Role of metal center in reactions of polynuclear nickel(II) and cobalt(II) trimethylacetates with 8-amino-2,4-dimethylquinoline

The reactions of 8-amino-2,4-dimethylquinoline (L) (1) with polynuclear nickel(II) and cobalt(II) hydroxotrimethylacetato complexes under anaerobic conditions were studied. The nonanuclear cluster Ni-9(mu(4)-OH)(3)(mu(3)-OH)(3)(mu(n)-OOCCMe3)(12)(HOOCCMe3)(4) gave the mononuclear complex Ni(eta(2)-L) (eta(2)-OOCCMe3)(2) (2). The tetranuclear complex Ni-4(eta(3)-OH)(2)(mu-OOCCMe3)(4)(eta(2) (2)- OOCCMe3)(2)(EtOH)(6) produced the mononuclear complex Ni(eta(2)-L)(eta(2-)OOCCMe(3))(OOCCMe3)L (3). At room temperature, the cobalt-containing polynuclear trimethylacetates, viz., the polymer [Co(OH)(n)(OOCCMe3)(2-n)](x) and the tetranuclear complex Co-4(mu(3)-OH)(2)(mu-OOCCMe3)(4)(eta(2)-OOCCMe3)(2)(EtOH)(6), were transformed into the trinuclear cobalt(II) complex CO3(mu(3)-OH)(mu-OOCCMe3)(4)(eta(2)-L)(2)(OOCCMe3) (4). Meanwhile, at 80degreesC these compounds generated the binuclear cobalt(in) complex CO2(mu(2)eta(2)-(HN)C9NMe2)(2)(mu-OOCCMe3)(L)(OOCCMe3)(3) (5). The structures of the resulting compounds were established by X-ray diffraction analysis. Compounds 2-4 exhibit the antiferromagnetic spin-spin exchange coupling, whereas compound 5 is diamagnetic.