Extended Structures containing Pt(II)-Tl(I) Bonds. Effect of these interactions on the Luminescence of cyclometalated Pt(II) compounds

  1. Forniés, J. 1
  2. Fuertes, S. 1
  3. Martín, A. 1
  4. Sicilia, V. 2
  5. Gil, B. 3
  6. Lalinde, E. 3
  1. 1 Universidad de Zaragoza
    info

    Universidad de Zaragoza

    Zaragoza, España

    GRID grid.11205.37

  2. 2 Instituto de Ciencia de Materiales de Aragón
    info

    Instituto de Ciencia de Materiales de Aragón

    Zaragoza, España

    GRID grid.466773.7

  3. 3 Universidad de La Rioja
    info

    Universidad de La Rioja

    Logroño, España

    GRID grid.119021.a

Journal:
Dalton Transactions

ISSN: 1477-9226

Year of publication: 2009

Volume: 12

Pages: 2224-2234

Type: Article

Export: RIS
DOI: 10.1039/b819323a SCOPUS: 2-s2.0-67649303367 WoS: 000263990200022 GOOGLE SCHOLAR

Metrics

Cited by

  • Scopus Cited by: 0 (12-06-2021)

Journal Citation Reports

  • Year 2009
  • Journal Impact Factor: 4.081
  • Best Quartile: Q1
  • Area: CHEMISTRY, INORGANIC & NUCLEAR Quartile: Q1 Rank in area: 7/44 (Ranking edition: SCIE)

SCImago Journal Rank

  • Year 2009
  • SJR Journal Impact: 0.766
  • Best Quartile: Q2
  • Area: Inorganic Chemistry Quartile: Q2 Rank in area: 27/68

Summary

Neutralization reactions of the appropriate precursors (NBu 4)[Pt(bzq)(CC-R)2] and (NBu4)[Pt(CN)(CN) 2] (CN = bzq, ppy) with TlI salts afford [{PtTl(bzq)(CC-R)2}2] [R = Ph (1), C5H 4N-2 (2)] and [PtTl(CN)(CN)2] [CN = bzq (3), ppy (4)], respectively. X-Ray diffraction studies of complexes 2-4 show the existence of PtII-TlI bonds. In 2·CH2Cl2 the platinum-thallium units are associated in tetranuclear Pt2Tl 2 entities which generate a 3-D network through short Tl⋯π(2-py) and π⋯π(bzq) contacts and additional weak Cl2HC-H⋯π(CC) nonclassical interactions. Compounds 3 and 4 show extended 2-D networks by connection of the organometallic "PtTl(CN)(CN)2" units, through secondary Tl⋯NC contacts and moderate π⋯π(bzq) interactions in the case of 3. Complexes 1-3 containing the bzq group exhibit in the solid state "luminescence thermochromism" associated to dual emission. At room temperature they show an intense, visible orange (1: λmax 625 nm), orange-red (2: λmax 640 nm) or yellow (3: λmax 582 nm) luminescence that changes to yellowish-green (1: λmax 532 nm) or green [2: λmax 524 nm; 3: λmax 512 nm] upon cooling to 77 K. The unstructured low energy (LE) bands attributed to 3π-π* excimeric emissions due to extensive π-π interactions are dominant at room temperature. By contrast, the high energy (HE) bands are highly structured and predominant at 77 K. Due to the presence of Pt-Tl bonds these HE emissions are bathochromically shifted in relation to the precursors′ ones and have been tentatively assigned to a metal-metal′-to-ligand (bzq) charge transfer MM′LCT [d/s σ*(Pt,Tl) →π*(CN)] mixed, as in the corresponding precursors, with some intraligand 3IL[π(CN′) →π*(CN)] in 3 and 4 or ligand-to-ligand charge transfer (alkynyl to bzq) 3LL′CT in complexes 1 and 2. Complex [PtTl(ppy)(CN)2] 4, which does not show short contacts between the phenylpyridinate groups in solid state, only shows the HE green structured band both at 298 K and at 77 K. Only the cyanide derivatives are soluble and both spectroscopic (NMR and UV-Vis) and emission data (MeOH, 298 K and 77 K) indicate that the PtII-TlI bond breaks down in solution. © 2009 The Royal Society of Chemistry.