title: Non-covalent stacking interactions directing the structural and photophysical features of mono- and dinuclear cyclometalated palladium(ii) complexes.
abstract: The solution/solid state luminescence properties of selected orthometalated palladium complexes have been investigated in parallel with the relevant structural information provided by their X-ray crystal structures and theoretical calculations. Two cyclometalated backbones with different stacking abilities and a selection of bridging O^O, O^N or N^S ligands comprise the series under study, [{Pd(μ-L) (C^N)}2] (C^N = N-phenylpyrazole (Phpz) ; N-benzylideneaniline (Bza) ; L = acetate (Aco) , succinimidate (succ) , phthalimidate (phthal) , 1-methylimidazoline-2 thionate (Smeimid) ), completed with mononuclear [Pd(C^N)(N-pClPhsal)] (N-pClPhsal = chlorophenylsalycilaldiminate) complexes. New compounds , and were synthesized and the X-ray structures of , , , and have been elucidated in order to examine and compare solid-state Pd(C^N)-Pd(C^N) and ligand-ligand interactions with the rest of the series. The molecular structures of the complexes reveal intramolecular PdPd distances between 2.842 and 2.999 Å and π-π and C-Hπ interactions. All complexes studied show emission in the solid state at room temperature and a relationship is observed between emission energy, the nature of the lowest energy excited state, and metal-metal interactions. DFT calculations are undertaken to gain insight into the relationship between the structure and photophysical properties of the complexes.
authors.affiliation: Departamento de Química Inorgánica and Regional Campus of International Excellence (Campus Mare Nostrum), Universidad de Murcia, E-30071 Murcia, Spain. dsl@um.es.
authors.forename: M D
authors.initials: MD
authors.lastname: Santana
authors.affiliation: Departamento de Química Inorgánica and Regional Campus of International Excellence (Campus Mare Nostrum), Universidad de Murcia, E-30071 Murcia, Spain. dsl@um.es.
authors.forename: L
authors.initials: L
authors.lastname: López-Banet
authors.affiliation: Departamento de Química Inorgánica and Regional Campus of International Excellence (Campus Mare Nostrum), Universidad de Murcia, E-30071 Murcia, Spain. dsl@um.es.
authors.forename: G
authors.initials: G
authors.lastname: Sánchez
authors.affiliation: Departamento de Ingeniería Minera, Geológica y Cartográfica. Área de Química Inorgánica. Universidad Politécnica de Cartagena, Regional Campus of International Excellence "Campus Mare Nostrum", 30203, Cartagena, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Pérez
authors.affiliation: Departamento de Ingeniería Minera, Geológica y Cartográfica. Área de Química Inorgánica. Universidad Politécnica de Cartagena, Regional Campus of International Excellence "Campus Mare Nostrum", 30203, Cartagena, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Pérez
authors.affiliation: Departamento de Ingeniería Minera, Geológica y Cartográfica. Área de Química Inorgánica. Universidad Politécnica de Cartagena, Regional Campus of International Excellence "Campus Mare Nostrum", 30203, Cartagena, Spain.
authors.forename: L
authors.initials: L
authors.lastname: García
authors.affiliation: Departamento de Ingeniería Minera, Geológica y Cartográfica. Área de Química Inorgánica. Universidad Politécnica de Cartagena, Regional Campus of International Excellence "Campus Mare Nostrum", 30203, Cartagena, Spain.
authors.forename: J L
authors.initials: JL
authors.lastname: Serrano
authors.affiliation: Departamento de Química Orgánica, Universidad de Murcia, Campus de Espinardo, E-30071 Murcia, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Espinosa