+ Site Statistics
+ Search Articles
+ PDF Full Text Service
How our service works
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ Translate
+ Recently Requested

UV and IR spectroscopic studies of cold alkali metal ion-crown ether complexes in the gas phase

UV and IR spectroscopic studies of cold alkali metal ion-crown ether complexes in the gas phase

Journal of the American Chemical Society 133(31): 12256-12263

We report UV photodissociation (UVPD) and IR-UV double-resonance spectra of dibenzo-18-crown-6 (DB18C6) complexes with alkali metal ions (Li(+), Na(+), K(+), Rb(+), and Cs(+)) in a cold, 22-pole ion trap. All the complexes show a number of vibronically resolved UV bands in the 36,000-38,000 cm(-1) region. The Li(+) and Na(+) complexes each exhibit two stable conformations in the cold ion trap (as verified by IR-UV double resonance), whereas the K(+), Rb(+), and Cs(+) complexes exist in a single conformation. We analyze the structure of the conformers with the aid of density functional theory (DFT) calculations. In the Li(+) and Na(+) complexes, DB18C6 distorts the ether ring to fit the cavity size to the small diameter of Li(+) and Na(+). In the complexes with K(+), Rb(+), and Cs(+), DB18C6 adopts a boat-type (C(2v)) open conformation. The K(+) ion is captured in the cavity of the open conformer thanks to the optimum matching between the cavity size and the ion diameter. The Rb(+) and Cs(+) ions sit on top of the ether ring because they are too large to enter the cavity of the open conformer. According to time-dependent DFT calculations, complexes that are highly distorted to hold metal ions open the ether ring upon S(1)-S(0) excitation, and this is confirmed by extensive low-frequency progressions in the UVPD spectra.

Please choose payment method:

(PDF emailed within 0-6 h: $19.90)

Accession: 056732372

Download citation: RISBibTeXText

PMID: 21728334

DOI: 10.1021/ja2046205

Related references

Coordination trends in alkali metal crown ether uranyl halide complexes: the series [A(crown)]2[UO(2)X(4)] where A=Li, Na, K and X=Cl, Br. Inorganic Chemistry 40(14): 3389-3394, 2001

Electrolyte dropping electrode polarographic studies solvent effect on stability of crown ether complexes of alkali metal cations. Analytical Chemistry 62(10): 1010-1015, 1990

Ab initio models of cation/ether complexes 15-Crown-5 and its alkali metal complexes. Abstracts of Papers American Chemical Society 219(1-2): ENVR 205, 2000

Crown Ether Complexes of Alkali-Metal Chlorides from SO 2. Chemistry 23(40): 9607-9617, 2017

DFT Study of Crown Ether-BridgedZ-Stilbenes and Their Complexes with Alkali Metal Cations. 2011

Emergence of symmetry and chirality in crown ether complexes with alkali metal cations. Journal of Physical Chemistry. A 114(26): 7048-7054, 2010

Theoretical Study of Cation/Ether Complexes: Alkali Metal Cations with 1,2-Dimethoxyethane and 12-Crown-4. Journal of Physical Chemistry A 102(21): 3813-3819, 1998

Ultraviolet photodepletion spectroscopy of dibenzo-18-crown-6-ether complexes with alkali metal cations. Journal of Physical Chemistry. A 113(29): 8343-8350, 2009

Spectroscopic investigation of the gas-phase conformations of 15-crown-5 ether complexes with K+. Journal of Physical Chemistry. A 113(27): 7748-7752, 2009

Diaza crown ether complexes of alkali metal and ammonium cations paired with organic anions. Inorganica Chimica Acta 86(1): 61-64, 1984

Infrared spectroscopy of ionophore-model systems: hydrated alkali metal ion 18-crown-6 ether complexes. Journal of the American Chemical Society 131(47): 17277-17285, 2010

Stability of crown-ether complexes with alkali-metal ions in ionic liquid-water mixed solvents. Journal of Inclusion Phenomena and Macrocyclic Chemistry 59(3-4): 377-381, 2007

First observation of alkali metal ion induced trans-cis isomerization of palladium(II) phosphane complexes containing crown ether moieties. Angewandte Chemie 42(29): 3385-3388, 2003

Evaluation of the hydrophilic properties of crown ether-ion-pair complexes with alkali metal picrates by their distribution into less-polar diluents. Analytical Sciences 25(4): 563-566, 2009

Unexpected structural diversity in alkali metal azide-crown ether complexes: syntheses, X-ray structures, and quantum-chemical calculations. Chemistry 12(9): 2620-2629, 2005