ISSN:
0947-3440
Keywords:
Thiocrown donors
;
Iodine complexes
;
Structure elucidation
;
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Studies of π and σ interactions in molecular crystals of donoracceptor complexes have stimulated interest in the crystallization and structure determination of {1,3,5-trithiane…I2}, {1,5,8,12-tetrathiocyclotetradecane…I2} and {1,4,7,10,13,16-hexathiocyclooctadecane…(I2)3} in order to detect structural changes. The I—I bond lengths are stretched by up to 0.16 Å relative to the gas-phase value and prove iodine to be the acceptor species. Additional distance data 〉S…I2 and I—I from the Cambridge Structural Database establish a nonlinear correlation. In contrast, bond lengths and bond angles of the sulphide donors remain largely unperturbed on complexation, even when considerable conformational changes are observed. For example, on addition of four iodine molecules, the rather flexible 18-thio-crown-6 with a C2-symmetric bowl-shape is flattened to a Cs-symmetric rectangle. The structural results complement those reported for stronger acceptor effects of metal cations.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jlac.199719971018
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