Lancheros Andrés, Goswami Subhadip, Mian Mohammad Rasel, Zhang Xuan, Zarate Ximena, Schott Eduardo, Farha Omar K, Hupp Joseph T
Departamento de Química Inorgánica, Facultad de Química y Farmacia, Centro de Energía UC, Centro de Investigación en Nanotecnología y Materiales Avanzados CIEN-UC, Pontificia Universidad Católica de Chile, Avenida Vicuña Mackenna 4860, Santiago, Chile.
Dalton Trans. 2021 Feb 28;50(8):2880-2890. doi: 10.1039/d0dt03166f. Epub 2021 Feb 5.
Metal-organic frameworks (MOFs) have attracted significant attention as sorbents due to their high surface area, tunable pore volume and pore size, coordinatively unsaturated metal sites, and ability to install desired functional groups by post-synthetic modification. Herein, we report three new MOFs with pillar-paddlewheel structures that have been synthesized solvothermally from the mixture of the carboxylate-pyrazole flexible linker (HL), 4,4-bipyridine (BPY)/triethylenediamine (DABCO), and Zn(ii)/Cu(ii) ions. The MOFs obtained, namely [Zn(L)BPY], [Cu(L)BPY], and [Cu(L)DABCO], exhibit two-fold interpenetration and dinuclear paddle-wheel nodes. The Zn(ii)/Cu(ii) cations are coordinated by two equatorial L linkers that result in two-dimensional sheets which in turn are pillared by BPY or DABCO in the perpendicular direction to obtain a neutral three-dimensional framework that shows one-dimensional square channels. The three pillar-layered MOFs were characterized as microporous materials showing high crystalline stability after activation at 120 °C and CO adsorption. All MOFs contain uncoordinated Lewis basic pyrazole nitrogen atoms in the framework which have an affinity toward CO and hence could potentially serve as CO adsorption material. The CO uptake capacity was initially enhanced by replacing Zn with Cu and then replacing the pillar, going from BPY to DABCO. Overall, all the MOFs exhibit low isosteric heat (Q) of adsorption which signifies an advantage due to the energy required for the adsorption and regeneration processes.
金属有机框架材料（MOFs）因其高比表面积、可调节的孔体积和孔径、配位不饱和金属位点以及通过后合成修饰引入所需官能团的能力，作为吸附剂受到了广泛关注。在此，我们报道了三种具有柱撑桨轮结构的新型MOFs，它们是通过溶剂热法由羧酸酯 - 吡唑柔性连接体（HL）、4,4 - 联吡啶（BPY）/三乙烯二胺（DABCO）与Zn(ii)/Cu(ii)离子的混合物合成的。所得到的MOFs，即[Zn(L)BPY]、[Cu(L)BPY]和[Cu(L)DABCO]，呈现出二重互穿结构和双核桨轮节点。Zn(ii)/Cu(ii)阳离子由两个赤道面的L连接体配位，形成二维片层，这些片层又在垂直方向上由BPY或DABCO支撑，从而获得一个具有一维方形通道的中性三维框架。这三种柱撑层状MOFs被表征为微孔材料，在120°C活化和CO吸附后显示出高结晶稳定性。所有MOFs在框架中都含有未配位的路易斯碱性吡唑氮原子，它们对CO具有亲和力，因此有可能用作CO吸附材料。通过用Cu取代Zn，然后将支撑体从BPY换成DABCO，CO吸附容量最初得到了提高。总体而言，所有MOFs都表现出较低的吸附等量热（Q），这对于吸附和再生过程所需的能量来说是一个优势。
