THE CRYSTAL STRUCTURE OF N5O3 CRYPTAND
L.-X. Pan1, B. Zhang2, Y. Su2, Z. Ma2
1National Engineering Research Center for Non-Food Biorefinery, Guangxi Academy of Sciences, Nanning, Guangxi, P. R. China
2Guangxi University, Guangxi, P. R. China
Keywords: cryptand, crystal structure, condensation, rare earth, tris(2-aminoethyl)amine
Abstract
The title compound, 1,4,13,22,27-pentaaza-6,9:17,20:29,32-tribenzo-10,16,33-trioxabicyclo [11,11,11] pentatriacontane (C33H45N5O3), is synthesized by [1+1] tripodal condensation of trialdehyde (4,4',4"-triformyl-triphenoxytriethylamine) with tris(2-aminoethyl)amine (tren) in the presence of La(NO3)3x6H2O as a template, followed by reduction with KBH4. There are six unique molecules in the unit. The molecule has a threefold symmetry axis passing through the bridgehead nitrogen atoms in the structure. As a result, only one strand of the cryptand molecule is present in the asymmetric unit. The structure presents an endo-endo conformation, with the distance between the two bridgehead nitrogen atoms of 10.030(8) Å.
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