Crystal structure and magnetic properties of an ionic multi-component complex of fullerene (OMTTF·I3)·C60

A new ionic multi-component complex (OMTTF·I3)·C60 comprising neutral C60 molecules and OMTTF+ and I3− ions has been obtained by the diffusion method. The complex has a layered structure with the alternation of closely packed hexagonal C60 layers and the layers composed of OMTTF+ and I3− ions arranged in a chequer-like manner. The polycrystalline complex shows a strongly asymmetric EPR signal consisting of four components in the 4-293 K range attributable to OMTTF+. Temperature dependent magnetic susceptibility indicates an antiferromagnetic interaction of spins localized on OMTTF+ with an antiferromagnetic hump near 4.5 K. According to the one-dimensional Heisenberg antiferromagnet model the exchange interaction was estimated to be J/kB = −3.3 K. Two possible pathways contribute to this interaction: through the diamagnetic I3− anions and the direct interaction between adjacent OMTTF+. The crystal structures of three phases of the OMTTF·I3 salt are also presented.