Abrupt Spin Transition in a Heteroleptic Fe(II) Complex with Pendant Naphthalene Functionality
Abrupt Spin Transition in a Heteroleptic Fe(II) Complex with Pendant Naphthalene Functionality
复制标题
具有侧萘官能团的杂配 Fe(II) 配合物中的突变自旋跃迁
DOI：
10.1021/acs.inorgchem.2c01490
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发表时间：
2022
影响因子：
4.6
通讯作者：
Shatruk, Michael
中科院分区：
文献类型：
--
作者：
Yergeshbayeva, Sandugash;Hrudka, Jeremy J.;Jo, Minyoung;Gakiya-Teruya, Miguel;Meisel, Mark W.;Shatruk, Michael
通过四齿tpma和二齿xnap-bim与Fe（II）的前驱盐反应，合成了一个异配体自旋交叉配合物[Fe（tpma）（xnap-bim）]（ClO 4）2（1; tpma =三（2-吡啶甲基）胺，xnap-bim = 8，15-二氢二咪唑并[1，2-a：2′，1 ′-c]萘并[2，3-f][1，4]二氮杂环辛四烯）.根据结晶条件的不同，得到了1·2.25py·0.5H2O和1·py两种不同的溶剂化物。前者很容易失去间隙溶剂，在过滤时产生1的粉末样品，或者如果将1·2.25py·0.5H2O晶体置于乙醚中以减缓溶剂损失，则产生1的晶体。相比之下，1·py对溶剂损失表现出更高的稳定性。溶剂合物和无溶剂结构的晶体堆积的特征在于由tpma配体的吡啶基之间的有效π-π相互作用形成的[Fe（tpma）（xnap-bim）]2+阳离子的双柱，以及由xnap-bim配体的叉指萘片段之间的π-π相互作用支持的堆叠。虽然这两种溶剂化物之间的高自旋（HS）和低自旋（LS）的Fe（II）离子的状态，无溶剂络合物1表现出突然的自旋转变中心在127 K，与窄的2 K的热滞后之间的渐进SCO。配合物1在5 K的白色光照射下，表现为LS → HS的光诱导自旋激发态俘获效应。当加热到65 K以上时，亚稳态HS态弛豫到基态LS态.
A heteroleptic spin-crossover (SCO) complex, [Fe(tpma)(xnap-bim)](ClO4)2(1; tpma = tris(2-pyridylmethyl)amine, xnap-bim = 8,15-dihydrodiimidazo[1,2-a:2′,1′-c]naphtho[2,3-f][1,4]diazocine), has been obtained by reacting a Fe(II) precursor salt with tetradentate tpma and bidentate xnap-bim ligands. Depending on crystallization conditions, two different solvates have been obtained,1·2.25py·0.5H2O and1·py. The former readily loses the interstitial solvent to produce either a powder sample of1upon filtration or crystals of1if the solvent loss is slowed by placing the crystals of1·2.25py·0.5H2O in diethyl ether. In contrast,1·py exhibits higher stability toward solvent loss. The crystal packing of both solvates and of the solvent-free structure features double columns of [Fe(tpma)(xnap-bim)]2+cations formed by efficient π–π interactions between the pyridyl groups of tpma ligands, as well as by stacks supported by π–π interactions between interdigitated naphthalene fragments of xnap-bim ligands. While both solvates show a gradual SCO between the high-spin (HS) and low-spin (LS) states of the Fe(II) ion, solvent-free complex1exhibits an abrupt spin transition centered at 127 K, with a narrow 2 K thermal hysteresis. Complex1also shows a light-induced excited spin state trapping effect, manifested as LS → HS conversion upon irradiation with white light at 5 K. The metastable HS state relaxes to the ground LS state when heated above 65 K.