Molecules containing rare-earth atoms solely bonded by transition metals

Abstract

Although metal-metal bonding is important in the chemistry of both solid-state intermetallic compounds and molecular species, the study of this bonding is limited by the compounds available and it is rarely possible to identify connections between these two areas. In this study, molecular intermetalloids [Ln(ReCp(2))(3)] (Ln = Sm, Lu and La) have been synthesized that contain lanthanoid metals bound only to transition metals. Although they are highly reactive species, such lanthanoid-core transition-metal-shell compounds can be stable in solution. They mimic the bonding situation of intermetallic compounds, as revealed by a direct comparison of molecular and solid state lanthanoid-transition metal bonding.

Rare Earth Arene-Bridged Complexes Obtained by Reduction of Organometallic Precursors

“…Although the first structurally characterized lanthanide-transition metal bonds were reported in the early 1990s, ([(MeCN)3YbFe(CO)4]2·MeCN)∞ (Deng and Shore, 1991) and Cp2Lu(THF)-RuCp(CO)2 (Beletskaya et al, 1993), the field started developing at a fast pace only in the last decade Butovskii et al, 2010;Liddle and Mills, 2009;Minasian et al, 2009;Oelkers et al, 2012), spurred by Kempe's report of [O(SiMe2N-2-C5H3N-4-Me)2]2NdRh( 2 -C2H4) and…”

“…Probably the most thought-provoking molecule reported in this area is Sm(ReCp2)3, also by Kempe, 12 which does not feature any traditional supporting ligands for samarium and, instead, is bound solely by transition metals (Chart 5) (Butovskii et al, 2010).…”

Molecular Lanthanoid–Transition‐Metal Cluster through CH Bond Activation by Polar Metal–Metal Bonds

“…[9] Since the reaction of [Cp 2 Y(thf)(CH 2 SiMe 3 )] (Me = methyl) with the above-mentioned rhenium hydride proceeds in very good yields, [7] it was suspected, that the presence of one Ln-carbon bond brings about side reactions of the Ln-TM bond leading to those polymeric materials. Now, if one wants to understand and to use such (side) reactions purposefully, a bis(alkyl) Ln compound which allows the substitution of one of the two alkyl ligands by Cp 2 Re-ligands should be exploited.…”

“…[12][13][14] The high bond polarity should allow a systematic approach towards highly aggregated systems. [9,10,15] To date there has been little exploration of the reactivity of such Ln-TM bonds. [6][7][8][9][10] Herein we show how metal clusters can be prepared by multiple C À H bond activations at Ln-TM bonds, which leads to the formation of doubly deprotonated Cp ligands.…”

Molekulare Lanthanoid‐Übergangsmetall‐Cluster mittels C‐H‐Bindungsaktivierung an polaren Metall‐Metall‐Bindungen

“…[9] Da die Umsetzung von [Cp 2 Y(thf)(CH 2 SiMe 3 )] (Me = Methyl) mit [Cp 2 ReH] in sehr guten Ausbeuten verläuft, [7] wurde vermutet, dass die Gegenwart einer Ln-Kohlenstoff-Bindung zu Nebenreaktionen der Ln-ÜM-Bindung führt, deren Produkt diese polymeren Materialien sind. Will man nun solche (Neben)Reaktionen gezielt nutzen, sollte eine Lanthanoid-Dialkylverbindung als Ausgangsubstanz eingesetzt werden, in der selektiv einer der beiden Alkylliganden durch den Cp 2 Re-Liganden substituiert werden kann.…”