Electronic versus steric control in palladium complexes of carboranyl phosphine-iminophosphorane ligands.

A new family of carboranyl phosphine-iminophosphorane ligands was prepared and characterized. The new ligands present a carboranyl group directly attached to the iminophosphorane nitrogen atom through a cage carbon atom (C-carboranyl derivatives L1-L3) or through the B3 boron atom (B-carboranyl derivatives L4 and L5), and the phosphine group on a side chain derived from the diphosphine dppm, i.e.

Metal complexes of a novel heterocyclic benzimidazole ligand formed by rearrangement-cyclization of the corresponding Schiff base. Electrosynthesis, structural characterization and antimicrobial activity.

The electrochemical oxidation of anodic metals (M = cobalt, nickel, copper, zinc and cadmium) in a solution of the ligand 1H-anthra[1,2-d]imidazol-6,11-dione-2-[2-hydroxyphenyl] [HL] afforded homoleptic [ML] compounds. The addition to the electrochemical cell of coligands (L') such as 2,2'-bipyridine (bpy) or 1,10-phenanthroline (phen) allowed the synthesis, in one step, of heteroleptic [MLL'] compounds. The crystal structures of HL (1), [CoL(MeOH)] (2), [CoL(phen)] (3), [NiL(bpy)] (4), [CuL(bpy)] (5), [CuL(phen)] (6) and [CdL(bpy)] (7) have been determined by X-ray diffraction techniques.

Deactivation of the coordinating ability of the iminophosphorane group by the effect of ortho-carborane.

The C-carboranyl iminophosphorane compounds derived from triphenylphosphine (I1) and o-(methylthiophenyl)-diphenylphosphine (I2) were obtained and structurally characterized. Functionalization with sulfur on the other cage carbon atom gave the corresponding disulfides (L1L1 and L2L2). In the case of I1 it was also possible to isolate the trisulfide (L1SL1) and the thiol (L1H), which is not in the expected zwitterionic form, showing that the carborane group reduces the basicity of the nitrogen atom.

Fluorescence of new o-carborane compounds with different fluorophores: can it be tuned?

Two sets of o-carborane derivatives incorporating fluorene and anthracene fragments as fluorophore groups have been successfully synthesized and characterized, and their photophysical properties studied. The first set, comprising fluorene-containing carboranes 6-9, was prepared by catalyzed hydrosilylation reactions of ethynylfluorene with appropriate carboranylsilanes. The compound 1-[(9,9-dioctyl-fluorene-2-yl)ethynyl]carborane (11) was synthesized by the reaction of 9,9-dioctyl-2-ethynylfluorene and decaborane (B10H14).

Using the Wittig reaction to produce alkenylcarbaboranes.

This communication reports the first use of the Wittig reaction to produce alkenylcarbaboranes.