Cyclometalated NHCs Pt(II) Compounds with Chelating P^P and S^S Ligands: From Blue to White Luminescence

Jaime, S. ; Arnal, L. (Universidad de Zaragoza) ; Sicilia, V. (Universidad de Zaragoza) ; Fuertes, S.

Resumen: Ionic [Pt(C^C*A/B)(P^P)]PF6 and neutral [Pt(C^C*A/B)(S^S)] complexes were designed and synthesized containing cyclometalated N-heterocyclic carbenes (C^C*A/B) and diphosphines (P^P: dpfppe, dcypm) or dithiocarbamates (S^S: dmdtc, pdtc) as chelating ligands. Their structural and spectroscopic properties were investigated and found to be dependent on both cyclometalated (C^C*A/B) and ancillary (P^P, S^S) ligands. The photophysical and computational studies for the [Pt(C^C*A/B)(P^P)]+complexes disclose the nature of the low-lying electronic transitions to be mainly intraligand charge transfer [ILCT (C^C*A/B)] with some contribution of ligand-to-ligand charge transfer (LL''CT) or ligand-to metal charge transfer (LMCT) for the dpfppe or dcypm derivatives, respectively. The blue and cyan emissions of PMMA films doped with the [Pt(C^C*A/B)(P^P)]+ complexes exhibited very high quantum yields (QYs) reaching up to ~90%. However, the low-energy absorptions and emissions of the [Pt(C^C*A/B)(S^S)] complexes in solution (rt or 77 K) arise from mixed ILCT [C^C*A/B]/MLCT [dp(Pt) ¿ p*(C^C*A/B)] excited states, showing no change with the different S^S ligands. In solid-state and in doped films, these dithiocarbamate complexes, excluding 8B, display dual emissions with the high-energy vibronic band (3ILCT /3MLCT) appearing together with an additional low-energy structureless band. The latter is attributed to 3pp* transitions originated from p-stacked aggregates, as reported in the X-ray structure of 7A. Thus, white light emissions can be obtained with photo- and colorimetric values lying inside the stipulated limits for general lighting applications; yet, they display low QY. Copyright

Idioma: Inglés

DOI: 10.1021/acs.organomet.0c00510

Año: 2020

Publicado en: Organometallics 39, 20 (2020), 3695-3704
ISSN: 0276-7333

Factor impacto JCR: 3.876 (2020)

Categ. JCR: CHEMISTRY, ORGANIC rank: 13 / 57 = 0.228 (2020) - Q1 - T1
Categ. JCR: CHEMISTRY, INORGANIC & NUCLEAR rank: 11 / 45 = 0.244 (2020) - Q1 - T1

Factor impacto SCIMAGO: 1.231 - Inorganic Chemistry (Q1) - Physical and Theoretical Chemistry (Q1) - Organic Chemistry (Q1)

Financiación: info:eu-repo/grantAgreement/ES/CSIC/2018801070-PIE-147
Financiación: info:eu-repo/grantAgreement/ES/DGA/E17-20R
Financiación: info:eu-repo/grantAgreement/ES/DGA-FEDER/Construyendo Europa desde Aragón
Financiación: info:eu-repo/grantAgreement/ES/MICIU-FEDER/PGC2018-094749-B-I00

Tipo y forma: Article (PostPrint)

Área (Departamento): Área Química Inorgánica (Dpto. Química Inorgánica)