New highly selective macrocycle for K{sup +} and Ba{sup 2+}. Effect of formation of a pseudo second macroring through complexation

Journal Article · Wed Nov 22 04:00:00 EST 1995 · Journal of the American Chemical Society

DOI:https://doi.org/10.1021/ja00151a014· OSTI ID:159698

Zhang, X X; Bordunov, A V; Bradshaw, J S; Dalley, N K; Kou, X; Izatt, R M ^[1]

---

1. Brigham Young Univ., Provo, UT (United States)

A new macrocyclic compound capable of forming a pseudo second macroring upon complexation has been characterized. The compound, 5-chloro-8-hydroxyquinoline (CHQ)-substituted diaza-18-crown-6 (1), exhibits unique complexing properties. log K values for the formation of K{sup +} and Ba{sup 2+} complexes with 1 in methanol are larger than those for the K{sup +} and Ba{sup 2+} complexes with all other lariat ethers. The log K value for the 1-Ba{sup 2+} complex is the same magnitude as that of the cryptand [2.2. 2]-Ba{sup 2+} complex. Selectivity factors for Ba{sup 2+} over other alkaline-earth cations and for K{sup +} over Na{sup +} in methanol are >10{sup 7} and nearly 10{sup 3}, respectively, which are the highest factors ever reported for lariat ethers. Moreover, the selectivity of 1 for Ba{sup 2+} over other alkaline-earth cations is larger than that of any other cryptand studied to date. UV-visible, {sup 1}H NMR spectral, and X-ray crystallographic studies indicate that a pseudo second macroring is formed through {pi}-{pi} interaction between the two CHQ rings upon complexation with K{sup +} and Ba{sup 2+}. This effect results in a cryptate-like structure and therefore highly stable complexes with high selectivity for these cations. 28 refs., 5 figs., 3 tabs.

• Sponsoring Organization: USDOE
• DOE Contract Number: FG02-86ER13463
• OSTI ID: 159698
• Journal Information: Journal of the American Chemical Society, Journal Name: Journal of the American Chemical Society Journal Issue: 46 Vol. 117; ISSN JACSAT; ISSN 0002-7863
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
BARIUM COMPLEXES
BARIUM IONS
CATIONS
CHEMICAL PREPARATION
CHEMICAL REACTIONS
CRYSTALLOGRAPHY
INTERACTIONS
NMR SPECTRA
ORGANIC COMPOUNDS
POTASSIUM COMPLEXES
POTASSIUM IONS
X-RAY DIFFRACTION