(Received: March 31, 2005; Accepted for publication: July 21, 2005; Published on Web: September 1, 2005)
As a design of high-spin organic molecules and polymer ferromagnets, the spin states of isoelectronic non-Kekule-type molecules tetramethylenepropane, biguanide trication, and biuret trication are discussed using the molecular orbital method. The quartet ground states of these molecules are predicted to lie below the corresponding doublet states. Furthermore, the spin-density distribution of the quartet states obeyed the spin-polarization rule characteristic of high-spin organic molecules. On the basis of these calculations, possible polymer ferrromagnets based on polyguanide and polyuret are suggested.
Keywords: Non-Kekule-type molecules, Molecular orbital method, High-spin organic molecule, Polymer ferromagnet, Polyguanide, Polyuret