A new bcu-MOF based upon a C_2v-symmetrical [Cu₄Cl(COO)₄N₈] cluster, [Cu₄(Cl⁻)(L)₄·4H₂O]·(DMA⁺)·xDMF·yMeOH (SNNU-Bai66, SNNU-Bai = Shaanxi Normal University Bai's group), has been sucessfully synthesized. By post-synthetic ion exchange experiments for the preparation of phases to be activated successfully, two new anionic derivatives, [Cu₄(Cl⁻)(L)₄·4H₂O]·[Li(H₂O)₄]⁺·xDMK (Li⁺-SNNU-Bai66, DMK = dimethyl ketone) and [Cu₄(Cl⁻)(L)₄·4H₂O]·(DMA⁺)·xDMK (DMA⁺-SNNU-Bai66, DMA⁺ = Me₂NH₂), have been achieved and their selective CO₂ or CH₄ adsorptions over N₂ gas have been systematically investigated in depth by both experimental and simulation studies. With the ionic pore surface and counterions cooperating with Lewis base N or O sites of the organic ligands in both Li⁺-SNNU-Bai66 and DMA⁺-SNNU-Bai66, the two MOFs exhibit highly selective CO₂ and CH₄ adsorption, especially for CH₄ gas. Moreover, with the counterion being tuned from Li(H₂O)₄⁺ to DMA⁺, selective CO₂ adsorption properties are slightly optimized due to the higher polarizability of DMA⁺ and the preferred adsorption site changing from site I [the opposite side of Cl⁻ toward Li(H₂O)₄⁺] in Li⁺-SNNU-Bai66 to site II (the position between the H_c atom of the L₁ ligand and DMA⁺) in DMA⁺-SNNU-Bai66, whereas those of CH₄ of both MOFs are similar due to their having the same preferred adsorption site, namely, site I [the opposite side of Cl⁻ toward DMA⁺ or Li(H₂O)₄⁺], in their frameworks. This work may further enrich the investigation of anionic MOFs in the field of selective gas adsorption with their inherent natures being more definitely displayed.

中文翻译：

---

具有两种不同抗衡离子的两种阴离子bcu-MOF的选择性CO2或CH4吸附：实验和模拟研究

基于C _2v不对称的[Cu ₄ Cl（COO）₄ N ₈ ]簇，[Cu ₄（Cl ^-）（L）₄ ·4H ₂ O]·（DMA ⁺）· x DMF·的新的bcu-MOF Ý的MeOH（SNNU-Bai66，SNNU佰=陕西师范大学白族的基团），已经成功地合成。通过合成后离子交换实验成功制备被激活的相，两种新的阴离子衍生物，[Cu ₄（Cl ^-）（L）₄ ·4H ₂ O]·[Li（H ₂ O）₄ ] ⁺· x DMK（Li ⁺ -SNNU-Bai66，DMK =二甲基酮）和[Cu ₄（Cl ^-）（L）₄ ·4H ₂ O]·（DMA ⁺）· x DMK（DMA ⁺ -SNNU-Bai66，DMA ⁺ = Me ₂ NH ₂），已经通过实验和模拟研究对它们在N ₂气体上的选择性CO ₂或CH ₄吸附进行了深入研究。离子孔表面和抗衡离子与Li ⁺ -SNNU-Bai66和DMA中有机配体的Lewis碱N或O位点配合⁺ -SNNU-Bai66，这两个MOF表现出高度选择性的CO ₂和CH ₄吸附，特别是对于CH ₄气体。此外，将抗衡离子从Li（H ₂ O） ₄ ^+调整为DMA ^+时，由于DMA ^+的极化率较高，并且优选的吸附位点从位置I改变，因此选择性CO ₂吸附性能略有优化。氯^-对李（H ₂ O） ₄ ⁺ ]在锂⁺ -SNNU-Bai66至位点II（为H之间的位置_ç为L的原子₁配体和DMA ⁺）在DMA ⁺ -SNNU-Bai66，而那些CH的₄二者的MOF是与具有相同的优选吸附位，即，位点I [Cl组成的相反侧的类似因^-朝向DMA ⁺或Li（ H ₂ O）₄ ⁺ ]，在他们的框架中。这项工作可能会进一步丰富在选择性气体吸附领域中阴离子MOF的研究，更明确地展示其固有性质。