Molecular Dynamics Simulation Study of 18-Crown-6 in Aqueous Solution. 2. Free Energy Profile for the Association 18C6.cntdot. .cntdot. .cntdot.K+ in Water

Quantum mechanical calculations of the interactions between diazacrowns and the sodium cation: an insight into Na+ complexation in diazacrown-based synthetic ion channels

“…Many insights into the complexation and conformation of the crown ethers have been previously gained by quantum mechanical [24][25][26][27][28][29][30][31][32][33][34][35][36][37][38] and force eld simulations. [39][40][41][42][43][44][45][46][47][48][49][50][51][52][53][54] These studies, due to the similarity of 18-crown-6 to the diaza-18-crown-6, provide us with a point of reference for comparison. Specically, in work by Al-Kahtani et al, 24 the binding energy of 18crown-6 with Li + , Na + , K + , Rb + and Cs + was calculated by HF, B3LYP, CAM-B3LYP, M06 and MP2 levels of theory.…”

Potential of mean force calculation of solute molecules in water by a modified solvent-accessible surface method

“…The complexation energy of the crown᎐K q complex was reported to be 18 kcalrmol in 1989, 55 7 kcalrmol in 1990, 56 and 2.9 kcalrmol in 1995. 44 Furthermore, the two older calculations showed no activation energy for complexation. Thus, our result is the first physical explanation of the activation energy of K q ᎐18-crown-6 complexation.…”

Diffusive motions in liquid 18-crown-6: A molecular dynamics study

“…Apart from slightly different charges, this potential was used by Kowall and Geiger in their study of the structure and dynamics of the hydration shell of 18-crown-6 and their calculation of the free energy for association of 18-crown-6 and K ϩ in water. 30,31 Potential C differs from B in only the torsional part of the potential. In this case all parameters were taken from the GROMOS force field.…”