Milan Nádvorník

Coordination compounds of nickel with trithiocyanuric acid: Part III. Crystal and molecular structure of [Ni(bapen)(ttcH)]·2H2O (bapen=N,N′-bis(3-aminopropyl)ethylenediamine, ttcH3=trithiocyanuric acid)

Abstract Coordination compounds of compositions [Ni(bapen)(ttcH)]·2H2O (1), [Ni(bappn)(ttcH)] (2), [Ni(mdpta)(ttcH)(H2O)] (3), [Ni(nphen)2(ttcH)]·H2O (4), [Ni(nphen)3](ttcH)·2H2O (5), [Ni(ampy)2(ttcH)]·H2O (6) and [Ni(aepy)2(ttcH)]·2H2O (7), where bapen=N,N′-bis(3-aminopropyl)ethylenediamine, bappn=N,N′-bis(3-aminopropyl)-1,3-propanediamine, mdpta=3,3′-diamino-N-methyldipropylamine, nphen=5-nitro-1,10-phenanthroline, ampy=2-aminomethylpyridine, aepy=2-aminoethylpyridine and ttcH3=trithiocyanuric acid, have been prepared. The crystal and molecular structure of (1) was determined by X-ray analysis. Nickel atom is six-coordinated by four N atoms of amine and S and N donor atoms of trithiocyanuric dianion, whereas two water molecules are situated outside the coordination sphere. Cyclic voltammetry showed that the complexes undergo an oxidation attributable to Ni2+→Ni3+ in the range 550–950 mV. The magnetic behaviour of (6) and (7) has been studied in the 291–94 K temperature range. Magnetic susceptibility follows the Curie-Weiss law.

Chiral nucleophilic glycine and alanine synthons: nickel(II) complexes of Schiff bases of (S)-N-(2,4,6-trimethylbenzyl)proline (2-benzoylphenyl)amide and glycine or alanine

A new chiral auxilliary, (S)-N-(2,4,6-trimethylbenzyl)proline (2-benzoylphenyl)amide, has been synthesised as a potential building block for the preparation of chiral synthons of amino acids. The nickel(II) complex of its Schiff base derivative with glycine has been methylated with 97% d.e. (diastereomeric excess), whilst the nickel(II) complex of its Schiff base derivative with (RS)alanine has been 13C-methylated with 66% d.e.

27Al, 15N, 13C and 1H NMR spectra and negative-ion electrospray mass spectra of the 2:1 aluminium(III) complexes of azo dyes derived from anthranilic acid

Abstract The 27 Al, 15 N, 13 C and 1 H NMR spectra in DMSO and mass spectra of 2:1 aluminium(III) complexes ( 1b – 4b ) derived from anthranilic acid azo coupling products with 4-tert.butylphenol ( 1a ), 2-naphthol ( 2a ) acetoacetanilide ( 3a ) 3-methyl-1-phenylpyrazol-5-one ( 4a ) were measured and analysed. It was found that the aluminium atom was six-coordinated, being bound to two oxygens and the nitrogen originating from anthranilic acid.

Binuclear iron(III)-iron(III) complexes with the tetradentate Schiff base N,N′-bis(salicylidene)ethylenediamine and dicarboxylic acids or dithiooxamide as bridging ligands

SummaryComplexes of the type [(Fe(salen))2L]·xH2O (L = glutarate, adipate, pimelate or suberate dianion, x = 0 or L = dithio oxamidate dianion, x = 2) have been prepared and studied by elemental analyses, i.r. and electronic spectra, and magnetic measurements. A dimeric structure with an octahedral arrangement of FeIII (S = 5/2) is proposed. Some of the complexes have been characterized by temperature-dependent magnetic susceptibilities, but an antiferromagnetic exchange interaction was found only for [(Fe(salen))2dta]·2H2O (H2dta = dithio-oxamide).

Improved synthesis of the Ni(II) complex of the Schiff base of (S)-2-[N-(N′-benzylprolyl)amino]benzophenone and glycine

The environmental impact of a known synthesis of the Ni complex of the Schiff base of (S)-2-[N-(N′-benzylprolyl)amino]benzophenone and glycine was decreased by optimisation of the ratio the starting materials; a new starting material, Ni(NO3)2·6NH3, was evaluated as a nickel source.

