Mononuclear and dinuclear manganese compounds stabilized by supramolecular interactions.

New manganese compounds [Mn(HphpzMe)(2)(H(2)phpzMe)(HCO(2))] (1), [Mn(2)(phpzMe)(2)(HphpzMe)(2)(OCH(3))]·2CH(3)OH (2), Na{[Mn(HphpzPh)(phpzPh)(MeOH)(2)](2)}(HCO(2)) (3), [Mn(HphpzPh)(2)(EtOH)(2)]ClO(4)·2EtOH (4) and [Mn(HphpzPh)(2)N(3)] (5) were synthesized and characterized with various techniques. 1, 4 and 5 are mononuclear manganese(III) compounds, 2 is a mixed-valence dinuclear manganese(III/IV) compound, and 3 is a trinuclear compound containing two manganese(III) ions and a sodium(I) ion. A remarkable feature is the spontaneous formation of the formate ion as a result of the methanol or methoxide oxidation in compounds 1 and 3.

Tetra-hedral zinc in tetra-kis-(1-methyl-1H-imidazole-κN)zinc bis-(tetra-fluorido-borate).

In the title compound, [Zn(C(4)H(6)N(2))(4)](BF(4))(2), the Zn(II) ion is in a slightly distorted tetra-hedral coordination geometry, with Zn-N distances in the range 1.980 (2)-1.991 (2) Å.

High nuclearity manganese(III) compounds containing phenol-pyrazole ligands: the influence of the ligand on the core geometry.

Three high-nuclearity manganese(III) clusters have been synthesized and characterized: [Mn₈(μ₄-O)₄(phpzH)₈(thf)₄] (1), [Mn₈(μ₄-O)₄(phpzH)₄(EtOH)₄]·2EtOH (2), and [Mn₆(μ₃-O)₄(μ₃-Br)₂(HphpzEt)₆(phpzEt)] (3). Compounds 1 and 2 contain a [Mn₈(μ₄-O₄)(phpzH)₈] core in which antiferromagnetic interactions between the manganese(III) ions are found. Compound 3 is a hexanuclear manganese(III) cluster in which weak ferromagnetic interactions appear to be operative.

Discrete tetrairon(III) cluster exhibiting a square-planar Fe4(mu4-O) core: structural and magnetic properties.

The aerobic reaction of the Schiff-base ligand N-(benzimidazol-2-yl)salicylaldimine (Hbisi) with iron(II) perchlorate in methanol leads to the formation of the remarkable coordination compound [Fe(4)(mu(4)-O)(mu-MeO)(4)(bisi)(4)](ClO(4))(2) x 4 MeOH (1), whose single-crystal X-ray structure reveals the presence of a discrete Fe(III)(4)(mu(4)-O) core. Magnetic and Mossbauer studies both show that the exchange interaction within the square tetranuclear iron(III) unit is dominated by the central bridging mu(4)-oxido ligand, the involvement of the mu-methoxido bridges being negligible.

Manganese(III) compounds with phenol-pyrazole based-ligands: impact of the co-ligand and the carboxylate ligand on the trinuclear core [Mn3(mu3-O)(phpzR)3(O2CR')n](1-n).

The reaction of H2phpzR (R = Me, Ph; H2phpzMe = 3(5)-(2-hydroxyphenyl)-5(3)-methylpyrazole and H2phpzPh = 3(5)-(2-hydroxyphenyl)-5(3)-phenylpyrazole) with Mn(O2CR').nH2O (R' = Me and Ph) and (nBu4N)MnO4 in ethanol (EtOH) affords three new manganese(III) compounds, [Mn3(mu3-O)(phpzMe)3(O2CMe)(EtOH)].EtOH (1), (nBu4N)[Mn3(mu3-O)(phpzMe)3(O2CPh)2] (2) and (nBu4N)[Mn3(mu3-O)(phpzPh)3(O2CPh)2] (3).

Cytotoxic activity and cellular processing in human ovarian carcinoma cell lines of a new platinum(II) compound containing a fluorescent substituted propylene diamine ligand.

A new fluorescent platinum(II) compound containing the N,N'-bis-(anthracen-9-ylmethyl)propane-1,3-diamine as a carrier ligand has been designed, synthesized and characterized. High cytotoxic activity of cis-[Pt(bapda)Cl2] is observed in A2780 and A2780R cells (human ovarian carcinoma sensitive and cisplatin-resistant, respectively). Nevertheless, cross-resistance to platinum from cis-[Pt(bapda)Cl2] in the A2780R cells was found.

Concurrent anion...pi interactions between a perchlorate ion and two pi-acidic aromatic rings, namely pentafluorophenol and 1,3,5-triazine.

The rational design of a ligand containing two electron-poor pi-rings, i.e. a triazine and a pentafluorophenoxy groups, has allowed the preparation of a copper complex where both the anticipated anion.

A copper complex bearing a TEMPO moiety as catalyst for the aerobic oxidation of primary alcohols.

A new bifunctional, triazine-based ligand has been designed with the aim to generate a copper(II) complex holding a TEMPO (2,2,6,6-tetramethylpiperidinyloxy) moiety. The coordination compound obtained from the ligand 4-(2-(3-(pyridin-2-yl)-1H-pyrazol-1-yl)ethoxy)-6-(4-amino-2,2,6,6-tetramethylpiperidine-1-oxyl)-N,N-diphenyl-1,3,5-triazin-2-amine (pypzt-1) and copper(II) bromide (i.e.

