A Co_(16) cluster and a 1-D Mn chain complex supported by benzohydroxamic acid

摘要

The syntheses, crystal structures and magnetic properties are described for a {Co_(16)} cluster [Co~(II) _(16)O(OH) _2(bha)_(12)(PhCO_2)_4(Phen) _2(MeOH)_4]·2MeOH (1) and a 1-D MnII chain complex [Mn(Hbha)_2]n·(2MeOH)_n (2) (H_2bha = benzohydroxamic acid; Phen = 1,10-phenanthroline). The 1,:,1,:,0.5 reaction of Co(O_2CMe)_2·4H_2O, H2bha and 1,10-phenanthroline in MeOH at 100 °C under autogenous pressure gave cluster 1. Complex _2 was obtained from the 1,:,1 reaction mixture of Mn(O_2CMe)_2·2H_2O and H_2bha in MeOH under solvothermal conditions. The {Co_(16)} cluster can be thought as a face-centered cube with two wings. The H_2bha ligands show hydroximic form in 1 and exhibit hydroxamic mode in 2. The hydroximate ligands in 1 display three distinct binding modes, one of which is novel. Variable-temperature solid-state dc magnetic susceptibility studies have been performed in the 2.0-300 K range for complexes 1 and 2. Antiferromagnetic M ~(II)?M~(II) exchange interactions were found for both 1 and 2. This work also demonstrates that solvothermal method is a potential synthetic approach for the design and growth of high nuclearity clusters or chain complexes of the H_2bha ligand. This journal is