Publications by authors named "Connor J V Halliday"

Modular tetraphenolate ligands tethered with a protective arene platform (-phenyl or -terphenyl) are used to support mononuclear An(IV) (An = Th, U) complexes with an exceptionally large and open axial coordination site at the metal. The base-free complexes and a series of neutral donor adducts were synthesized and characterized by spectroscopies and single-crystal X-ray diffraction. Anionic Th(IV) -ate complexes with an additional axial aryloxide ligand were also synthesized and characterized.

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Neutral arenes such as benzene have never been considered suitable ligands for electropositive actinide cations, yet we find that even simple U UX aryloxide complexes such as U(ODipp) bind and reduce arenes spontaneously at room temperature, forming inverse arene sandwich (IAS) complexes XU(μ-CD)UX (X = ODipp, =2, =3; X = OBMes n=m=2 or 3) (ODipp = OCHPr-2,6; Mes = 2,4,6-Me-CH). In some of these cases, further arene reduction has occured as a result of X ligand redistribution. These unexpected spontaneous reactions explain the anomalous spectra and reported lack of further reactivity of strongly reducing U centers of U(ODipp).

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The activation of abundant molecules such as hydrocarbons and atmospheric nitrogen (N) remains a challenge because these molecules are often inert. The formation of carbon-nitrogen bonds from N typically has required reactive organic precursors that are incompatible with the reducing conditions that promote N reactivity, which has prevented catalysis. Here we report a diketiminate-supported iron system that sequentially activates benzene and N to form aniline derivatives.

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The use of cationic gold(i) species in the activation of substrates containing C[triple bond, length as m-dash]C bonds has become a valuable tool for synthetic chemists. Despite the seemingly simple label of 'alkyne activation', numerous patterns of reactivity and product structure are observed in systems employing related substrates and catalysts. The complications of mechanistic determination are compounded as the number of implicated gold(i) centres involved in catalysis increases and debate about the bonding in proposed intermediates clouds the number and importance of potential reaction pathways.

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The coordination modes of the [Au(PPh3)](+) cation to metal alkynyl complexes have been investigated. On addition to ruthenium, a vinylidene complex, [Ru(η(5)-C5H5)(PPh3)2([double bond, length as m-dash]C[double bond, length as m-dash]CPh{AuPPh3})](+), is obtained while addition to a gold(iii) compound gives di- and trinuclear gold complexes depending on the conditions employed. In the trinuclear species, a gold(i) cation is sandwiched between two gold(iii) alkynyl complexes, suggesting that coordination of multiple C-C triple bonds to gold is facile.

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