586352-94-5Relevant academic research and scientific papers
Aggregation of [(tBu3SiS)MX]: Structures of {[Br 2Fe(μ-SSitBu3)2FeBr(THF)]Na(THF) 4}∞, cis[(THF)Fel]2(μ-SSitBu 3)2
Sydora, Orson L.,Henry, Thomas P.,Wolczanski, Peter T.,Lobkovsky, Emil B.,Rumberger, Evan,Hendrickson, David N.
, p. 609 - 626 (2008/10/09)
A convenient synthesis of tBu3SiSH and tBu3SiSNa(THF)x led to the exploration of tBu3SiSMX aggregation. The dimer, [( tBu3SiS)Fe]2(μ-SSitBU 3)2 (12), was formed from [{(Me 3Si)2N}Fe]2(μ-N(SiMe3) 2)2 and the thiol, and its dissolution in THF generated (tBu3SiS)2Fe(THF)2 (1-(THF) 2). Metathetical procedures with the thiolate yielded aggregate precursors [X2Fe](μ-SSitBu3) 2[FeX(THF)]Na(THF)4 (3-X, X = Cl, Br) and cis-[(THF)IFe]2(μ-SSitBu3)2 (4). Thermal desolvations of 3-Cl, 3-Br and 4 afforded molecular wheels [Fe(μ-X)(μ-SSitBu3)]12(C 6H6)n (5-FeX, X = Cl, Br) and the ellipse [Fe(μ-l)(μ-SSitBu3)]14(C 6H6)n (6-Fel). Related metathesis and desolvation sequences led to wheels [Co(μ-Cl)(μ-SSitBu 3)]12(C6H6)n (5-CoCl) and [Ni(μ-Br)(μ-SSitBu3)]12(C 6H6)n (5-NiBr). The nickel wheel disproportionated to give, in part, [(tBu3SiS)Ni] 2(μ-SSitBu3)2 (7), which was also synthesized via salt metathesis. X-ray structural studies of 12 revealed a roughly planar Fe2S4 core, while 1-(THF) 2, 3-Br, and 4 possessed simple distorted tetrahedral and edge-shared tetrahedral structures. X-ray structural studies revealed 5-MX (MX = FeCl, FeBr, CoCl, NiBr) to be wheels based on edge-shared tetrahedra, but while the pseudo-D6d wheels of 5-FeCl, 5-CoCl, and 5-FeBr pack in a body-centered arrangement, those of pseudo-C6v 5-NiBr exhibit hexagonal packing and two distinct trans-annular d(Br...Br). Variable-temperature magnetic susceptibility measurements were conducted on 5-FeCl, 5-CoC, 5-FeBr, and 6-Fel, and the latter three are best construed as weakly antiferromagnetic, while 5-FeCl exhibited modest ferromagnetic coupling. Features suggesting molecular magnetism are most likely affiliated with phase changes at low temperatures.
