Organometallic and Inorganic Derivatives of the Tetrathiometallates

Howard, Kevin Edward

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Description

Title

Organometallic and Inorganic Derivatives of the Tetrathiometallates

Author(s)

Howard, Kevin Edward

Issue Date

1988

Doctoral Committee Chair(s)

Rauchfuss, Thomas B.

Department of Study

Chemistry

Discipline

Chemistry

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

Chemistry, Inorganic

Abstract

• In an effort to study the tetrathiometallates as ligands in heterometallic complexes, which may bind $\pi$-acidic coligands, the preparation of a number of low-valent organometallic derivatives of MoS$\sb4\sp{2-}$ and WS$\sb4\sp{2-}$ was undertaken. The complex ((COD)Rh) $\sb2$WS$\sb4$ 1 was prepared from the direct reaction of equimolar amounts of ((COD)RhCl) $\sb2$ and (Ph$\sb4$P)$\sb2$WS$\sb4$. Compound 1 was found to exhibit extensive ligand substitution chemistry, involving organophosphines, CO, and $t$-BuNC. It was found that 1 could only support two strongly $\pi$-acidic CO ligands; ((PPh$\sb3$)(CO)Rh) $\sb2$WS$\sb4$ was found to be the stable species. The reaction of Pd(WS$\sb4)\sb2\sp{2-}$ with an equimolar amount of ((COD)RhCl) $\sb2$ gave the insoluble species, (COD)Rh($\mu$-S)$\sb2$W($\mu$-S)$\sb2$Pd($\mu$-S)$\sb2$W($\mu$-S)$\sb2$Rh(COD). This complex reacted with excess PPh$\sb3$, giving the CH$\sb2$Cl$\sb2$-soluble species: (PPh$\sb3)\sb2$Rh($\mu$-S)$\sb2$W($\mu$-S)$\sb2$Pd($\mu$-S)$\sb2$W($\mu$-S)$\sb2$Rh(PPh$\sb3)\sb2$.
• Complexes of general formula (($\eta\sp5$-C$\sb5$H$\sb4$R)Ru(PPh$\sb3$)) $\sb2$ME$\sb4$ (where R = H, CH$\sb3$; M = Mo, W; E = S, Se) were synthesized from two equivalents of ($\eta\sp5$-C$\sb5$H$\sb4$R)Ru(PPh$\sb3)\sb2$Cl and one equivalent of the corresponding (Ph$\sb4$P)$\sb2$ME$\sb4$. The WSe$\sb4$ derivative was prepared using ($t$-BuNH$\sb3)\sb2$WSe$\sb4$, which was obtained from the reaction of W(NH-$t$-Bu)$\sb2$(N-$t$-Bu)$\sb2$ with H$\sb2$Se. These compounds undergo single one electron oxidations in their cyclic voltammograms. Trialkylphosphines, carbon monoxide, and isocyanides (RNC, R = $t$-Bu, Me, and Bz) were found to displace the PPh$\sb3$ ligands in (CpRu(PPh$\sb3$)) $\sb2$WS$\sb4$ 2. In the case of CO however, substitution was observed to occur at only one ruthenium center. A kinetic study of the substitution of PPh$\sb3$ by $t$-BuNC in 2 revealed that the rate was independent of ($t$-BuNC), indicating a dissociative mechanism.
• A number of (L$\sb{\rm n}$M$\sp\prime$) $\sb2$WS$\sb4$ complexes were prepared from WS$\sb4\sp{2-}$ and compounds of the type (L$\sb{\rm n}$M($\mu$-Cl)) $\sb2$. These included complexes where L$\sb{\rm n}$M was (NBD)Rh, (COD)Ir, ($\eta\sp5$-C$\sb5$Me$\sb5$)RhCl, and (allyl)Pd. The Rh(III) and Pd(II) derivatives were characterized by X-ray crystallography which showed M-W distances of 2.90A(av.) and 2.80A(av.) respectively. Poorly soluble complexes of the type (COD)PtMS$\sb4$ (M = Mo, W) were prepared from the reaction of (COD)PtCl$\sb2$ and (Ph$\sb4$P)$\sb2$MS$\sb4$. The thermal gravimetric analyses of ((COD)Rh) $\sb2$MS$\sb4$ and (COD)PtMS$\sb4$ over temperature ranges of 50-900$\sp\circ$C indicate the formation of MRh$\sb2$S$\sb{\rm x}$ (x = 2 or 2.5) and PtMS formulas. We suggest that these complexes should be examined as precursors to new ternary metal sulfides. (Abstract shortened with permission of author.)

Graduation Semester

1988

Type of Resource

text

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