Silylated 1,1‘-Diaminoferrocene:  Ti and Zr Complexes of a New Chelating Diamide Ligand

Abstract

Silylation of 1,1′-diaminoferrocene afforded 1,1′-Fc(NHSiMe 3 ) 2 (LH 2 ) as red air-sensitive crystals. Reaction with M(CH 2 Ph) 4 (M ) Ti, Zr) afforded the corresponding LM(CH 2 Ph) 2 (M ) Zr; Ti), where the Fc(NSiMe 3 ) 2 2group serves as a diamide ligand. Alternatively, the magnesium salt LMg(THF) 2 was reacted with TiCl 4 (THF) 2 to give LTiCl 2 as purple airsensitive crystals. Methylation of the latter with MeLi affords LTiMe 2 .

Five‐ and Four‐Coordinate 1,3‐Diaza‐2‐yttria‐ and 1,3‐Diaza‐2‐scandia‐[3]ferrocenophanes

“…The first yttrium complexes containing 1,3-bis(trimethylsilyl)-1,3-diaza-2-yttria- [3]ferrocenophane units were prepared, and their structures were characterized both in solution and in the solid state. The size of the Y 3+ ion is very similar to those of the late lanthanide Ln 3+ ions, and it can therefore be expected that the chemistry observed here mirrors that of these lanthanide ions.…”

“…[1,2] In this context, the 1,1Ј-diaminoferrocene derivatives 1 [3] and 1Ј [4] (Scheme 1) have already been used to prepare 1,3-diaza-2-metalla- [3]ferrocenophanes with titanium, [3,5] zirconium, [3,5,6] vanadium, [7] uranium [4,8] and scandium, [9] respectively, in the 2-position of the bridge. 1,3-Diaza-2-metalla- [3]ferrocenophanes bearing other substituents than silyl groups at the nitrogen atoms have also been synthesized, [10a,10b] including complexes of polyazaferrocene macrocyclic ligands.…”

“…Moreover, structural studies of 1,n-diaza-[n]ferrocenophanes with different other main group elements in the bridge have been Scheme 1. 1,1Ј-Bis(silylamino)ferrocene derivatives as starting materials for the synthesis of 1,3-diaza-2-metalla- [3]ferrocenophanes.…”

“…The 89 Y nuclear magnetic shielding of amido complexes appears to increase with the coordination number (3, 4, 5) of yttrium. Table 1. 13 C, 29 Si, and 89 Y NMR spectroscopic data [a] of the [3]ferrocenophanes 3-6.…”

Ethylene polymerization catalyzed by diamide complexes of Ti(IV) and Zr(IV)

“…The success of these ligands can be attributed to the hard nature of the N donor atoms, the diversity and relative easy manipulation of ligand topology, chirality, and coordination number, as well as the ''tunability'' of the associated steric factors. 6,7 Park and coworkers 8 reported titanium(IV) and zirconium(IV) complexes containing rigid diamide ligands derived from N,N-disilylated 1,8-diaminonaphthalene.When the lithiated diamide was reacted with titanium or zirconium tetrachloride, a bis(diamide) titanium(IV) or zirconium(IV) complex, [1,8- The dichloride titanium complex showed moderate activity in ethylene polymerization, but the zirconium complex was not active. The same author reported later, 9 an amine elimination reaction leading to the less bulky mono(diamide) complex [1,8- 3 ) which showed to be less active than the rigid linkage.…”