13C NMR Study of 3,9-Di(alkylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiroundecanes
13C NMR chemical shifts and 13C-31P coupling constants of fourteen derivatives from 3,9-di(alkylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiroundecane and of eight derivatives of the 3.9-dioxo type are reported.All investigated compounds possess a chair conformation with the lone pair or the phosphoryl oxygen in the equatorial position.The alkylphenoxy groups are in a cis position with respect to the lone pair or the phosphoryl oxygen.Conformational changes about the aryl-O bond can be minitored via 31P-O-C-13C couplings and their angular dependence was found to be non-symmetric.
Paatoprsty, V.,Malik, L.,Goljer, I.,Goeghova, M.,Karvas, M.,Durmis, J.
Organophosphorus Antioxidants. III. Kinetics and Mechanism of the Decomposition of Cumyl Hydroperoxide by Cyclic Phosphites
The reaction mechanism of cyclic esters of phosphorous acids I to VIII with cumyl hydroperoxide has been studied kinetically by means of 31P n.m.r. spectroscopy, high performance liquid chromatography and iodometric titration.The five-membered cyclic phosphites (I and II) react with cumyl hydroperoxide to give the corresponding phosphates (AI and AII) and cumyl alcohol.With more hydroperoxide or water they form the open chain phosphate esters (BI and BII) which decompose cumyl hydroperoxide catalytically giving phenol and acetone.Higher membered cyclic phosphites (III to VIII) react with cumyl hydroperoxide to give the corresponding phosphates and alcohol only.The mode of reaction depends on the hydrolysis behaviour of the cyclic phosphates (AI to AVIII).Only fivemembered cyclic phosphites which give easily hydrolyzable phosphates are able to decompose cumyl hydroperoxide catalytically.The nature of the exocyclic group in the phosphites has no influence on this behaviour.The kinetic parameters of the separate reaction steps are given.The ionic mechanism of hydroperoxide decomposition is accompanied by a homolytic one.
Rueger, C.,Koenig, T.,Schwetlick, K.
p. 622 - 632
(2007/10/02)
More Articles about upstream products of 55120-33-7