Structure and Properties of Non-Classical Polymers. XI. Heteroatomic Analogues of Poly(1,3-phenylenemethylene)’s

Abstract

Abstract The magnetic properties of a new class of high-spin organic 1-D polymers were studied theoretically. The polymers have the same topology as poly(1,3-phenylenemethylene)s (PMP) and are derived from the latter by substitution of the exocyclic radical center –C•R– by –B•−R–, –N•–, –N+•H–, –O+•– or –S+•–. All of these polymers possess a narrow half-filled band (HFB) within the energy gap. The nature of spin-exchange interactions of π-electrons within the HFB has been investigated. The three components of the effective exchange integral, Jeff, in the Heisenberg Hamiltonian representing the potential (direct), kinetic and exchange (due to the spin polarization—indirect exchange) interaction of the π-electrons in the HFB were calculated. In all cases, the potential (Coulomb) exchange was the main contribution to the ferromagnetic (Jeff > 0) exchange interaction.