Anion/Naphthalenediimide Interactions in a Pd(II)-Based Tetrameric Metallocycle
Anion/Naphthalenediimide Interactions in a Pd(II)-Based Tetrameric Metallocycle
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DOI：
10.1021/acs.cgd.9b00874
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发表时间：
2019-09
影响因子：
3.8
通讯作者：
M. A. Gordillo;P. A. Benavides;S. Saha
中科院分区：
文献类型：
--
作者：
M. A. Gordillo;P. A. Benavides;S. Saha
合成了由四个 dppp 封端的 Pd(II) 角（dppp = 1,3-双（二苯基鏻）丙烷）和四个线性 π-酸性 N,N'-二（4-吡啶基）-1,4,5,8-萘二亚胺（DPNDI）配体组成的四聚金属环 [Pd(dppp)(DPNDI)]4·8TfO，及其单晶结构首次被阐明。金属环的晶体结构揭示了缺电子DPNDI配体和TfO-抗衡离子之间的阴离子−π、孤对−π和CH·阴离子相互作用，并为其阴离子识别和复分解能力提供了有价值的见解。 1H、19F和31P NMR研究表明，在硝基甲烷和二氯甲烷等非配位溶剂中，[Pd(dppp)(DPNDI)]48+金属环以单晶到单晶的方式进行阴离子交换，没有任何结构变化。然而，金属环在极性溶剂 DMSO 中经历缓慢解离，可以通过热处理轻松逆转。
A tetrameric metallocycle [Pd(dppp)(DPNDI)]4·8TfO consisting of four dppp-capped Pd(II) corners (dppp = 1,3-bis(diphenylphosphonium)propane) and four linear π-acidic N,N′-di(4-pyridyl)-1,4,5,8-naphthalene diimine (DPNDI) ligands has been synthesized, and its single-crystal structure has been elucidated for the first time. The crystal structure of the metallocycle revealed anion−π, lone-pair−π, and CH···anion interactions between electron-deficient DPNDI ligands and TfO– counterions and provided valuable insights into its anion recognition and metathesis capabilities. The 1H, 19F, and 31P NMR studies demonstrated that in noncoordinating solvents, such as nitromethane and dichloromethane, the [Pd(dppp)(DPNDI)]48+ metallocycle underwent anion exchange in a single-crystal to single-crystal fashion without any structural changes. However, the metallocycle experienced slow dissociation in a polar solvent DMSO, which could be reversed easily by thermal treatment.