Synthesis and characterization of tetrakis(μ-hydroxo)tetrakis(2,2′-dipicolylamine)tetranickel perchlorate, a nickel-hydroxy cubane complex

A novel tetranuclear complex, [Ni(μ3-OH)(DPA)]4(ClO4)4 (where DPA = 2,2′-dipicolylamine) has been synthesized, with characterization including electronic and infrared spectroscopy, elemental analysis, mass spectrometry, crystal structure analysis, and variable-temperature and variable-field magnetic susceptibility measurements. The complex features a 4Ni–4OH cubane-type cluster, displaying both ferromagnetic and antiferromagnetic intracluster interactions in a 2J model (J1 = −3.4 cm−1, J2 = 4.7 cm−1, D = 2.0 cm−1). Each nickel atom sits in a pseudooctahedral environment, with one DPA molecule facially coordinated and the remaining three coordination sites occupied by the bridging hydroxide anions that make up the cubane core.