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X‐ray and NMR investigation of 25,27‐dihydroxy‐26,28‐bis(diethoxyphosphoryloxy)‐ tert ‐butylcalix[4]arene in the 1,2‐alternate conformation
Author(s) -
Lipkowski Janusz,
Vysotsky Myroslav,
Slowikowska Joanna,
Kalchenko Vitaly I.,
Markovsky Leonid N.
Publication year - 1998
Publication title -
journal of physical organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.325
H-Index - 66
eISSN - 1099-1395
pISSN - 0894-3230
DOI - 10.1002/(sici)1099-1395(199801)11:1<63::aid-poc966>3.0.co;2-4
Subject(s) - chemistry , intramolecular force , calixarene , intermolecular force , molecule , methylene , hydrogen bond , crystallography , proton nmr , crystal structure , ring (chemistry) , stereochemistry , methylene bridge , phenol , crystal (programming language) , medicinal chemistry , organic chemistry , computer science , programming language
The crystal structure of 25,27‐dihydroxy‐26,28‐bis(diethoxyphosphoryloxy)‐ tert ‐butylcalix[4]arene ( 1 ) (hexane solvate, 1:1) was determined by x‐ray crystallography. The crystal data are P 2 1 / n, a = 12.652(1) Å, b = 12.564(2) Å, c = 18.781(4) Å, β = 105.56(1)°, V = 2876.0(8) Å 3 , Z = 2. In this complex the molecule adopts a 1,2‐alternate conformation. Both the calixarene and hexane molecules are centrosymmetric. The phenol units in the asymmetric part of the calix are inclined with respect to the main macrocyclic plane by 115.46(6)° and 128.01(7)° for the phosphorylated and the non‐phosphorylated ring, respectively. Self‐inclusion of the ethyl chains in the half‐cavities is observed. One intramolecular O—H…O and several intermolecular C—H…O hydrogen bonds are present. In the 1 H NMR spectrum one average AX spin system for methylene bridge protons can be interpreted as fast (on the NMR time‐scale) interconversion of non‐phosphorylated phenol fragments. © 1998 John Wiley & Sons, Ltd.