Chiroptical property enhancement of chiral Eu(III) complex upon association with DNA-CTMA

Abstract

DNA-based materials have attracted much attention due to their unique photo-functional properties and potential applications in various fields such as luminescent and biological systems, nanodevices, etc. In this study, the photophysical properties of a chiral Eu(III) complex, namely (Eu(D-facam)3), within DNA films were extensively investigated. The enhancement of photoluminescence (more than 25-folds increase of luminescence quantum yield) and degree of circularly polarization in luminescence (glum = − 0.6) was observed upon interaction with DNA. Various photophysical analyses suggested that the emission enhancement was mainly due to an increase of the sensitization efficiency (high ηsens) from the ligands to Eu(III) and suppression of the vibrational deactivation upon immobilization onto the DNA molecule. From CD and VCD measurements, it was suggested that the coordination structure of Eu(D-facam)3 was affected by the interaction with DNA, suggesting that the structural change of Eu(D-facam)3 contributed to the improvement of its luminescent properties.

Rational design of a photoswitchable DNA glue enabling high regulatory function and supramolecular chirality transfer

“…39,41,61,76 These reports highlight the possibility of using CD spectroscopy both to follow the process, usually showing a decrease of the Cotton effect for the Z isomer 38,58,76 to assign the binding mode of both photoisomers, if they are used as ligands, by the pattern of the ICD signal. 38,39 Furthermore, we and others have reported that the chiral environment provided by DNA can influence the chiroptical properties of organic chromophores [77][78][79][80] as well as the stereochemical outcome of a photoisomerization reaction as shown, for instance, for DNA-binding diarylethenes. 29 The same experiment, however, cannot easily be repeated for azobenzenes, as the E isomer is achiral and the Z(P) and Z(M) enantiomers (interconverting helical conformers, Figure 8A) undergo fast isomerization (racemization) in solution 81 i.e.…”

Synthesis, Characterization and Biological Activity Study of Cobalt(II), Nickel(II) and Copper(II) Complexes Derived from Mixed Bi dentate Ligands of Oxime and Phenanthroline11

“…The experimental analytical data of (C,H,N) were in good agreement with the theoretical assigning the proposed chemical structures of oxime ligand and it's metal complexes. [10,12]. The thermal decomposition of all complexes are lie at around (278-290) o C temperature and are greater than the free ligands which mainly show good indication for the formation of covalent character among bi dentate 1,10phenanthroline and oxime ligands with cobalt(II), nickel(II) and copper(II) ions…”

“…The antimicrobial activity of the synthesized compounds was evaluated in form of minimum inhibitory concentration (MIC) against the tested microbes via micro-broth dilution method following the procedure stipulated by Clinical Laboratory Standard Institute [10,11]. The microorganisms in this study are Staphylococcus aureus, Streptococcus pneumonia, E. Coli, Salmonella typhi, klebsiella pneumonia.…”

“…Furthermore, the mass spectrum of nickel (II) complex exhibited m/e=442 with low intensity due to the molecular ion of complex and the other peaks at around 398, 356, 266, 184 and 85 may be assigned to breaking of weak bonds of -OH, Ni-Cl and cleavage of 10-phenanthroline ligand in the next steps of decomposition in the gas phase of analysis [10,14].…”

“…The ligands derived from 4-hydroxy coumarine and 3-acetylcoumarine area vital component of various drugs employed in medicine as anti-tumor, sedatives, antiepileptic's, antiinflammatory, antibacterial, anti-tuberculosis [5-7] and antiviral [8,9]. The DNA binding to the chiral mixed ligands complexes of europium(III) have stuied extensively by Haruki, M. etal [10] and the antioxidation activity encouraged many researchers to synthesized novel complexes of this type of oxime complexes . The phenanthroline is a poly aromatic hetro cyclic compound and considered as classic ligand in co-ordination chemistry [11] which couples in a very versatile manner with different metal atoms/ions to give different peculiar characteristics to the metal complexes formed by it such as metal complexes with nitrogenic ligands that they can be showed to develop new molecular " Chromo sensors" for metal cations and anions, ionophores as well as new intercalating agents for polynucleotide's especially in case of DNA cleavage [12].…”