Cyclometalated heteronuclear Pt/Ag and Pt/Tl complexes: A structural and photophysical study

  1. Jamali, S. 2
  2. Ghazfar, R. 2
  3. Lalinde, E. 3
  4. Jamshidi, Z. 1
  5. Samouei, H. 5
  6. Shahsavari, Hamid Reza. 3
  7. Moreno, M.T. 3
  8. Escudero-Adán, E. 5
  9. Benet-Buchholz, J. 5
  10. Milic, D. 4
  1. 1 Chemistry and Chemical Engineering Research Center of Iran
    info

    Chemistry and Chemical Engineering Research Center of Iran

    Teherán, Irán

    ROR https://ror.org/020sjp894

  2. 2 Sharif University of Technology
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    Sharif University of Technology

    Teherán, Irán

    ROR https://ror.org/024c2fq17

  3. 3 Universidad de La Rioja
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    Universidad de La Rioja

    Logroño, España

    ROR https://ror.org/0553yr311

  4. 4 University of Zagreb
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    University of Zagreb

    Zagreb, Croacia

    ROR https://ror.org/00mv6sv71

  5. 5 Instituto Catalán de Investigación Química
    info

    Instituto Catalán de Investigación Química

    Tarragona, España

    ROR https://ror.org/013j2zh96

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Revista:
Dalton Transactions

ISSN: 1477-9226

Año de publicación: 2014

Volumen: 43

Número: 3

Páginas: 1105-1116

Tipo: Artículo

DOI: 10.1039/C3DT52209A SCOPUS: 2-s2.0-84890488735 WoS: WOS:000328654000024 GOOGLE SCHOLAR

Otras publicaciones en: Dalton Transactions

Resumen

To investigate the factors influencing the luminescent properties of polymetallic cycloplatinated complexes a detailed study of the photophysical and structural properties of the heteronuclear complexes [Pt2Me 2(bhq)2(μ-dppy)2Ag2(μ-acetone) ](BF4)2, 2, [PtMe(bhq)(dppy)Tl]PF6, 3, and [Pt2Me2(bhq)2(dppy)2Tl]PF 6, 4, [bhq = benzo[h]quinoline, dppy = 2-(diphenylphosphino)pyridine] was conducted. Complexes 3 and 4 synthesized by the reaction of [PtMe(bhq)(dppy)], 1, with TlPF6 (1 or 1/2 equiv.) and stabilized by unsupported Pt-Tl bonds as revealed by multinuclear NMR spectroscopy and confirmed by X-ray crystallography for 3. DFT calculations for the previously reported butterfly Pt2Ag2 cluster 2 reveal that in the optimized geometry the bridging acetone molecule is removed and the metal core displays a planar-shaped geometry in which according to a QTAIM calculation and natural bond orbital (NBO) analysis the Ag⋯Ag metallophilic interaction is strengthened. In contrast to the precursor 1, which is only emissive in glassy solutions (3MLCT 485 nm), all 2-4 heteropolynuclear complexes display intense emissions in the solid state and in glassy solutions. Time-dependent density functional theory (TD-DFT) is used to elucidate the origin of the electronic transitions in the heteronuclear complexes 2 and 3. The low energy absorption and intense orange emission for cluster 2 (solid 77 K and glass) are attributed to metal-metal to ligand charge transfer (MM′LCT) with a minor L′LCT contribution. For 3 and 4 two different bands are developed: the high energy band (602-630 nm) observed for 4 at 77 K (solid, glass) and in diluted glasses for 3 is ascribed to emission from discrete Pt2Tl units of mixed 3L′LCT/3LM′CT origin. However, the low energy band (670-690 nm) observed at room temperature (solid) for both complexes and also in concentrated glasses for 3 is assigned to 3ππ excited states arising from intermolecular interactions. © The Royal Society of Chemistry 2014.