Synthesis and Pd(II) Complexes of an Unsymmetric and Flexible Ferrocene Bisphosphine

<jats:p> To expand the family of flexible homologated analogs of 1,1′‐bis(diphenylphosphino)ferrocene, the unsymmetric bisphosphine 1‐(diphenylphosphino)‐1′‐[2‐(diphenylphosphino)ethyl]ferrocene ( <jats:bold>1</jats:bold> ) was prepared and examined as a ligand in Pd(II) complexes. The compound was obtained by hydrophosphination of 1‐(diphenylphosphino)‐1′‐vinylferrocene ( <jats:bold>2</jats:bold> ) and was further converted to the corresponding bis(phosphine selenide) ( <jats:bold>3</jats:bold> ). While the reactions of <jats:bold>1</jats:bold> with [PdCl <jats:sub>2</jats:sub> (cod)] and [(L <jats:sup>NC</jats:sup> )Pd(MeCN) <jats:sub>2</jats:sub> ](ClO <jats:sub>4</jats:sub> ) (cod = cycloocta‐1,5‐diene, L <jats:sup>NC</jats:sup> = [2‐(dimethylamino)methyl]phenyl) were unselective and yielded no defined product, cleavage of the dimeric precursor [(L <jats:sup>NC</jats:sup> )Pd(μ‐Cl)] <jats:sub>2</jats:sub> cleanly produced the P,P′‐bridged palladium(II) complex [(μ(P,P′)‐ <jats:bold>1</jats:bold> ){Pd(L <jats:sup>NC</jats:sup> )Cl} <jats:sub>2</jats:sub> ] ( <jats:bold>4</jats:bold> ). These experiments suggested that <jats:bold>1</jats:bold> has a decreased ability to form chelate complexes, typical of the more rigid dppf. Compounds <jats:bold>1</jats:bold> , <jats:bold>3</jats:bold> , and <jats:bold>4</jats:bold> were characterized by spectroscopic methods, elemental analysis, and single‐crystal X‐ray diffraction, and the electrochemical properties of <jats:bold>1</jats:bold> and the dipalladium complex <jats:bold>4</jats:bold> were investigated using cyclic voltammetry. </jats:p>