Catherine E. Housecroft

An element of surprise - efficient copper-functionalized dye-sensitized solar cells

Dye-sensitized solar cells with carboxylate-derivatized {Cu(I)L(2)} complexes are surprisingly efficient and offer a long-term alternative approach to ruthenium-functionalized systems.

A supramolecularly-caged ionic iridium (III) complex yielding bright and very stable solid-state light-emitting electrochemical cells

A new iridium(III) complex showing intramolecular interligand pi-stacking has been synthesized and used to improve the stability of single-component, solid-state light-emitting electrochemical cell (LEC) devices. The pi-stacking results in the formation of a very stable supramolecularly caged complex. LECs using this complex show extraordinary stabilities (estimated lifetime of 600 h) and luminance values (average luminance of 230 cd m-2) indicating the path toward stable ionic complexes for use in LECs reaching stabilities required for practical applications.

Copper(I) complexes for sustainable light-emitting electrochemical cells

Four prototype heteroleptic copper(I) complexes [Cu(bpy)(pop)][PF6] (bpy = 2,2′-bipyridine, pop = bis(2-(diphenylphosphino)phenyl)ether), [Cu(phen)(pop)][PF6] (phen = 1,10-phenanthroline), [Cu(bpy)(pdpb)][PF6] (pdpb = 1,2-bis(diphenylphosphino)benzene) and [Cu(phen)(pdpb)][PF6] are presented. The synthesis, X-ray structures, solution and solid-state photophysical studies, and the performance in light-emitting electrochemical cells (LECs) of these complexes are described. Their photophysical properties are interpreted with the help of density functional theory (DFT) calculations. The photophysical studies in solution and in the solid-state indicate that these copper(I) complexes show good luminescent properties which allow them to be used as active materials in electroluminescent devices such as LECs. Additionally, these materials are very attractive since we can take advantage of their low-cost, due to the copper abundance, and their limited environmental damaging effects for producing cheap large-area panels based on the LEC technology for lighting applications. LEC devices were fabricated using the four prototype copper(I) complexes together with an ionic liquid (IL), 1-ethyl-3-methylimidazolium hexafluoridophosphate, at a molar ratio of 1 : 1. They yield devices that are comparable to those obtained for most LEC devices based on ruthenium(II) and iridium(III) complexes. Hence, this work shows that promising electroluminescent devices can be prepared using cheap and environmentally friendly copper(I) complexes.

The first example of a coordination polymer from the expanded 4,4 `-bipyridine ligand [Ru(pytpy)(2)](2+) (pytpy=4 `-(4-pyridyl)2,2 `: 6 `,2 ``-terpyridine)

The complex cation ligand [Ru(pytpy)2]2+ (pytpy = 4′-(4-pyridyl)-2,2′∶6′,2″-terpyridine) is an expanded 4,4′-bipyridine; we describe the first example of a coordination polymer in which [Ru(pytpy)2]2+ plays the role of a bridging bidentate ligand.

Stereoselective Double‐Helicate Assembly from Chiral 2,2′:6′,2″:6″,2′′′‐Quaterpyridines and Tetrahedral Metal Centres

PorMhelicates are formed in diastereoselective reactions of chiral 2,2′:6′,2″:6″,2′′′-quaterpyridine ligands with copper(I) and silver(I) salts.

Bucky Ligands: Synthesis, Ruthenium(II) Complexes, and Electrochemical Properties

Oligopyridine ligands with attached methanofullerene C60units have been prepared (e.g., 1) and their coordination behaviour investigated. The electrochemical properties of the resulting ruthenium(II) complexes are also described.

Light-emitting electrochemical cells based on a supramolecularly-caged phenanthroline-based iridium complex

The complex [Ir(ppy)(2)(pphen)][PF(6)] (Hppy = 2-phenylpyridine, pphen = 2-phenyl-1,10-phenanthroline) has been prepared and evaluated as an electroluminescent component for light-emitting electrochemical cells (LECs). Like in analogous LECs using bpy-based iridium(III) complexes a significant enhancement of the device stability is observed.

Transition metal boride clusters at the molecular level

Abstract Low oxidation state transition metal clusters which contain one or two boron atoms in fully or semi-interstitial sites are reviewed. In such environments, the boron atom does not bear a terminal hydrogen atom. This area of research has been developed primarily over the last decade, and now includes a range of homo- and heterometallic systems. Metal frameworks that are represented include the Ma butterfly, the MS square-based pyramid, the M 6 octahedron and the M 6 trigonal prism, together with a variety of more unusual geometries. Synthetic and structural studies form the basis of the review. Chemical reactivity patterns of the butterfly clusters (which support semi-interstitial boron atoms) are discussed in detail; reactions include BC and BN couplings at the semi-interstitial atom as well as metal framework expansion which transforms the boron atom from semi- to fully interstitial.

Zinc(II) coordination polymers, metallohexacycles and metallocapsules—do we understand self-assembly in metallosupramolecular chemistry: algorithms or serendipity?

Using a strategy of layering solvents and solutions of ligands and metal salts under ambient conditions, we observe the assembly of a discrete molecular metallohexacycle from ZnCl2 and 4′-(4-ethynylphenyl)-4,2′:6′,4′′-terpyridine, polycatenated, triply interlocked metallocapsules from ZnI2 and 4′-(4-pyridyl)-4,2′:6′,4′′-terpyridine, and 1-dimensional coordination polymers from either ZnCl2 or ZnI2 with 4′-{4-(3-chloropyridyl)}-4,2′:6′,4′′-terpyridine. On the basis of these studies and a comparison with related structures in the literature, we urge crystal engineers to be wary of drawing conclusions about self-assembly algorithms in solution using data from single crystal determinations.

In search of enantioselective catalysts for the Henry reaction: are two metal centres better than one?

Catalysts for the asymmetric Henry reaction involving copper(II) complexes of the chiral Schiff bases N,N′-(1R,2R)-(−)-1,2-cyclohexylenebis(3-hydroxysalicylideneamine) (H21) and N,N′-(1R,2R)-(−)-1,2-cyclohexylenebis(3-ethoxysalicylideneamine) (H22), and H23, which is the reduced analogue of H21, have been studied. Whereas [Cu(1)] and [Cu(2)] give poor yields and enantioselectivity, [Cu(3)] produced moderate to high yields and enantioselectivities were optimal when reactions were carried out in toluene rather than a polar solvent. A significant finding is that both yield and enantioselectivity are enhanced when a second equivalent of Cu(OAc)2 is added to the catalyst. The single-crystal structures of [Cu(3)] and [Cu(1)(H2O)] are presented, and the host–guest interactions and molecular packing in the latter are compared with those in [Cu(2)(H2O)].