Formation of a [ONN(allyl)O]⁻ Anion via NO Insertion and Coupling Using Yttrium and Lanthanide Allyl Metallocenes

Abstract

Nitric oxide (NO) reacts with (C5Me5)2Ln(η3-CH2CHCH2)(THF) to form the first crystallographically characterized group 3 and organolanthanide NO insertion products, namely, {(C5Me5)2Ln[μ-ONN(CH2CHCH2)O]}2 (Ln = Y, La, Sm). The [ONN(allyl)O]− anions adopt an unusual trans geometry and presumably arise from insertion of NO into the Ln−C(allyl) bond followed by coupling of the (allyl-NO) radical anion with a second molecule of NO. Heating a solution of the yttrium product at 110 °C for 20 h affords (C5Me5)2Y[ONN(CH2CHCH2)O-κ2 O,O′], resulting from cleavage of the dimer and formation of the monomer as the thermodynamic product. The NN, N−O, and Ln−O bond distances suggest that a zwitterionic (−)O−NN(+)(R)−O(−) resonance structure is a main contributor to the bonding of these N-allyl-N-nitrosohydroxylaminato ligands.

C–H Activation via Carbodiimide Insertion into Yttrium–Carbon Alkynide Bonds: An Organometallic Alder-ene Reaction

“…Because most of the structural features in 1 – 3 and 5 – 7 are in the normal range (Tables S2–S6 in the Supporting Information), only a few select data will be discussed. For all of these complexes, the metallocene units have structural parameters within previously reported ranges. , For example, complex 1 (Figure ) displays typical 2.367 and 2.377 Å Y–(C 5 Me 5 ring centroid) lengths and a 137.7° (C 5 Me 5 ring centroid)–Y–(C 5 Me 5 ring centroid) bond angle.…”

Recent Advances in Rare Earth Complexes Bearing Allyl Ligands and Their Reactivity towards Conjugated Dienes and Styrene Polymerization

“…Thereafter, allylic-substituted rare earths, ranging from mono-to tetra-substituted allyl complexes, have been explored, and the group of Taube was probably the most successful in this area during the 1980s and 1990s [8]. In terms of reactivity, the allyl moiety is of specific interest because it makes it possible to carry out a certain number of elementary organometallic reactions, such as those involved in catalytic processes (insertion reactions [9], hydrogenolysis [10,11], hydrosilylation [12], alkyl exchange [13], etc.). Consequentially, the [RE-(allyl)] species has demonstrated its ability to catalyze polymerization reactions, with a particular behavior towards non-polar monomers (Scheme 1), some of which are highly stereo-selective [14][15][16].…”

σ Bond Metathesis Reactivity of Allyl Scandium Metallocenes with Diphenyldichalcogenides, PhEEPh (E = S, Se, Te)

“…This present study was initiated to remedy this deficiency and to provide information on σ bond metathesis between Sc–C and PhEEPh in a conventional (C 5 Me 4 H) − metallocene complex. Reactions with (C 5 Me 4 H) 2 Sc(η 3 -C 3 H 5 ), 1 , were studied because it is the only hydrocarbyl scandium (C 5 Me 4 H) − metallocene complex in the literature and also because allyl complexes of lanthanide metallocenes have proven to be conveniently synthesized, reliable sources of M–C bond reactivity. − The reactivity of 1 with PhEEPh is reported here and compared to the reactivity of (η 5 -C 5 Me 4 H) 2 Sc(η 1 -C 5 Me 4 H).…”