title: Interpreting effects of structure variations induced by temperature and pressure on luminescence spectra of platinum(II) bis(dithiocarbamate) compounds.
abstract: Luminescence spectra of two square-planar dithiocarbamate complexes of platinum(II) with different steric bulk, platinum(II) bis(dimethyldithiocarbamate) (Pt(MeDTC)2) and platinum(II) bis(di(o-pyridyl)dithiocarbamate) (Pt(dopDTC)2), are presented at variable temperature and pressure. The spectra show broad d-d luminescence transitions with maxima at approximately 13500 cm(-1) (740 nm). Variations of the solid-state spectra with temperature and pressure reveal intrinsic differences due to subtle variations of molecular and crystal structures, reported at 100 and 296 K for Pt(dopDTC)2. Luminescence maxima of Pt(MeDTC)2 shift to higher energy as temperature increases by +320 cm(-1) for an increase by 200 K, mainly caused by a bandwidth increase from 3065 to 4000 cm(-1) on the high-energy side of the band over the same temperature range. Luminescence maxima of Pt(dopDTC)2 shift in the opposite direction by -460 cm(-1) for a temperature increase by 200 K. The bandwidth of approximately 2900 cm(-1) does not vary with temperature. Both ground and emitting-state properties and subtle structural differences between the two compounds lead to this different behavior. Luminescence maxima measured at variable pressure show shifts to higher energy by +47 ± 3 and +11 ± 1 cm(-1)/kbar, for Pt(MeDTC)2 and Pt(dopDTC)2, respectively, a surprising difference by a factor of 4. The crystal structures indicate that decreasing intermolecular interactions with increasing pressure are likely to contribute to the exceptionally high shift for Pt(MeDTC)2.
authors.affiliation: †Département de Chimie, Université de Montréal, Montréal, Québec H3C 3J7, Canada.
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Poirier
authors.affiliation: ‡Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia V5A 1S6, Canada.
authors.forename: Ryan J
authors.initials: RJ
authors.lastname: Roberts
authors.affiliation: ‡Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia V5A 1S6, Canada.
authors.forename: Debbie
authors.initials: D
authors.lastname: Le
authors.affiliation: ‡Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia V5A 1S6, Canada.
authors.forename: Daniel B
authors.initials: DB
authors.lastname: Leznoff
authors.affiliation: †Département de Chimie, Université de Montréal, Montréal, Québec H3C 3J7, Canada.
authors.forename: Christian
authors.initials: C
authors.lastname: Reber