Brunet Gabriel, Habib Fatemah, Korobkov Ilia, Murugesu Muralee
Department of Chemistry, University of Ottawa, 10 Marie-Curie, Ottawa, Ontario K1N 6N5, Canada.
Inorg Chem. 2015 Jul 6;54(13):6195-202. doi: 10.1021/acs.inorgchem.5b00343. Epub 2015 Jun 19.
The encapsulating N1,N3-bis(3-methoxysalicylidene)diethylenetriamine (H2valdien) ligand was employed to isolate two novel Dy(III) compounds which contain rare bridging pathways for lanthanide systems. Compound 1, [Na2Dy(III)2(valdien)2(μ-OH)(dbm)2(H2O)2][Na2Dy(III)2(valdien)2(μ-OH)(NO3)2(dbm)2], where dbm(-) is dibenzoylmethanido, and compound 2, [Na3Dy(III)2(valdien)2(μ-F)(μ3-F)2(Cl)2(MeOH)2]n·0.5(MeOH)·(H2O), both exhibit linear lone hydroxo- and fluoro-bridges, respectively, between the metal centers. The unit cell of 1 comprises two discrete dinuclear molecules, which differ slightly, forming a cation-anion pair, while 2 forms a coordination polymer. The magnetic investigations indicate that both compounds display ferromagnetic coupling between the Dy(III) ions. Magnetic susceptibility measurements in the temperature range 1.8-300 K reveal that the Dy(III) ions in 1 are weakly coupled, resulting in a mononuclear single-molecule magnet-like behavior under an applied field. In the case of 2, the stronger coupling arising from the fluoride-bridge, leads to zero-field single-molecule magnet (SMM) behavior with a non-negligible anisotropy barrier (Ueff) of 42 K.
采用封装的N1,N3-双(3-甲氧基水杨醛)二亚乙基三胺(H2valdien)配体分离出两种新型Dy(III)化合物，它们包含稀土系统中罕见的桥连途径。化合物1，[Na2Dy(III)2(valdien)2(μ-OH)(dbm)2(H2O)2][Na2Dy(III)2(valdien)2(μ-OH)(NO3)2(dbm)2]，其中dbm(-)为二苯甲酰甲烷基，化合物2，[Na3Dy(III)2(valdien)2(μ-F)(μ3-F)2(Cl)2(MeOH)2]n·0.5(MeOH)·(H2O)，两者分别在金属中心之间呈现线性单羟基和氟桥。1的晶胞由两个略有不同的离散双核分子组成，形成阳离子-阴离子对，而2形成配位聚合物。磁性研究表明，两种化合物在Dy(III)离子之间均表现出铁磁耦合。在1.8 - 300 K温度范围内的磁化率测量表明，1中的Dy(III)离子弱耦合，在施加磁场下导致单核单分子磁体样行为。对于2，由氟桥引起的更强耦合导致零场单分子磁体(SMM)行为，具有42 K的不可忽略的各向异性势垒(Ueff)。
