Alcohol-bridged dinuclear dysprosium single-molecule magnets

Herein we showcase triple-bridged symmetric dinuclear dysprosium complexes with the core structure of general chemical formula Dy2(L1)2(L2)2(R-OH) (R = Me, 1; Et, 2; iPr, 3; pH-CH2, 4) involving bridging alcohol molecules. L1 and L2 represent the deprotonated form of oxazole 4-tert-butyl-2-(7-methoxybenzo[d]oxazol-2-yl) phenol and Schiff-base (E)-2,4-di-tert-butyl-6-((3,5-di-tert-butyl-2-hydroxybenzylidene)amino)phenol, respectively. Single-crystal X-ray structural characterization revealed an unprecedented long Dy-O bond length for the benzyl alcohol analogue. The corresponding long Dy-O bond lengths in 1-4 are 2.7825, 2.6651, 2.6021 and 2.9955 & Aring;, respectively. Alternating current magnetic susceptibility measurements at zero dc field revealed that all four complexes display clear frequency dependence signal peaks, indicating single-molecule magnet behavior. The spin reversal energy barrier heights for 1, 2 and 4 are 31.1, 27.6 and 17.4 K. The dynamic magnetic behavior is influenced by the different Dy-O bond lengths derived from the bridging alcohol molecules. Theoretical calculations were employed to establish magneto-structural correlations in 1-4. Magneto-structural correlations with respect to the alcohol molecule participating in triple-bridged symmetric dinuclear dysprosium complexes is established with the help of quantum-chemical calculations.