Stanna‐closo‐dodecaborate: The Crystal Structure of [Li(thf)3]2[SnB11H11], Vibrational Spectroscopy, Thermal Analysis and DFT Calculations

Abstract

AbstractThe lithium salt of stanna‐closo‐dodecaborate was prepared and single‐crystalline material was obtained from tetrahydrofurane. The salt crystallizes as [Li(thf)3]2[SnB11H11] in the monoclinic space group P21/c (a = 15.0608(10) Å, b = 14.0778(8) Å, c = 18.3890(12) Å and β = 110.324(5)°) and both lithium ions are coordinated to triangular cluster faces via B–H–Li bonds. DFT calculations in combination with a natural population analysis reveal that the tin vertex exhibits a positive partial charge while all boron atoms of the stannaborate cluster carry a negative charge. The boron atoms of the first B5‐belt display the largest negative partial charges. Raman and IR spectra of the cesium salt of [SnB11H11]2− reveal that the cluster breathing modes which involve the tin vertex are found at around 250 cm−1. Furthermore, the thermal stability of the group‐14‐heteroborate is remarkably large with a decomposition temperature of above 900 °C as determined with TG/DTA measurements.