Metal-organic frameworks represent a new class of hybrid inorganic-organic materials which are characterized by high stability, high porosity and well-defined crystalline structures. One of their applications is in Catalysis, where bifunctional catalysts may be developed, with both acidic and basic sites. Zeolitic imidazole framework (ZIF) is a subfamily of MOFs which combines the advantages of MOFs with high thermal and chemical stability of zeolites. The objective of this work is to evaluate the basic character of synthetized ZIFs (ZIF-8 and ZIF-67). Samples were characterized by N₂ adsorption, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and thermal gravimetric analysis (TGA). The Knoevenagel condensation of benzaldehyde with ethyl cyanoacetate was chosen as model reaction to evaluate the basic sites. The reaction was conducted at 40 °C and aniline was used as homogeneous catalyst for comparison. Characterization has shown high crystallinity, the presence of functional groups typical of ZIFs structures and high thermal stability. Both ZIF catalysts have shown good catalytic activity (around 90% at 8 h of reaction), similar to the activity of aniline, a homogeneous catalyst. So the presence of basic sites of ZIF-8 and ZIF-67 and their activity were proven in this work.

金属有机骨架代表了一类新的杂化无机有机材料，其特征是高稳定性，高孔隙率和明确的晶体结构。它们的应用之一是在催化领域，在该领域可能会开发出具有酸性和碱性位点的双功能催化剂。沸石咪唑骨架（ZIF）是MOF的一个子家族，结合了MOF的优点以及沸石的高热稳定性和化学稳定性。这项工作的目的是评估合成的ZIF（ZIF-8和ZIF-67）的基本特征。样品用N ₂表征吸附，X射线衍射（XRD），傅里叶变换红外光谱（FTIR）和热重分析（TGA）。选择苯甲醛与氰基乙酸乙酯的Knoevenagel缩合作为模型反应，以评估碱性位点。反应在40℃下进行，苯胺用作均相催化剂进行比较。表征显示出高结晶度，ZIFs结构典型的官能团的存在和高热稳定性。两种ZIF催化剂均显示出良好的催化活性（反应8小时时约90％），类似于均相催化剂苯胺的活性。因此，这项工作证明了ZIF-8和ZIF-67基本位点的存在及其活性。