Magnetic interactions through fluoride: magnetic and spectroscopic characterization of discrete, linearly bridged [Mn(III)2(μ-F)F4(Me3tacn)2](PF6).

The nature of the magnetic interaction through fluoride in a simple, dinuclear manganese(III) complex (1), bridged by a single fluoride ion in a perfectly linear fashion, is established by experiment and density functional theory. The magnitude of the antiferromagnetic exchange interaction and the manganese(III) zero-field-splitting parameters are unambiguously determined by inelastic neutron scattering to yield J = 33.0(2) cm(-1) (Ĥ = JŜ1·Ŝ2 Hamiltonian definition) and single-ion D = -4.

X-ray magnetic circular dichroism (XMCD) study of a methoxide-bridged Dy(III)-Cr(III) cluster obtained by fluoride abstraction from cis-[Cr(III)F2(phen)2](+).

An isostructural series of dinuclear chromium(III)-lanthanide(III) clusters is formed by fluoride abstraction of cis-[CrF2(phen)2](+) by Ln(3+) resulting in LnF3 and methoxide-bridged Cr-Ln clusters (Ln = Nd (1), Tb (2), Dy (3)) of formula [Cr(III)(phen)2(μ-MeO)2Ln(NO3)4]·xMeOH (x = 2-2.73). In contrast to fluoride, methoxide bridges in a nonlinear fashion, which facilitates chelation.

Fluoride bridges as structure-directing motifs in 3d-4f cluster chemistry.

The use of kinetically robust chromium(III) fluorido complexes as synthons for mixed 3d-4f clusters is reported. The tendency toward linear {Cr(III)-F-Ln(III)} units dictates the cluster topology. Specifically, we show that reaction of cis-[Cr(III)F(2)(NN)(2)]NO(3) (NN = 1,10-phenanthroline ("phen") or 2,2'-bipyridine ("bpy")) with Ln(NO(3))(3)·xH(2)O produces isostructural series of molecular {Ln(2)Cr(2)} squares (1-9) with linear fluoride bridges.

cyclo-Tetra-μ-fluorido-1:2κF;2:3κF;3:4κF;1:4κF-octa-nitrato-1κO,O';3κO,O'-tetra-kis-(1,10-phenanthroline)-2κN,N';4κN,N'-2,4-dichromium(III)-1,3-dineodymium(III) methanol tetra-solvate monohydrate.

In the title compound, [Cr(2)Nd(2)F(4)(NO(2))(8)(C(12)H(8)N(2))(4)]·4CH(3)OH·H(2)O, two cis-difluoridobis(1,10-phenanthroline)chromium(III) fragments containing octa-hedrally coordinated chromium(III) bridge via fluoride ions to two tetra-nitratoneodymate(III) fragments, forming an uncharged tetra-nuclear square-like core. The fluoride bridges are fairly linear, with Cr-F-Nd angles of 168.74 (8)°.

Magnetic properties of a manganese(III) Chain with monoatomic bridges: catena-MnF(salen).

In the solid state, MnF(salen) forms chains wherein fairly linear fluoride bridges between high-spin Mn(III) centers are observed. We interpret the magnetic properties of these chains by use of the classical Fisher model and by use of the high-temperature expansion approach, as well as by exact matrix diagonalization of the spin Hamiltonian, of model rings. In solution, electron paramagnetic resonance shows the chains to be symmetrically cleaved to monomeric MnF(salen).

cis-Aqua-bis(2,2'-bipyridine-κN,N')fluoridochromium(III) bis-(perchlorate) dihydrate.

The title mixed aqua-fluoride complex, [CrF(C(10)H(8)N(2))(2)(H(2)O)](ClO(4))(2)·2H(2)O, has been synthesized by aqua-tion of the corresponding difluoride complex using lanthan-ide(III) ions as F(-) acceptors. The complex crystallizes with a Cr(III) ion at the center of a distorted octa-hedral coordination polyhedron with a cis arrangement of ligands. The crystal packing shows a hydrogen-bonding pattern involving water mol-ecules, the coordinated F atom and the perchlorate anions.

cis-Difluoridobis(1,10-phenanthroline)chromium(III) perchlorate monohydrate.

The title complex, [CrF(2)(C(12)H(8)N(2))(2)]ClO(4)·H(2)O, displays a slightly distorted octa-hedral coordination geometry around the central chromium(III) ion. The Cr environment is composed of a cis arrangement of two 1,10-phenanthroline [average Cr(III)-N = 2.0726 (10) Å] and two fluoride [average Cr(III)-F = 1.

Molecular and electronic structure of chromium(V) nitrido complexes with azide and isothiocyanate ligands.

The first use of [Cr(N)Cl4]2- as a starting material in chromium(v) nitrido chemistry is demonstrated in simple, high yield, metathesis reactions with the pseudohalogens SCN- and N3- yielding five-coordinate, labile complexes: [Cr(N)(NCS)4]2- and [Cr(N)(N3)4]2-, which have been crystallized and characterized by single-crystal X-ray diffraction. Reaction of [Cr(N)(NCS)4]2- with 1,10-phenanthroline furnishes six-coordinate [Cr(N)(NCS)3(phen)]- wherein phenanthroline coordinates to the position trans to the nitrido ligand. The trans influence of the nitrido ligand leads to a bond length difference of 0.

Two square-pyramidal chromium(V)-nitride complexes: bis(2-methylquinolin-8-olato)nitridochromium(V) and nitridobis(2-sulfidopyridine N-oxide)chromium(V).

Two new chromium(V)-nitride complexes with a coordination sphere completed by bidentate ligands have been synthesized and structurally characterized. Bis(2-methylquinolin-8-olato)nitridochromium(V), [Cr(C10H8NO)2(N)], has the coordination sphere completed by an equatorial N2O2 set of ligators. The compound crystallizes with the five-coordinate complexes at sites with twofold rotational symmetry and all Cr-N bond directions aligned with the crystallographic b axis.

Atom transfer as a preparative tool in coordination chemistry. Synthesis and characterization of Cr(V) nitrido complexes of bidentate ligands.

The transfer of a terminal nitrido ligand from Mn(V)(N)(salen) to Cr(III) complexes is explored as a new preparative route to Cr(V) nitrido complexes. Reaction of Mn(V)(N)(salen) with labile CrCl(3)(THF)(3) in acetonitrile solution precipitates [Mn(Cl)(salen)].(CH(3)CN) and yields a solution containing a mixture of Cr(V) nitrido species with only labile auxiliary ligands.