High-nuclearity nickel(II) clusters: Ni 13 complexes from the use of 1-hydroxybenzotriazole

Abstract

The reaction of 1-hydroxybenzotriazole, btaOH, with nickel(II) acetate tetrahydrate, in the absence of an external base, has been investigated. The reaction of Ni(O 2CMe) 2 · 4H 2O with one equivalent of btaOH in nPrOH leads to the the first structurally characterized tridecanuclear nickel(II) cluster and the biggest metal/btaOH or btaO − cluster discovered to date, [Ni 13(OH) 6(O 2CMe) 8(btaO) 12(H 2O) 6( nPrOH) 4] · 6.6H 2O · 4( nPrOH) ( 1 · 6.6H 2O · 4( nPrOH)). The centrosymmetric molecule contains the {Ni 13(μ 3-ΟΗ) 6(μ 3-ONNNR) 12} 8+ core (R– = C 6H 4–) and is characterized by competitive antiferromagnetic exchange interactions within its pentanuclear subunits containing the μ 3-ΟΗ − bridges. The reaction of 1 with an excess of N 3 - ions in refluxing MeOH has led to the azido-bridged product [Ni 13(N 3) 6(O 2CMe) 8(btaO) 12(MeOH) 10] ( 2), in which the spin frustration observed in 1 seems to disappear.