Selective copper-catalysed atom transfer radical addition (ATRA) in water under environmentally benign conditions.

Simple and green conditions for copper-catalysed ATRA reactions in water have been developed. Firstly, [Cu(ADPA)(HO)(ClO)] (1b, ADPA = 9-[(2,2'-dipicolylamino)methyl]anthracene) was demonstrated to be capable of selectively catalysing the ATRA of CCl to styrene using L-ascorbic acid (AsH) as a reducing agent in organic solvent mixtures under ambient atmosphere. Mechanistic investigation suggested that our ATRA reaction proceeded a single-electron transfer (SET) mechanism through an inner-sphere complex, which is consistent with the widely accepted mechanism for copper-catalysed ATRA.

Stabilisation of copper(i) polypyridyl complexes toward aerobic oxidation by zinc(ii) in combination with acetate anions: a facile approach and its application in ascorbic acid sensing in aqueous solution.

A new and facile approach to stabilise copper(i) complexes in aqueous solution by the addition of zinc(ii) ions in combination with acetate ions (OAc-) was demonstrated. This stability enhancement toward the aerobic oxidation of copper(i) species was investigated by various techniques including UV-vis spectroscopy, 1H-NMR, FT-IR, and ESI-MS. Our experimental results together with DFT calculations led to a proposed structure of [(adpa)Cu-OAc-Zn(OAc)(H2O)2]+/2+.

Tuning the reactivity of copper complexes supported by tridentate ligands leading to two-electron reduction of dioxygen.

A series of copper complexes bearing polypyridyl tridentate ligands have been prepared to fine tune their reactivity toward the oxygen reduction reaction (ORR). During the process of preparation of our copper complexes, we successfully obtained two new crystal structures which are [Cu2(μ-Cl)2(adpa)2](ClO4)2 (2b) and [Cu2(addpa)(CH3CN)2(ClO4)2](ClO4)2 (3a) and a new structure [Cu2(addpa)(CH3CN)2(H2O)2](ClO4)4 (3b) captured after the catalytic ORR. Electrochemical studies and stoichiometric chemical reduction of copper(ii) complexes by ascorbic acid indicated that the presence of an anthracene unit helps to facilitate the reduction of Cu(ii) as well as the stabilisation of Cu(i) species.

Discriminate sensing of pyrophosphate using a new tripodal tetramine-based dinuclear Zn(II) complex under an indicator displacement assay approach.

In this research, the dinuclear Zn(ii) complex of anthracene based tripodal tetramine Zn2L was synthesized, and its sensing abilities towards anions was investigated using the indicator displacement assay (IDA) approach with four complexometric indicators: pyrocatechol violet (PV), bromopyrogallol red (BPG), methylthymol blue (MTB) and xylenol orange (XO). UV-vis spectrophotometry results indicated that the Zn2L-MTB ensemble sensor could discriminate the pyrophosphate anion (PPi) from other phosphate containing anions. (1)H and (31)P NMR spectroscopy as well as DFT calculations confirmed that PPi bound to Zn2L in a 2 : 2 manner.