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

The intramolecularly coordinated heteroleptic organolead(II) compounds {4‐tBu‐2,6‐[P(O)(OEt)2]2C6H2}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, iPr2NLi, and lithium bis(trimethylsilyl)methane, (Me3Si)2CHLi, respectively, to provide in situ the corresponding organolead(II) compounds {4‐tBu‐2,6‐[P(O)(OEt)2]2C6H2}PbX (4, X = iPr2N; 5, X = (Me3Si)2CH], 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‐tBu‐2,6‐[P(O)(OEt)2]2C6H2}Pb+PF6− from the reaction of 2 with TlPF6 also failed. Instead, the unprecedented salt [{5‐tBu‐1,3‐[P(O)(OEt)2]2C6H3}4·(Pb2F)] [PF6]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)