Facile reaction of the model urease complex [Ni2(OAc)3(urea)(tmen)2][OTf] (A) with acetohydroxamic acid (AHA) gives the monobridged hydroxamate complex (I) [Ni2(OAc)2(AA)(urea)(tmen)2][OTf] with a Ni−Ni distance of 3.434(1) Å compared to that of 3.5 Å in urease (OAc, CH3COO-; tmen, N,N,N‘,N‘-tetramethylethylenediamine; OTf, CF3SO3; AHA, acetohydroxamic acid; AA, acetohydroxamate anion). I is a close model of one proposed mode of urease inhibition by hydroxamic acids, recently observed in the acetohydroxamate-inhibited C319A variant of Klebsiella aerogenes urease. Reaction of [Ni2(OH2)(OAc)4(tmen)2] (B) with AHA gives the dibridged hydroxamate complex (II) [Ni2(OAc)(AA)2(tmen)2][OAc] with a Ni−Ni distance of 3.005(1) Å. Infrared spectroscopic studies provide evidence for the bridging acetate groups undergoing carboxylate shifts thereby assisting replacement of acetate by hydroxamate. Both I and II show ferromagnetic exchange coupling.

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Combinatorial parallel synthesis has led to the rapid generation of a single-compound library of novel fluorinated quaterphenyls. Subsequent automated screening revealed liquid crystalline (LC) behaviour and gave qualitative relationships of molecular structures and solid state properties.