Synthesis,crystal structure and magnetic properties of diaquabis(2,6‐diamino‐7H‐purin‐1‐ium‐κN9)bis(4,4′‐oxydibenzoato‐κO)cobalt(II) dihydrate |
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Abstract: | The title mononuclear CoII complex, Co(C5H7N6)2(C14H8O5)2(H2O)2]·2H2O, has been synthesized and its crystal structure determined by X‐ray diffraction. The complex crystallizes in the triclinic space group P, with one formula unit per cell (Z = 1 and Z′ = ). It consists of a mononuclear unit with the CoII ion on an inversion centre coordinated by two 2,6‐diamino‐7H‐purin‐1‐ium cations, two 4,4′‐oxydibenzoate anions (in a nonbridging κO‐monodentate coordination mode, which is less common for the anion in its CoII complexes) and two water molecules, defining an octahedral environment around the metal atom. There is a rich assortment of nonbonding interactions, among which a strong N+—H…O? bridge, with a short N…O distance of 2.5272 (18) Å, stands out, with the H atom ostensibly displaced away from its expected position at the donor side, towards the acceptor. The complex molecules assemble into a three‐dimensional hydrogen‐bonded network. A variable‐temperature magnetic study between 2 and 300 K reveals an orbital contribution to the magnetic moment and a weak antiferromagnetic interaction between CoII centres as the temperature decreases. The model leads to the following values: A (crystal field strength) = 1.81, λ (spin‐orbit coupling) = ?59.9 cm?1, g (Landé factor) = 2.58 and zJ (exchange coupling) = ?0.5 cm?1. |
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Keywords: | cobalt complex magnetism antiferromagnetic interaction crystal structure AIM computational chemistry temperature dependence |
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