Resolution of isomeric multi‐ruthenated porphyrins by travelling wave ion mobility mass spectrometry

Abstract

The ability of travelling wave ion mobility mass spectrometry (TWIM-MS) to resolve cationic meta/para and cis/trans isomers of mono-, di-, tri- and tetra-ruthenated supramolecular porphyrins was investigated. All meta isomers were found to be more compact than the para isomers and therefore mixtures of all isomeric pairs could be properly resolved with baseline or close to baseline peak-to-peak resolution (R(p-p)). Di-substituted cis/trans isomers were found, however, to present very similar drift times and could not be resolved. N(2) and CO(2) were tested as the drift gas, and similar α but considerably better values of R(p) and R(p-p) were always observed for CO(2).

Investigation of the photophysical and eletrochemical properties of a free base tetrapyridyl porphyrin with meso carbon linked ruthenium(II) groups

“…Efforts in this direction have been made through changes of the central ion [11,12], aggregate formation [13,14], insertion of lateral and axial ligands [15,16], oligomers [17], supramolecular isomeric structures [10,[18][19][20], presence of cationic groups [21,22], and others. In order to better understand the impact of structural modification on porphyrins systematic studies of their photophysical and photochemical properties is highly necessary.…”

Structural Resolution of 4-Substituted Proline Diastereomers with Ion Mobility Spectrometry via Alkali Metal Ion Cationization

“…Therefore, several mass spectrometric strategies for distinguishing isomeric species using mass spectrometry have been developed, including the kinetic method based on the dissociation of cluster ions, 12,22 collision induced dissociation of diastereomeric adducts, 23,27 host-guest ion molecule reactions, [23][24][25][26][28][29] and ion mobility analysis. [12][13][14][15][16][17][18][19][20][30][31][32][33][34][35][36][37] Ion mobility spectrometry (IMS) has the ability to rapidly separate isomeric species based on their mobilities through a drift gas under the influence of an electric field, which depends primarily on the shape and charge of the gas-phase ion. The IMS-MS combination has therefore provided a proven mechanism for the gas-phase separation and characterization of isomers and conformers ranging from small 5 molecules 31,33,36,38 and amino acids 16,33,39 to proteins 40-42 and large native protein complexes.…”

Separation of glycosidic catiomers by TWIM‐MS using CO2 as a drift gas

“…In TWIM, ions are accumulated and periodically released into a stacked ring ion guide (T‐wave cell) where they drift under the action of a continuous train of transient voltage pulses applied to a pair of stacked ring electrodes that work as an ion mobility cell. We have used TWIM‐MS to separate and characterize geometrical isomers such as meta/para and cis/trans cationic ruthenates meso‐pyridylporphyrins, corrole isomers and isomeric disaccharides …”