Chain‐Like Pentanuclear Complexes: Syntheses, Crystal Structures and Long‐Range Electronic Interactions of Cyanido‐Bridged M₂Ru₃ (M=Fe, Ru)

Abstract

In this work, we report the design and synthesis of two chain‐like pentanuclear cyanido‐bridged complexes trans‐[Ru(bpy)2(μ‐CN)2][cis‐Ru(bpy)2(μ‐NC)M(dppe)Cp*]2[PF6]4(M = Fe, 14+; M = Ru, 24+) and the electronic communication properties of their oxidized products 1m+ (m = 6, 7, 8) and 2n+ (n = 5, 6, 7, 8). The single‐crystal X‐ray diffraction analysis of 1m+ (m = 4, 6, 7) and 24+ show that 14+ and 24+ possess a Z‐type array structure, 17+ is a U‐type one, and 16+ exhibits both the types. The investigations indicate that both 1 and 2 show an extraordinarily strong electronic interaction between the two side Ru across the central NC‐Ru‐CN, leading to the formation of a fully delocalized cyanidometal Ru‐Ru‐Ru bridge for both three‐electron oxidized states 17+ and 27+. Moreover, it should be noted that in 1 there exists no electronic interaction between the two terminal Fe ions. Upon substitution of Fe by Ru, however, 2 exhibits an electronic interaction between the two terminal metal ions across the trinuclear cyanidometal CN‐Ru‐NC‐Ru‐CN‐Ru‐NC bridge which is up to 20 Å.