Naslov
Gas-phase VUV photoionisation and photofragmentation of the silver deuteride nanocluster [Ag10D8L6]2+ (L = bis(diphenylphosphino)methane). A joint experimental and theoretical study

Autori
Daly, Steven ; Krstić, Marjan ; Giuliani, Alexandre ; Antoine, Rodolphe ; Nahon, Laurent ; Zavras, Athanasios ; Khairallah, George N. ; Bonačić-Koutecký, Vlasta ; Dugourd, Philippe ; O'Hair, Richard A. J.

Izvornik
Physical Chemistry Chemical Physics (1463-9076) 17 (2015), 39; 25772-25777

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
gas-phase, VUV photoionisation, photofragmentation, silver deuteride nanocluster, DFT

Sažetak
The bis(diphenylphosphino)methane (L = Ph2PCH2PPh2) ligated silver deuteride nanocluster dication, [Ag10D8L6]2+, has been synthesised in the condensed phase via the reaction of bis(diphenylphosphino)methane, silver nitrate and sodium borodeuteride in the methanol : chloroform (1 : 1) mixed solvent system. The photoionisation and photofragmentation of this mass-selected cluster were studied using a linear ion trap coupled to the DESIRS VUV beamline of the SOLEIL Synchrotron. At 15.5 eV the main ionic products observed are [Ag10D8L5]2+, [Ag10D8L4]2+, [Ag10D8L6]3+˙, [Ag9D8L4]2+˙, and [AgL2]+. The later two products arise from fragmentation of [Ag10D8L6]3+˙. An analysis of the yields of these product ions as a function of the photon energy reveals the onset for the formation of [AgL2]+ and [Ag9D8L4]2+˙ is around 2 eV higher than that for ionisation to produce [Ag10D8L5]3+˙. The onset of ionisation energy of [Ag10D8L6]2+ was determined to be 9.3 ± 0.3 eV from a fit of the yield of the product ion, [Ag10D8L6]3+˙, as a function of the VUV photon energy. DFT calculations at the RI- PBE/RECP-def2-SVP level of theory were carried out to search for a possible structure of the cluster and to estimate its vertical and adiabatic ionisation energies. The calculated lowest energy structure of the [Ag10D8L6]2+ nanocluster contains a symmetrical bicapped square antiprism as a silver core in which hydrides are located as a mix of triangular faces and edges. Four of the bisphosphines bind to the edges of the cluster core as bidentate ligands, the remaining two bisphosphines bind via a single phosphorus donor atom to each of the apical silver atoms. The DFT calculated adiabatic ionisation energy for this structure is 8.54 eV, in satisfactory agreement with experiment.

Izvorni jezik
Engleski

Znanstvena područja
Fizika, Kemija

POVEZANOST RADA