Two Heterometallic Nanoclusters [DyNi] and [DyMnMn]: Structure, Assembly Mechanism, and Magnetic Properties.

A full understanding of the assembly mechanisms of coordination complexes is of great importance for a directional synthesis under control. We thus explored here the formation mechanisms of the two new heterometallic nanoclusters [DyNi(μ-OH)(L)(OAc)(HO)]·3.25EtOH·4CHCN () and [DyMnMnO(OH)(OAc)(L)(HL)(EtOH)]·2EtOH·2CHCN·2HO () with different cubane-based squarelike ring structures, which were obtained from the reactions of 4-bromo-2-[(2-hydroxypropylimino)methyl]phenol (HL) with Dy(NO)·6HO and the transition metal salt Ni(OAc)·4HO or Mn(OAc)·4HO. The high-resolution electrospray ionization mass spectrometry (HRESI-MS) tests showed that the skeletons of clusters and have a high stability under the measurement conditions for HRESI-MS. The intermediates formed in the reaction courses of clusters and were tracked using time-dependent HRESI-MS, which helped to determine the proposed hierarchical assembly mechanisms for (HL → NiL → NiL → NiL → NiL → DyNiL → DyNiL → DyNiL → DyNiL → DyNiL) and (HL → MnL → DyMnL → DyMnL → DyMnL → DyMnL → DyMnL → DyMnL and HL → DyL → DyL → DyL → DyMnL → DyMnL → DyMnL). This is one of the rare examples of investigating the assembly mechanisms of 3d-4f heterometallic clusters. Magnetic studies indicated that the title complexes both show slow magnetic relaxation behaviors and cluster is a field-induced single-molecule magnet.