Plumboccnes with sec- und tert-Alkyl Substituents

摘要

[(C_5H_2tBu_3-1,2,4)_2Pb] (1), [(C_5HiPr_4)_2Pb] (2), and [(C_5iPr_5)_2Pb] (3) have been obtained from PbCl_2 and Li(C_5H_2tBu_3-1,2,4), Na(C_5HiPr_4) and Na(C_5iPr_5), respectively. 3 exists as a 1:1 mixture of meso-3 and rarc-3 which interconvert at elevated temperature via one-at-a-time rotation of isopropyl groups with ΔG~# = 73.0 ± 1.5/73.7 ± 1.5 kJ/mol at 348 K. 3 is slightly bent in the solid State with an angle of 170(1)° bet-ween the ring normals.