14783-10-9Relevant articles and documents
Synthesis and photophysical properties of metal complexes of curcumin dyes: Solvatochromism, acidochromism, and photoactivity
Bello Forero, Josué S.,Mello, Thaís P.,Oliveira, Simone S. C.,Santos, André L. S.,Souza, Lucieri O. P.,de Fran?a, Bruna M.
, (2021/12/10)
Curcumin and its dyes have attracted attention due to their environment-sensitivity and optical properties. However, the free molecule has low photoactivity, which is a limitation for use in photodynamic therapy. To overcome this limitation, we proposed the chelation of a D-π-A-π-D curcumin dye (1) with the metals Cu (II) and Pd (II). The photophysical properties of the curcumin dyes were investigated in different solvents, using UV–vis spectroscopy and time-resolved/steady-state fluorescence techniques. In our results, all curcumin dyes exhibited a positive solvatochromism from non-polar to polar solvents, with the Stokes’ shift in the range of 1895–4970 cm?1. The acidochromism studies were performed in chloroform solution and TLC plates using trifluoroacetic acid (TFA). The results exhibited a negative acidochromism and fluorescence quenching upon gradual addition of TFA, demonstrating reversibility upon addition of triethylamine (TEA). The main mechanism which influences the solvatochromism/acidochromism is the ICT system and fluorescence lifetime decays exhibited mono-exponential fit for aprotic solvents and bi-exponential fit for protic solvents (EtOH and MeOH). Compared to the curcumin ligand (1), the metal complexes (1a-b) exhibited higher singlet oxygen quantum yields (ΦΔ = 0.36 and 0.54, respectively). The in vitro antimicrobial photoactivity of the compounds was evaluated against six different microorganisms. The results showed that the metal complexes (1a-b) exhibited both antileishmanial (MIC = 2.29 μM against Leishmania amazonensis promastigotes) and antifungal (IC50 = 10 μM against Sporothrix brasiliensis yeasts) activities, while the ligand showed no activity, suggesting the chelation with the metals Cu (II) and Pd (II) may improve its photoactivity.
Structures, hydrolysis, stabilities of palladium(II) complexes containing biologically active ligands and species distribution in aqueous solution
?nci, Duygu,Ayd?n, Rahmiye
, p. 23 - 37 (2019/03/28)
[PdACl2](n-1)H2O complexes {A: 1,10-phenanthroline (phen), 4-methyl-phenanthroline (4-mphen), 5-methyl-1,10-phenanthroline (5-mphen), 4,7-dimethyl-1,10-phenanthroline (dmphen), 3,4,7,8-tetramethyl-1,10-phenanthroline (tmphen)} were synthesized and characterized by CHN elemental analysis, ATR-FT-MIR and ATR-FT-FIR, 1H NMR and 13C NMR spectral measurements. n is the number of crystal water molecules in the complexes. The n value for the complexes [Pd(phen)Cl2], [Pd(4-mphen)Cl2] and [Pd(5-mphen)Cl2] is 1; for the complex [Pd(tmphen)Cl2]H2O is 2; for the complex [Pd(dmphen)Cl2]2H2O is 3. [PdACl2](n-1)H2O complexes were converted into aqua complexes derived from 1,10-phenanthroline, [PdA(H2O)2]2+, and investigated [PdAB]+ mixed ligand complexes formed between [PdA(H2O)2]2+ complexes and amino acids {B: glycine (gly) and tyrosine (tyr)}. Protonation constants of the gly and tyr, the acid dissociation constants of the coordinated water molecules in [PdA(H2O)2]2+ complexes and the stepwise stability constant of the [PdAB]+ mixed ligand complexes were determined in aqueous 0.1 M KNO3 ionic media at 298.15 K by potentiometric methods. The protonation constants of ligands, the acid dissociation constants of aqua complexes and the stepwise stability constants of mixed ligand complexes were calculated from the potentiometric data using the “BEST” software package. The concentration distribution of the various species formed in aqueous solution was obtained using the “SPE” software package under the experimental conditions described. The order of stepwise stability of the mixed ligand complexes in terms of the gly and tyr was [Pd(tmphen)(gly/tyr)]+ > [Pd(dmphen)(gly/tyr)]+ > [Pd(4-mphen)(gly/tyr)]+ > [Pd(phen) (gly/tyr)]+ > [Pd(5-mphen)(gly/tyr)]+. This study could contribute to a better understanding of the behavior of the palladium(II) complexes in biological systems.
The imidazo{[4,5-f][1,10]-phenanthrolin}l-2-ylidene and its palladium complexes: Synthesis, characterization, and application in C-C cross-coupling reactions
G?k, Lütfiye,Günnaz, Salih,?ahin, Zarife Sibel,Pelit, Levent,Türkmen, Hayati
, p. 96 - 104 (2016/11/21)
1,3-dibutyl-1H-imidazo[4,5-f][1,10]phenanthrolinium iodide, L5.2HI ligand and their mono-, di-, tri-, tetra-nuclear palladium(II) complexes (5.HPF6, 6–8) were synthesized and characterized by elemental analysis, FTIR, UV–visible and
