The title salt, [CoBr(C11H27N5)]Br2·2H2O, contains a complex cation with mirror symmetry and two Br(-) counter-anions that are likewise located on the mirror plane. The central Co(III) atom of the complex cation has one Br(-) ion in an axial position, one N atom of the penta-dentate macrocyclic ligand in the other axial position and four N atoms of the ligand in equatorial positions, defining a...

Influence of the axial ligand of PD1 chlorophyll (D1-His-198) on the Em of monomer chlorophylls PD1 and PD2, and the PD1•+/PD2•+ charge ratio was investigated by theoretical calculations using the PSII crystal structure of Thermosynechococcus vulcanus analyzed at 1.9-Å resolution. It was found that the Em(PD1)/Em(PD2) values and PD1•+/PD2•+ ratio remained unchanged upon D1-H198Q mutation. Howev...

The epoxidation of olefins with tetra n-butylammonium periodate, n-Bu4/NIO4, is catalyzed by six different tetrakis (4-substituted phenyl) porphyrinatomanganese(III) acetate, Mn(T4-XPP)OAc, Complexes in the presence of imidazole as an axial ligand with low to high yields and complete selectivity at room temperature. While the electronic effects of the highly electron-w...

We present the synthesis and cytotoxic potencies of new Pt(IV) complexes with bexarotene, an anticancer drug that induces cell differentiation and apoptosis via selective activation of retinoid X receptors. In these complexes bexarotene is positioned as an axial ligand. The complex of one bexarotene ligand attached to Pt(IV) oxaliplatin moiety was potent whereas its counterpart carrying two bex...

An iron porphyrin catalyst with four electron donor groups is reported. The porphyrin ligand bears a distal hydrogen bonding pocket which inverts the normal axial ligand binding selectivity exhibited by porphyrins bearing sterically crowded distal structures. This catalyst specifically reduces O(2) by four electrons under both fast and slow electron fluxes at pH 7.

A multidentate and flexible diolefin-diphosphine ligand, based on the dibenzylidene acetone core, namely dbaphos (1), is reported herein. The ligand adopts an array of different geometries at Pt, Pd and Rh. At Pt(II) the dbaphos ligand forms cis- and trans-diphosphine complexes and can be defined as a wide-angle spanning ligand. (1)H NMR spectroscopic analysis shows that the β-hydrogen of one o...

In the title compound, [ReBr(C(27)H(27)NP(2))(CO)(3)], the Re(I) atom is octa-hedrally surrounded by three carbonyl ligands in a facial arrangement, a bromide ligand and the P,P'-bidentate ligand Bis(diphenyl-phosphino)propyl-amine. The compound exhibits substitutional disorder of the bromide ligand and the axial carbonyl ligand, with almost 50% occupancy for both Br amd CO [0.538 (4) and 0.462...

Within Cu-containing electron transfer active sites, the role of the axial ligand in type 1 sites is well defined, yet its role in the binuclear mixed-valent CuA sites is less clear. Recently, the mutation of the axial Met to Leu in a CuA site engineered into azurin (CuA Az) was found to have a limited effect on E(0) relative to this mutation in blue copper (BC). Detailed low-temperature absorp...

Cyclic voltammogram and differential pulse polarograph of octaethyl porphyrin iron(III) chloride in dichloromethane was investigated in the presence of pyridine, imidazole and collidine. Values of E1/2 for FeIII/FeII redox reaction were monitored as a function of axial group concentration, and on the basis of these data, an overall oxidation-reduction and ligand addition scheme was formulated. ...