Incorporating Trigonal-Prismatic Cobalt(II) Blocks into an Exchange-Coupled [CoCu] System.

Taking advantage of a rigid tetradentate ligand of bis(pyrazoly)(3-pyrazolypyridinyl)methane (PyPz) and the [Cu(opba)] unit [opba = -phenylenebis(oxamato)], the trinuclear complex [{Co(PyPz)}Cu(opba)][ClO]·5MeCN·MeOH () was constructed, in which the Co centers adopt a trigonal-prismatic geometry, while considerable intramolecular magnetic coupling was successfully introduced through the oxamido bridges, representing another very first example of single-molecule magnets marrying both selected coordination geometry and magnetic exchanges.

Probing the Axial Distortion Effect on the Magnetic Anisotropy of Octahedral Co(II) Complexes.

Three mononuclear octahedral Co(II) complexes are reported, [Co(py)(SCN)] (), [Co(py)(Cl)]·HO (), and [Co(py)(Br)] (), that exhibit different distortions with compression () or elongation ( and ) of the axial positions. Easy plane magnetic anisotropy was confirmed by magnetic, HF-EPR, and computational studies for all complexes. Further analyses indicate that both the sign and magnitude of zero-field splitting parameters experience a significant change ( ≥ ±150 cm) by tuning of the axial and equatorial ligand field strength.

Synthesis and magnetic studies of pentagonal bipyramidal metal complexes of Fe, Co and Ni.

Three mononuclear metal complexes [MII(L-N3O2)(MeCN)2][BPh4]2 (M = Fe, 1; Co, 2; Ni, 3) were isolated and structurally characterized. Magnetic studies revealed uniaxial magnetic anisotropy for 1 (D = -17.1 cm-1) and 3 (D = -14.