“…While many different bridging systems exist, 14,18,19 few examples have demonstrated the importance of planar aromatic organometallic ligands towards garnering favourable magnetic interactions. 20–22 These systems are an appealing design strategy as they may be employed as building blocks to generate higher nuclearity compounds, while they are more notably effective in harnessing the inherent magnetic anisotropy of 4f and 5f ions. 13,15–17,23,24 Our recent reports with cyclooctatetraenyl 20,21 and arene-bridged 22 systems shows that a weak, yet non-negligible, interaction can be observed with coupling constants between Gd III ions of –0.644 cm –1 and –0.488 cm –1 respectively, utilizing the isotropic spin Hamiltonian ( H = –2 JS
a
S
b , S
a = S
b = 7/2) for each system respectively.…”