Constrained ferromagnetic coupling in dinuclear µ1,3-azido nickel(II) cryptate compounds. Crystal structure and magnetic behaviour of [Ni2(L1)(N3)(H2O)][CF3SO3]3·2H2O·EtOH {L1 = N[(CH2)2NHCH2(C6H4-m)CH2NH(CH2)2]3N}†

Abstract

The new dinuclear compounds [Ni₂(L1)(N₃)(H₂O)][CF₃SO₃]₃·4H₂O 1, [Ni₂(L1)(N₃)][ClO₄]₃·MeCN· 2H₂O 2, [Co₂(L1)(N₃)][ClO₄]₃·H₂O 3, and [Mn₂(L2)(N₃)][CF₃SO₃]₃ 4 have been prepared {L1 = N[(CH₂)₂NHCH₂(C₆H₄-m)CH₂NH(CH₂)₂]₃N; L2 = N[(CH₂)₂NHCH₂(C₆H₄-p)CH₂NH(CH₂)₂]₃N}. The crystal structure of [Ni₂(L1)(N₃)(H₂O)][CF₃SO₃]₃·2H₂O·EtOH: has been determined. From magnetic measurements 1 and 2 show ferromagnetic coupling, whereas 3 and 4 show antiferromagnetic coupling. The best fit parameters are: 2J = 11.82 cm^–1, g = 2.13, D = 0.096 cm^–1 and 2z′J′ = –0.72 cm^–1 for 1, 2J = 7.72 cm^–1, g = 2.12, D = –2.38 cm^–1 and 2z′J′ = –0.95 cm^–1 for 2, 2J = –4.1 cm^–1, g = 2.11 for 3, and 2J = –12.1 cm^–1, g = 1.98 for 4. The magnetic results can be correlated with those predicted on the basis of an earlier model.