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研究揭示决定层状配位聚合物卷起的关键因素
作者:小柯机器人 发布时间:2021/10/17 16:08:28

南京大学郑丽敏团队揭示了层还是管是揭示决定层状配位聚合物卷起的关键因素。相关研究成果发表在2021年10月13日出版的《美国化学会杂志》。

自从碳纳米管被发现以来,纳米管材料已经引起了广泛的关注。尽管层到管的卷起机制已被广泛用于解释许多无机纳米管的形成,但它尚未普遍应用于配位聚合物(CPs)。

为了揭示决定层状CPs卷起的关键因素,研究人员选择了Co/R-,S-Xpemp[Xpemp=(4-X-1-苯乙氨基)甲基膦酸,X=H,F,Cl,Br]系统,并研究弱相互作用如何影响层状或管状结构的形成。得到了四对具有管状结构的同手性同构化合物R-, S-Co(Xpemp)(H2O)2 [X = H (1H), F (2F), Cl (3Cl), Br (4Br)]。当X为Cl(5Cl)和Br(6Br)时,3,3′-偶氮联吡啶(ABP)客体分子的包合导致化合物R-, S-[Co(Xpemp)(H2O)2]4·ABP·H2O具有层状结构,而当X为H和F时则形成管状化合物1H和2F。外消旋化合物meso-Co(Xpemp)(H2O)2 [X = F (7F), Cl (8Cl), Br (9Br)] 使用外消旋体XpempH2作为反应前体,但在X=H时不使用。

对R-6Br的详细研究表明,在水热条件下去除ABP时发生层到管的转变,形成具有管状结构的R-4Br。有机溶剂中没有发生类似的层到管转化。结果表明,弱的层间相互作用是层卷起的先决条件,但并不充分。在目前的情况下,水也为层到管的转换提供了驱动力。通过理论计算,验证了实验结果的合理性。

附:英文原文

Title: Layer or Tube Uncovering Key Factors Determining the Rolling-up of Layered Coordination Polymers

Author: Jia-Ge Jia, Chen-Chen Zhao, Song-Song Bao, Lan-Qing Wu, Ge-Hua Wen, Allan J. Jacobson, Jing Ma, Li-Min Zheng

Issue&Volume: October 13, 2021

Abstract: Nanotubular materials have garnered considerable attention since the discovery of carbon nanotubes. Although the layer-to-tube rolling up mechanism has been well recognized in explaining the formation of many inorganic nanotubes, it has not been generally applied to coordination polymers (CPs). To uncover the key factors that determine the rolling-up of layered CPs, we have chosen the Co/R-, S-Xpemp [Xpemp = (4-X-1-phenylethylamino)methylphosphonic acid, X = H, F, Cl, Br] systems and study how the weak interactions influence the formation of layered or tubular structures. Four pairs of homochiral isostructural compounds R-, S-Co(Xpemp)(H2O)2 [X = H (1H), F (2F), Cl (3Cl), Br (4Br)] were obtained with tubular structures. The inclusion of 3,3′-azobipyridine (ABP) guest molecules led to compounds R-, S-[Co(Xpemp)(H2O)2]4·ABP·H2O with layered structures when X was Cl (5Cl) and Br (6Br), but tubular compounds 1H and 2F when X was H and F. Layered structures were also obtained for racemic compounds meso-Co(Xpemp)(H2O)2 [X = F (7F), Cl (8Cl), Br (9Br)] using racemic XpempH2 as the reaction precursor, but not when X = H. A detailed study on R-6Br revealed that layer-to-tube transformation occurred upon removal of ABP under hydrothermal conditions, forming R-4Br with a tubular structure. Similar layer-to-tube conversion did not occur in organic solvents. The results demonstrate that weak interlayer interactions are a prerequisite but not sufficient for the rolling-up of the layers. In the present cases, water also provides a driving force in the layer-to-tube transformation. The experimental results were rationalized by theoretical calculations.

DOI: 10.1021/jacs.1c07517

Source: https://pubs.acs.org/doi/10.1021/jacs.1c07517

 

期刊信息

JACS:《美国化学会志》,创刊于1879年。隶属于美国化学会,最新IF:14.612
官方网址:https://pubs.acs.org/journal/jacsat
投稿链接:https://acsparagonplus.acs.org/psweb/loginForm?code=1000