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The new titanium(IV) coordinative compound (dpp-bian)TiCl 2 ( 2 ) was obtained by metathesis of the disodium salt (dpp-bian)Na 2 ( 1 ) (dpp-bian = 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene) with TiCl 4 . It was shown that the chlorido ligands can be exchanged for chelating dpp-bian ligands, or tert -butoxy groups, with the formation of (dpp-bian) 2 Ti ( 3 ) and (dpp-bian)Ti(O t Bu) 2 ( 4 ), respectively. Complexes 2 – 4 were isolated and fully characterized. It was demonstrated that dpp-bian is in the reduced dianionic form and acts as a σ 2 π-donor ligand. [ABSTRACT FROM AUTHOR]

Abstract: Synthesis and characterization of a novel type of ambident bridging ligands joining together the functional prerequisites for visible-light absorption, photoinduced electron transfer and catalytic proton reduction is presented. This class of compounds consists of a chromophoric 1,2-diimine-based π-acceptor site and a rigid polyaromatic dithiolate chelator. Due to the presence of a common conjugated linker moiety with an intrinsic two-electron redox reactivity and a suitable orbital coupling of the subunits, a favourable situation for vectorial multielectron transfer from attached electron donors to a catalytic acceptor site is provided. As an example for the application of this kind of bifunctional ligand systems, a [FeFe]-hydrogenase enzyme model compound is prepared and structurally characterized. Electrocatalytic hydrogen formation with this complex is demonstrated. [Copyright &y& Elsevier]

Co, Ni and Cu complexes with a non-innocent ortho -aminophenol were synthesized by the reaction of metal(II)acetates with a ligand precursor. • Metal complexes with redox-active non-innocent ligands. • Structurally analogous square-planar complexes of Co, Ni and Cu. • High near-IR absorption. Bench top stable transition metal (M = Co, Ni, Cu) complexes with a non-innocent ortho -aminophenol derivative were synthesized by the reaction of metal(II)acetates with a ligand precursor in 2:1 ratio. The solid-state structures reveal the formation of neutral molecular complexes with square planar coordination geometries. The Co(II) and Cu(II) complexes are paramagnetic, whereas the Ni complex is a diamagnetic square planar low-spin Ni(II) complex. All complexes, and Ni(II) complex in particular, show strong absorption in the near-IR region. [ABSTRACT FROM AUTHOR]