Synthesis, structure, and spectroscopic properties of ortho-metalated platinum(II) complexes

Journal Article · Wed Apr 26 04:00:00 EDT 1995 · Inorganic Chemistry

DOI:https://doi.org/10.1021/ic00113a013· OSTI ID:450677

Mdleleni, M M; Bridgewater, J S; Watts, R J; Ford, P C ^[1]

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1. Univ. of California, Santa Barbara, CA (United States)

The ortho-metalated Pt(II) complexes Pt(ppy)(CO)Cl (1), Pt(ptpy)(CO)Cl (2), and Pt(ppy)(Hppy)Cl (3) (where ppy and ptpy are respectively the ortho-C-deprotonated forms of 2-phenylpyridine and 2-p-tolylpyridine and Hppy is 2-phenylpyridine) have been prepared. The CO ligand is coordinated trans to the nitrogen atom of the ortho-metalated ligand and exerts a strong trans effect resulting in a relatively long Pt-N bond [2.114(19) {angstrom}]. This structure shows both the bidentate ppy ligand and the monodentate Hppy with the nitrogens of these ligands trans to each other. The UV/vis electronic absorption spectra of 1-3 have intense bands in the near-UV region ({approximately}375 nm) which have been assigned as metal to ligand charge transfer (MLCT) transitions, and higher energy bands were assigned as ligand-centered transitions. Each complex exhibits relatively long-lived structured emissions in the solid state at ambient temperature and at 77 K and 77 K glassy toluene solutions. These emissions are proposed to originate from triplet MLCT states. Notably, in solution both the lifetime and spectrum of 2 proved to be a function of the concentration, a phenomenon interpreted in terms of the propensity of square planar d{sup 8} complexes to oligomerize. In contrast, the more sterically hindered complex 3 displayed no such tendency toward oligomerization.

• Sponsoring Organization: USDOE
• DOE Contract Number: FG03-85ER13317; FG05-91ER79039
• OSTI ID: 450677
• Journal Information: Inorganic Chemistry, Journal Name: Inorganic Chemistry Journal Issue: 9 Vol. 34; ISSN 0020-1669; ISSN INOCAJ
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
ABSORPTION SPECTROSCOPY
CHEMICAL PREPARATION
CRYSTAL STRUCTURE
EMISSION SPECTROSCOPY
ORGANOMETALLIC COMPOUNDS
PLATINUM COMPLEXES
X-RAY DIFFRACTION