Stannabenzenes 3, neutral stannaaromatic compounds having the simplest aromatic unit, were successfully generated by the reaction of the corresponding bromostannanes 5-Br with diisopropylamide mm, hexane at -40 degrees C. The generation of 3 was indicated by the formation of the [4 + 2] dimer 6 at room temperature. The thermal stability of 3 was completely different from that of the sila- and germabenzenes bearing the same substituent. The structural and electronic properties of stannabenzene were estimated by theoretical calculations.
The first stableneutral stannaaromatic compound, 2-stannanaphthalene , was synthesized by taking advantage of an extremely bulky and efficient steric protection group, 2,4,6-tris[bis(trimethylsilyl)methyl]phenyl (Tbt). The molecular structure and aromaticity of were discussed on the basis of X-ray crystallographic analysis, NMR, UV-vis, and Raman spectroscopy, cyclic voltammetry, and theoretical calculations