Magnetic Behavior of Odd- and Even-Electron Metal Carbonyl Clusters: the Case Study of [Co8Pt4C2(CO)24]n– (n = 1, 2) Carbide Cluster

: The reaction of [Co6C(CO)15]2- with 2 equiv of PtCl2(Et2S)2 affords the new heterobimetallic [Co8Pt4C2(CO)24]2-, [1]2-, carbonyl cluster. [1]2- undergoes reversible chemical and electrochemical oxidation and reduction processes disclosing a complete series of [1]n- (n ) 1-4) clusters. The mono- and dianion of [1]n- have been isolated as their tetra-substituted ammonium salts and fully characterized by means of IR, 13C NMR, ESI-MS, and X-ray crystallography. Variable-temperature (VT) solid-state EPR studies on pure crystalline samples indicate that both [1]2- and [1]-• are paramagnetic, due to a doublet state of the latter and a triplet state of [1]2-. This conclusion is supported by SQUID measurements on the same crystalline sample of [1]2-. The present study indisputably demonstrates that even-electron transition metal carbonyl clusters (TMCC) can be magneti