Synthesis and crystal structures of triruthenium clusters containing phosphinidene ligands

The manipulation of trinuclear ruthenium clusters [Ru3(CO)9(μ-H)2(μ3-PMes)] (1) with PH2Ph, in refluxing hexane, produces [Ru3(CO)8(PH2Ph)(μ-H)2(μ3-PMes)] (2) where PH2Ph coordinates as a terminal ligand. Cluster 2 gets converted to [Ru3 (CO)9(μ3-PMes)(μ3-PPh)] (3) when heated in a toluene solution in the presence of CO. This study provides the solutions of the X-ray structures for clusters 2 and 3

Crystal structure of [1,2-bis(diphenylphosphanyl)benzene]heptacarbonyldi-μ-hydrido-(μ3-2,4,6-trimethylphenylphosphinidene)-triangulo-triruthenium

The title trinuclear ruthenium cluster, [Ru3(C30H24P2)(C9H11P)(CO)7(μ-H)2], has a triangular Ru3 core that is capped with a mesitylphosphinidene ligand, μ3-PMes (Mes = mesityl = 2,4,6-trimethylphenyl). The 1,2-bis(diphenylphosphanyl)benzene molecule acts as a bidentate phosphine ligand via two P atoms connecting to a single Ru atom. The title compound crystallizes with two independent molecules in the asymmetric unit

Octacarbonyldi-μ2-hydrido-[μ3-(1,3,5-trimethylphenyl)phosphinidene](triphenylphosphane)-triangulo-triruthenium

In the crystal structure of the title compound, [Ru3(C9H11P)H2(C18H15P)(CO)8], the triangular Ru3 unit is capped with one mesitylphosphinidene ligand. In the trigonal–pyramidal Ru3P core, one RuII atom is coordinated by a triphenylphosphane ligand in a terminal fashion. Two hydride ligands bridge over two Ru—Ru bonds. These Ru—Ru bonds [2.9400 (4) and 2.9432 (4) Å] are slightly longer than the nonhydride-bridged Ru—Ru bond [2.8146 (4) Å]. The terminal triphenylphosphane ligand coordinates to the RuII atom, which is involved in two hydride bridges

Enzymatic Screening of β-Amyloid Precursor Protein-Based Substrates

We performed an enzymatic screening of synthetic peptides based on β-amyloid precursor protein substrates. The template peptide sequence was a decapeptide derived from our previous screening study, which determined several effective unnatural amino acids. In this study, new libraries containing some unnatural amino acid compounds were prepared in the solid phase and digested with the β-site amyloid precursor protein-cleaving enzyme. The reaction mixture was analyzed using high-performance liquid chromatography combined with mass spectrometry. The peptides that showed a higher cleavage than the template sequence were determined and reported