cis-Dithiolatonickel as metalloligand to dinitrosyl iron units: the di-metallic structure of Ni(μ-SR)[Fe(NO)2] and an unexpected, abbreviated metalloadamantyl cluster, Ni2(μ-SR)4[Fe(NO)2]3

Abstract

The reaction of Fe(CO)₂(NO)₂ and Ni(N₂S₂) (N₂S₂ = N,N′-Bis(2-mercaptoethyl)-1,4-diazacycloheptane) by a single CO replacement yields [Ni(N₂S₂)]Fe(NO)₂(CO), while an excess of Fe(CO)₂(NO)₂ leads to triply bridging thiolate sulphurs in a cluster of core composition Ni₂S₄Fe₃, lacking one Fe(NO)₂ unit to complete the adamantane-like structure. This structural type was earlier identified in a Cu^ICl aggregate of M^II(N₂S₂) (M^II = Ni, Cu), in which complete M^II₂S₄Cu^I₄ core structures were obtained as the major, and, in the case of Cu^II(N₂S₂), the incomplete Cu^II₂S₄Cu^I₃ as a minor, product. The full Ni₂S₄Fe₄ cluster has not yet been realized for Fe = Fe(NO)₂. Computational analysis of the NiFe-heterobimetallic complex addresses structural issues including a ∠Ni–S–Fe of 90° in the bimetallic complex.