Tuning the photophysical properties of a (P,N)ReI complex by adding a -NH- fragment into a P,N-bidentate ligand: The case of [P,N-{(C6H5)2(C5H4N)NHPRe(CO)3Br]

Pablo Mella, Juan Carlos Palma, Marjorie Cepeda-Plaza, Pedro Aguirre, Jorge Manzur, Germán Günther, Nancy Pizarro, Andrés Vega

Resultado de la investigación: Contribución a una revistaArtículorevisión exhaustiva

3 Citas (Scopus)

Resumen

The spectroscopic, electrochemical and photophysical properties of the new complex [P,N-{(C6H5)2(C5H4N)NHP}Re(CO)3Br] (RePNN) are reported. The UV-Vis spectrum in dichloromethane (DCM) shows an absorption maximum centered at 300 nm and a shoulder at 350 nm. These absorption bands have been characterized, having a πpy → π∗py and a MLCT character. Excitation at the first wavelength (higher energy) leads to an emission band centered at 365 nm. Cyclic voltammetry shows a fully irreversible oxidation wave around +1.45 V, assigned to ReI/ReII couple, whereas two irreversible reduction signals centered at -0.75 and -1.20 V are assigned to ligand reduction processes. The photophysical results show that emission from the RePNN complex comes exclusively from the ligand. The MLCT excited state shows to be non-emissive by coupling to vibrational modes leading to non-radiative decay path to ground state. The luminescent decay fits to a bi-exponential function. DFT calculations suggest that intra-ligand πpy → π∗py and πpy → π∗py excited states may account for the existence of these two decay lifetimes. The additional -NH- fragment present in the 2-(diphenylphosphinoamino)pyridine ligand compared to 2-pyridylphosphine, makes it more flexible and in consequence, enhances the non-radiative decay rate constant from the 3MLCT to the ground state in the RePNN complex compared to those of 2-pyridylphosphine, [P,N-{(C6H5)2(C5H4N)PRe(CO)3Br] (RePN).

Idioma originalInglés
Páginas (desde-hasta)64-70
Número de páginas7
PublicaciónPolyhedron
Volumen111
DOI
EstadoPublicada - 17 jun 2016

Áreas temáticas de ASJC Scopus

  • Química física y teórica
  • Química inorgánica
  • Química de los materiales

Huella

Profundice en los temas de investigación de 'Tuning the photophysical properties of a (P,N)Re<sup>I</sup> complex by adding a -NH- fragment into a P,N-bidentate ligand: The case of [P,N-{(C<sub>6</sub>H<sub>5</sub>)<sub>2</sub>(C<sub>5</sub>H<sub>4</sub>N)NHPRe(CO)<sub>3</sub>Br]'. En conjunto forman una huella única.

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