Abstract Reaction of Tl(OTf) with 2 equiv of bis(diisopropylamino)cyclopropenylidene (BAC) in THF results in formation of Tl(BAC) 2 (OTf) ( 1 ) in moderate yields. Subsequent reaction of 1 with KH 2 ‐9‐BBN (H 2 ‐9‐BBN − = dihydrido 9‐boratabicyclo3.3.1nonane) in THF results in formation of Tl(BAC)(μ‐H 2 ‐9‐BBN) 2 ( 3 ), also in moderate yield. Complex 3 is the first reported thallium borohydride. We attribute its thermal stability to the strong donor ability of the BAC co‐ligand. Both 1 and 3 exhibit trigonal pyramidal geometries about Tl + in the solid‐state, indicative of the presence of stereochemically active lone pairs. The hydride environment in 3 is calculated to exhibit a 3.9 ppm downfield shift attributed to spin‐orbit effects from the adjacent Tl center.
Nguyen et al. (Fri,) studied this question.