Reactivity of tetrel functionalized heptapnictogen clusters towards heteroallenes.

Despite being known for decades, the solution-state molecular chemistry of heptapnictogen ([Pn 7 ] 3- ; Pn = P, As) clusters is not well established. Here we study heavy element derivatives of tetrel functionalized heptapnictogen clusters towards heteroallene capture, specifically isocyanates, an isothiocyanate and CO 2 are probed. Clusters (Me 3 Ge) 3 P 7 (1), (Et 3 Ge) 3 P 7 (2), ( n Bu 3 Sn) 3 P 7 (3), and (Me 3 Si) 3 As 7 (4) were all found to capture isocyanates between all three of their tetrel-pnictogen bonds. In the case of phenyl isocyanate insertion, tetrel coordination at the isocyanate nitrogen atoms is preferred, while in the case of p -toluenesulfonyl isocyanate insertion, tetrel coordination at oxygen is preferred. Furthermore, the reaction of (Me 3 Si) 3 P 7 with CO 2 gave NMR spectra consistent with the capture of the greenhouse gas. Heteroallene insertion at these clusters was also studied using density functional theory.