Experimental consideration of covalent-bonding interactions in stacks of singlet biradicals having Kekule structures

Kekule singlet biradicals stabilized by phenalenyl rings afford one-dimensional stacks in the solid state, in which covalent-bonding interactions exist not only within a molecule but also between molecules. Through the covalent-bonding interactions spreading over the stack, the lowest-energy absorption band shifts to a lower-energy region in the solid state relative to the solution band, and an electro-conductive property in a single component state is also observed. Copyright (C) 2011 John Wiley & Sons, Ltd.