Jennifer C. Manton

Ian P. Clark; Michael W. George; Gregory M. Greetham; Emma C. Harvey; Conor Long; Jennifer C. Manton; Mary T. Pryce

The photochemistry of (η(6)-methylbenzoate)Cr(CO)(3), (η(6)-naphthalene)Cr(CO)(3), and (η(6)-phenanthrene)Cr(CO)(3) in n-heptane solution was investigated by picosecond time-resolved infrared spectroscopy (TRIR). The observation of two transient IR features in the organic carbonyl region at 1681 and 1724 cm(-1) following 400 nm excitation of (η(6)-methylbenzoate)Cr(CO)(3) confirms formation of two excited states which are classified as metal-to-arene charge transfer (MACT) and metal-to-CO charge transfer (MCCT), respectively. Time-dependent density functional theory calculations have been used to support these assignments. Population of the MCCT excited state results in a slow (150 ps) expulsion of one CO ligand. Excitation of (η(6)-naphthalene)Cr(CO)(3) or (η(6)-phenanthrene)Cr(CO)(3) at either 400 or 345 nm produced two excited states: the MCCT state results in CO loss, while the MACT excited state results in a change to the coordination mode of the polyaromatic ligands before relaxing to the parent complex. A comparison of the infrared absorptions observed following the population of the MACT excited state with those calculated for nonplanar polyaromatic intermediates provides a model for the reduced hapticity species.

Suraj Soman; Jennifer C. Manton; Jane L. Inglis; Yvonne Halpin; Brendan Twamley; Edwin Otten; Wesley R. Browne; Luisa De Cola; Johannes G. Vos; Mary T. Pryce

A high yield synthetic route for the preparation of N6 coordinated heteroleptic Ir(III) complexes using bidentate polypyridyl type ligands is described. The complexes are near-blue emitters and show microsecond emission lifetimes, high emission quantum yields and have two quasi-reversible reduction processes between -1.0 and -1.3 V vs. Ag/AgCl.

Ian P. Clark; Michael W. George; Gregory M. Greetham; Emma C. Harvey; Conor Long; Jennifer C. Manton; Hazel McArdle; Mary T. Pryce

The photochemistry of (η(6)-anisole)Cr(CO)(3) and (η(6)-thioanisole)Cr(CO)(3) was investigated by picosecond time-resolved infrared spectroscopy in n-heptane solution at 298 K. Two independent excited states are populated following 400 nm excitation of each of these complexes. An excited state with some metal-to-CO charge-transfer character is responsible for the CO-loss process, which is slow compared to CO-loss from Cr(CO)(6). Observed first order rate constants of 1.8 × 10(10) s(-1) and 2.5 × 10(10) s(-1) were obtained for the anisole and thioanisole complexes, respectively. The second excited state has metal-to-arene charge transfer character and results in a haptotropic shift of the thioanisole ligand. DFT calculations characterized the excited states involved and the nature of the haptotropic shift intermediate observed for the thioanisole species.

Suraj Soman; Gurmeet Singh Bindra; Avishek Paul; Robert Groarke; Jennifer C. Manton; Finn M. Connaughton; Martin Schulz; Danilo Dini; Conor Long; Mary T. Pryce; Johannes G. Vos

Jennifer C. Manton; Conor Long; Johannes G. Vos; Mary T. Pryce

Ian P. Clark; Michael W. George; Gregory M. Greetham; Emma C. Harvey; Conor Long; Jennifer C. Manton; Mary T. Pryce

Jennifer C. Manton; Conor Long; Johannes G. Vos; Mary T. Pryce

Andy G. Harry; William E. Butler; Jennifer C. Manton; Mary T. Pryce; Norma O'Donovan; John Crown; Dilip K. Rai; Peter T.M. Kenny

Suzanne McMahon; Jonathan Rochford; Yvonne Halpin; Jennifer C. Manton; Emma C. Harvey; Gregory M. Greetham; Ian P. Clark; A. Denise Rooney; Conor Long; Mary T. Pryce

Andy G. Harry; James T. Murphy; William E. Butler; Rachel Tiedt; Áine Mooney; Jennifer C. Manton; Mary T. Pryce; Norma O'Donovan; Naomi Walsh; John Crown; Dilip K. Rai; Peter T.M. Kenny