Pentamethylcyclopentadienylrhodaborane chemistry. Part 1. High-yield planned synthesis, molecular structure, and nuclear magnetic resonance properties of the ten-vertex nido-6-rhodadecaborane [(η5-C5Me5)RhB9H13]

Abstract

The dimeric pentamethylcyclopentadienylrhodium complex [{Rh(η⁵-C₅Me₅)Cl₂}₂] is potentially a high-yield rhodaborane synthon, and reacts quantitatively with arachno-[B₉H₁₄]^– to give [6-(η⁵C₅Me₅)-nido-6-RhB₉H₁₃] as an orange-red air-stable solid, which has been examined by X-ray crystallography. Crystals are orthorhombic, space group Pbca, with a= 1 977.2(3), b= 1 440.1 (2), c= 2 450.1(4) pm, and Z= 16; the final R factor is 0.0429 for 3 678 observed reflections. N.m.r. data are also presented and briefly discussed; these together with the molecular structure confirm the complex to be a nido-decaborane analogue in which the HB(6) unit is replaced by an isolobal and isoelectronic Rh(η⁵-C₅Me₅) centre.