Unique resonance Raman spectra were obtained when manganese(III) tetraphenylporphin halides in noncoordinating solvents were illuminated by laser frequencies around 500 nm. Of particular interest is the observation of a feature that is sensitive to the nature of the axial ligand. This feature disappears when the coordinating solvent pyridine is employed, and it, therefore, appears to be diagnos...

Conversion of a myo-inositol derivative into a scyllo-inositol-derived scaffold with C₃(v) symmetry bearing three axial pyridyl appendages is presented. This pre-organized hexadentate ligand allows complexation of silver(I). The crystal structure of the complex was established.

An empirical equation, describing the relationship between the porphyrin methyl hyperfine shifts and the position of the axial ligand(s), has been applied to an artificial heme-protein in order to obtain insight into the active site properties of heme-protein models.

The Sn atom of the title compound, [Sn(C(6)H(5))(2)(C(11)H(11)NO(4))], adopts a distorted SnNC(2)O(2) trigonal-bipyramidal geometry with the O atoms in the axial positions. The metal atom forms five- and six-membered chelate rings with the O,N,O'-tridentate ligand.

In the title manganese(III) complex, [MnCl(2)(C(10)H(24)N(4))]BF(4) or trans-[MnCl(2)(cyclam)]BF(4) (cyclam is the tetra-dentate amine ligand 1,4,8,11-tetra-azacyclo-tetra-deca-ne), the Mn(III) ions occupy the center of a distorted octa-hedron coordinated by all four ligand nitro-gen donors in the macrobicyclic cavity and two chloride ions occupy the axial positions. Intra-molecular hydrogen bo...

The Ni atom in the title complex, [Ni(SO(4))(C(15)H(13)N(5))(H(2)O)]·H(2)O, has a distorted trigonal-bipyramidal coordination formed by the tridentate 2,6-bis-(2-pyridylamino)pyridine (tpdaH(2)) ligand, one sulfate and one coordinated water mol-ecule. The tpdaH(2) ligand is three-coordinated, with the N atom of the central pyridine ring in the equatorial position [Ni-N = 1.9961 (14) Å] and the ...

A series of mononuclear Mn(II), Mn(III), and Mn(IV) complexes was prepared using a single tripodal ligand (H(3)L). Addition of a cation (NH(4)(+), K(+), Na(+)) to [Mn(III)L] showed a pronounced effect on the redox potentials. Different variants of Jahn-Teller distortion, axial elongation and compression, were observed in the Mn(III) complexes.

A new measure of the crystal-field strength, complementary to the conventional one, is defined. It is based on the rotational invariants |Bk0|av or | ∑ k Bk0|av, k = 2, 4, 6, of the crystal-(ligand)-field (CF) HamiltonianHCF parametrizations, i.e. on the axial CF parameters modules averaged over all reference frame orientations. They turn out to be equal to ∣

The Sb atom in the centrosymmetric title complex, [Sb(2)(C(6)H(5))(6)(C(2)H(2)ClO(2))(2)O], has a distorted trigonal-bipyramidal geometry. The bridging oxide O atom occupies one of the axial sites, while the O atom of the chloroacetate ligand occupies the other.

Methylmalonyl-CoA mutase is an adenosylcobalamin (AdoCbl)-dependent enzyme that catalyzes the rearrangement of methylmalonyl-CoA to succinyl-CoA. The crystal structure of this protein revealed that binding of the cofactor is accompanied by a significant conformational change in which dimethylbenzimidazole, the lower axial ligand to the cobalt in solution, is replaced by His-610 donated by the a...