Two Distinct Thermal Stabilities of DNA and Enzymatic Activities of DNase I in a Multistep Assembly with Carbazole Ligands: Different Binding Characteristics for Duplex and Quadruplex DNA

OFF-ON-OFF Dual Emission at Visible and UV Wavelengths from Carbazole Functionalized β-Diketonate Europium(III) Complex

This work demonstrates dual emission "OFF-ON-OFF" switching at visible and UV wavelengths of a carbazole functionalized β-diketone (LH) by a simple change of a europium(III) ion (Eu(3+)) concentration in the submicromolar concentration range. In the presence of 0.25 equiv of Eu(3+) (5 μM), LH forms a luminescent 4:1 complex ([Eu(3+)(L(-))4](-)) exhibiting dual emission at 357 and 613 nm resulting from the local excitation of the carbazole ring and ligand-sensitized luminescence from the Eu(3+)-β-diketonate unit, respectively. The 4:1 complex begins to convert into a 2:1 complex ([Eu(3+)(L(-))2](+)) via a 3:1 complex [Eu(3+)(L(-))3] above a molar ratio ([Eu(3+)]/[LH]) of 0.25, which provides the opportunity for binding of solvent methanol molecules to the vacant site of the Eu(3+) ion in the complex ([Eu(3+)(L(-))2(MeOH)n](+)). The OH oscillators of coordinated methanol molecules facilitate the nonradiative pathway of the Eu(3+) emission; hence the emission at 613 nm almost disappears above the 0.50 equivalent of Eu(3+) (11 μM), while the UV emission at 357 nm remains mostly constant over the whole concentration range.

A luminescent europium(iii)–platinum(ii) heterometallic complex as a theranostic agent: a proof-of-concept study

We present a luminescent heterometallic multifunctional theranostic Eu–Pt₂ complex, [{cis-PtCl₂(DMSO)}₂Eu(L)(H₂O)], possessing two cytotoxic Pt-centers with four DNA-binding sites, which shows intracellular Eu-based red luminescence sensitized by platinum based MLCT excited states.

Targeting of DNA molecules, BSA/c-Met tyrosine kinase receptors and anti-proliferative activity of bis(terpyridine)copper(ii) complexes

The newly synthesized bis(terpyridine)copper(ii) complexes may act as DNA-targeting metallo-anticancer agents to overcome cisplatin resistance.

Metal ion clip: fine-tuning aromatic stacking interactions in the multistep formation of carbazole-bridged zinc(ii) complexes

A carbazole-based triple bridging ligand (LH) consisting of two imidazole moieties with a diketone unit forms carbazole-bridged zinc(ii) complexes with structures of [(L⁻)₄(Zn²⁺)_n] (n = 2–6), where the strength of aromatic stacking interactions between the carbazole rings increases with an increase in the number of Zn²⁺ ions bridged.