A phosphine-mediated through-space exchange coupling pathway for unpaired electrons in a heterobimetallic lanthanide-transition metal complex.

The reaction of P(CH2OH)3 with methyl anthranilate NH2C6H4-2-CO2Me produced the ligand precursor P(CH2NHC6H4-2-CO2Me)3 (1). The reaction of 1 with [Y{N(SiMe3)2}3] produced hexadentate yttrium complex [Y{P(CH2NC6H4-2-CO2Me)3}] (2), in which the metal centre is coordinated by three amido donors and the three carbonyl oxygen atoms of the ester groups. The 31P{1H} NMR spectrum features 1J Y,P=15 Hz, and DFT calculations demonstrate that through-space interaction between the minor lobe of the phosphine lone pair and the yttrium centre allows a large Fermi contact contribution to this spin coupling constant.

Assembly of triangular trimetallic complexes by triamidophosphine ligands: spin-frustrated Mn2+ plaquettes and diamagnetic Mg2+ analogues with a combined through-space, through-bond pathway for 31P-31P spin-spin coupling.

The reactions of 2 equiv of the ligand precursor P(CH2NHPh)3 or P[CH2NH-3,5-(CF3)2C6H3]3 with 3 equiv of Mn[N(SiMe3)2]2 provide high-yielding routes to the triangular trinuclear Mn(II) complexes [P(CH2NPh)3]2Mn3(THF)3.1.5THF and [P(CH2N-3,5-(CF3)2C6H3)3]2Mn3(THF)3.