An interesting metallacarborane cage closure and dismantling reaction including the facile halogenation of a cluster carbon atom: Structure of [1,2-(η5-C5Me5)2-μ-1,2-H-closo-1,2,3-Rh2CB4H4-3-I]

Cage closure, together with the loss of two boron vertices, of [2,5-(η5-C5Me5)2-10-Me-μ-2,5-H-nido-2,5,1-Rh2CB6H8] (1) using an approximately molar equivalent of elemental iodine and excess triethylamine results in the formation of a new species [1,2-(η5-C5Me5)2-μ-1,2-H-closo-1,2,3-Rh2CB4H4-3-I] (2), which is characterized by multinuclear NMR spectroscopy, mass spectrometry, and single-crystal X-ray crystallography. The formation of compound 2 involves the elimination of a {B2CH3} moiety from 1 and an iodination of the single carbon vertex.