Enhanced stability and complex phase behaviour of organic-inorganic green-emitting ionic manganese halides.

Light-emitting materials based on earth-abundant metals, such as manganese hold great promise as emitters for organic lighting devices. In order to apply such emitter materials and, in particular, to overcome the problem of self-quenching due to cross-relaxation, we investigated a series of tetrabromidomanganate ([MnBr]) salts with bulky tetraalkylphosphonium counter cations [P], namely [P][MnBr] ( = 4 (1), 6 (2) and 8 (3)), which can be obtained by a straightforward reaction of the respective phosphonium bromide and MnBr. Variation of the cation size allows control of the properties of the resulting ionic materials.

Shape Preserving Single Crystal to Amorphous to Single Crystal Polymorphic Transformation Is Possible.

Many crystalline materials form polymorphs and undergo solid-solid transitions between different forms as a function of temperature or pressure. However, there is still a poor understanding of the mechanism of transformation. Conclusions about the transformation process are typically drawn by comparing the crystal structures before and after the conversion, but gaining detailed mechanistic knowledge is strongly impeded by the generally fast rate of these transitions.

Magnetic, Photo- and Electroluminescent: Multifunctional Ionic Tb Complexes.

In the search for new multifunctional materials, particularly for application in solid-state lighting, a set of terbium salicylato (Sal) complexes of general composition [Cat][Tb(Sal)] with the commonly ionic liquid-forming (IL) cations [Cat] = (2-hydroxyethyl)trimethylammonium (choline) (Chol), diallyldimethylammonium (DADMA), 1-ethyl-3-methylimidazolium (CCIm), 1-butyl-3-methylimidazolium (CCIm), 1-ethyl-3-vinylimidazolium (CVim), and tetrabutylphosphonium (P) were synthesized. All Tb compounds exhibit strong green photoluminescence of high color purity by energy transfer from the ligand in comparison with what the analogous La compounds show, and quantum yields can reach up to 63% upon ligand excitation. When excited with an HF generator, the compounds show strong green electroluminescence with the same features of mission.

Asialo-transferrin: Biochemical aspects and association with alcohol abuse investigation.

Asialo-human transferrin (asialo-hTf) is a glycoform of the human serum protein transferrin characterized by the lack of the sialic acid (SA) terminal unit. It is known that glycosylation micro-heterogeneity and the presence of SA are strongly involved in protein functioning and pathophysiological activities. Some hTf glycoforms are valuable biomarkers for the detection of both genetic defects of glycosylation and/or sialoform distribution changes.

Terbium chelation, a specific fluorescent tagging of human transferrin. Optimization of conditions in view of its application to the HPLC analysis of carbohydrate-deficient transferrin (CDT).

Transferrin (Tf) is the major iron-transporting protein in the human body and, for this reason, has been extensively studied in biomedicine. This protein undergoes a complex glycosylation process leading to several glycoforms, some of which are important in the diagnosis of alcohol abuse and of congenital glycosylation defects under the collective name of carbohydrate-deficient transferrin (CDT). Exploiting the Tf ability to bind not only iron but also other ions, specific attention has been devoted to binding activity towards Tb, which was reported to greatly enhance its intrinsic fluorescence upon the interaction with Tf.

Optical Study of Diamine Coupling on Carboxyl-Functionalized Mesoporous Silicon.

A functionalization strategy, consisting of a silylation reaction by acrylic acid followed by diamine coupling, preserves and stabilizes the photoluminescence (PL) of porous silicon (pSi) microparticles suspended in ethanol. We found that under the condition of efficient amine coupling, besides the orange emission typical of the native pSi, an emission band in the blue region appears. The investigation of the interaction between pSi and diamine shows that diamine quenches and shifts the orange band meanwhile it induces an increase of the intensity of the blue one.