
TY  - JOUR
A1  - Curtis, NJ 
A1  - Lawrance, GA 
A1  - Sargeson, AM 
T1  - Base-catalysed linkage isomerization of pentaamminechromium(III) complexes of urea and formamide
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1983
VL  - 36
IS  - 7
SP  - 1495
EP  - 1501
KW  - 
UR  - https://doi.org/10.1071/CH9831495 
N2  - The complexes Cr(NH3)5L3+ [L = OCHNH2, OC(NH2)2 and OC(NHMe)2] have been synthesized as the O-bound isomers. At 25ºC in aqueous base (pH c. 10-14) they isomerize to the deprotonated N-bound isomers without competitive hydrolysis. Reacidification regenerates the O-bound isomer rapidly and completely. The second-order rate constants and pKa values of the amide complexes (I 1.0 M, 25ºC) are respectively: 37.0 ± 1.5 dm3 mol-1 s-1 and 11.72 ± 0.06 for formamide; 0.324 ± 0.004 dm3 mol-1 s-1 and l3.50 ± 0.05 for urea; 0.0375 ± 0.0020 dm3 mol-1 s-1 and 14.0 ± 0.2 for N,N'-dimethylurea. The observations for chromium(III) parallel similar behaviour in cobalt(III) and rhodium(III) analogues, but are unusual for chromium(III) chemistry. 
ER  -

