ISSN:
1573-1111
Keywords:
Potassium
;
3,5-dinitrobenzoate
;
benzo-15-crown-5
;
X-ray diffraction analysis
;
charge-separated sandwich
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract The interaction of K(35-Dnb) (35-Dnb=3,5-dinitrobenzoate) with benzo-15-crown-5 (B15C5) in ethanol yields a charge-separated sandwich structured complex [K(B15C5)2]+[35-Dnb(35-DnbH)2]− even when equimolar amounts of reactants were used and no external 35-DnbH was added to the reaction mixture. The complex (KC49H51O28N6, FW=1211.1), is monoclinic,P21/c,a=11.063(2),b=10.680(1),c=46.548(8) Å, β=91.629(2)0,Z=4,D 0=1.485 g/cm3,D c=1.468 g/cm3, CuKα λ=1.5418 Å, μ=17.01 cm−1, 2θ〈1300,F(000)=2520,T=298 K. FinalR for the 6618 observed reflections was 0.071. In the sandwich moiety, the K+ is 10-coordinated through all the oxygens of the crown molecules (K+−O, 2.76–3.11 Å). The 35-Dnb anion lies 5.3 Å below the lower crown mean plane and is charge separated with respect to K+ (K+−O−〉7 Å) but undergoes strong hydrogen bonding (2.59 and 2.49 Å) through each carboxylate oxygen with the carboxylic protons of two separate 35-DnbH molecules.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00687990
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