Intramolecular energy transfer and its influence on the overall quantum yields of Eu and Tb chelates with dimethyl(phenylsulfonyl)amidophosphate ligands.

Lanthanide chelates with dimethyl(phenylsulfonyl)amidophosphate (labeled as HSP) and Lewis base ligands (bpy = 2,2;-bipyridine and phen = 1,10-phenanthroline) of formula Na[Ln(SP)] (1Ln), [Ln(SP)bpy] (2Ln); [Ln(SP)phen] (3Ln) (Ln = Eu, Gd, Tb and Lu) were obtained and characterized by the X-ray, photoluminescence spectroscopy at 293 and 77 K as well as by intrinsic (Q) and overall (Q) luminescence quantum yields. These phosphors manifest a very strong emission after excitation in the UV range of the molecular singlet states (S) and two of them have very high Q values (Eu and Tb chelates of the type 2Ln and 3Ln). The dynamics of the excited states are discussed based on the intramolecular energy transfer theory, considering the dipole-dipole, the dipole-multipole and the exchange mechanisms.

Crystal structure of the sodium salt of mesotrione: a triketone herbicide.

The crystal structure of the sodium salt of mesotrione, namely, -poly[[sodium-μ-2-[(4-methane-sulfonyl-2-nitro-phen-yl)carbon-yl]-3-oxo-cyclo-hex-1-en-1-olato] ethanol monosolvate], {[Na(CHNOS)]CHOH}, is described. The X-ray structural analysis results reveal that the coordination sphere is established by two chelating O atoms, the O atom of the coordinated ethanol mol-ecule, and an O atom from the methyl-sulfonyl group of a neighboring mol-ecule. Simultaneously, an O atom of the cyclo-hexane fragment serves as a bridge to a neighboring sodium ion, forming a flat Na-O-Na-O quadrangle, thereby forming a mono-periodic polymer.

Enzymatic nucleosome acetylation selectively affects activity of histone methyltransferases in vitro.

Posttranslational modification of histones plays a critical role in regulation of gene expression. These modifications include methylation and acetylation that work in combination to establish transcriptionally active or repressive chromatin states. Histone methyltransferases (HMTs) often have variable levels of activity in vitro depending on the form of substrate used.

New Luminescent Lanthanide Tetrakis-Complexes NEt [LnL ] Based on Dimethyl-N-Benzoylamidophosphate.

New lanthanide dimethyl-N-benzoylamidophosphate (HL) based tetrakis-complexes NEt [LnL ] (Ln =La, Nd, Sm, Eu, Gd, Tb, Dy) are reported. The complexes are characterized by means of NMR, IR, absorption, and luminescent spectroscopy as well as by elemental, X-Ray, and thermal gravimetric analyses. The phenyl groups of the four ligands of the complex anion are directed towards one side, while the methoxy groups are directed in the opposite side, which makes the complexes under consideration structurally similar to calixarenes.

Spectroscopic aspects for the Yb coordination compound with a large energy gap between the ligand and Yb excited states.

We present the experimental and theoretical results that made it possible to propose the energy transfer mechanism for a Yb complex with a large energy gap between the ligand and Yb excited states using a theoretical model and experimental data. Absorption and emission spectroscopy in the 300-4 K range is used for the study of the Yb compound with N-phosphorylated sulfonamide (Na[YbL]), which, despite the large energy gap, is characterized by high emission sensitization efficiency (η = 40%) and relatively long Yb emission lifetime (27 μs). The crystal structure of Na[YbL], radiative lifetime (930 μs), refractive index (1.