Mononuclear manganese(III) complexes as building blocks for the design of trinuclear manganese clusters: study of the ligand influence on the magnetic properties of the [Mn3(mu3-O)](7+) core.

The synthesis, crystal structure, and magnetic properties of three new manganese(III) clusters are reported, [Mn 3(mu 3-O)(phpzH) 3(MeOH) 3(OAc)] (1), [Mn 3(mu 3-O)(phpzMe) 3(MeOH) 3(OAc)].1.5MeOH (2), and [Mn 3(mu 3-O)(phpzH) 3(MeOH) 4(N 3)].

Structure and DNA cleavage properties of two copper(II) complexes of the pyridine-pyrazole-containing ligands mbpzbpy and Hmpzbpya.

The DNA-cleavage properties of the two copper(II) complexes, [Cu(mbpzbpy)Br(2)](H(2)O)(2.5) (1) and [Cu(mpzbpya)Cl](CH(3)OH) (2), obtained from the ligands 6,6'-bis(3,5-dimethyl-N-pyrazolmethyl)-2,2'-bipyridine) (mbpzbpy) and 6'-(3,5-dimethyl-N-pyrazolmethyl)-2,2'-bipyridine-6-carboxylic acid) (Hmpzbpya), respectively, are reported. Upon coordination to Cu(II) chloride in methanol, one arm of the ligand mbpzbpy is hydrolyzed to form mpzbpya.

Controlled copper-mediated chlorination of phenol rings under mild conditions.

The very unusual case of copper-mediated chlorination of phenol rings under mild conditions at room temperature is reported. Reaction of the ligand 1,7-bis(2-hydroxyphenyl)-2,6-diaza-4-hydroxylheptane (H3L1) with CuCl2 in acetonitrile leads to either the formation of a tetranuclear copper(II) complex [Cu4(HL3)2(mu-Cl)2Cl2](CH3CN) (1) or a linear trinuclear complex [Cu3(HL1)2Cl2(CH3CN)2](CH3CN)2 (2), depending on the reaction conditions. Both compounds have been fully characterized, including the determination of their 3D structures by X-ray diffraction.

Remarkable steric effects and influence of monodentate axial ligands l on the spin-crossover properties of trans-[FeII(N4 ligand)L] complexes.

Iron(II) complexes obtained from tetradentate, rigid, linear N4 ligands have been investigated to appraise the influence of steric effects and the impact of trans-coordinated anions on the spin-transition behavior. As expected, the well-designed ligands embrace the metal center, resulting in octahedral iron(II) complexes where the basal plane is fully occupied by the pyridine/pyrazole N4 ligand, while anions or solvent molecules are exclusively axially coordinated. Precursor complexes, namely, [Fe(bpzbpy)(MeOH)2](BF4)2 (where bpzbpy symbolizes the ligand 6,6'-bis(N-pyrazolylmethyl)-2,2'-bipyridine) and [Fe(mbpzbpy)(MeOH)2](BF4)2 (where mbpzbpy symbolizes the ligand 6,6'-bis(3,5-dimethyl-N-pyrazolmethyl)-2,2'-bipyridine), have been used for the in situ preparation of a series of structural analogues via the exchange of the weakly coordinated trans methanol molecules by various anions, such as thiocyanate, selenocyanate, or dicyanamide.

The self-assembly between C2-symmetric (methanol)6 or S6-symmetric (ethanol)6 cyclohexamers and paddle-wheel dinuclear copper units leads to unique 1D polymer chains.

The first crystallographic evidences of the theoretically suggested C2-symmetric cyclohexameric form of liquid methanol and the S6-symmetric cyclohexameric form of liquid ethanol are reported, trapped inside a hydrophilic pocket shielded by tert-butyl groups.

Versatility in the binding of 2-pyrazinecarboxylate with iron. Synthesis, structure and magnetic properties of iron(II) and iron(III) complexes.

The synthesis and characterization of two new iron(II) complexes, [Fe(pca)2(py)2].py (1) and {[Fe(pca)2(H2O)].H2O}n (2) and one new iron(III) complex, Na2{[Fe(pca)()]2O}.

Moisture-triggered 1,3,5-triazine-based Cu(II) molecular switch: a combined X-ray single-crystal and powder diffraction study.

A solvothermal synthetic procedure has been exploited to prepare the new [Cu(3)L(NO(3))(6)](n) coordination polymer (1) by reaction of the polydentate N,N'-{2,4-di-[(di-pyridin-2-yl)amine]-1,3,5-triazine}ethylenediamine ligand (opytrizediam L) with copper(II) nitrate. 1 has been structurally characterized by means of the conventional X-ray single-crystal diffraction technique. It crystallizes in the monoclinic C2/c space group with a = 16.

Aqua[bis(pyrimidin-2-yl-kappa N)amine](carbonato-kappa 2O,O')copper(II) dihydrate.

The title mononuclear complex, [Cu(CO(3))(C(8)H(7)N(5))(H(2)O)] x 2H(2)O, was obtained by fixation of CO(2) by a mixture of copper(II) tetrafluoroborate and the ligand bis(pyrimidin-2-yl)amine in ethanol/water. The Cu(II) ion of the complex has a distorted square-pyramidal environment, with a basal plane formed by two N atoms of the ligand and two chelating O atoms of the carbonate group, while the apical position is occupied by the O atom of the coordinating water molecule. In the solid state, hydrogen-bonding interactions are dominant, the most unusual being the Watson-Crick-type coplanar ligand pairing through two N--H.