Seminários

Design of organic molecular magnetic materials – successes and limitations with second row element paramagnetic systems

Paul M. Lahti
Department of Chemistry, University of Massachusetts, Amherst, USA

A major theme of 21^st century chemistry and materials science is the organizing of solid state molecules and polymers to design or at least to understand intermolecular interactions. Purely organic materials can give bulk magnetically ordered states, if their crystal organization is appropriate to assist with intermolecular, inter-electronic exchange interactions.  The magnetic properties in some cases can be related to inter-molecular contacts in the crystal lattice, although more frequently a large number of contacts need to be considered for even partial understanding.  This talk will focus on using so-called “crystal engineering” – or at least highly detailed crystallographic analysis – to understand and even design particular types of intermolecular magnetic exchange behavior.  Actual magnetic bulk ordering of metal-free organic materials will be described for select cases.  Ordering temperatures remain low (<2 K) for materials composed only with second row elements, but there is promise for systems having lower row elements with larger orbital extents, or for combining organic radicals with paramagnetic organic ions to make hybrid materials.