Heterodimetallaboranes of Group 4 and 9 Metals: Analogues of Pentaborane(11) and Hexaborane(12)

• Published in: European journal of inorganic chemistry 2017-10, Vol.2017 (38-39), p.4452-4458
• Main Authors: Roy, Dipak Kumar, De, Anangsha, Prakash, Rini, Barik, Subrat Kumar, Ghosh, Sundargopal
• Format: Article
• Language: English
• Subjects: Analogs; Boranes; Boron; Chemical bonds; Crystallography; Hafnium; Inorganic chemistry; Iridium; Rhodium; Zirconium
• ISSN: 1434-1948; 1099-0682
• DOI: 10.1002/ejic.201700330

Several early–late heterodimetallaborane clusters have been isolated and structurally characterized through spectroscopic and crystallographic analysis. The thermolysis of [Cp2Zr(BH4)2] (Cp = η5‐C5H5) with [Cp*IrB3H9] (Cp* = η5‐C5Me5) and [(Cp*Rh)2B2H6] yielded arachno‐[(Cp2Zr)(Cp*Ir)B3H9] (2) and arachno‐[(Cp2Zr)(Cp*Rh)B4H10] (4), respectively. In a similar fashion, the reaction of [Cp2Hf(BH4)2] was performed with the same set of group 9 metallaboranes that led to the formation of arachno‐[(Cp2Hf)(Cp*M′)B4H10] (5: M′ = Ir; 6: M′ = Rh). To the best of our knowledge, 2 is the first structurally characterized pentaborane(11) analogue containing zirconium, while the clusters 5 and 6 are the first examples with Hf in a hexaborane(12) core. The bonding between the Zr atoms and the boron ring was studied computationally by DFT methods, and 2 can be defined as a dimetallic analogue of arachno‐B5H11 on the basis of the combined experimental and computational results. We present a series of heterometallaborane analogues of pentaborane(11) and hexaborane(12) incorporating metals from the two ends of the d‐block. These compounds were prepared by the borane condensation method, which enables us to include hafnium in a hexaborane(12) system.