimaging and cancer phototherapy

“…Moreover, in 2014, Nie and co-workers [225] synthesized two novel, six-coordinated cadmium(II) and zinc(II) complexes (Fig. 28, 66 (Fig.…”

A Schiff base colorimetric chemosensor for CN‐ ion and its dioxidomolybdenum (VI) complexes: Evaluation of structural aspects and optoelectronic properties

“…The values of these parameters for the molybdenum complexes follows the order 6 > 5 > 2 > 3 > 1 > 4 . It can be explained that, when the Schiff base coordinates to molybdenum, its planarity changes which in turn will promote the ability of delocalising the electron thereby increasing the two photon absorption properties . Moreover in comparison to the Schiff base all the complexes can be best described as Donor‐Acceptor type compounds.…”

Adducts of Zinc(II) Acetylacetonate with Various Aminoquinolines: Synthesis, Structure and Luminescence

“…Thus, a series of cyclometalated iridium complexes with red or green high efficient emission was used as phosphorescent emitters with a long lifetime . Zn II and Cd II complexes of carbazole β ‐diketonate ligands are potential fluorescent probes for biological research . Heteroleptic zinc(II) compounds, adducts of 2,2’‐bipyridine or 1,10‐phenanthroline show a green luminescence with a reversible redshift that depends on the temperature of the medium .…”