Collision-induced dissociation and photodetachment of singly and doubly charged anionic polynuclear transition metal carbonyl clusters: Ru3Co(CO)13−, Ru6C(CO)162−, and Ru6(CO)182−

Abstract

Three polynuclear transition metal carbonyl cluster anions, Ru3Co(CO)13−, Ru6C(CO)162−, and Ru6(CO)182− have been studied using energy-dependent electrospray ionization mass spectrometry (EDESI–MS) and photodetachment photoelectron spectroscopy (PES). EDESI–MS maps show a simple collision-induced dissociation (CID) process for Ru3Co(CO)n− by stripping CO down to the metal core. For the doubly charged species, two competing CID channels were observed, viz. loss of neutral CO and loss of CO+e−. It was found that the parent dianions first lose neutral CO down to n=9, producing a series of dianions, Ru6C(CO)n2− (n=9–16) and Ru6(CO)n2− (n=9–18). For n<9, the dianions become electronically unstable against autodetachment, and singly charged anions, Ru6C(CO)n− and Ru6(CO)n− (n=0–9), were observed. The PES spectra of the dianions show the electron binding energies decrease monotonically as n decreases and become ∼0.0 eV for n=9, in exact agreement with the CID patterns that reflect the electronic instability of the doubly charged metal complexes with n<9. All of the PES spectra show congested features, indicating very high density of low-lying electronic states for the transition metal carbonyl clusters. The electron binding energies of Ru3Co(CO)n− are similar for n=4–13, but decrease sharply from n=4 to 0. The intramolecular Coulomb repulsion in the dianions was observed to increase with loss of CO, ranging from ∼1.8 eV for Ru6C(CO)162− to ∼2.4 eV for Ru6C(CO)92−.

Insights into the Post‐Translational Methylation of Arginine from Studies of Guanidinium–Water Nanodroplets

“…EDESI-MS is a method of collecting and visualizing collections of data from collision-induced dissociation (CID) experiments. [14][15][16][17] Similar CID studies have been performed on metal-centered water clusters to probe solvation, fragmentation pathways, and solvent coordination chemistry. [18,19] Herein, we used EDESI-MS to observe the loss of water molecules from nanodroplets of water that contained different methylated guanidinium ions.…”

Infrared spectroscopy of mass-selected metal carbonyl cations

“…Again, the 18-electron rule is useful to describe stable stoichiometries. Unsaturated metal carbonyls have also been produced and isolated in rare gas matrices [6,22] or in the gas phase via photoelectron spectroscopy of mass-selected anions [23][24][25][26]. The frequency of the CO stretch in all of these systems shifts systematically depending on the electronic structure and bonding, and these effects have been studied extensively with theory [6,22,[27][28][29][30][31].…”

A Hypothetical Model for the Formation of Transition Metal Carbonyl Clusters Based upon 4n Series Skeletal Numbers

“…The corresponding cluster k values of the fragment should be on the increase. Very interesting extensive work on the metal carbonyls that involves stripping off the CO ligands has been done by several research groups (Butcher, et al, 2002(Butcher, et al, , 2003Crawford, et al, 2006;Critchley, et al, 1999;Dyson, et al, 2001;Henderson, et al, 1998Henderson, et al, , 2009 Table 7). Although the series and the skeletal numbers predict that each of the Re skeletal atoms except one should have a hydrogen atom, the structural determination indicates all the hydrogen atoms are bridging (Miessler, et al, 2014) as observed in borane clusters.…”

“…These opposing processes are reflected in Tables 7 and 8. The removal of CO ligands from transition metal carbonyl clusters has been an intense field of research (Critchley, et al, 1999, Douglas, et al, 2001, Butcher, et al, 2002, 2003, Crawford, et al, 2006, Henderson, et al, 2009). The silicon clusters Si n (n=4-10) were theoretically studied (Slee, et al, 1989) (Hughes, et al, 2000).…”