In the course of our investigations into sterically hindered group IV-A organometallics, we prepared several previously unreported organotin compounds containing the 2, 2-dimethyl- 2-phenylethyl (neophyl), the 2-phenylpropyl, the 3-phenylpropyl, and the 2, 2, 4- trimethylpentyl groups. In addition several more as yet unreported rieopentyltins were~ repared.~ The typical reactions associated with this bulky group were again observed. ...