title: A platinum acetylide polymer with sterically demanding substituents: effect of aggregation on the triplet excited state.
abstract: The effect of interchain interaction on the triplet excited state is explored in two Pt-acetylide polymers of the type [-trans-Pt(PBu(3))(2)-C triple bond C-Ar-C triple bond C-](n), where Ar is either 1,4-phenylene or is based on the pentiptycene unit (polymers 2 and 3, respectively). To explore the effect of interchain interaction in Pt-acetylide materials, the optical properties of parent polymer 2 are compared with those of polymer 3 in which interchain interaction is precluded by the sterically bulky pentiptycene moiety. Insight into the effect of the pentiptycene unit on packing in the solid state comes from the X-ray structure of monomer 1b, Ph-C triple bond C-[trans-Pt(PBu(3))(2)]-C triple bond C-Ar-C triple bond C-[trans-Pt(PBu(3))(2)]-C triple bond C-Ph. Spectroscopic studies indicate that weak phosphorescence emission from an interchain aggregate is observed from parent polymer 2, both in solution and in the solid state. By contrast, the photophysics of 3 is dominated by the intrachain triplet exciton. Interestingly, the phosphorescence emission of polymer 3 in the solid state is nearly superimposable with that of a single crystal of monomer 1b, suggesting that the solid polymer experiences an environment that is similar to that of the monomer in the crystal.
authors.affiliation: Department of Chemistry, University of Florida, P.O. Box 117200, Gainesville, Florida 32601-7200, USA.
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Zhao
authors.forename: Thomas
authors.initials: T
authors.lastname: Cardolaccia
authors.forename: Richard T
authors.initials: RT
authors.lastname: Farley
authors.forename: Khalil A
authors.initials: KA
authors.lastname: Abboud
authors.forename: Kirk S
authors.initials: KS
authors.lastname: Schanze