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|Title:||Roussin's Red Salt Revisited: Synthesis and Characterization of Metal Nitrosyl Dimers and Clusters (Cubanes, Heterobimetallic, Metal Sulfides)|
|Author(s):||Weatherill, Timothy Donald|
|Department / Program:||Chemistry|
|Degree Granting Institution:||University of Illinois at Urbana-Champaign|
|Abstract:||Since its preparation in 1858, "Roussin's Red Salt," M(,2)Fe(,2)((mu)-S)(,2)(NO)(,4) (M = Na('+), K('+)), has elicited little interest from the inorganic community. While our initial investigations into the chemistry of Roussin's Red Salt began as a simple query of the reactivity of this compound towards electrophiles, our findings prompted us to investigate the synthesis of metal nitrosyl dimers in general, later evolving into a study of metal nitrosyl clusters.
Metathetical replacement of the bridging iodo ligands in Fe(,2)((mu)-I)(,2)(NO)(,4) with Na(,2)E (E = S,Se,Te) was found to be an efficient route to the corresponding Red Salts. Anhydrous solutions of Fe(,2)((mu)-E)(,2)(NO)(,4)('2-) could be generated and derivatized with a variety of alkylating or metalating agents. Similarly, the compound Co(NO)(,2)I (,x) was found to be a versatile starting material for the esters Co(,2)((mu)-ER)(,2)(NO)(,4).
Relative kinetic stabilities of 34 and 36 electron dimers were studied from the perspective of reactivity. "Mixed esters" of the type M(,2)((mu)-SR)((mu)-SR')(NO)(,4) could be isolated for the formally M-M bonded 34e dimers whereas the 36e mixed esters prove to be too labile to isolate. Extension of the mixed ester synthesis led to the preparation of the mixed-metal dimer, CoFe((mu)-SPh)(,2)(NO)(,3)(PPh(,3)).
Our studies on metal nitrosyl sulfides were extended to the synthesis of mixed-metal sulfide clusters. The compound (MeCp)(,2)V(,2)S(,4) exhibits rich and varied coordination chemistry and has been used to prepare a number of clusters containing both early and late transition metals. In this way complexes of the type (MeCp)(,2)V(,2)S(,4)*ML(,n) were prepared for ML(,n) = Fe(NO)(,2), CoCp, Ir(PPh(,3))Cl, and Ni(MeCp)(,2)V(,2)S(,4) .
A series of novel, electron deficient cubanes (MeCp)(,2)M(,2)S(,4)M'(,2)(NO)(,2) (M = V,Mo; M' = Fe,Co,Ni) have been prepared. The V(,2)S(,4)Fe(,2) cubane undergoes transmetalation with Co(CO)(,3)NO to produce the hybrid species (MeCp)(,2)V(,2)S(,4)CoFe(NO)(,2). Other cubanes obtained from (MeCp)(,2)V(,2)S(,4) include (MeCp)(,2)V(,2)S(,4)Cr(,2)Cp(,2) and (MeCp)(,2)V(,2)S(,4)Cu(,2)(PPh(,3))(,2). The structural data for the V(,2)S(,4)Fe(,2), V(,2)S(,4)Co(,2), and V(,2)S(,4)Ni(,2) cubanes together with the results of electrochemical and magnetic studies is discussed.
Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1985.
|Date Available in IDEALS:||2014-12-15|