Experimental and theoretical insights into the photomagnetic effects in trinuclear and ionic Cu(II)-Mo(IV) systems
Experimental and theoretical insights into the photomagnetic effects in trinuclear and ionic Cu(II)-Mo(IV) systems
复制标题
DOI：
10.1039/d1qi01469b
复制
发表时间：
2022-01-12
影响因子：
7
通讯作者：
Ohkoshi, Shin-Ichi
中科院分区：
文献类型：
--
作者：
Pai, TingYun;Stefanczyk, Olaf;Ohkoshi, Shin-Ichi
八氰钼酸盐（IV）离子和铜（II）配合物与两种类型的螯合配体的结晶工程：多齿阻断配体，tren =（三（2氨基乙基）胺）和双齿配体，tn = 1,3-二氨基丙烷，形成{(Cu(tren)](2)(mu-tn)}中心点[Mo(CN)(8)]中心点7.5H(2)O(1)和{[Cu(tren)](2)(mu-tn)}中心点[Mo(CN)(8)]。{[Cu(CN)(2)[Mo(CN)(8)]}中心点9H(2)O(2)。1的晶体结构由孤立的阴离子[Mo(CN)(8)]（4-）包裹由广泛的氢键网络稳定的电荷补偿单元{[Cu(tren)](2)(mu-tn)}（4+）组成。化合物2由与1相同的离子和中性氰基桥接的v型三核分子{[Cu(tren)(2)[Mo(CN)(8)]}组成交替层。此外，还合成了两个先前报道的v形三核参比体系：[Cu(tn)(2)](2)[MO (CN)(8)]中心点2H(2)O(3)和[Cu(tren)](2)[MO (CN)(8)]中心点5.25H(2)O(4)。紫外-可见-近红外吸收光谱，在量子化学计算（DFT和TD-DFT）的支持下，证实了Mo(v)到Cu(s)电荷转移带的存在，集中在三核分子（2-4）上，而对于没有CN-桥的离子样品1，它们不存在。此外，还详细描述了具有前沿分子轨道的1-4能级图和可能的光学跃迁。磁学研究表明，在低温下具有弱反铁磁相互作用的顺磁性行为。最后，对1-3的光磁学研究表明，在473和410 nm光的10k照射下，磁化强度增加。所有数据的对比分析表明，1中的光磁效应很好地描述为Mo（iv）中心的光诱导激发自旋态捕获（wesst）效应，而其他氰基桥接化合物更倾向于金属到金属的电荷转移，而wesst效应的贡献较小。
The crystal engineering of octacyanidomolybdate(IV) ions and copper(II) complexes with two types of chelating ligands: multidentate blocking ligand, tren = (tris(2 aminoethyl)amine), and bidentate ligand capable of forming unusual organic bridges, tn = 1,3-diaminopropane, resulted in the formation of {(Cu(tren)](2)(mu-tn)}center dot[Mo(CN)(8)]center dot 7.5H(2)O (1) and {[Cu(tren)](2)(mu-tn)}center dot[Mo(CN)(8)].{[Cu(tren)(2)[Mo(CN)(8)]}center dot 9H(2)O (2). The crystal structure of 1 comprises isolated anions [Mo(CN)(8)](4-) wrapped with charge-compensating units {[Cu(tren)](2)(mu-tn)}(4+) stabilised by extensive H-bond networks. Compound 2 forms alternating layers consisting of the same ions as 1 and neutral cyanido-bridged V-shaped trinuclear molecules {[Cu(tren)(2)[Mo(CN)(8)]}. Additionally, two previously reported V-shaped trinuclear reference systems were synthesised: [Cu(tn)(2)](2)[MO (CN)(8)]center dot 2H(2)O (3) and [Cu(tren)](2)[Mo(CN)(8)]center dot 5.25H(2)O (4). UV-Vis-NIR absorption spectroscopy, supported by quantum chemical calculations (DFT and TD-DFT), confirmed the presence of Mo(v) to Cu(s) charge transfer bands centred on trinuclear molecules (2-4) and their absence for the ionic sample 1 without CN--bridges. Additionally, detailed descriptions of the energy level diagrams of 1-4 with the frontier molecular orbitals and possible optical transitions were made. Magnetic studies indicated paramagnetic behaviour with weak antiferromagnetic interactions at low temperature. Finally, photomagnetic studies of 1-3 showed the increase of magnetization after irradiation with 473 and 410 nm light at 10 K. Comparative analysis of all data suggests that the photomagnetic effect in 1 is well described by the light-induced excited spin-state trapping (UESST) effect in the Mo(iv) centre, while other cyanido-bridged compounds prefer the metal-to-metal charge transfer with minor contribution of UESST effects.