COMPETITION STUDY FOR THE BASE HYDROLYSIS OF TRANS-[CO(NH3)(4)(NH2CH3)X](N+) COMPLEXES

Nitrite ion competition has been measured for the base hydrolysis reac tion of trans-Co(NH3)(4)(NH2CH3)Xn+ ions (X = Cl-, Br-, NO3- and SO42- ) in 1.0 M NaNO2 at 25 degrees C. Both O- and N-bonded Co(NH3)(4)(NH2C H3)NO22+ are formed. Subsequently the Co(NH3)(4)(NH2CH3)NO22+ isomer r earranges in OH- to give the thermodynamically more stable Co(NH3)(4)( NH2CH3)NO22+ ion. The total NO2- captured shows a slight dependence on the overall charge of the complex and on the nature of X (R = 2.2, 2. 1, 3.6 and 1.2+/-0.5% for X = Cl-, Br-, NO3- and SO42-, respectively). These results differ from those observed with complexes of the type C o(NH3)(5)Xn+ and Co(NH2CH3)(5)Xn+ where X includes a variety of anions . (C) 1998 Elsevier Science Ltd. All rights reserved.