The kinetics of adduct formation between heteropolymetallic targets (mu(4)-O)N4Cu4-xMxX6 and Cu(NS)(2) reagent in nitrobenzene

摘要

The rate laws for the earliest events in the specific stoichiometric monotransmetalation of heteropolymetallic targets (mu(4)-O)(amine)(4)Cu4-xMxX6, where the amine ligand is pyridine (py) or monodentate N,N,-diethylnicotinamide (N), x is 1-3, M is Co or Ni(H2O), X is Cl or Br, by transmetalators M'(NS)(2) and their solution adduct formation by reagent Cu(NS)(2) in nitrobenzene, where M' is Co, Ni or Zn and NS is monoanionic S-methylisopropylidinchydrazine-carbodithioate, depends on the amine, M, M', x and X. The observed event can be the formation of reaction precursors P-1, P-2 or P-3, metal exchange within the precursors, rearrangement of successors S-1, S-2, or S-3 complexes or their dissociation to separate products. The kinetic and thermodynamic data are compared with those of a neutral monomeric target Cu(ac.ac-)(2) containing only oxygen donor atoms. The structural-mechanistic origins of monotransmetalation specificity and adduct formation in these systems are discussed. (C) 2003 Elsevier Ltd. All rights reserved. [References: 20]