Manfredo Hörner

Antitumor and antimycobacterial activities of cyclopalladated complexes: X-ray structure of [Pd(C2,N-dmba)(Br)(tu)] (dmba = N,N-dimethylbenzylamine, tu = thiourea)

The reactions between [Pd(C(2),N-dmba)(micro-X)](2) (dmba=N,N-dimethylbenzylamine; X=Cl, Br) and thiourea (tu) in the 1:2 molar ratio at room temperature resulted in the mononuclear compounds [Pd(C(2),N-dmba)(Cl)(tu)] (1) and [Pd(C(2),N-dmba)(Br)(tu)] (2), which were characterized by elemental analyses and infrared (IR), (1)H- and (13)C{(1)H} NMR spectroscopies. The crystal and molecular structures of 2 were determined by single-crystal X-ray diffraction. In vitro cytotoxicity assays of the compounds 1, 2, tu, dmba and cisplatin were carried out using two murine tumor cell lines, namely mammary adenocarcinoma (LM3) and lung adenocarcinoma (LP07). The compounds 1, 2, tu and dmba were also tested against Mycobacterium tuberculosis and their MIC values were determined.

Synthesis and crystal structure of di [(μ-acetato)(2-acetylpyridine4N-ethylthiosemicarbazonato)zinc(II)]

Abstract The reaction between zinc(II) acetate and the tridentate ligand 2-acetylpyridine4N-ethylthio semicarbazone (H4EL) produces a dinuclear complex in which two deprotonated ligands are coordinated to two zinc(II) ions, one penta- and other hexacoordinatevia the sulfur thiolato (on deprotonation) atom and the azomethine and pyridine nitrogen atoms. The coordination spheres of the metal atoms being completed by acetate oxygen atoms. One of the acetate ions chelates one zinc atom and bridges between the twovia a single oxygen, while in the other each oxygen coordinates to a different zinc atom. The results of elemental analysis and IR spectroscopy are included.

An iron-based cytosolic catalase and superoxide dismutase mimic complex.

The development of metallodrugs with antioxidant activities is of importance as a way to protect organisms exposed to stressful conditions. Although iron chemistry in the presence of H(2)O(2) is usually associated with pro-oxidant activity, mainly via the Fenton reaction, we found that the mononuclear compound [Fe(HPClNOL)Cl(2)]NO(3) (1; C(15)H(18)Cl(3)FeN(4)O(4), a = 8.7751(3) A, b = 9.0778(4) A, c = 24.3869(10) A, beta = 93.370(2) degrees , monoclinic, P2(1)/c, Z = 4), containing the tripodal ligand 1-[bis(pyridin-2-ylmethyl)amino]-3-chloropropan-2-ol, decomposes hydrogen peroxide and superoxide anion in vitro as well as shows in vivo protection because it prevents the harmful effects promoted by H(2)O(2) on Saccharomyces cerevisiae cells, decreasing the level of lipid peroxidation. This protective effect was observed for wild-type cells, as well as for mutant cells, which do not present the antioxidant metalloenzymes catalase (Ctt1) or copper/zinc superoxide dismutase (Sod1).

PREPARATION, CHARACTERIZATION AND ELECTROCHEMICAL STUDIES OF 1,1'-BIS( DIPHENYLPHOSPHINO)FERROCENE (DPPF) DERIVATIVES. CRYSTAL STRUCTURE OF DPPFCO(NO) 2 SBF6

Abstract The neutral dppfFe(NO)2 (1), the novel cationic [dppfCo(NO)2][SbF6] (2), as well as the dppfFe(CO)3 (3) dppf = 1,1′-bis-(diphenylphosphino)ferrocene) complexes were prepared and characterized. The interaction between the two metallic centers through the dppf ligand was studied in the solid state by 57Fe Mossbauer spectroscopy and in solution by cyclic voltammetry. The Mossbauer parameters are compared with those of other dppfMLn, complexes. Electrochemical studies performed on these complexes show the great influence of the MLn moiety on the redox processes of the dppf iron center. The crystal structure of complex 2 was determined (C34H28CoF6FeN2O2P2Sb). The compound crystallizes in the triclinic, space group P 1 , a = 10.441(2), b = 10.755(2), c = 17.320(5) A , α = 104.10(2), β = 0.504(10), γ = 111.504(10)°, U = 1744.7(7) A 3 , Z = 2, R = 0.0765, wR2 = 0.1878 . In this complex, the cobalt atom is coordinated to two nitrosyl ligands and to phosphorus atoms of the dppf ligand, providing a distorted tetrahedral geometry.

Facile conversion of bis(alkynyl) into diyne ligand on platinum assisted by electrophilic gold phosphine

Abstract 31P NMR spectroscopy measurements were used to establish the course for the stoichiometric-dependent reactions between [Au(PPh3)]+ and [Pt(CCPh)2(dppf)] (1), which for equimolar amounts afford as the unique product [Pt-{η3-C(CCPh)C(Ph)Au(PPh3)}(dppf)]+ (2), but any excess of 1 gives also [Pt(η2-PhCCCCPh)(dppf)] (3) [dppf=1,1′-bis(diphenylphosphine)ferrocene]. Both compounds 2 and 3 were obtained straightforwardly by the reactions of 3 with [Au(PPh3)]+ and [Pt(C2H4)(dppf)] with 1,4-diphenylbutadiyne, respectively. The X-ray crystal structure analysis of 3 confirmed a trigonal-planar coordination geometry about the platinum atom, and a bent η2-coordinated diyne ligand.

