Phenyl‐Bridged Ferrocene/Ruthenium Alkynyl Heterobimetallic Complexes: Syntheses, Characterization, and Electrochemical, Spectroscopic, and Computational Investigation

Two isomeric phenyl‐bridged ferrocenyl and ruthenium alkynyl complexes 1 and 2 are synthesized and characterized through NMR, elemental analysis, and X‐ray single‐crystal diffraction. The electronic properties of the complexes are investigated via electrochemical studies, UV/Vis‐NIR and IR spectroelectrochemistry, and theoretical calculations. Cyclic voltammetry and square‐wave voltammetry technologies show two successive redox behaviors from Ru(II) and ferrocenyl centers in 1 and 2 , respectively. These behaviors are supported by the dominant spin–spin density distribution in RuCp*(dppe) terminals. The large potential difference (Δ E 1/2 ) and comproportionation constants ( K c ) observed in complex 1 suggest that 1 + has better chemical stability than 2 + . Strong electronic communication from 1 + are detected through the observed NIR absorption band in 1 + and large Δ ν (C≡C) value of 1 → 1 + . The broad NIR absorption in 1 + is reproduced and assigned to ferrocenyl to the Ru(III) center charge transfer transition with major contributions from the β‐HOSO→β‐LUSO transition.