Dodecanuclear-ellipse and decanuclear-wheel nickel(II) thiolato clusters with efficient femtosecond nonlinear absorption.-猫眼课题宝

DOI：

10.1002/anie.200907074

发表时间：

2010-06

期刊：

Angewandte Chemie

影响因子：

通讯作者：

中科院分区：

文献类型：

作者：

Chi Zhang;Tsuyoshi Matsumoto;Marek Samoc;Marek Samoc;Simon Petrie;S. Meng;T. Corkery;R. Stranger;Jinfang Zhang;M. Humphrey;K. Tatsumi

硫酸盐配体长期以来一直受到人们的关注，原因有很多：1)它们不同的结合方式产生了一系列在配位化学中至关重要的成键基序；2)金属-硫酸盐相互作用是许多金属蛋白的关键元素，在更广泛的生物无机化学领域发挥着关键作用；3)硫酸盐介导的磁偶联是新型分子磁体的重要组成部分。在一系列金属硫酸盐衍生结构中，环状(或冠状)结构的合成、结构和磁性引起了人们的极大兴趣。然而，到目前为止，已知的类冠状[M(m-SR)]n(M=Ni，Pd)簇合物大多是由单一的硫酸盐配体构成的，并且具有几何相似的环系，这在一定程度上限制了冠状化合物家族例子的丰富性和结构的多样性。开发具有优化的非线性光学(NLO)性能的高性能分子材料也是当前研究的热点。7]以前的研究表明，大的p电子离域和对称的平面结构的存在在决定非线性生色团的性质方面起着至关重要的作用。奇怪的是，尽管在镍环物种中提出了准芳香键的性质，但它们的光学性质很少被研究；特别是，目前还没有关于NLO性质的研究。我们用一种新的方法合成了迄今为止最大的冠状硫代镍(II)-硫酸盐簇合物，其结构研究揭示了[Ni(m-StBu)(m-Eet)]12(Eet=2-乙基硫代乙硫酸酯)和两个新的十核轮状镍(II)-硫醇簇合物[Ni(m-StBu)(m-Pite)]10(Pite=2-(2-巯基乙基)吡啶)和[Ni(MStBu)(m-Aet)]10(ATet=2-氨基乙硫醇)，第一次对这类重要分子的例子进行了NLO研究，以及揭示了光学行为的依赖于时间的密度泛函研究。NiCl2·6H2O与1当量K(Ett)反应生成可分离的[(CH3C6H5){Ni(m-StBu)(Etet)}10](1a)和[Ni(m-StBu)(m-ett)]12·(CH3C6H5)2(1b)，而与K(Pite)或K(Atet)的反应类似，而不是与K(Ett)。分别得到[(CH3C6H5){Ni(m-StBu)(m-Pite)}10]·(CH3C6H5)4(2)和[(0.5CH3C6H5){Ni(m-StBu)(m-atet)}10]·(CH3C6H5)2(3)。通过低温面阵CCDX-射线衍射研究，明确确定了化合物1a、1b、2和3的原子排列和化学计量。1b的单晶X射线分析揭示了一个迄今未知的十二方椭圆Ni12S24框架，如图1所示。循环Ni12S24结构的俯视图(图1a)显示，12个定域平面[NiS4]亚基沿相对的非键边S-S边缘融合产生了近似符合伪D2对称性的三层椭圆几何结构。1b的跨环距为11.343(6)~13.528(7)，而相邻[NiS_2]面间的二面角为140.32~157.848，这是由于这一独特的12元Ni环具有不对称的椭圆几何构型。环面图(图1b)[*]江苏大学化学与化工学院科学研究院分子材料研究中心张春章教授、孟春春博士、张军锋博士212013(P.R.中国)传真：(+86)511-8879-7815电子邮件：chizang@ujs.edu.cn

Thiolate ligands have been of longstanding interest for a variety of reasons: 1) their diverse binding modes give rise to an array of bonding motifs that are of fundamental importance in coordination chemistry, 2) metal–thiolate interactions are key elements of numerous metalloproteins and play a crucial role in the broader field of bioinorganic chemistry, and 3) thiolate-mediated magnetic coupling is an essential component in novel molecular magnets. Amongst the range of metal thiolate-derived structures, the synthesis, structure, and magnetic properties of toroidal (or tiara-like) architectures have raised considerable interest. However, most of the known tiara-like [M(m-SR)]n (M = Ni, Pd) clusters to date have been constructed by single thiolate ligands and possess geometrically similar ring systems, which has restricted, to some extent, the abundance of examples and structural diversity of the tiara family. The development of high-performance molecular materials with optimized nonlinear optical (NLO) properties has also been the focus of much current research. 7] Previous studies have demonstrated that the presence of large pelectron delocalization and a symmetrical planar structure play crucial roles in determining the properties of nonlinear chromophores. 8] Curiously, though, despite the quasiaromatic nature of the bonding that has been proposed in nickel toroidal species, their optical properties are little explored; in particular, no study of the NLO properties is extant. We present here the synthesis of the largest tiara-like nickel(II)–thiolate cluster thus far by a novel route that employs two different thiolate bridges, structural studies that reveal an unprecedented elliptical structure for [Ni(m-StBu)(m-etet)]12 (etet = 2-ethylthioethanethiolate) and two new decanuclear-wheel nickel(II)–thiolato clusters [Ni(m-StBu)(m-pyet)]10 (pyet = 2-(2-mercaptoethyl)pyridine) and [Ni(mStBu)(m-atet)]10 (atet = 2-aminoethanethiol), and the first NLO studies of examples from this important class of molecules, together with time-dependent DFT studies that shed light on the optical behavior. The reaction of NiCl2·6 H2O with 1 equivalent K(etet) gave, after work-up, separable [(CH3C6H5) {Ni(m-StBu)(metet)}10] (1a) and [Ni(m-StBu)(m-etet)]12·(CH3C6H5)2 (1 b), whereas similar reactions with K(pyet) or K(atet), instead of K(etet), afforded [(CH3C6H5) {Ni(m-StBu)(m-pyet)}10]·(CH3C6H5)4 (2) and [(0.5CH3C6H5) {Ni(m-StBu)(m-atet)}10]·(CH3C6H5)2 (3), respectively. The atomic arrangements and stoichiometries of 1 a, 1b, 2, and 3 were unequivocally established from low-temperature CCD area-detector X-ray diffraction studies. The single-crystal X-ray analysis of 1b reveals a heretofore unknown dodecagonal-ellipse Ni12S24 framework, as displayed in Figure 1. The top view (Figure 1 a) of the cyclic Ni12S24 architecture shows that edge-fusion of the 12 localized planar [NiS4] subunits along opposite nonbonding S–S edges gives rise to a triple-layer elliptical geometry that approximately conforms to pseudo-D2 symmetry. The transannular Ni···Ni distances of 1 b are in the range of 11.343(6)–13.528(7) , while the dihedral angles between adjoining [NiS2] planes vary from 140.32 to 157.848 because of the unsymmetrical elliptical geometry of this unique 12membered Ni ring. The side view (Figure 1b) of the toroid 1b [*] Prof. Dr. C. Zhang, Dr. S. C. Meng, Dr. J. F. Zhang Molecular Materials Research Center, Scientific Research Academy, School of Chemistry and Chemical Engineering, Jiangsu University Zhenjiang 212013 (P.R. China) Fax: (+ 86)511-8879-7815 E-mail: chizhang@ujs.edu.cn

Dodecanuclear-ellipse and decanuclear-wheel nickel(II) thiolato clusters with efficient femtosecond nonlinear absorption.

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