The ruthenacarboranes 2-(p-cymene)-2,1,7-closo-RuC2B 9H11 (2) (p-cymene = 1-methyl-4-isopropylbenzene) and 2-(p-cymene)-2,1,12-closo-RuC2B9H11 (3) have been synthesised by simple metallation of [7,9-nido-C2B 9H11]2- and [2,9-nido-C2B 9H11]2-, respectively. In preparing the known cobaltacarborane 2-(?-C5H5)-2,1,12-closo-CoC 2B9H11 (6), the new bis(dicarbollide) [2,2'-Co(1,12-closo-C2B9H11)2] - (as its [(?-C5H5)2Co] + salt; 7) was also formed. Molecular structures of 2, 3, 6 and 7 and that of the known compound 2-(?-C5H5)-2,1,7-closo- CoC2B9H11 (5) have been determined. Patterns in <d(11B)>, the weighted average 11B NMR chemical shift, of these metallacarboranes, together with those in 3-(p-cymene)-3,1,2-closo-RuC2B9H11 (1) and 3-(?-C5H5)-3,1,2-closo-CoC2B 9H11 (4) are discussed in relation to <d(11B)> in the parent carboranes 1,2-closo-C2B10H12, 1,7-closo-C2B10H12 and 1,12-closo-C 2B10H12. The similarity between the 1H and 11B spectra of 6 and 7 confirm the isolobality of the [C5H 5]- and [C2B9H11] 2- ligands. An electrochemical study of 7 confirms that trends in the potential of the CoIII/CoII couple for the series of isomers of (?-C5H5)CoC2B9H 11 are reproduced for the bis(dicarbollides) [Co(C2B 9H11)2]-. The molecular structures of compounds 1-3 as a family and 4-6 as a family provide a unique opportunity to consider structural patterns in simple isomeric metallacarboranes. © 2010 Institute of Organic Chemistry and Biochemistry.
|Number of pages||17|
|Journal||Collection of Czechoslovak Chemical Communications|
|Publication status||Published - Aug 2010|
- Boron clusters
- X-ray diffraction