Easy and quantitative access to Fe(ii) and Fe(iii) di(aryl)alkynylphosphine oxides featuring [Fe(dppe)Cp*] endgroups: terminal PO functionality blocks the dimerisation of the Fe(iii) derivatives

Abstract

A series of paramagnetic di(aryl)alkynylphosphine oxides [PF6] featuring an open-shell [Fe(κ(2)-dppe)(η(5)-C5Me5)](+) endgroup were obtained by oxidation of their neutral Fe(II) parents 3a-c, themselves obtained in a simple and nearly quantitative fashion from the corresponding Fe(II) metallophosphines 1a-c. The new organometallic radicals were characterised by NMR and ESR and were shown to be perfectly stable in solution, in contrast to species such as 1a-b[PF6] which readily dimerise.

Rise of Conjugated Poly-ynes and Poly(Metalla-ynes): From Design Through Synthesis to Structure–Property Relationships and Applications

“…However, this dimerization could be seized by oxidizing the phosphine group (Scheme ). Interestingly, the metallophosphine oxide species 160 could be used to achieve monomeric cation 161 , with improved photophysical properties.…”