Lanthanide paramagnetic probes for NMR spectroscopic studies of molecular conformational dynamics in solution: Applications to macrocyclic molecules

摘要

In 1969 it was reported [1] that the 1H NMR chemical shifts of organic compounds containing donor-active heteroatoms with lone electron pairs (O, N, S, etc.) change dramatically when so-called lanthanide (Ln) shift reagents (LSR) are added to solutions of these compounds in relatively inert nonaqueous solvents. Since that time, many original papers and reviews have been published on various aspects of using the properties of LSR, on interactions of LSR with various types of organic compounds [1–23], on nuclear spin interactions with the paramagnetic metal center [27–51], and on the lanthanide-induced shifts (LIS) and relaxation rate enhancement both in aqueous [13,14,24,25,35,36,46] and nonaqueous solvents [2,5,9,31].