Zirconium Chelates of a Bulky Ferrocene-Based Diamido Ligand

Abstract

The arylamino-substituted ferrocene deriVatiVe {Fe-[C 5 H 4 4, 3 -C 6 H 2 )] 2 } (1b) reacts with Zr(CH 2 Ph) 4 and Zr(NMe 2 ) 4 to afford the respectiVe zirconium chelates [( PhCH 2 ) 2 -Zr{Fe[C 5 H 4 (N-2,4,6-iPr 3 -C 6 H 2 )] 2 }] (2) and [ which exhibit unexpectedly low catalytic actiVity in the polymerization of ethylene after actiVation with MAO and [Ph 3 C][B(C 6 F 5) 4 ], respectiVely. In order to elucidate stereoelectronic effects of the bulky aryl substituents, the structures of 2 and 3 and of their parent ferrocene deriVatiVe 1b haVe been determined as well as that of the phenylamino analogue {Fe[C 5 H 4 (NHPh)] 2 } (1a), for which an improVed synthesis has been deVeloped.

Ferrocene‐Based N‐Heterocyclic Carbenes with Functionalised Benzyl Substituents

“…Ferrocene 2a exhibits a crystallographically imposed inversion symmetry (molecular point group C i ), reflected in a fully staggered orientation of the cyclopentadienyl rings with diametrically opposed alkylamino substituents (Figure 4). These substituents are not involved in hydrogen bonds, which is in contrast to the structurally characterised analogues with secondary aryl‐30 or heteroarylamino substituents 31. The C–NH bond lengths of around 1.40 (C ipso ) and 1.46 Å (CH 2 ) are in accord with single bonds between an sp 3 ‐hybridised nitrogen atom and sp 2 ‐ and sp 3 ‐hybridised carbon atoms, respectively 32…”

On the Way to N‐Heterocyclic Silylenes with a 1,1′‐Ferrocenediyl Backbone: Synthesis and Structures of Silicon(IV) Compounds of the Type [Fe{(η5‐C5H4)NR}2SiX2]

“…The cyclopentadienyl rings of 1c H 2 are in an essentially eclipsed synperiplanar orientation. Such an arrangement was also found for [Fe{(η 5 ‐C 5 H 4 )NHPh} 2 ] . In contrast, a staggered antiperiplanar conformation with diametrically opposed amino groups was observed for [Fe{(η 5 ‐C 5 H 4 )NHMes} 2 ] and [Fe{(η 5 ‐C 5 H 4 )NHTIPP} 2 ], which contain bulkier aryl substituents.…”

“…Such an arrangement was also found for [Fe{(η 5 ‐C 5 H 4 )NHPh} 2 ] . In contrast, a staggered antiperiplanar conformation with diametrically opposed amino groups was observed for [Fe{(η 5 ‐C 5 H 4 )NHMes} 2 ] and [Fe{(η 5 ‐C 5 H 4 )NHTIPP} 2 ], which contain bulkier aryl substituents. Closer inspection of the crystal packing of 1c H 2 reveals that neighboring molecules are aggregated as dimers by intermolecular NH ··· π(cyclopentadienyl) interactions, whose metric parameters are similar to those reported for Fc–C≡C– p ‐C 6 H 4 NH 2 and compatible with weak hydrogen bonding (NH ··· C ca.…”

[Fe{(η5‐C5H4)N(SiMe2tBu)}2Al]2: A Stable Redox‐Functionalized Dialumane(4)

“…The cyclopentadienyl rings of 1c H 2 are in an essentially eclipsed anticlinal orientation (Figure ). In contrast, a staggered antiperiplanar conformation with diametrically opposed amino groups was observed for [Fe{(η 5 ‐C 5 H 4 )NH(C 6 H 2 ‐2,4,6‐Me 3 )} 2 ] and [Fe{(η 5 ‐C 5 H 4 )NH(C 6 H 2 ‐2,4,6‐ i Pr 3 )} 2 ], which also contain bulky, but trisubstituted, aryl groups.…”