A novel class of Ru(II)-based polypyridyl complexes with an auxiliary salicylaldehyde ligand Ru(phen)
(X-Sal)BF
{X: H (
), 5-Cl (
), 5-Br (
), 3,5-Cl
(
), 3,5-Br
(
), 3-Br,5-Cl (
), 3,5-I
(
), 5-NO
(
...), 5-Me (
), 4-Me (
), 4-OMe (
), and 4-DEA (
), has been synthesized and characterized by elemental analysis, FT-IR, and
H/
C NMR spectroscopy. The molecular structure of
,
,
,
, and
was determined by single-crystal X-ray diffraction analysis which revealed structural similarities. DFT and TD-DFT calculations showed that they also possess similar electronic structures. Absorption/emission spectra were recorded for
,
,
, and
. All Ru-complexes, unlike the pure ligands and the complex lacking the salicylaldehyde component, displayed outstanding antiproliferative activity in the screening test (10 μM) against CCRF-CEM leukemia cells underlining the crucial role of the presence of the auxiliary ligand for the biological activity. The two most active derivatives, namely
and
, were selected for continuous assays showing IC
values in the submicromolar and micromolar range against drug-sensitive CCRF-CEM and multidrug-resistant CEM/ADR5000 leukemia cells, respectively. These two compounds were investigated in silico for their potential binding to duplex DNA well-matched and mismatched base pairs, since they showed remarkable selectivity indexes (2.2 and 19.5 respectively) on PBMC cells.
We describe the synthesis of fluorogenic arylureas and amides and their interaction with primary or secondary amines under air and light in organic-aqueous mixtures to give rise to a new class of ...persistent organic radicals, described on the basis of their electron paramagnetic resonance (EPR), as well as UV-vis, fluorescence, NMR, and quantum mechanics calculations, and their prospective use as multi-signal reporters in a smart label for fish freshness.
Ru(II) polypyridyl complexes are widely used in biological fields, due to their physico-chemical and photophysical properties. In this paper, a series of new chiral Ru(II) polypyridyl complexes (1-5) ...with the general formula {Δ/Λ-Ru(bpy)
(X,Y-sal)BF
} (bpy = 2,2'-bipyridyl; X,Y-sal = 5-bromosalicylaldehyde (1), 3,5-dibromosalicylaldehyde (2), 5-chlorosalicylaldehyde (3), 3,5-dichlorosalicylaldehyde (4) and 3-bromo-5-chlorosalicylaldehy (5)) were synthesized and characterized by elemental analysis, FT-IR, and
H/
C NMR spectroscopy. Also, the structures of complexes 1 and 5 were determined by X-ray crystallography; these results showed that the central Ru atom adopts a distorted octahedral coordination sphere with two bpy and one halogen-substituted salicylaldehyde. DFT and TD-DFT calculations have been performed to explain the excited states of these complexes. The singlet states with higher oscillator strength are correlated with the absorption signals and are mainly described as
MLCT from the ruthenium centre to the bpy ligands. The lowest triplet states (T
) are described as
MLCT from the ruthenium center to the salicylaldehyde ligand. The theoretical results are in good agreement with the observed unstructured band at around 520 nm for complexes 2, 4 and 5. Biological studies on human cancer cells revealed that dihalogenated ligands endow the Ru(II) complexes with enhanced cytotoxicity compared to monohalogenated ligands. In addition, as far as the type of halogen is concerned, bromine is the halogen that provides the highest cytotoxicity to the synthesized complexes. All complexes induce cell cycle arrest in G0/G1 and apoptosis, but only complexes bearing Br are able to provoke an increase in intracellular ROS levels and mitochondrial dysfunction.
A fluorogenic perylenediimide‐functionalized polyacrylate capable of generating color and fluorescence changes in the presence of triacetone triperoxide TATP), an improvised explosive used in ...terrorist attacks, under solvent‐free, solid‐state conditions has been developed. The material works by accumulating volatile TATP until it reaches a threshold; therefore, triggering colorimetric and fluorescent responses.
Spontaneous glow: A fluorogenic perylenediimide‐functionalized polyacrylate is capable of generating color and fluorescence changes in the presence of triacetone triperoxide (TATP), which is an improvised explosive used in terrorist attacks, under solvent‐free, solid‐state conditions (see figure).
The reaction of N-(2-phthalimidoethyl)-N-alkylisopropylamines and S2Cl2 gave 4-N-(2-phthalimidoethyl)-N-alkylamino-5-chloro-1,2-dithiol-3-thiones that quantitatively cycloadded to dimethyl or diethyl ...acetylenedicarboxylate to give stable thioacid chlorides, which in turn reacted with one equivalent of aniline or a thiole to give thioanilides or a dithioester. Several compounds of this series showed atropisomers that were studied by a combination of dynamic NMR, simulation of the signals, conformational analysis by DFT methods, and single crystal X-ray diffraction, showing a good correlation between the theoretical calculations, the experimental values of energies, and the preferred conformations in the solid state. The steric hindering of the crowded substitution at the central amine group was found to be the reason for the presence of permanent atropisomers in this series of compounds and the cause of a unique disposition of the thioxo group at close-to-right angles with respect to the plane defined by the 1,3-dithiole ring in the dithiafulvene derivatives, thus breaking the sulfur-sulfur hypervalent bond that is always found in this kind of compounds.
We report new indene derivatives that are good fluorogenic probes for the cyanide anion, one of which is a highly selective and sensitive fluorogenic probe for the fluorescent detection--as well as ...reliable quantification--of the cyanide anion in water or buffer, with a 10(3)-fold increase of fluorescence and low detection limit. It is therefore useful for the quantification of natural cyanide from aqueous extracts of green almond seeds, thus proving that the system is suitable for fast detection and quantification of cyanide from natural sources.
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