Voltammetric, Specular Reflectance Infrared, and X-ray Electron Probe Characterization of Redox and Isomerization Processes Associated with the [Mn(CO)2(η3-P2P‘)Br]+/0 (P2P‘ = {Ph2P(CH2)2}2PPh), [Mn(CO)2(η3-P3P‘)Br]+/0 (P3P‘ = {Ph2PCH2}3P), and [{Mn(CO)2(η2-dpe)Br}2(μ-dpe)]2+/0 (dpe = Ph2P(CH2)2PPh2) Solid State Systems

Abstract

Extremely well defined voltammetric responses are obtained for both oxidation of microcrystalline mononuclear trans- and cis,mer-Mn(CO)2(η3-P2P‘)Br (P2P‘ = {Ph2P(CH2)2}2PPh) and cis,mer-Mn(CO)2(η3-P3P‘)Br (P3P‘ = {Ph2PCH2}3P) and binuclear cis,fac-{Mn(CO)2(η2-dpe)Br}2(μ-dpe) (dpe = Ph2P(CH2)2PPh2) and reduction of cationic trans-[Mn(CO)2(η3-P2P‘)Br]BF4, trans-[Mn(CO)2(η3-P3P‘)Br]BF4, and trans-[{Mn(CO)2(η2-dpe)Br}2(μ-dpe)](BF4)2 when they are attached to a graphite electrode and placed in water containing either 0.1 M NaCl or KCl as the electrolyte. The combination of access to species in different oxidation states and different isomeric forms, as well as mononuclear and binuclear species, enables the rates of isomerization and the extent of electronic communication between the metal centers to be evaluated in the solid state and compared to data in organic solvent systems previously reported. The voltammetric data, combined with specular reflectance IR and X-ray electron probe data, established that the ...