A reaction system consisting of terephtha
lic acid, NaOH, inorganic Mn(II) or Mn(III) salt, and sa
licy
lidene alky
limineresulted in dinuclear manganese complexes (salpn)
2Mn
2(
-phth)(CH
3OH)
2 (
1, salpn =
N,
N'-1,3-propylene-bis(sa
licy
lideneiminato); phth = terephthalate dianion), (salen)
2Mn
2(
-phth)(CH
3OH)
2 (
2, salen =
N,
N'-ethylene-bis(sa
licy
lideneiminato)), (salen)
2Mn
2(
-phth)(CH
3OH)(H
2O) (
3), and (salen)
2Mn
2(
-phth) (
4), while the absence ofNaOH in the reaction led to a mononuclear Mn complex (salph)Mn(CH
3OH)(NO
3) (
5, salph =
N,
N'-1,2-phenylene-bis(sa
licy
lideneiminato)). In addition, a trinuclear mixed metal complex H{Mn
2Na(salpn)
2(
-OAc)
2(H
2O)
2}(OAc)
2 (
6)was obtained from the reaction system by using maleic acid instead of terephtha
lic acid. Five-coordinate Mn ionswere found in
4 giving rise to an intermolecular interaction and constructing a one-dimensional
linear structure.Antiferromagnetic exchange interactions were observed for
1-
3, and a total ferromagnetic exchange of
4 wasconsidered to stem from intermolecular magnetic coup
ling.
1H NMR signals of phenolate ring and alkylene (orphenylene) backbone of the diamine are similar to those reported in the
literature, and the phth protons are at -2.3to -10.1 ppm. Studies on structure, bond valence sum analysis, and magnetic properties indicate the oxidationstates of the Mn ions in
6 to be +3, which are also indicated by ESR spectra in dual mode. Ferromagnetic exchangeinteraction between the Mn(III) sites was observed with
J = 1.74 cm
-1. A quasireversible redox pair at -0.29V/-0.12V has been assigned to the redox of Mn
2(III)/Mn(III)Mn(II), implying the intactness of the complex backbonein solution.