Mass spectrometry and UV‐VIS spectrophotometry of ruthenium(II) [RuClCp(mPTA)₂](OSO₂CF₃)₂ complex in solution

Abstract

Ruthenium(II) complexes are of great interest as a new class of cancerostatics with advantages over classical platinum compounds including lower toxicity. The stability of the [RuClCp(mPTA)2](OSO2CF3)2 complex (I) (Cp cyclopentadienyl, mPTA N-methyl 1,3,5-triaza-7-phosphaadamantane) in aqueous solution was studied using spectrophotometry, matrix-assisted laser desorption/ionization (MALDI) and laser desorption/ionization (LDI) time-of-flight (TOF) mass spectrometry (MS). Spectrophotometry proves that at least three different reactions take place in water. Dissolution of I leads to fast coordination of water molecules to the Ru(II) cation and then slow hydrolysis and ligand exchange of chloride and mPTA with water, hydroxide or with trifluoromethane sulfonate itself. Via MALDI and LDI of the hydrolyzed solutions the formation of singly positively charged ions of general formula RuCl(p)(Cp)(q)(mPTA)(r)(H2O)(s)(OH)(t) (p = 0-1, q = 0-1, r = 0-2, s = 0-5, t = 0-2) and of some fragment ions was shown. The stoichiometry was determined by analyzing the isotopic envelopes and computer modelling. The [RuClCp(mPTA)2](OSO2CF3)2 complex can be stabilized in dilute hydrochloric acid or in neutral 0.15 M isotonic sodium chloride solution.

Coordination compounds in cancer: Past, present and perspectives

“…The [RuCpCl(mPTA) 2 ] (OSO 2 CF 3 ) 2 (Fig. 12b), shows interesting behaviour during hydrolysis as documented by mass spectrometry (MS) and UV-Vis spectrophotometry (Peña-Méndez et al, 2009). It was found that this complex forms hydrated species and exchanges chloride ions or mPTA and Cp ligands with water, hydroxyl or counter ions following the hydrolysis scheme ( Fig.…”

Synthesis and electrochemical characterization of new ruthenium–terthiophene complexes

“…1. Ruthenium complexes usually present strong bands at high energy (200-350 nm) and weaker bands in the visible region (400-600 nm) [37]. In this case, both spectra showed an intense absorption band in the UV region at 325 nm for 1 and 316 nm for 2 attributed to electron transitions p-p ⁄ produced by the aromatic ligands that form part of the structure.…”

Laser desorption ionisation quadrupole ion trap time‐of‐flight mass spectrometry of titanium‐carbon thin films

“…The problem of distinguishability of isotopic patterns for different models can be shown by considering the peaks at m/z~852.4. The following group of species can be suggested to explain the observed isotopic pattern: [Ti 8 The general least-squares program SPEC (section 'Software and computation') was used to select the most suitable species and to evaluate their relative abundances. The 'best fit' was obtained by assuming the formation of the following species: [Ti 8 C 29 O 7 H 10 ] -(38.3 AE 0.6%) and [Ti 9 C 29 O 4 H 9 ] -(61.8 AE 0.5%).…”

“…MS can also be used for the structural analysis of coordination compounds, organic and inorganic polymers and films, especially by laser desorption ionisation (LDI). [5][6][7] For example, matrix-free LDI-MS was successfully used to characterise the hydrolysis products of a ruthenium complex in aqueous solution, [8] and LDI has been widely used during the last 15 years in our laboratory for the analysis of inorganic materials such as chalcogenide glasses and nano-layers, and to elucidate the structural fragments of different solids. [9][10][11][12] An overview of matrix-free LDI-MS and its wide applications was provided in a review by Peterson.…”