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Composés d'addition des halogénures de niobium(V) et de tantale(V). VII. Composés du chlorure de niobium(V) avec l'oxytrichlorure et l'oxytribromure de phosphore
Author(s) -
Bünzli J. C.,
Merbach A.
Publication year - 1972
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19720550819
Subject(s) - chemistry , adduct , niobium , enthalpy , chloroform , standard enthalpy of formation , crystallography , thermodynamics , organic chemistry , physics
The adducts NbCl 5 · OPCl 3 and NbCl 5 · OPBr 3 are observed in chloroform solution by 31 P‐NMR spectroscopy. The enthalpy and entropy of activation for the exchange reaction between bulk and coordinated OPCl 3 are found equal to 17 ± 3 kcal/mole and 18 ± 10 cal/°mole. The stability of NbCl 5 · OPCl 3 is compared on a semi‐quantitative basis to the stability of other adducts NbCl 5 · OPR 3 (R = Br, OMe, NMe 2 ).