Sodium Tetra-tert-butylcyclopentaphosphanide: Synthesis, Structure, and Unexpected Formation of a Nickel(0) Tri-tert-butylcyclopentaphosphene Complex

Abstract

Forming a phosphorus envelope: The first structurally characterized cyclooligophosphanide ion [cyclo-(P₅ tBu₄ )]^- to be obtained by a targeted synthesis reacts with [NiCl₂ (PEt₃ )₂ ] by loss of a tBu group to give (η² -3,4,5-tri-tert-butylcyclopentaphosphene)bis(triethylphosphane)nickel(0) (1). The previously unknown cyclopentaphosphene ring in 1 has an envelope conformation in solution and in the solid state, and the tBu groups adopt an all-trans configuration.