Darstellung,11B-NMR- und Schwingungsspektren der closo-Hexaborate [B6(SCN)6]2- und [B6(SeCN)6]2- / Preparation, 11 B-NMR and Vibrational Spectra of the closo-Hexaborates [B6(SCN)6]2- and [B6(SeCN)6]2-

Abstract

On treatment of [N(C4H9)4][B6H7] with (SCN)2 or (SeCN)2 in dichloromethane in the presence of solid KOH the hexaborates [N(C4H9)4]2[B6(SCN)6] and [N(C4H9)4]2[B6(SeCN)6] are formed. The octahedral structure for the B6 cage is proven by 11B NMR spectroscopy. The chemical shifts in relation to BF3 · OEt2 of —9,7 (SCN) and —10,2 ppm (SeCN) show the influence of — I and +M effects of the substituents. The S(Se) coordination is deduced from vibrations within the substituents: νCN is observed at frequencies higher than 2100 cm-1 in the IR and Raman spectra, vcs at 662 and νcse at 556 cm-1 (intense IR bands).