Characterization of Ni(II) complexes of Schiff bases of amino acids and (S)-N-(2-benzoylphenyl)-1-benzylpyrrolidine-2-carboxamide using ion trap and QqTOF electrospray ionization tandem mass spectrometry

This work demonstrates the application of electrospray ionization mass spectrometry (ESI-MS) using two different mass analyzers, ion trap and hybrid quadrupole time-of-flight (QqTOF) mass analyzer, for the structural characterization of Ni(II) complexes of Schiff bases of (S)-N-(2-benzoylphenyl)-1-benzylpyrrolidine-2-carboxamide with different amino acids. ESI enables the determination of molecular weight on the basis of rather simple positive-ion ESI mass spectra containing only protonated molecules and adducts with sodium or potassium ions. Fragmentation patterns are characterized by tandem mass spectrometric experiments, where both tandem mass analyzers provide complementary information. QqTOF data are used for the determination of elemental composition of individual ions due to mass accuracies always better than 3 ppm with the external calibration, while multistage tandem mass spectra obtained by the ion trap are suitable for studying the fragmentation paths. The novel aspect of our approach is the combination of mass accuracies and relative abundances of all isotopic peaks in isotopic clusters providing more powerful data for the structural characterization of organometallic compounds containing polyisotopic elements. The benefit of relative and absolute mean mass accuracies is demonstrated on the example of studied Ni(II) complexes.

Cyano-Bridged Bimetallic Complexes of Copper(II) with Nitroprusside. Crystal Structure of [Cu(H2NCH2CH(NH2)CH3)2Fe(CN)5NO] . H2O

Five new complexes of compositions [Cu(1,2-pn)2Fe(CN)5NO]·H2O (1,2-pn = propane-1,2-diamine) and [Cu(L)Fe(CN)5NO]·xH2O (L = tmen (N,N,N′,N′-tetramethylethane-1,2-diamine), x = 0.5; L = trimeen (N,N,N′-trimethylethane-1,2-diamine), x = 1; L = dien (N-(2-aminoethyl)ethane-1,2-diamine), x = 0; L = medpt (N-(3-aminopropyl)-N-methylpropane-1,3-diamine), x = 2) have been isolated from the reaction mixture of Cu(ClO4)2·6H2O (or CuCl2·2H2O), the amine and Na2 [Fe(CN)5NO]·2H2O in water. The complexes have been characterized by infrared and ultraviolet–visible spectroscopies, and magnetic measurements. Single-crystal X-ray structural analysis revealed that the [Cu(1,2-pn)2Fe(CN)5NO]·H2O complex assumes a cyanide-bridged binuclear structure in which iron(II) is six-coordinated by five cyanide ligands and one nitrosyl group (the nitrosyl group lies cis to the bridging cyanide group), while copper(II) is five-coordinated by two propane-1,2-diamine ligands and a bridging cyanide ligand in a distorted tetragonal pyramidal arrangement.

Long-range J(15N,13C) and J(13C,13C) coupling constants via the metal atom in 13C NMR spectra of square-planar Ni(II) complexes of the Schiff base of (S)-2-(N-benzylprolyl)aminobenzophenone and 13C-1-, 13C-2- or 15N-labelled glycine

Chiral synthons containing either 13C‐ or 15N‐labelled glycine were prepared. The 13C and 15N NMR spectra of the Ni(II) complex of the Schiff base of (S)‐2‐(N‐benzylprolyl)aminobenzophenone and 13C‐1‐, 13C‐2‐ or 15N‐labelled glycine were measured and assigned. The observed splitting of the carbon signals is due to long‐range J(13C,13C) and J(15N,13C) couplings. The mutual influence of nuclei is transferred via the central Ni(II) atom in square‐planar complexes.

The Polynuclear Complexes of Iron(II,III) and Copper(II) with Cyanide as Bridging Ligand

Abstract Five novel complexes of the type [CuL2][Fe(CN)5NO]. xH2O (L = ethylenediamine (en), x = 0; L = o-phenanthroline (phen) or 2,2′-bipyridine (bpy), x = 2), [CuL2]3[Fe(CN)6]2. xH2O (L = bpy, x = 6; L = phen, x = 9) have been prepared and studied by elemental analyses, thermal analyses, IR and UV-vis. spectra and magnetic measurements. The structures are proposed with cyanide bridges between Fe(II) and Cu(II) (nitroprusside complexes) or between Fe(III) and Cu(II) (hexacyanoferrate(III) complexes). The temperature dependence of the magnetic susceptibility of the complex [Cu(bpy)2]3[Fe(CN)6]2. 6H2O was measured in the range 94.4–293.5 K but no exchange interaction was found. The product of the thermal decomposition of the complex [Cu(bpy)2]3[Fe(CN)6]2. 6H2O is a mixture of CuO and CuFe2O4, as determined by X-ray powder diffraction.

{2-[(S)-({2-[(S)-1-Benzylpyrrolidine-2-carboxamido]phenyl}(phenyl)methylene)amino]-4-hydroxybutanoato-kappa N-4,N ',N '',O}nickel(II)

The central Ni atom of the title compound, [Ni(C29H29N3O4)], is coordinated by three N atoms [Ni—N = 1.955 (2), 1.844 (2) and 1.872 (2) Å] and by one O atom [Ni—O = 1.862 (2) Å] in a pseudo-square-planar geometry. The conformation of the hydroxybutanoate side chain is controlled by a strong intramolecular hydrogen bond (H⋯O = 1.84 Å).