Tracking the conical intersection dynamics for the photoinduced Jahn-Teller switch of a Mn(iii) complex.

Octahedral Mn(iii) ions predominantly exhibit an axially elongated Jahn-Teller (JT) distortion, which is responsible for their large uniaxial magnetic anisotropy. As a result, they are often used in the synthesis of single-molecule magnets (SMMs). Modulation of the JT distortion using femtosecond laser pulses could offer a route to controlling the magnetisation direction, and therefore is promising for the development of data storage devices that work on ultrafast timescales.

A dual action coumarin-camptothecin polymer for light responsive drug release and photodynamic therapy.

A light-responsive polymer allowing the controlled release of camptothecin and the generation of reactive oxygen species (ROS) is reported. The polymer was prepared by controlled copolymerisation of water-soluble ,-dimethyl acrylamide with a bromocoumarin methacrylate monomer. The lipophilic chemotherapy agent camptothecin was caged onto the coumarin unit a photo-cleavable carbonate ester enabling light-triggered cargo release.

Equatorial restriction of the photoinduced Jahn-Teller switch in Mn(iii)-cyclam complexes.

Ultrafast transient absorption spectra were recorded for solutions of [Mn(cyclam)(HO)(OTf)][OTf] (cyclam = 1,4,8,11-tetraazacyclotetradecane and OTf = trifluoromethanesulfonate) in water to explore the possibility to restrict the equatorial expansion following photoexcitation of the d ← d electronic transition, often resulting in a switch from axial to equatorial Jahn-Teller distortion in Mn complexes. Strong oscillations were observed in the excited state absorption signal and were attributed to an excited state wavepacket. The structural rigidity of the cyclam ligand causes a complex reaction coordinate with frequencies of 333, 368, 454 and 517 cm, and a significantly shorter compressed-state lifetime compared to other Mn complexes with less restricted equatorial ligands.