Correlating Bridging Ligand with Properties of Ligand-Templated [MnX] Clusters (X = Br, Cl, H, MeO).

Polynuclear manganese compounds have garnered interest as mimics and models of the water oxidizing complex (WOC) in photosystem II and as single molecule magnets. Molecular systems in which composition can be correlated to physical phenomena, such as magnetic exchange interactions, remain few primarily because of synthetic limitations. Here, we report the synthesis of a family of trimanganese(II) complexes of the type MnXL (X = Cl, H, and MeO) where L is a tris(β-diketiminate) cyclophane.

Insights into small molecule activation by multinuclear first-row transition metal cyclophanates.

The rational design of trimetallic transition metal clusters supported by a trinucleating cyclophane ligand, L(3-), and the reactivities of these complexes with dinitrogen and carbon dioxide are discussed. Emphasis is placed on the differences in the observed reactivity between these trimetallic cyclophane complexes and that of the mono- and dinuclear transition metal compounds.

Reactivity of Hydride Bridges in High-Spin [3M-3(μ-H)] Clusters (M = FeII, CoII).

The designed [3M-3(μ-H)] clusters (M = Fe(II), Co(II)) Fe3H3L (1-H) and Co3H3L (2-H) [where L(3-) is a tris(β-diketiminate) cyclophane] were synthesized by treating the corresponding M3Br3L complexes with KBEt3H. From single-crystal X-ray analysis, the hydride ligands are sterically protected by the cyclophane ligand, and these complexes selectively react with CO2 over other unsaturated substrates (e.g.

Nitride-bridged triiron complex and its relevance to dinitrogen activation.

Using a simple metathesis approach, the triiron(II) tribromide complex Fe3Br3L (1) reacts with tetrabutylammonium azide to afford the monoazide dibromide analogue Fe3(Br)2(N3)L (2) in high yield. The inclusion of azide was confirmed by IR spectroscopy with a ν(N3) = 2082 cm(-1) as well as combustion analysis and X-ray crystallography. Heating 2 in the solid state results in the complete loss of the azide vibration in the IR spectra and the isolation of the olive-green mononitride complex Fe3(Br)2(N)L (3).

An Air- and Water-Tolerant Zinc Hydride Cluster That Reacts Selectively With CO2.

The reaction of [Zn3Cl3L], in which L(3-) is a tris(β-diketiminate) cyclophane, with K(sBu)3BH afforded [Zn3(μ-H)3L] (2), as confirmed by NMR spectroscopy, NOESY, and X-ray crystallography. The complex 2 was air-stable and unreactive towards water, methanol, and other substrates (e.g.

Preorganized assembly of three iron(II) or manganese(II) β-diketiminate complexes using a cyclophane ligand.

A trinucleating cyclophane bearing three β-diketimine arms, and the corresponding iron(II) and manganese(II) complexes have been synthesized and characterized. The three metal ions are oriented towards the internal void space, and are coordinated by a N2Br2 donor set, in which a unique combination of μ(3), μ, and terminal coordination modes are observed for the halide donors.