A dipotassium 1,2,4-diazaphospholide dianion radical as an organometallic building block: the first 1,2-diaza-4-phosphine ruthenocene

Abstract

A persistent dipotassium 3,5-diphenyl-1,2,4-diazaphospholide dianion radical {K⁺₂[(3,5-Ph₂dp)]˙^2–} (2) was synthesized and investigated by EPR analysis and magnetic susceptibility measurement, and it can be used as a transfer agent for the preparation of an unusual 1,2-diaza-4-phosphine ruthenocene (4) with exclusive σ(P)-coordination. A plausible mechanism for the formation of 4 was proposed as one that involves a reactive radical intermediate {K⁺[(η⁵-CpMe₅Ru)(σ(P),σ(C)-(3,5-Ph₂dp)˙]⁻)} (K⁺[5A˙]⁻) with σ(P)-coordination due to the high spin density (SD) at the phosphorus (σ²λ³) atom.