Crystal Engineering of a Permanently Porous Network Sustained Exclusively by Charge-Assisted Hydrogen Bonds

A permanently porous crystalline solid is reported that is sustained exclusively by charge-assisted H-bonds. The single-crystal X-ray structure of a layered H-bonded solid, compound 1, {[Ni(tame)2]1(PES)2}∞ (tame = 1,1,1-tris(aminomethyl)ethane, PES = 2-phenylethynesulfonate), is reported which shows a hexagonal H-bonding motif between divalent metal complexes and sulfonate anions. This targeted motif, which orients pendant groups such that porosity could be generated, is obtained after two stages of design modification. Compound 1 is not porous as pendant groups interdigitate. Employing a disulfonate anion, the pillared layered solid {[Ni(tame)2]1(BSEB)1}∞ (BSEB = 4,4‘-bis(sulfoethynyl)biphenyl), 2e, is obtained. This is a highly robust solid for which a likely structure was extracted from powder X-ray diffraction data by analogy to 1. Unit cell indexing and Pawley refinement give parameters which correlate exceptionally well for the desired structure. Reversible CO2 and N2 sorption isotherms show that compound 2e retains permanent porosity.

报道了一种永久多孔的晶体固体，其结构完全由电荷辅助的氢键维系。报道了层状氢键固体化合物1的单一晶体X射线结构，[Ni(tame)2]1(PES)2∞（tame = 1,1,1-三氨基甲基乙烷，PES = 2-苯基乙炔磺酸），其展现出在二价金属配合物与磺酸根离子之间的六边形氢键模式。通过两阶段的设计改良，获得此定向的目标模式，使得悬挂基团得以生成孔隙。化合物1本身不具备多孔性，因为悬挂基团相互交织。采用二磺酸根离子，得到柱状层状固体{[Ni(tame)2]1(BSEB)1}∞（BSEB = 4,4'-双(磺乙炔基)联苯），即化合物2e。这是一种高度稳定的固体，其结构通过粉末X射线衍射数据与化合物1类比而推测。单胞指数和Pawley精修提供了与所需结构极为吻合的参数。可逆的CO2和N2吸附等温线表明化合物2e保留了永久的多孔性。