Theoretical design on molecular tweezers of sodium cyanide by zinc porphyrin‐azo‐crown ether triads receptor

Theoretical study on a novel zinc porphyrin‐azobenzene‐crown ether triads receptor was explored. The( Z )‐5‐(4‐((4‐((4‐((4‐(1,4,7,10,13‐pentaoxacyclopentadecan‐2‐yl)benzyl)oxy)phenyl) diazenyl)phenoxy) methyl)phenyl)porphyrin ( L 1 ), the complex L 2 ( L 1 with the metal ion Zn 2+ ), and the corresponding complex L 2 of ditopic receptor with sodium cyanide are investigated by density functional theory (DFT). The full optimized geometric structures are calculated at PBE0/6‐311G** level, natural bond orbital (NBO) analysis is used to study the interaction of L 2 and L 2 ·NaCN molecules. The absorption spectra of L 1 , L 2 , and L 2 ·NaCN are studied by time‐dependent DFT (TD‐DFT) and CAM‐B3LYP method. DFT calculations show that the geometric structure of compound L 2 binding sodium cyanide change greatly. The absorption peak is significant red‐shifted because of the formation of a 1:1 complex with sodium cyanide. Furthermore, it demonstrates that novel zinc porphyrin‐azo‐crown ethimer triads L 2 is suitable ditopic receptor to recognize sodium cyanide salt.