The Cobalt cyclo-Pb>4b> Sandwich Complex and Its Role in the Formation of Polyphosphorus Compounds

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• 作者：Dr. Fabian Dielmann ; Prof. Dr. Alexey Timoshkin ; M. Sc. Martin Piesch ; Dr. G&aacute ; bor Bal&aacute ; zs and Prof. Dr. Manfred Scheer
• 刊名：Angewandte Chemie International Edition
• 出版年：2017
• 出版时间：February 1, 2017
• 年：2017
• 卷：56
• 期：6
• 页码：1671-1675
• 全文大小：2090K
• ISSN：1521-3773

文摘

A synthetic approach to the sandwich complex [Cp′′′Co(η⁴-Pb>4b>)] (<b>2b>) containing a cyclo-Pb>4b> ligand as an end-deck was developed. Complex <b>2b> is the missing homologue in the series of first-row cyclo-Pb>nb> sandwich complexes, and shows a unique tendency to dimerize in solution to form two isomeric Pb>8b> complexes [(Cp′′′Co)b>2b>(μ,η⁴:η²:η¹-Pb>8b>)] (<b>3b> and <b>4b>). Reactivity studies indicate that <b>2b> and <b>3b> react with further [Cp′′′Co] fragments to give [(Cp′′′Co)b>2b>(μ,η²:η²-Pb>2b>)b>2b>] (<b>5b>) and [(Cp′′′Co)b>3b>Pb>8b>] (<b>6b>), respectively. Furthermore, complexes <b>2b>, <b>3b>, and <b>4b> thermally decompose forming <b>5b>, <b>6b>, and the Pb>12b> complex [(Cp′′′Co)b>3b>Pb>12b>] (<b>7b>). DFT calculations on the Pb>4b> activation process suggest a η³-Pb>4b> Co complex as the key intermediate in the synthesis of <b>2b> as well as in the formation of larger polyphosphorus complexes via a unique oligomerization pathway.