Ahmad Mohammad Shahwaz, Samokhvalov Alexander
Department of Chemistry, Morgan State University, 1700 East Cold Spring Lane, Baltimore, MD 21251, USA.
Materials (Basel). 2024 Dec 17;17(24):6160. doi: 10.3390/ma17246160.
Metal-organic frameworks (MOFs) are hybrid inorganic-organic 3D coordination polymers with metal sites and organic linkers, which are a "hot" topic in the research of sorption, separations, catalysis, sensing, and environmental remediation. In this study, we explore the molecular mechanism and kinetics of interaction of the new copper porphyrin aluminum metal-organic framework (actAl-MOF-TCPPCu) compound with a vapor of the volatile organic sulfur compound (VOSC) diethyl sulfide (DES). First, compound was synthesized by post-synthetic modification (PSM) of Al-MOF-TCPPH compound by inserting Cu ions into the porphyrin ring and characterized by complementary qualitative and quantitative chemical, structural, and spectroscopic analysis. Second, the interaction of compound with DES vapor was analyzed dynamically by the novel method of in situ time-dependent attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy at controlled humidity levels. The sorbent-adsorbate interactions, as analyzed by the shifts in IR peaks, indicate that the bonding includes the hydroxy O-H, carboxylate COO, and phenyl groups. The kinetics of sorption obeys the Langmuir pseudo-first-order rate law. The pre-adsorption of water vapor by compound at the controlled relative humidity under static (equilibrium) conditions yields the binary stoichiometric adsorption complex (Al-MOF-TCPPCu)(HO). The pre-adsorption of water vapor makes the subsequent sorption of DES slower, while the kinetics obey the same rate law. Then, static pre-adsorption of water vapor was followed by static sorption of DES vapor, and the ternary adsorption complex (Al-MOF-TCPPCu)(HO)(DES). was obtained. Despite the pre-adsorption of significant amounts of water, the binary complex adsorbs a large amount of DES: ca. 36.6 wt. % (per compound ). Finally, the ternary complex is facilely regenerated by gentle heating under vacuum. Compound and related MOFs are promising for adsorptive removal of vapor of DES and related VOSCs from dry and humid air.
金属有机框架（MOFs）是具有金属位点和有机连接体的无机 - 有机杂化三维配位聚合物，是吸附、分离、催化、传感及环境修复研究中的一个“热点”课题。在本研究中，我们探究了新型铜卟啉铝金属有机框架（actAl - MOF - TCPPCu）化合物与挥发性有机硫化合物（VOSC）二乙硫醚（DES）蒸气相互作用的分子机制及动力学。首先，通过将铜离子插入卟啉环，对Al - MOF - TCPPH化合物进行后合成修饰（PSM）来合成该化合物，并通过互补的定性和定量化学、结构及光谱分析对其进行表征。其次，通过原位时间相关衰减全反射傅里叶变换红外（ATR - FTIR）光谱这一新颖方法，在受控湿度水平下动态分析该化合物与DES蒸气的相互作用。通过红外峰的位移分析得出，吸附剂 - 吸附质相互作用表明其键合包括羟基O - H、羧酸盐COO和苯基。吸附动力学遵循朗缪尔准一级速率定律。在静态（平衡）条件下，在受控相对湿度下该化合物对水蒸气的预吸附产生二元化学计量吸附络合物（Al - MOF - TCPPCu）（H₂O）。水蒸气的预吸附使随后DES的吸附变慢，但其动力学遵循相同的速率定律。然后，先进行水蒸气的静态预吸附，接着进行DES蒸气的静态吸附，得到三元吸附络合物（Al - MOF - TCPPCu）（H₂O）（DES）。尽管预吸附了大量的水，但二元络合物仍能吸附大量的DES：约36.6 wt.%（基于每个化合物）。最后，通过在真空中温和加热可轻松再生三元络合物。该化合物及相关的MOFs有望用于从干燥和潮湿空气中吸附去除DES及相关VOSCs的蒸气。
