Kumar Naveen, Wang Shi-Qiang, Mukherjee Soumya, Bezrukov Andrey A, Patyk-Kaźmierczak Ewa, O'Nolan Daniel, Kumar Amrit, Yu Mei-Hui, Chang Ze, Bu Xian-He, Zaworotko Michael J
Department of Chemical Sciences , Bernal Institute , University of Limerick , Limerick V94 T9PX , Republic of Ireland . Email:
Faculty of Chemistry , Adam Mickiewicz University , Uniwersytetu Poznanskiego 8 , 61-614 , Poznan , Poland.
Chem Sci. 2020 Jun 16;11(26):6889-6895. doi: 10.1039/d0sc02123g. eCollection 2020 Jul 14.
Separation of the C8 aromatic isomers, -xylene (PX), -xylene (MX), -xylene (OX) and ethylbenzene (EB), is relevant thanks to their widespread application as chemical feedstocks but challenging because of their similar boiling points and close molecular dimensions. Physisorptive separation could offer an energy-efficient solution to this challenge but sorbents which exhibit strong selectivity for one of the isomers remain a largely unmet challenge despite recent reports of OX or PX selective sorbents with high uptake capacity. For example, the square lattice, , topology coordination network exhibits the rare combination of high OX selectivity and high uptake capacity. Herein we report that a crystal engineering approach enabled isolation of the mixed-linker coordination network (, bipy = 4,4'-bipyridine, bptz = 4,4'-bis(4-pyridyl)tetrazine) and study of its C8 vapour and liquid sorption properties. was found to exhibit high adsorption capacity from liquid xylenes (∼37 wt%) and is to our knowledge the first sorbent to exhibit high selectivity for each of xylene isomer over EB ( , , > 5). Insights into the performance of are gained from structural studies which reveal stacking interactions between electron-deficient bptz linkers and the respective xylenes. is the first N-donor mixed-linker coordination network studied for its gas/vapour sorption properties and represents a large and diverse class of understudied coordination networks.
C8芳烃异构体，即对二甲苯（PX）、间二甲苯（MX）、邻二甲苯（OX）和乙苯（EB）的分离具有重要意义，因为它们作为化学原料有着广泛的应用，但由于它们沸点相近且分子尺寸相近，所以分离具有挑战性。物理吸附分离可以为这一挑战提供一种节能解决方案，但尽管最近有关于具有高吸附容量的OX或PX选择性吸附剂的报道，但对其中一种异构体表现出强选择性的吸附剂在很大程度上仍未得到满足。例如，方形晶格拓扑结构的配位网络展现出高OX选择性和高吸附容量这一罕见的组合。在此，我们报道一种晶体工程方法能够分离出混合连接体配位网络（，联吡啶 = 4,4'-联吡啶，双吡啶四嗪 = 4,4'-双(4-吡啶基)四嗪）并研究其对C8蒸汽和液体的吸附性能。发现其对液态二甲苯具有高吸附容量（约37 wt%），据我们所知，它是第一种对每种二甲苯异构体相对于EB都表现出高选择性的吸附剂（，，> 5）。通过结构研究深入了解了的性能，该研究揭示了缺电子的双吡啶四嗪连接体与各自的二甲苯之间的堆积相互作用。是首个因其气体/蒸汽吸附性能而被研究的含氮混合连接体配位网络，代表了一大类研究较少的配位网络。