Preparation, crystallography and spectroscopic properties of the polymeric {(1-(E)-2-pyridinylmethylidene)semicarbazone)(aqua)copper(II)} sulphate dihydrate complex: Evidence of dynamic Jahn–Teller effect

Pyridine-2-carbaldehyde semicarbazone ligand (HL) reacts with copper(II) sulphate in water solution to yield the coordination polymer [{Cu(II)(HL)(H(2)O)(SO(4))}(n)] (1). The crystals are triclinic with space group P(-1) and the metal ion is occupying a distorted octahedral geometry. EPR results show that a dynamic Jahn-Teller (J-T) effect is operative in water solutions and also support the stability of the polymeric chains as they continue to show a characteristic half-field Δm(S)=±2 transitions. UV-visible spectrum analysis allowed access to the J-T stabilization energy of 5995 cm(-1) in water. Thermogravimetric/differential thermal analysis curves showed a step-by-step decomposition of complex 1 with loss of water, release of SO(3) and oxidation of the semicarbazone ligand in the 30-422°C range.

Molecular Structure of Heterocycles: NMR Spectroscopy, Semiempirical MO Calculations and X-Ray Diffraction of 3,3a,4,5,6,7-Hexahydro-3-trichloromethyl[2,1]benzoisoxazole

Abstract 1H and 13C NMR data, AMI calculations and X-ray diffraction in 3,3a,4,5,6,7-hexahydro-3-trichloromethyl[2,1]benzo isoxazole (1), obtained from the cyclization of trichloroacetyl cyclohexanone with hydroxylamine, are reported. 1H and 13C NMR data shown that only one pair of the diastereoisomers was obtained and the AMI calculations indicated that 1a (3S3aS/3R3aR) is 2.63 kc:al.mol−1 more stable than 1b (3S3aR/3R3aS). The X-Ray diffraction data confirmed that only the structure 1a was obtained. Crystals of 1 (C8H10Cl3NO2, Mr = 258.52) were obtained from acetone/n-hexane solution. The compound crystallizes in the monoclinic space group P21/c with the cell dimensions a = 10.153(2), b = 8.271(2) and c = 14.225(3) A, β = 103.8(3)°, V = 1160.0(4) A3, Z= 4, Dcalcd. = 1.480 Mg/m3, λ(MoKα) = 0.71073 A, = 0.764 mm-1, F(000) = 528, T= 293(2) K, R = 7.31 % and Rw = 17.91 % for an F 2 refinement on unique data with 2082 reflections and 1994 independent (Rint = 6.70%) were collected.

In vitro evaluation of triazenes: DNA cleavage, antibacterial activity and cytotoxicity against acute myeloid leukemia cells

). The observation of intermolecular hydrogen bonding in the solid state of compound 3, based on the structural analysis by X-ray crystallography, as well as the results of IR and UV-Vis spectroscopic analyses of compounds 1, 2 and 3 are discussed in the present work.

Cis and trans nucleophilic additions on CC bonds assisted by Pt(II) complexes. X-ray crystal structure of trans-{Pt[cis-(o-NC5H4)CHC(Ph)(NEt2)]Cl2(HNEt2)}

The reaction between PtCl 2 (PhCN) 2 and N,N-dimethylphenyl propargyl amine ( 1 ) affords trans -[Pt(N(Me 2 )CH 2 CCPh)(NCPh)Cl 2 ] ( 3 ) which formally undergoes trans -Cl −3 addition onto its CC bond to give [Pt(C(Ph)  C(Cl)CH 2 NMe 2 )(NCPh)Cl] ( 4 ). On the other hand, the cis -nucleophilic addition product trans -{Pt[ cis -( o -NC 5 H 4 ) CHC(Ph)(NEt 2 )]Cl 2 (HNEt 2 )} ( 6 ) was obtained quantitatively from the reaction of a large excess of diethylamine with trans -[Pt( o -NC 5 H 4 )CHC(Ph)(SEt 2 )Cl 2 ] ( 5 ).

1,3-Bis(4-nitrophenyl)triazene

The structure of the title compound, C(12)H(9)N(5)O(4), reveals an almost planar molecule (r.m.s. deviation = 0.061 A), in which the interplanar angle between the phenyl rings is 5.7 (1) degrees and the largest interplanar angle is that between the phenyl ring and the nitro group of one of the 4-nitrophenyl substituents [8.8 (3) degrees ]. The observed molecular conformation suggests a delocalization of pi-electrons extended over the diazoamine group and the terminal aryl substituents. Intermolecular N-H.O interactions between the twofold screw-related molecules give rise to helical chains along the [010] direction. Intermolecular C-H.O interactions then generate sheets of molecules in the (10-1) plane, and these sheets are held together by N.C and O.O pi-pi interactions.