No abstract

No abstract

A Mn3 chain bridged by four bidentate and two monodentate carboxylate ligands characterizes the MnII title complex 1. Unique features are the monodentate acetate bridges, which have a “dangling” oxygen atom that influences the molecular structure through weak interactions with the terminal Mn atoms.

The thermal and light-induced spin transition in [Fegn, -,(mtz),] [CIO,], (mtz = 1 -methyl-1 H-tetrazole) was studied b y 57Fe Mossbauer spectroscopy and magnetic susceptibility measurements. The pure iron compound possesses two different lattice sites A and B for the complex molecules. A t temperatures below 100 K a high spin (h.s.) --+ low spin ( I.s.) transition of the complexes at site A was observed, whereas the B molecules stay in the h.s. state at all temperatures down t o 4.2 K. On isotypic dilution with zinc the spin transition was shifted to lower temperatures and became more gradual with decreasing iron content x of the mixed-metal crystals. A t T < 40 K the I.s.(A) state can be converted by green light into the long-lived metastable h.s.(A) state [light-induced excited spin state trapping (LIESST) (Ih ) ] and the h.s.(B) state can be converted into a metastable long-lived I.s.(B) state using red light [LIESST (h --+ I)]. Reverse LIESST using red and green light, respectively, is possible in both cases.

No abstract