Beijing Key Laboratory for Science, and Application of Functional Molecular and Crystalline Materials, Department of Chemistry, University of Science and Technology Beijing, Beijing, 100083, China.
Department of Chemistry and Beijing Key Laboratory of Energy Conversion and Storage Materials, Beijing Normal University, Beijing, 100875, China.
Chemistry. 2018 Jun 7;24(32):8066-8070. doi: 10.1002/chem.201800408. Epub 2018 May 15.
The non-peripherally substituted 1,4,8,11,15,18,22,25-octa(butoxy)-phthalocyanine-involved unsymmetrical heteroleptic bis(phthalocyaninato) terbium double-decker, Tb(Pc){H[Pc(α-OC H ) ]} (Pc=unsubstituted phthalocyanine) (1), was revealed to exhibit typical single ion magnet (SIM) behavior with effective energy barrier, 180 K (125 cm ), and blocking temperature, 2 K, due to the severe deviation of the terbium coordination polyhedron from square-antiprismatic geometry. Fabrication of this double-decker compound into the novel tetrakis(phthalocyaninato) terbium pseudo-quadruple-decker Na {Tb(Pc)[Pc(α-OC H ) ]} (2) single molecule magnet (SMM) not only optimizes the coordination polyhedron of terbium ion towards the square-antiprismatic geometry and intensifies the coordination field strength, but more importantly significantly enhances the molecular magnetic anisotropy in the unsymmetrical bis(phthalocyaninato) double-decker unit, along with the change of the counter cation from H of 1 to Na of 2, leading to an significantly enhanced magnetic behavior with spin-reversal energy barrier, 528 K (367 cm ), and blocking temperature, 25 K. The present result is surely helpful towards developing novel tetrapyrrole lanthanide SMMs through rational design and self-assembly from bis(tetrapyrrole) lanthanide single ion magnet (SIM) building block.
非外围取代的 1,4,8,11,15,18,22,25-辛氧基-酞菁基钽不对称双酞菁双夹心配合物，Tb(Pc){H[Pc(α-OC H ) ]}（Pc=未取代的酞菁）（1），由于钽配位多面体严重偏离四方反棱柱几何形状，表现出典型的单离子磁体（SIM）行为，有效能垒为 180 K（125 cm），阻塞温度为 2 K。将这种双夹心化合物制成新型四（酞菁基）钽伪四重夹心 Na {Tb(Pc)[Pc(α-OC H ) ]}（2）单分子磁体（SMM），不仅优化了钽离子的配位多面体朝向四方反棱柱几何形状，增强了配位场强度，而且更重要的是，显著增强了非对称双酞菁双夹心单元中的分子磁各向异性，同时将抗衡阳离子从 1 的 H 变为 2 的 Na，导致磁行为显著增强，自旋反转能垒为 528 K（367 cm），阻塞温度为 25 K。本研究结果通过合理设计和自组装双四吡咯镧系元素单离子磁体（SIM）构筑块，对开发新型四吡咯镧系 SMM 肯定是有帮助的。
