Alsmail Nada H, Suyetin Mikhail, Yan Yong, Cabot Rafel, Krap Cristina P, Lü Jian, Easun Timothy L, Bichoutskaia Elena, Lewis William, Blake Alexander J, Schröder Martin
School of Chemistry, University of Nottingham, Nottingham NG7 2RD (UK).
Chemistry. 2014 Jun 10;20(24):7317-24. doi: 10.1002/chem.201304005. Epub 2014 May 7.
The porous framework [Cu2(H2O)2L]⋅4 H2O⋅2 DMA (H4L = oxalylbis(azanediyl)diisophthalic acid; DMA = N,N-dimethylacetamide), denoted NOTT-125, is formed by connection of {Cu2(RCOO)4} paddlewheels with the isophthalate linkers in L(4-). A single crystal structure determination reveals that NOTT-125 crystallises in monoclinic unit cell with a = 27.9161(6), b = 18.6627(4) and c = 32.3643(8) Å, β = 112.655(3)°, space group P2(1)/c. The structure of this material shows fof topology, which can be viewed as the packing of two types of cages (cage A and cage B) in three-dimensional space. Cage A is constructed from twelve {Cu2(OOCR)4} paddlewheels and six linkers to form an ellipsoid-shaped cavity approximately 24.0 Å along its long axis and 9.6 Å across its central diameter. Cage B consists of six {Cu2(OOCR)4} units and twelve linkers and has a spherical diameter of 12.7 Å taking into account the van der Waals radii of the atoms. NOTT-125 incorporates oxamide functionality within the pore walls, and this, combined with high porosity in desolvated NOTT-125a, is responsible for excellent CO2 uptake (40.1 wt % at 273 K and 1 bar) and selectivity for CO2 over CH4 or N2. Grand canonical Monte Carlo (GCMC) simulations show excellent agreement with the experimental gas isotherm data, and a computational study of the specific interactions and binding energies of both CO2 and CH4 with the linkers in NOTT-125 reveals a set of strong interactions between CO2 and the oxamide motif that are not possible with a single amide.
多孔骨架[Cu2(H2O)2L]⋅4 H2O⋅2 DMA（H4L = 草酰双（氮杂二亚基）二间苯二甲酸；DMA = N,N-二甲基乙酰胺），记为NOTT-125，由{Cu2(RCOO)4}桨轮与L(4-)中的间苯二甲酸酯连接体相连形成。单晶结构测定表明，NOTT-125以单斜晶胞形式结晶，a = 27.9161(6)、b = 18.6627(4)和c = 32.3643(8) Å，β = 112.655(3)°，空间群为P2(1)/c。这种材料的结构呈现fof拓扑结构，可看作是两种类型的笼（笼A和笼B）在三维空间中的堆积。笼A由十二个{Cu2(OOCR)4}桨轮和六个连接体构成，形成一个沿其长轴约24.0 Å、横跨其中心直径9.6 Å的椭球形空腔。笼B由六个{Cu2(OOCR)4}单元和十二个连接体组成，考虑到原子的范德华半径，其球形直径为12.7 Å。NOTT-125在孔壁内包含草酰胺官能团，这与脱溶剂后的NOTT-125a中的高孔隙率相结合，使得其对CO2具有出色的吸附能力（在273 K和1 bar下为40.1 wt%）以及对CO2相对于CH4或N2的选择性。巨正则蒙特卡罗（GCMC）模拟与实验气体等温线数据显示出极好的一致性，并对CO2和CH4与NOTT-125中的连接体的特定相互作用和结合能进行的计算研究揭示了CO2与草酰胺基序之间存在一组单个酰胺不可能具有的强相互作用。
