A ruthenium(II) allenylidene complex with a 4,5-diazafluorene functional group: A new building-block for organometallic molecular assemblies

The synthesis of the new ruthenium(II) allenylidene complex [ClRu(dppe)₂CCC₁₁H₆N₂][OTf] (4) (dppe = 1,2-bis(diphenylphosphino)ethane) terminated with a 4,5-diazafluorene ligand is reported. Further coordination of that metal allenylidene to ruthenium and rhenium moieties leads to the bimetallic adducts [ClRu(dppe)₂CCC₁₁H₆N₂{Ru(bpy)₂}][B(C₆F₅)₄]₃ (5a), [ClRu(dppe)₂CCC₁₁H₆N₂{Ru(^tBu-bpy)₂}][PF₆]₃ (5b) and [ClRu(dppe)₂CCC₁₁H₆N₂{Re(CO)₃Cl}][OTf] (6). Their optical and electrochemical properties show that the allenylidene moiety is an attractive molecular clip for the access to larger original redox-active homo/heteronuclear multi-component supramolecular assemblies. The X-ray crystal structure of the allenylidene metal building block is also described.     

Chromatographic Separation and Mass Spectrometric Analysis of Bacterial Cell Wall Synthesizing Enzyme Complexes

ABSTRACT

Penicillin-binding proteins (PBPs) were shown to associate non-covalently with many other morphogene proteins (MGPs). Specific associations were assigned. The PBPs were labeled with spectroscopic/fluorescence (F/S) groups in the form of dansylated β-lactam probes. Competitive β-lactam binding of non-denatured PBP/MGP complexes led to characteristic patterns of F/S labeling by the probes. The salt-bridge specific reagent, ethanedinitrile, covalently linked various MGPs to the F/S labeled PBPs. Proteolysis of chromatographically purified F/S labeled fractions gave sets of peptides analyzed by MALDI-TOF to give MH data. Peptide mass-fingerprinting analysis revealed that covalent linkage occurred with other MGPs and not with non-MGP proteins of ～3400 proteins in the SWISS-PROT r33 data base for E. coli K-12.