Kumar Kunal, Stefańczyk Olaf, Chorazy Szymon, Nakabayashi Koji, Sieklucka Barbara, Ohkoshi Shin-Ichi
Department of Chemistry, School of Science , The University of Tokyo , 7-3-1 Hongo , Bunkyo-ku , Tokyo 113-0033 , Japan.
Faculty of Chemistry , Jagiellonian University , Gronostajowa 2 , 30-387 Kraków , Poland.
Inorg Chem. 2019 May 6;58(9):5677-5687. doi: 10.1021/acs.inorgchem.8b03634. Epub 2019 Apr 18.
Self-assembly of lanthanide(III) complexes of 2,2':6',2″-terpyridine (terpy) with dicyanidoargentate(I) and dicyanidoaurate(I) anions in water results in the formation of six isostructural dinuclear systems [Ln(terpy)(HO)(NO)][M(CN)] (Ln/M = Dy/Ag, 1; Dy/Au, 2; Yb/Ag, 3; Yb/Au, 4; Er/Ag, 5; Er/Au, 6). They form three-dimensional supramolecular networks based on dinuclear molecules linked by hydrogen bonds, π-π interactions, and argentophilic (Ag···Ag) or aurophilic (Au···Au) interactions. All of the assemblies show complex solid-state strong UV and weak vis-NIR absorption due to overlapping contributions from 2,2':6',2″-terpyridine, dicyanidoargentate(I), dicyanidoaurate(I), and lanthanide(III) ions. Moreover, they exhibit excitation-wavelength-dependent multicolor photoluminescence ranging from bright white to blue via yellow, green, and cyan colors due to variable contributions from the dicyanidometalate and ligand. Assemblies 3-6 show NIR emission originating from Yb and Er metal centers. Furthermore, compounds 1-6 and their magnetically diluted samples are magnetic-field-induced single-molecule magnets with energy barriers of up to 35 K. The effect of noble metal substitution on the magnetic properties of particular lanthanide ions is described. The influence on the thermal anisotropic energy barrier, which relates to the strength of the magnetic anisotropy, depends on the type of lanthanide used. The Ag-to-Au substitution enhances the anisotropy of the prolate Yb ion and decreases it for the oblate Dy ion. It also modifies the strength of dipolar interactions affecting the slow magnetic relaxation processes.
2,2':6',2″-三联吡啶（terpy）与氰基银（I）和氰基金（I）阴离子形成的镧系元素（III）配合物在水中自组装，形成了六个同构的双核体系[Ln(terpy)(HO)(NO)][M(CN)]（Ln/M = 镝/银，1；镝/金，2；镱/银，3；镱/金，4；铒/银，5；铒/金，6）。它们基于通过氢键、π-π相互作用以及亲银（Ag···Ag）或亲金（Au···Au）相互作用连接的双核分子形成三维超分子网络。由于2,2':6',2″-三联吡啶、氰基银（I）、氰基金（I）和镧系元素（III）离子的重叠贡献，所有组装体在固态下均表现出复杂的强紫外和弱可见-近红外吸收。此外，由于氰基金属酸盐和配体的贡献不同，它们表现出激发波长依赖性的多色光致发光，范围从亮白色到蓝色，经过黄色、绿色和青色。组装体3-6显示出源自镱和铒金属中心的近红外发射。此外，化合物1-6及其磁稀释样品是磁场诱导的单分子磁体，能垒高达35 K。描述了贵金属取代对特定镧系离子磁性的影响。对与磁各向异性强度相关的热各向异性能垒的影响取决于所用镧系元素的类型。从银到金的取代增强了长轴镱离子的各向异性，而对于扁轴镝离子则降低了各向异性。它还改变了影响慢磁弛豫过程的偶极相互作用的强度。
