Pal Tapan K, De Dinesh, Senthilkumar S, Neogi Subhadip, Bharadwaj Parimal K
Department of Chemistry, Indian Institute of Technology , Kanpur 208016, India.
Inorganic Materials & Catalysis Division, Central Salt & Marine Chemicals Research Institute , Bhavnagar 364002, Gujarat, India.
Inorg Chem. 2016 Aug 15;55(16):7835-42. doi: 10.1021/acs.inorgchem.6b00154. Epub 2016 Jul 26.
A partially fluorinated, angular tetracarboxylic acid linker (H4L) incorporating a pendant amine moiety forms a three-dimensional Zn(II) framework, 1. The structure consists of paddle-wheel Zn2(CO2)4 secondary building units (SBUs) and Zn12(CO2)24 supramolecular building blocks (SBBs). Thermal stability of 1 is found to be low. However, it undergoes transmetalation reaction with Cu(II) at room temperature without losing crystallinity affording an isostructural framework, 1Cu. Framework 1Cu is thermally robust and allows generation of the solvent-free porous framework 1Cu' upon activation with coordinatively unsaturated metal centers. Framework 1Cu' exhibits water stability and at 77 K, adsorbs 2.56 wt % of H2 up to 1 bar that significantly increases to 4.01 wt % at 13 bar. Also, this framework gives a high adsorption of 164.70 cc/g of CH4 (11.7 wt %) at 303 K and 60 bar. The channel surfaces decorated with -NH2 group and unsaturated metal centers in 1Cu' allow a promising 36.4 wt % of CO2 adsorption at 1 bar and 273 K. Moreover, it exhibits pronounced selectivity of CO2 adsorption over N2 and H2 at 273 K. Finally, the versatility of 1Cu' is shown by its excellent heterogeneous catalytic activity in the Biginelli coupling reactions involving an aldehyde, urea, and ethylacetoacetate to afford dihydroprimidinones.
一种带有侧链胺基部分的部分氟化角型四羧酸连接体（H4L）形成了三维锌（II）框架结构1。该结构由桨轮状的Zn2(CO2)4二级结构单元（SBUs）和Zn12(CO2)24超分子结构单元（SBBs）组成。发现结构1的热稳定性较低。然而，它在室温下与铜（II）发生金属交换反应且不失结晶性，得到同构框架结构1Cu。框架结构1Cu具有热稳定性，在用配位不饱和金属中心活化后可生成无溶剂多孔框架结构1Cu'。框架结构1Cu'具有水稳定性，在77 K时，在1 bar压力下可吸附2.56 wt%的H2，在13 bar压力下显著增加到4.01 wt%。此外，该框架在303 K和60 bar压力下对CH4的吸附量高达164.70 cc/g（11.7 wt%）。在1Cu'中，由 -NH2基团和不饱和金属中心修饰的通道表面在1 bar和273 K下对CO2的吸附量可达36.4 wt%。此外，在273 K时，它对CO2的吸附表现出对N2和H2的显著选择性。最后，1Cu'的多功能性体现在其在涉及醛、尿素和乙酰乙酸乙酯的Biginelli偶联反应中具有优异的多相催化活性，可生成二氢嘧啶酮。
