title: Large d-d luminescence energy variations in square-planar bis(dithiocarbamate) platinum(ii) and palladium(ii) complexes with near-identical MS4motifs: a variable-pressure study.
abstract: We present the variable-pressure luminescence spectra of crystals of isostructural palladium(ii) and platinum(ii) complexes with bis-N-benzyl-N'-3-methylpyridyldithiocarbamate (bmpDTC) ligands. The d-d luminescence band maxima Emaxfor these complexes are compared to others with different peripheral substituents on the dithiocarbamate ligands in the solid state. The comparison reveals significant variations of Emaxdespite very similar metal coordination geometries. Emaxvaries by 3000 cm-1and 1300 cm-1among four dithiocarbamate complexes of platinum(ii) and palladium(ii), respectively. Variations of Emaxwith pressure reveal the effects of intermolecular MH-C interactions on several complexes. ΔEmax/ΔP values are negative for the bmpDTC complexes, unprecedented in the dithiocarbamate family. Static orientation and pressure-induced movement of the C-H bonds involved in intermolecular interactions have a significant effect on Emaxand ΔEmax/ΔP, with a stronger impact on platinum(ii) complexes than on their palladium(ii) analogs.
authors.affiliation: Département de chimie, Université de Montréal, Montréal, Québec H3C 3J7, Canada. christian.reber@umontreal.ca.
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Poirier
authors.forename: Feriel
authors.initials: F
authors.lastname: Rahmani
authors.forename: Christian
authors.initials: C
authors.lastname: Reber