[NbAs8]3−, a Novel Type of Complex and an Unexpected One-Dimensional Chain Structure: [Rb{NbAs8}]2−

✍ Scribed by Prof. Dr. Hans-Georg von Schnering; Dipl.-Chem. Juliana Wolf; Dr. Dieter Weber; Dipl.-Chem. Rafael Ramirez; Dr. Teodoro Meyer

• Publisher: John Wiley and Sons
• Year: 1986
• Tongue: English
• Weight: 252 KB
• Volume: 25
• Category: Article
• ISSN: 0044-8249
• DOI: 10.1002/anie.198603531

✦ Synopsis

which would be in agreement with the (irregular) increase in the differences A6=16(x)-6(x+ 1)1 in the series [P7 -x A ~x ] 3 ~ with increasing x. It is also possible, however, that this heteroanion is unstable and decomposes into As: -and, for example, [P2Ass]37, because incorporation of the small P atom into the large As, cage is unfavorable. The "P-NMR spectra of solutions of mixtures of the pure compounds Rb3P7 and Rb3As, exhibit, even after several weeks, only the signal of P;-, so that no exchange between P:-and As:-occurs in solution.

The intensities of the 3'P-NMR signals-after correction with respect to the number of P atoms involved in the heteroanion-indicate a preference for the groups [P6AsI3and [P,As,]'-, but none for [P4As3I3-, as would have been expected based on the concept of topological charge stabilization. With increasing content of arsenic, the valence tautomerism becomes slower, as shown by the increasing halfwidths of the signals. The question remains open, therefore, whether As:-also has a fluxional structure in solution.