The reactivity of decamethylsamarocene with polycyclic hydrocarbons and organo-main group complexes

• Main Author: Gonzales, Shirley Louise
• Format: Dissertation
• Language: English
• Published: ProQuest Dissertations & Theses 01-01-1994
• Subjects: Chemistry; Inorganic chemistry; Organic chemistry
• ISBN: 9781392474013; 1392474019

The limits of organosamarium(II) chemistry were probed by examining the reactivity of ($\eta\sp5$-C$\sb5$Me$\sb5)\sb2$Sm, 1, with polycyclic aromatic hydrocarbons and organo-main group complexes. Although lanthanide complexes are thought to be mostly ionic in character and interactions of unsaturated systems with lanthanide metals were not previously expected, complex 1 reacts in arenes with polycyclic aromatic hydrocarbons and related nitrogen heterocycles with reduction potentials more positive than $-$2.22 V. The reactions of 1 and polycyclic aromatic hydrocarbons yield predominately bimetallic products of formula (($\eta\sp5$-C$\sb5$Me$\sb5)\sb2$Sm) $\sb2$(PAH) (PAH = anthracene, pyrene, 2,3-benzanthracene, 9-methylanthracene, and acenapthylene). The anthracene reaction product, (($\eta\sp5$-C$\sb5$Me$\sb5)\sb2$Sm) $\sb2$ ($\mu$-$\eta\sp3$:$\eta\sp3$-(C$\sb{14}$H$\sb{10}$)), is unique in that the two equivalent (C$\sb5$Me$\sb5)\sb2$Sm units are located on either side of the nearly planar C$\sb{14}$H$\sb{10}$ moiety. The pyrene reaction product, (($\eta\sp5$-C$\sb5$Me$\sb5)\sb2$Sm) $\sb2$ ($\mu$-$\eta\sp3$:$\eta\sp3$-(C$\sb{16}$H$\sb{10}$)), is similar in that both (C$\sb5$Me$\sb5)\sb2$Sm units are on opposite sides of the planar pyrene ring, but in this case they are located asymmetrically at the same end of the pyrene. The reaction of 1 and phenazine produces a bimetallic product analogous to the anthracene complex, (($\eta\sp5$-C$\sb5$Me$\sb5)\sb2$Sm) $\sb2$ ($\mu$-$\eta\sp3$:$\eta\sp3$-(C$\sb{12}$H$\sb8$N$\sb2$)), but a reductively coupled product is observed in the reaction of 1 with acridine, (($\eta\sp5$-C$\sb5$Me$\sb5)\sb2$Sm) $\sb2$- ($ \mu$-$\eta\sp3$:$\eta\sp3$-(C$\sb{13}$H$\sb9$N)$\sb2$). Complex 1 reacts with cyclooctatetraene to form the tris(pentamethylcyclopentadienyl) complex, ($\eta\sp5$-C$\sb5$Me$\sb5)\sb3$Sm, a complex not expected to exist due to the extreme steric demands of the large C$\sb5$Me$\sb5$ ligands. The reactions of 1 with azulene and decacyclene also produce (C$\sb5$Me$\sb5)\sb3$Sm. 1 reacts with BiPh$\sb3$ by completely cleaving all the Bi-Ph bonds to form ((C$\sb5$Me$\sb5)\sb2$Sm) $\sb2(\mu$-$\eta\sp2$:$\eta \sp2$-Bi$\sb2$), which is the first example of a complex containing a planar M$\sb2(\mu$-$\eta\sp2$:$\eta\sp2$-Bi$\sb2$) unit. The analogous reaction of 1 with SbBu$\sp{\rm n}\sb3$ led to isolation of ((C$\sb5$Me$\sb5)\sb2$Sm) $\sb3$($\mu$-$\eta\sp2$:$ \eta\sp2$:$\eta\sp1$-Sb$\sb3$)(THF) which contains the Zintl ion Sb$\sb3\sp{3-}$. This ion was postulated to exist as early as 1931, but had never been structurally characterized. The coordination chemistry of the organosamarium oxide complex, ((C$\sb5$Me$\sb5)\sb2$Sm) $\sb2(\mu$-O), was investigated and the adducts, ((C$\sb5$Me$\sb5)\sb2$SmL) $\sb2(\mu$-O) (L = THF and phthalan), were identified.