Mainz 2026 – scientific programme
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MO: Fachverband Molekülphysik
MO 25: Molecular Collisions and Kinetics
MO 25.2: Talk
Thursday, March 5, 2026, 14:45–15:00, P 105
Gas phase redox stability of the molecular ruby [Cr(ddpd)2]3+ and related complexes — •Boris Heeb, Jana Eck, and Jennifer Meyer — RPTU Kaiserslautern-Landau, Fachbereich Chemie und Landesforschungszentrum OPTIMAS, Kaiserslautern, Germany
Chromium(III) complexes, also known as molecular rubies, exhibit particularly good luminescence properties.[1,2] Studies on gas phase stability of these compounds are rare to date.
For this reason, the stability of the chromium complexes [Cr(ddpd)2]3+ (ddpd=N,N′-dimethyl-N,N′-dipyridin-2-ylpyridine-2,6-diamine), [Cr(bpmp)2]3+ (bpmp=2,6-bis(2-pyridylmethyl)pyridine), and [Cr(tpeF)2]3+ (tpeF=singly fluorinated 1,1,1-tris(pyrid-2-yl)ethane) with the corresponding reduced forms were examined in the gas phase through collision-induced dissociation. The experiments were performed on an electrospray ionization quadrupole mass spectrometer with in-situ reduction.
Quantum chemical calculations suggest that [Cr(ddpd)2]3+ undergoes a metal-centered transition upon photoexcitation, whereas [Cr(tpe)2]3+ undergoes a ligand-centered transition.[3]
However, fragmentation patterns of the reduced complexes show strong similarities, whereas the triply-charged complexes show different fragmentation behavior.
In contrast, a different pattern can be observed for [Cr(bpmp)2]3+, which is assigned a mixed behaviour in condensed phase.
[1] W. R. Kitzmann et al., Dalton Trans. 2022, 51, 6519-6525.
[2] F. Reichenauer et al., J. Am. Chem. Soc. 2021, 143, 11843-11855.
[3] S. Otto et al., Angew. Chem. Int. Ed. 2015, 54, 11572-11576.
Keywords: Gas phase; Electrospray ionisation; Electron transfer reduction; Collision induced dissociation