title: Wavelength-dependent photofragmentation of a mixed-ligand cyclometalated platinum(II) coordination compound in a molecular beam.
abstract: The photofragmentation of (3-Me-4',6'-dfppy)Pt(dpm) (dfppy = difluorophenylpyridinato; dpm = dipivaloylmethyl or 2,2,6,6,-tetramethyl-3,5-heptanedionato- O, O) in a molecular beam is reported. Time-of-flight mass spectra (TOF-MS) and resonance-enhanced multiphoton ionization (REMPI) data are presented and discussed. The dissociation patterns are strongly wavelength-dependent. With 355 nm excitation, the heaviest mass platinum-containing fragments are Pt(+) and diatomic PtC(+). The formation of PtC(+) is the result of an intramolecular rearrangement on the ligand. During irradiation with 410-500 nm light, the fragmentation pattern changes such that the parent ion and platinum-containing fragments of the parent are formed in abundant yield. The (3-Me-4',6'-dfppy) ligand remains intact and coordinated to platinum, but coordinated (dpm) successively breaks apart. A spin-forbidden charge-transfer absorption band centered at around 460 nm plays an important role in the gas-phase photoexcitation of the parent molecule; it is observed in the REMPI spectrum of the parent ion.
authors.affiliation: Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, USA.
authors.forename: Franklin P
authors.initials: FP
authors.lastname: Ow
authors.forename: Peter I
authors.initials: PI
authors.lastname: Djurovich
authors.forename: Mark E
authors.initials: ME
authors.lastname: Thompson
authors.forename: Jeffrey I
authors.initials: JI
authors.lastname: Zink