Hg2+-induced Aquation of trans-[Co(3,2,3-tet)X2]+ (3,2,3-tet = 4,7-diazadecane-1,10-diamine, X2 = Cl2, (NO2)Cl, Br2, (NO2)Br, and (NO3)2) Complexes in Aqueous Solution

摘要

Hg2+-induced aquation trans-[Co(3,2,3-tet)X2]+ (3,2,3-tet = 4,7-diazadecane-1,10-diamine, X2 = Cl2, (NO2)Cl, Br2, (NO2)Br, (NO3)2) complexes was investigated in aqueous solution. The products and the reaction mechanism were confirmed by chromatography, UV/Vis. spectrum, and circular dichroism (CD) spectrum. From the results, Hg2+-induced aquation of 3,2,3-tet system has been produced cis-￥a complex via trans complex. The kinetic studies on Hg2+-induced aquation of trans-[Co(3,2,3-tet)Cl2]+ complex and trans-[Co(3,2,3-tet)(NO2)Cl]+ complex were also carried out to study the reaction mechanism. The results show that trans-[Co(3,2,3-tet)Cl2]+ complex undergoes the D(dissociative)-mechanism and trans-[Co(3,2,3-tet)(NO2)Cl]+ complex Id(interchange dissociavite)-mechanism. In order to confirm steric course for the reaction mechanism, Hg2+-induced aquation on trans-[Co(R,R-3,2,3-tet)Cl2]+ complex to which chiral R,R-3,2,3-tet was coordinated instead of the racemic(R,R:S,S) 3,2,3-tet was used has been examined by CD spectrum. From the results, the final complex was confirmed to be ?a-cis-￥a-[Co(R,R-3,2,3-tet)(OH2)2]3+ complex indicating the chirality was retained through whole process.