Structural diversity and magnetic properties of six ferrocenyl monocarboxylate Mn(<scp>ii</scp>), Ni(<scp>ii</scp>) and Co(<scp>ii</scp>) complexes with 1D aqua, carboxyl or dinuclear hydroxyl bridges

Using asymmetric 2-chloro-4-ferrocenylbenzoic acid, six new complexes formulated as {[Mn(OOCClH3C6Fc)2(H2O)3]&#183;(CH3OH)}n (1), {[Ni(OOCClH3C6Fc)2(H2O)3](CH3OH)}n (2), [Co(OOCClH3C6Fc)2(H2O)3]n (3), [Co(η2-OOCClH3C6Fc)(fcz)]2&#183;CH3OH (4) [Hfcz = a-(2,4-difluorophenyl)-a-(1H-1,2,4,-triazol-1-ylmethyl)-1H-1,2,4-triazole-1-ethanol], [Ni(η2-OOCClH3C6Fc)(fcz)]2&#183;2CH3OH (5), and [Mn(OOCClH3C6Fc)2(phen)(H2O)] (6) [phen = 1,10-phenanthroline monohydrate] have been synthesized and structurally characterized. 1–3 are isostructural and display 1D aqua-bridged chain structures, in which 1–3 reveal antiferromagnetic coupling with J = −2.35 cm−1 for 1, J = −25.92 cm−1 for 2 and J = −3.98 cm−1 for 3. Notably, 2 and 3 with 1D μ2-aqua bridges haven&#39;t been reported before. Complexes 4 and 5 show dinuclear hydroxyl-bridged structures, in which 4 also exhibits antiferromagnetic coupling with J = −2.46 cm−1. For 6 with a 1D carboxyl-bridged chain structure, it also exhibits antiferromagnetic behaviour with J = −1.11 cm−1.