Synthesis, structure, and reactivity of Lewis base stabilized plumbacyclopentadienylidenes

Masaichi Saito; Tomoki Akiba; Misumi Kaneko; Toshiaki Kawamura; Minori Abe; Masahiko Hada; Mao Minoura

doi:10.1002/chem.201303672

Synthesis, structure, and reactivity of Lewis base stabilized plumbacyclopentadienylidenes

Chemistry. 2013 Dec 9;19(50):16946-53. doi: 10.1002/chem.201303672. Epub 2013 Nov 15.

Authors

Masaichi Saito¹, Tomoki Akiba, Misumi Kaneko, Toshiaki Kawamura, Minori Abe, Masahiko Hada, Mao Minoura

Affiliation

¹ Department of Chemistry, Graduate School of Science and Engineering, Saitama University, Shimo-okubo, Sakura-ku, Saitama, 338-8570 (Japan), Fax: (+81) 48-858-3700 http://www.chem.saitama-u.ac.jp/msaito-lab/English/indexEng.html. masaichi@chem.saitama-u.ac.jp.

PMID: 24243692
DOI: 10.1002/chem.201303672

Abstract

Plumbacyclopentadienylidenes, in which the lead atoms have divalent states and are coordinated by THF, pyridine and N-heterocyclic carbene, were synthesized and characterized. The THF- and pyridine-stabilized compounds can be regarded as rare examples of hypervalent 10-X-4 species. The equilibrium between the THF adduct and the free plumbacyclopentadienylidene was evidenced by spectroscopic analysis and theoretical calculations. The THF adduct in benzene converted into a plumbylene dimer, where one of the lead centers is coordinated by THF and the other lead atom is coordinated by a divalent lead atom, the dimer gradually decomposing into spiroplumbole. The THF adduct unexpectedly reacted with trifluoroborane and trichlorogallane to afford fluoroborole and chlorogallole, which are the first examples of non-annulated fluoroborole and gallole, respectively.

Keywords: Lewis bases; boron; gallium; lead; relativistic effects.