文摘
The self-assembly of DyIII–3-hydroxypyridine (3-OHpy) complexes with hexacyanidocobaltate(III) anions in water produces cyanido-bridged {[DyIII(3-OHpy)2(H2O)4] [CoIII(CN)6]}⋅H2O (1) chains. They reveal a single-molecule magnet (SMM) behavior with a large zero direct current (dc) field energy barrier, ΔE=266(12) cm−1 (≈385 K), originating from the single-ion property of eight-coordinated DyIII of an elongated dodecahedral geometry, which are embedded with diamagnetic [CoIII(CN)6]3− ions into zig-zag coordination chains. The SMM character is enhanced by the external dc magnetic field, which results in the ΔE of 320(23) cm−1 (≈460 K) at Hdc=1 kOe, and the opening of a butterfly hysteresis loop below 6 K. Complex 1 exhibits white DyIII-based emission realized by energy transfer from CoIII and 3-OHpy to DyIII. Low temperature emission spectra were correlated with SMM property giving the estimation of the zero field ΔE. 1 is a unique example of bifunctional magneto-luminescent material combining white emission and slow magnetic relaxation with a large energy barrier, both controlled by rich structural and electronic interplay between DyIII, 3-OHpy, and [CoIII(CN)6]3−.