Do perfluoroarene⋯arene and C–H⋯F interactions make a difference to the structures of 4,2′:6′,4′′-terpyridine-based coordination polymers?
作者:Edwin C. Constable、Catherine E. Housecroft、Srboljub Vujovic、Jennifer A. Zampese、Aurélien Crochet、Stuart R. Batten
DOI:10.1039/c3ce41384e
日期:——
The consequences for the structures of coordination polymers of introducing fluoro substituents into the terminal phenyl domain of 4â²-(biphenyl-4-yl)-4,2â²:6â²,4â²â²-terpyridine (1) have been investigated. Reaction between Cu(OAc)2·H2O and 4â²-(2â²,3â²,4â²,5â²,6â²-pentafluorobiphenyl-4-yl)-4,2â²:6â²,4â²â²-terpyridine (2) yields the one-dimensional coordination polymer [Cu2(μ-OAc)4(2)]n which contains paddle-wheel Cu2(OAc)4} nodes bridged by ligands 2. The compound is isostructural with [Cu2(μ-OAc)4(1)]n. When Cu(OAc)2·H2O reacts with a 1â:â1 mixture of 1 and 2, [Cu2(μ-OAc)4(1)]n and [Cu2(μ-OAc)4(2)]n co-crystallize with 1 and 2 disordered over one ligand site; the one-dimensional coordination polymer is isostructural with each of [Cu2(μ-OAc)4(1)]n and [Cu2(μ-OAc)4(2)]n indicating that replacing H by F substituents in the peripheral arene ring has no effect on the overall solid-state structure: tpyâ¯tpy Ï-stacking is preserved, areneâ¯arene ÏHâ¯ÏH interactions are replaced by perfluoroareneâ¯arene ÏFâ¯ÏH interactions, and Hâ¯H contacts are replaced by Hâ¯F interactions. In stark contrast to the latter observations, the reaction of Zn(OAc)2·2H2O with perfluoro derivative 2 yields [Zn5(OAc)10(2)4·11H2O]n as the dominant one-dimensional polymer; minor amounts of the anticipated polymer [Zn2(μ-OAc)4(2)]n are also formed. The solid-state structure of [Zn5(OAc)10(2)4·11H2O]n consists of quadruple-stranded polymer chains assembled from Zn5(2)4} subchains interconnected by Zn5(OAc)10} units. Within each chain, ÏFâ¯ÏF and ÏHâ¯ÏH stacking interactions are dominant, while the observed assembly of chains into sheets and Ï-stacking between arene units in adjacent sheets mimic the dominant interactions in the single-stranded chains observed in [Zn2(μ-OAc)4(1)]n, [Zn2(μ-OAc)4(2)]n, [Cu2(μ-OAc)4(1)]n, [Cu2(μ-OAc)4(2)]n and [Cu2(μ-OAc)4(1)]n·[Cu2(μ-OAc)4(2)]n.
4-(联苯-4-基)-4,2-:6-2,4-2-三联吡啶末端苯基结构域引入氟取代基对配位聚合物结构的影响 (1)已被调查。 Cu(OAc)2·H2O与4â2-(2â2,3â2,4â2,5â2,6â2-五氟联苯-4-基)-4,2â2:6â的反应²,4−−−三联吡啶 (2) 产生一维配位聚合物 [Cu2(μ-OAc)4(2)]n ,其中包含由配体 2 桥接的桨轮 Cu2(OAc)4} 节点。该化合物与 [Cu2(μ-OAc)4(1)]n 具有同构结构。当 Cu(OAc)2·H2O 与 1 和 2 的 1-:-1 混合物反应时,[Cu2(μ-OAc)4(1)]n 和 [Cu2(μ-OAc)4(2) ]n 与 1 和 2 在一个配体位点上无序共结晶;一维配位聚合物与 [Cu2(μ-OAc)4(1)]n 和 [Cu2(μ-OAc)4(2)]n 均具有同构结构,表明外围芳环中的 H 被 F 取代基取代对整体固态结构没有影响:tpy–tpy δ-堆积被保留,芳烃–芳烃ÏH–ÏH相互作用被全氟芳烃–芳烃ÏF–ÏH取代相互作用,并且 H–H 接触被 H–F 相互作用取代。与后面的观察形成鲜明对比的是,Zn(OAc)2·2H2O 与全氟衍生物 2 的反应产生了 [Zn5(OAc)10(2)4·11H2O]n 作为主要的一维聚合物;还形成了少量预期的聚合物 [Zn2(μ-OAc)4(2)]n。 [Zn5(OAc)10(2)4·11H2O]n的固态结构由由Zn5(OAc)10}单元互连的Zn5(2)4}子链组装而成的四链聚合物链组成。在每个链中,δF-δF 和δH-δH 堆积相互作用占主导地位,而观察到的链组装成片材和相邻片材中芳烃单元之间的δ-堆积模仿了主要相互作用在 [Zn2(μ-OAc)4(1)]n、[Zn2(μ-OAc)4(2)]n、[Cu2(μ-OAc)4(1)]n、[ 中观察到的单链Cu2(μ-OAc)4(2)]n 和 [Cu2(μ-OAc)4(1)]n·[Cu2(μ-OAc)4(2)]n。