Coupling between the photo-excited cyclic π system and the 4f electronic system in a lanthanide single molecule magnetElectronic supplementary information (ESI) available. See DOI: 10.1039/c7cc02960h

A new type of electronic interaction which couples two angular momenta, i.e. the angular momentum of a localized 4f system ( J ) and an orbital angular momentum generated in a cyclic π conjugated system by irradiation with a circularly-polarized light, has been identified in a lanthanide single molecule magnet. Does the angular momentum of the 4f system couple with a photo-induced orbital angular momentum L in the cyclic π system in a lanthanide SMM?