A joint experimental/theoretical study has been carried out on the putative MMA polymerization catalyzed by an yttrium isopropyloxide complex. Despite its high activity in lactone polymerization, this catalyst is found to be unreactive on methyl methacrylate (MMA) polymerization. This surprising result is rationalized using a computational approach at the DFT level. Indeed, the endothermicity o...

The preparation of yttrium metal by the reduction of yttrium trifluoride with calcium is described. Alternate methods employing the formation of a low melting Y-Zn or Y-Mg intermediate alloy are evaluated and data on chemical and microscopic purity of the resulting metal are presented.

Ligand substitution reactions and catalytic hydroamination/cyclization of aminoalkenes have been studied with a new oxazolinylborato yttrium compound, tris(4,4-dimethyl-2-oxazolinyl)phenylborato bis(trimethylsilylmethyl)yttrium ([Y(kappa(3)-To(M))(CH(2)SiMe(3))(2)(THF)], 1). THF exchange in 1 is rapid at room temperature, and activation parameters obtained by simulation of (1)H NMR spectra acqu...

Chiral alkyl or amido yttrium complexes were prepared from N-silyl- or N-cyclopentyl-substituted binaphthylamido ligands. According to the synthetic procedure, these complexes could be obtained in their neutral form or as heterobimetallic complexes in the presence of 1 equiv. LiCl. These new species were characterized by IR and NMR spectroscopies, elemental analyses and some of them by X-ray di...

A new family of Y(4)/M(2) and Y(5)/M heterobimetallic rare-earth-metal/d-block-transition-metal-polyhydride complexes has been synthesized. The reactions of the tetranuclear yttrium-octahydride complex [{Cp''Y(μ-H)(2)}(4)(thf)(4)] (Cp'' = C(5)Me(4)H, 1-C(5)Me(4)H) with one equivalent of Group-6-metal-pentahydride complexes [Cp*M(PMe(3))H(5)] (M = Mo, W; Cp* = C(5)Me(5)) afforded pentanuclear he...

Numerous bulk crystalline materials exhibit attractive nonlinear and luminescent properties for classical and quantum optical applications. A chip-scale platform for high quality factor optical nanocavities in these materials will enable new optoelectronic devices and quantum light-matter interfaces. In this article, photonic crystal nanobeam resonators fabricated using focused ion beam milling...

[reaction: see text]. Yttrium-salen complexes effect transacylation between enolesters and chiral secondary alcohols, resulting in varying degrees of kinetic resolution. Even though the enantioselectivity remains modest (k(fast)/k(slow) up to 4.81), these results represent the first demonstration of a conceptually new metal-catalyzed acyl transfer process that results in kinetic resolution. On ...

Rare-earth complexes are attractive catalyst systems due to their low cost, low toxicity and high reactivity. Modular ligand sets are ideal for complex formation since the steric and electronic properties of the resultant metal complexes can be easily varied. This thesis explores the structure and reactivity of new yttrium amidate complexes, which combine the highly reactive metal with the modu...

The first structurally authenticated yttrium-alkyl-alkylidene is reported; structural, spectroscopic, and theoretical analyses show that whilst the yttrium-alkylidene bond is short, it possesses a bond order less than one and is comparable to the Y-C(alkyl) single bond within the same molecule.