The Successive Stabilities and Proposed Models of the Rare Earth 1-Hydroxycyclopentanecarboxylic Acid Chelates

Abstract

20) Reference 18 shows that the first process is slow. The fraction of the enol isomer of 0-diketones is often measured by bromine titration; consequently, the isomerization must be slow.

Metal atom reactions with fluorocarbons. VI. Complexes of halogenated benzenes with vanadium(0) and chromium(0). Effects of strongly electron-withdrawing substituents, particularly trifluoromethyl groups

“…In the case of fluorine or chlorine substitution, air stability is also enhanced, but not as greatly.3•14 Also, in monofluoro and polyfluoro cases explosive character has been encountered.9 •14 In fact, when more than two fluorines are attached to the arene ligand, only unstable, very explosive chromium complexes are obtained. 14 Apparently the aryl fluorines are quite labile, and on decomposition Cr-F (or V-F) bonds are formed in a very exotherriiic process. (Workers should be wary of this possible behavior in any organohalogenated complexes of this type.)…”

Stabilité des carboxylates de terres rares, II. Bis‐hydroxyméthyl‐2,2‐propionates

“…La plupart des monocarboxylates des terres rares 6tudiCs 8. ce jour sont des hydroxy-1-carboxylates [2]. I1 a CtC montrk qu'en solution aqueuse ces complexes sont des chClates [3]. Par contre, il n'existe @re d'informations sur les hydroxy-2carboxylates.…”

Stabilité des carboxylates de terres rares I Furanne‐ et thiophène‐carboxylates‐2

“…- (4,30 . 10-3[I.-]), pK,, = 2,98 (p = 0,100, NaC10,) ; en corrigeant cette valeur B l'aide cle la relation de DAVXES r61, on obtient la constante thermodynamique (p + 0) : p t I<" = 3,198 (3,164 selon LUMNE 171).…”