{(S)-2-[({2-[1-(Anthracen-9-ylmeth-yl)pyrrolidine-2-carboxamido]-phen-yl}(phen-yl)methyl-idene)amino]-acetato(2-)-κ(4)N,N',N'',O(1)}nickel(II).

The title compound, [Ni(C(35)H(29)N(3)O(3))], includes a Schiff base ligand derived from (S)-1-[(anthracen-9-yl)meth-yl]-N-(2-benz-oyl-phen-yl)pyrrolidine-2-carboxamide and glycine. The Ni(II) atom is coordinated by three N atoms [Ni-N = 1.937 (3), 1.850 (3) and 1.850 (3) Å] and one O atom [Ni-O = 1.859 (2) Å], resulting in a pseudo-square-planar coordination environment.

[2-((R)-{2-[(S)-1-Benzylpyrrolidin-2-ylcarbonylazanidyl]-phen-yl}(phen-yl)methyl-idene-amino)-4-hy-droxy-butano-ato-κN,N',N'',O]nickel(II) toluene disolvate.

The central Ni atom in the title compound, [Ni(C(29)H(29)N(3)O(4))]·2C(7)H(8), is coordinated in a distorted square-planar environment by three N atoms [Ni-N = 1.942 (3), 1.843 (3) and 1.853 (3) Å] and one O atom [1.868 (3) Å] of the tetradentate ligand. The conformation of the hy-droxy-butano-ate side chain is controlled by an inter-molecular hydrogen bond.

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.

{2-[(S)-({2-[(S)-1-Benzyl-pyrrolidine-2-carboxamido]phen-yl}(phen-yl)methyl-ene)amino]-4-hydroxy-butanoato-κN,N',N'',O}nickel(II).

The central Ni atom of the title compound, [Ni(C(29)H(29)N(3)O(4))], 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 hydroxy-butanoate side chain is controlled by a strong intra-molecular hydrogen bond (H⋯O = 1.84 Å).

Off-line combination of reversed-phase liquid chromatography and laser desorption/ionization time-of-flight mass spectrometry with seamless post-source decay fragment ion analysis for characterization of square-planar nickel(II) complexes.

Characterization of square-planar nickel(II) complexes of the Schiff base of (S)-N-benzylproline (2-benzoylphenyl)amide and various amino acids that are used as efficient alpha-amino acids synthons was carried out using laser desorption/ionization time-of-flight mass spectrometry (LDI-TOF MS) in off-line combination with liquid chromatography. A mixture of four square-planar nickel(II) complexes was separated using reversed-phase liquid chromatography (RPLC) and the separated fractions from the chromatographic run were spotted on the metal target directly from the column outlet using a lab-made sample deposition device. The separated fractions were then analyzed by LDI-TOF MS. Seamless postsource decay (sPSD) fragment ion analysis was used for their structural characterization, which made possible the confirmation of expected chemical structures of the analyzed compounds. The off-line combination of the separation by RPLC and analysis by LDI-TOF MS allowed successful separation, sensitive detection and structure elucidation of the square-planar nickel(II) complexes.

Structural analysis of 2,6-[bis(alkyloxy)methyl]-phenyltin derivatives using electrospray ionization mass spectrometry.

Electrospray ionization (ESI) mass spectrometry was applied to the structural analysis of 23 2,6-[bis(alkyloxy)methyl]phenyltin(IV) derivatives. The mass spectra were measured in both polarity modes and multistage tandem mass spectrometric (MS(n)) measurements were performed on the ion trap analyser for positively charged tin-containing ions. The sum of complementary ions observed in the positive-ion mode (i.e. [M-R(3)](+) ion) and in the negative-ion mode (i.e. [R(3)](-) ion) permits molecular mass determination in spite of the fact that the molecular adducts were often missing even in the first-order mass spectra. The subsequent fragmentation of [M-R(3)](+) ions studied by MS(n) and the correlation of observed fragment ions with the expected structures of synthesized organotin(IV) compounds allowed us to understand the fragmentation behaviour and the mechanism of the ion formation for studied compounds. The typical neutral losses are alkenes, alcohols and aldehydes. The fragmentation pattern of one selected compound was supported by MS(n) measurements of an isotopically labelled analogue to confirm unusual ion-molecule reactions of some fragment ions with water in the ion trap.