Synthesis, Structure, and Reactivity of Novel Intramolecularly Coordinated Organolead( II ) Compounds

The intramolecularly coordinated heteroleptic organolead( II ) compounds {4‐ t Bu‐2,6‐[P(O)(OEt) 2 ] 2 C 6 H 2 }PbX ( 2 , X = Cl; 3 , X = SPh) have been synthesized. Single‐crystal X‐ray analyses reveal that both compounds adopt polymeric chain structures by intermolecular Pb−X ··· Pb bridges, a structural motif previously unknown for organolead( II ) derivatives. Compound 2 reacts with lithium diisopropylamide, i Pr 2 NLi, and lithium bis(trimethylsilyl)methane, (Me 3 Si) 2 CHLi, respectively, to provide in situ the corresponding organolead( II ) compounds {4‐ t Bu‐2,6‐[P(O)(OEt) 2 ] 2 C 6 H 2 }PbX ( 4 , X = i Pr 2 N; 5 , X = (Me 3 Si) 2 CH], which were identified by NMR spectroscopy but could not be obtained as analytically pure substances. Attempts to isolate the intramolecularly coordinated organolead( II ) hexafluorophosphate {4‐ t Bu‐2,6‐[P(O)(OEt) 2 ] 2 C 6 H 2 }Pb + PF 6 − from the reaction of 2 with TlPF 6 also failed. Instead, the unprecedented salt [{5‐ t Bu‐1,3‐[P(O)(OEt) 2 ] 2 C 6 H 3 } 4 ·(Pb 2 F)] [PF 6 ] 3 ·4THF ( 6 ) was obtained, in which the [(Pb−F−Pb)] 3+ cation is stabilized by eight intermolecular P=O⇄Pb interactions. Compound 6 was characterized by single‐crystal X‐ray analysis and electrospray mass spectrometry. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)