Ferromagnetically coupled chiral dysprosium hydroxysulfate and centrosymmetric dysprosium hydroxysulfate-oxalate: Dy-4(OH)(4) cubane based high-connected networks via in situ conversion of organosulfur to sulfate

摘要

Hydrothermal reaction of Dy(NO3)(3), 2-amino-5-mercapto-1,3,4-thiadiazole and (NH4)(2)C2O4 in the presence of triethylamine resulted in two dysprosium hydroxysulfates, namely [Dy-4(OH)(4)(SO4)(4)(H2O)(3)] (1) and [Dy-4(OH)(4)(SO4)(3)(ox)(H2O)(6)] (2) (ox = oxalate), in which the sulfates came from in situ oxidized conversion of the organosulfur of 2-amino-5-mercapto-1,3,4-thiadiazole. Both 1 and 2 are constructed from cubane-like Dy4O4 clusters, which extend via sulfate and oxalate into 3D highly-connected networks. Compound 1 crystallizes in the orthorhombic chiral space group P2(1)2(1)2(1) and has 3D (12,3)-connected Au4Ho-like topology in which Dy-4(mu(3)-OH)(4) cubane clusters serve as twelve-connected nodes and sulfates serve as three-connected nodes, while compound 2 crystallizes in the orthorhombic centrosymmetric space group Pbcm and shows a 3D (10,3)-connected unprecedented network with coordinated oxalates in which Dy-4(mu(3)-OH)(4) cubane clusters act as ten-connected nodes and sulfates act as three-connected nodes. Detailed comparison of experimental parameters indicated that the amount of lanthanide ions played a significant role in tuning the nuclearity of metal clusters and the local connectivity number of specific networks. Differing from antiferromagnetic coupling observed in known Dy-4(mu(3)-OH)(4) cubane-like compounds, 1 and 2 exhibit unusual ferromagnetic coupling.