Complexation of endohedral metallofullerene La@C82-A (1) with macrocyclic compounds, such as 1,4,7,10,13,16-hexaazacyclooctadecane (2), 1,4,7,10,13,16-hexamethyl-1,4,7,10,13,16-hexaazacyclooctadecane (3), mono-aza-18-crown-6 ether (4), 18-crown-6 ether (5), and p-tert-butylcalix[n]arenes (n = 4−8, 6−10), for the first time is examined. Among them, 1 forms a complex with azacrown ethers 2−4 while accompanying the electron transfer between them. This is characteristic of endohedral metallofullerene and caused by its low reduction potential. Activation energies, ΔGet, for the electron transfer from 2−4 to 1 are 4.6, 2.8, and 11 kcal/mol, respectively. These small ΔGet values indicate that the electron transfer from the azacrown ethers to 1 is facile in the ground state. Furthermore, the selective isolation of lanthanum endohedral metallofullerenes from the extracts of soot is accomplished by utilizing the complexation of 1 with 2.
A triarylamine-functionalized terpyridine ligand formed a highly coordinated complex with europium tris(β-diketonate), which displayed reversible ''ON–OFF'' luminescence switching coupled with a ligand redox process of triarylamine/triarylaminium cations.
Synthesis of ketene silyl acetals with high (E)- and (Z)-stereochemistry is achieved by increasing the size of alkoxy group or by employing an excess amount of esters over LDA.
