To enhance our comprehension of the magnetic coupling in these dimers, we examined the interactions between the degenerate spin-polarized orbitals. As illustrated in Figures and, the SOMOs of TRI-TRI and TAM-TAM are derived from their monomer orbitals. The up and down spins are situated on neighboring fragments, signifying the prevailing influence of kinetic exchange and AFM interactions. The two SOMOs of the TRI monomer are energetically degenerate. In the dimer, the SOMOs remain restricted within the monomers. However, the energetic degeneracy is lifted, and four single-occupied orbitals are present (Figure ). On the contrary, a stronger molecular overlap of the fragment orbitals gives extended SOMOs in TAM-TAM (Figure ). This is quantified by the much larger overlap integral of 0.448 and hopping integral of 0.56 eV in TAM-TAM, compared to 0.025 and 0.14 eV, respectively, in TRI-TRI. Consequently, the promoted electronic coupling in TAM-TAM enhances the kinetic exchange, yielding a stronger AFM coupling of -128 meV, ~16 times higher than that of -7.7 meV in TRI-TRI. Furthermore, HOMO-LUMO gaps larger than 0.5 eV show a positive correlation with the magnetic couplings in these spin dimer systems (Figure ). Hence, promoting the overlap of SOMOs and thus the electronic coupling between the fragments offers a prospective approach to enhance the magnetic interaction. This offers a rational design concept that focuses on non-Kekulé multi-radicals with large bandgap and high symmetry. We note that SOMOs with D3h symmetry (TAM, TOT, and PLY) have larger hopping integrals than those with C2v symmetry (TRI, TRI(N) and TRI(B)) (Table and Figure ). The highsymmetry TAM-TAM, TOT-TOT, and PLY-PLY have AFM couplings of -128, -60, and -22 meV, respectively, with corresponding hopping integrals of 0.56, 0.41, and 0.29 eV. In contrast, TRI-TRI, TRI(N)-TRI(N) and TRI(B)-TRI(B) exhibit significantly weaker magnetic couplings of -7.7, -0.4, and -0.2 meV, respectively, with hopping integrals of 0.14, 0.17, and 0.18 eV (Table and Figure ). The electronic and magnetic couplings, t and J, decrease with the length of the spacer in the dimer from direct linkage towards -CC-, -CCCC-and -Ph-spacers as the overlap between SOMOs weakens. An exception is -CC-linked TRI(N) dimer, as the effect of preserving its planarity and thus enhanced overlap predominate.