In Vitro Dissolution of Na-Ca-P-Oxynitrides

Sodium-calcium-phosphate based oxynitride glasses and glass-ceramics doped with Mg, Si, and Nb were studied in vitro in simulated body fluid (SBF) under static conditions. The release of ions and pH changes up to 7 days of immersion were investigated. The nitrogen incorporation into phosphate glass matrix was found to notably influence in vitro dissolution only of homogenous glasses. Increasing the nitrogen content in the samples decreased the mean mass loss, while the niobate incorporation increased it. The correlation between the nitrogen content and increase in pH of SBF was also observed. The presence of phosphates crystallites was found to support the dissolution process at the beginning step (up to 3 days).

S,N-Heteropentacenes – Syntheses of Electron-Rich Anellated Pentacycles

This review summarizes syntheses of S,N-heteropentacenes, i.e. electron-rich sulfur and nitrogen-embedding pentacycles, and briefly highlights selected applications in molecular electronics. Depending on the anellation mode and the number of incorporated heteroatoms, electron density can be raised by increasing nitrogen incorporation and polarizability is manifested by the sulfur content. In comparison to triacene analogues, the conjugation pathways of S,N-heteropentacenes are increased and the favorable acene-typical crystallization behavior allows for diverse application in organic electronics. Furthermore, substitution patterns allow fine-tuning the electronic properties, extending the π-systems, and supplying structural elements for further application.1 Introduction2 Thiophene-Centered S,N-Heteropentacenes2.1 Dipyrrolo-Fused Thiophenes2.2 Diindolo-Fused Thiophenes3 Pyrrole-Centered S,N-Heteropentacenes3.1 Dithieno-Fused Pyrroles3.2 Bis[1]benzothieno-Fused Pyrrole4 Fused 1,4-Thiazines4.1 Dinaphtho-Fused 1,4-Thiazines4.2 Bis[1]benzothieno-Fused 1,4-Thiazines5 Conclusions and Outlook