Acceleration and deceleration of chirality inversion speeds in a dynamic helical metallocryptand by alkali metal ion binding.

Autor: Ikbal SA; Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan., Zhao P; Research Center for Computational Science, Institute for Molecular Science, 38 Nishigo-Naka, Myodaiji, Okazaki 444-8585, Japan., Ehara M; Research Center for Computational Science, Institute for Molecular Science, 38 Nishigo-Naka, Myodaiji, Okazaki 444-8585, Japan., Akine S; Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan.; Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan.
Jazyk: angličtina
Zdroj: Science advances [Sci Adv] 2023 Nov 03; Vol. 9 (44), pp. eadj5536. Date of Electronic Publication: 2023 Nov 03.
DOI: 10.1126/sciadv.adj5536
Abstrakt: We report that the chirality inversion kinetics of a trinickel(II) cryptand can be controlled by guest recognition in the cryptand cavity. When the guest was absent, the nickel(II) cryptand underwent a dynamic interconversion between the P and M forms in solution, preferring the M form, with a half-life of t 1/2 = 4.99 min. The P / M equilibrium is reversed to P -favored by binding with an alkali metal ion in the cryptand cavity. The timescale of this M→P inversion kinetics was both notably accelerated and decelerated by the guest binding ( t 1/2 = 0.182 min for K + complex; 186 min for Cs + complex); thus, the equilibration rate constants differed by up to 1000-fold depending on the guest metal ions. This acceleration/deceleration can be explained in terms of the virtual binding constants at the transition state of the P / M chirality inversion; K + binding more stabilizes the transition state rather than the P and M forms to result in the acceleration.
Databáze: MEDLINE
Externí odkaz: