Lariat ethers. 3. Macrocylic polyethers bearing donor groups on flexible arms attached at a nitrogen pivot point

Bioorganic Chemistry

“…It is especially interesting to note that the high binding constant of the IS-crown-S with two oxygens in the side arm is comparable to a 18-crown-6 system with only one donor oxygen in the side arm (300). In fact, compounds having arms joined by a methyleneoxy group appear to be relatively inflexible and exhibit both relatively weak solventdependent cation binding.…”

Pyrazolic tripods synthesis and cation binding properties

“…It has been found that a donor atom in a side chain of lariat ethers increases the binding ability of the macrocycle. [7][8][9] Furthermore, structures with side arms attached at a nitrogen (N-pivot lariat ethers) instead of a carbon (C-pivot lariat ethers) have stronger binding properties because of greater flexibility, allowing the donor site to have the best binding position. 10…”

Probing the influence of solvent effect on the lithium ion binding affinity of 12-crown-O3N derivatives with unsaturated side arms: A computational study

“…N-pivot lariat ethers are known to have better cation-binding than C-pivot lariat ethers as the nitrogen atom provides a flexible sidearm due to its ability to perform an inversion in space [11]. It is also reported that if sidearms do not interact directly with the ring-bound cation, they may influence the binding by competing with solvent or counter ion [12].…”