Synthesis of switchable MOFs for gas and liquid phase separations: Tailored model materials for understanding selectivity

在已有了解的基础上，该项目将合成可切换柱层MOF作为模型系统，以展示气液混合吸附(QF1)中的高选择性分离过程。作为节点的双核浆轮(PW)配合物(M2(O2C-R)4，M=Mn，Co，Ni，Cu，Zn)和[1，1‘-联苯]-4，4’-二羧酸酯(BPDC)不仅会导致可切换的M2(BPDC)2(DABCO)材料(DUT-128)的孔径扩大，而且能够在连接物中整合更复杂的官能团，用于钥匙锁类型识别和选择性开孔。对预测的(T1，T2)跃迁的原位分析(QP2)将加强预测理论框架(PTF)。以2，6-萘二甲酸盐基材料(DUT-8(M)，M=Co，Ni，Cu，Zn)为模型体系，对二元混合气体吸附(QP4，QF1)的可切换性及其对选择性的影响有一个基本的认识。将DUT-8(M)系列提供给S1，用于合成可切换催化剂(QF2)。它们作为刚性和柔性体系(取决于颗粒大小)的可用性是核磁共振(P1)和EPR(P2)在混合气体中原位研究的重要基础，以分析恢复力对吸附结构的影响。外颗粒表面(壳)的作用将通过产生芯/壳模型材料(DUT-8)来分析，例如具有刚性壳和可切换芯。通过积分合适的顺磁探针中心，用EPR谱(P2)分析了芯壳中的开关和PW变形。基于扩展的DUT-128模型体系，将使用选择性溶液切换来分离更大的功能客体分子。通过模拟连接子和选定底物之间类似DNA的碱基配对相互作用，我们设想展示钥匙-锁切换机制，即在复杂的分子混合物中只有一个物种的孔洞打开。

Based on the developed understanding, the project will synthesize switchable pillared layer MOFs as model systems to demonstrate highly selective separation processes in gas- and liquid phase mixture adsorption (QF1). Di-nuclear paddle-wheel (PW) complexes (M2(O2C-R)4, M = Mn, Co, Ni, Cu, Zn) acting as nodes and [1,1'-biphenyl]-4,4'-dicarboxylates (bpdc) will not only lead to expanded pore size in switchable M2(bpdc)2(dabco) materials (DUT-128) but enable the integration of more complex functional groups in the linker for key-lock type recognition and selective pore opening. The in situ analysis (QP2) of predicted (T1, T2) switching transitions will strengthen the predictive theoretical framework (PTF). 2,6-Naphthalene dicarboxylate based materials (DUT-8(M), M = Co, Ni, Cu, Zn) will be used as model systems to achieve a fundamental understanding of the role of switchability and its impact on selectivity for binary gas mixture adsorption (QP4, QF1). The DUT-8(M) family is provided to S1 for synthesizing a switchable catalyst (QF2). Their availability as rigid and flexible systems (depending on particle size) is an important basis for NMR (P1) and EPR (P2) in situ studies in the presence of gas mixtures to analyze the implication of restoring forces on the adsorbate structure. The role of the outer particle surface (shell) will be analyzed by generating core/shell model materials (DUT-8) e.g. with a rigid shell and switchable core. The switching and PW deformation in the core vs. shell is analyzed by EPR spectroscopy (P2) by integrating appropriate paramagnetic probe centers. Based on the expanded DUT-128 model systems, selective switching in solution will be used to separate larger functional guest molecules. By mimicking DNA-like base pairing interactions between linker and selected substrates we envision to demonstrate key-lock switching mechanisms, i.e. pore opening for only a single species in a complex molecule mix.