Photoelectron spectroscopy of [Mo6X14](2-) dianions (X = Cl-I)

0517353 - ÚACH 2020 RIV US eng J - Článek v odborném periodiku
Li, R. Z. - Yuan, Q. - Yang, Z. - Aprà, E. - Li, Z. - Azov, V. A. - Kirakci, Kaplan - Warneke, J. - Wang, X. B.
Photoelectron spectroscopy of [Mo6X14](2-) dianions (X = Cl-I).
Journal of Chemical Physics. Roč. 151, č. 19 (2019), č. článku 194310. ISSN 0021-9606. E-ISSN 1089-7690
Grant CEP: GA ČR(CZ) GA18-05076S
Grant ostatní: AV ČR(CZ) StrategieAV21/10
Program: StrategieAV
Institucionální podpora: RVO:61388980
Klíčová slova: Photoelectron spectroscopy * Multiply-charged anions * Hexanuclear molybdenum
Obor OECD: Inorganic and nuclear chemistry
Impakt faktor: 2.991, rok: 2019
Způsob publikování: Open access s časovým embargem

Photoelectron spectroscopy and theoretical investigations have been performed to systematically probe the intrinsic electronic properties of [Mo6X14]2- (X = halogen). All three PE spectra of gaseous [Mo6X14]2- (X = Cl, Br, I) dianions, which were generated by electrospray ionization, exhibit multiple resolved peaks in the recorded binding energy range. Theoretical investigations on the orbital structure and charge distribution were performed to support interpretation of the observed spectra and were further extended onto [Mo6F14]2-, a dianion that was not available for the experimental study. The measured adiabatic (ADE) and vertical detachment energies (VDE) for X = Cl-I were well reproduced by density functional theory calculations (accuracy ∼0.1 eV). Corresponding ADE/VDE values for the dianions were found to be 1.48/2.13 (calc.) and 2.30/2.65, 2.30/2.62, and 2.20/2.42 eV (all expt.) for X = F, Cl, Br, and I, respectively, showing an interesting buckled trend of electron binding energy (EBE) along the halogen series, i.e., EBE (F) ≪ EBE (Cl) ∼ EBE (Br) > EBE (I). Molecular orbital analyses indicate different mixing of metal and halogen atomic orbitals, which is strongly dependent on the nature of X, and suggest that the most loosely bound electrons are detached mainly from the metal core for X = F and Cl, but from halide ligands for X = Br and I. The repulsive Coulomb barrier (RCB), estimated from the photon energy dependent spectra, decreases with increasing halogen size, from 1.8 eV for X = Cl to 1.6 eV for X = I. Electrostatic potential modeling confirms the experimental RCB values and predicts that the most favorable electron detaching pathway should lie via the face-bridging halide ligands.
Trvalý link: http://hdl.handle.net/11104/0302671