Versatile Reactivity of CH₃CN‐Coordinated Nickel‐Iron Heterodimetallic Complexes with Cp* Ligand on Diazadithiolate (N₂S₂) or Dithiadithiolate (S₄) Platforms

Abstract

Abstract By using 3,7‐dithianonane‐1,9‐dithiol (S 4 ) and N , N′ ‐dimethyl‐ N , N′ ‐bis(2‐mercaptoethyl)ethylenediamine (N 2 S 2 ) as ligands, two CH 3 CN‐coordinated nickel‐iron heterodimetallic complexes, [NiS 4 Fe(CH 3 CN)Cp*][PF 6 ] ( 1a ) and [NiN 2 S 2 Fe(CH 3 CN)Cp*][PF 6 ] ( 1b ) (Cp* = η 5 ‐C 5 Me 5 ), were synthesized and characterized spectroscopically and crystallographically. Reactivities of 1a and 1b towards CO, CH 2 Cl 2 , HBF 4 , and NOPF 6 have also been investigated. A series of complexes coordinated with small molecules [NiS 4 Fe(L)Cp*][PF 6 ] n [ n = 1, L = Cl ( 2a ), CO ( 3a ); n = 2, L = NO ( 4a )], [NiN 2 S 2 Fe(L)Cp*][PF 6 ] [L = Cl ( 2b ), CO ( 3b )] were obtained. We also studied the redox properties of 2a , 2b , 3a , and 3b by cyclic voltammetry in CH 2 Cl 2 and in CH 3 CN solution. Complex 3a was found to be an excellent electrocatalyst for proton reduction from HBF 4 .