New Water Soluble and Luminescent Platinum(II) Compounds, Vapochromic Behavior of [K(H2O)][Pt(bzq)(CN)2], New Examples of the Influence of the Counterion on the Photophysical Properties of d8 Square-Planar Complexes

Fornies, Juan (Universidad de Zaragoza) ; Fuertes, Sara ; Lopez, J. Antonio (Universidad de Zaragoza) ; Martin, Antonio ; Sicilia, Violeta (Universidad de Zaragoza)

Resumen: This work describes the synthesis of compounds [Pt(C∧N)(NCMe)2]ClO4 (C∧N = 7,8-benzoquinolinato (bzq), 2-phenylpyridinato (ppy)) and their use as precursors for the preparation of the cyanido complexes [Pt(C∧N)(CN)2]−, which were isolated as the potassium, [K(H2O)][Pt(C∧N)(CN)2] [C∧N = bzq (3a), ppy (4a)], and the tetrabutylammonium, NBu4[Pt(C∧N)(CN)2] [C∧N = bzq (5), ppy (6)], salts. The difference in the cation has an influence on the solubility, color, and emission properties of these compounds. Compounds 5 and 6 are yellow and soluble in organic solvents, while the potassium salts are also soluble in water and exhibit two forms: the water-containing [K(H2O)][Pt(C∧N)(CN)2] [C∧N = bzq (3a), ppy (4a)] complexes and the anhydrous ones K[Pt(C∧N)(CN)2] [C∧N = bzq (3b), ppy (4b)], the former being strongly colored [red (3a) or purple (4a)] and the latter being yellow. Compounds 3a and 4a transform reversibly into the yellow, 3b and 4b, compounds upon desorption/ reabsorption of water molecules from the environment. The red solid, 3a, also exhibits vapochromic behavior when it is exposed to volatile organic compounds, the shortest response times being those observed for methanol and ethanol. UV−vis and emission spectra of all compounds were recorded both in solution and in the solid state. In methanol solution, the difference in the cation causes no differences in the absorption nor in the emission spectra, which is as expected for the monomer species. However, in the solid state, the differences are notable. For both the red (3a) and purple (4a) compounds, a prominent absorption, which has maxima at about 550 nm and is responsible for their intense colors, as well as a structureless emission at λ > 700 nm that suffers a significant red-shift upon cooling, are due to 1,3MMLCT (= metal−metal-to-ligand charge transfer) [dσ*(Pt) → π*(C∧N)] transitions characteristic of linear-chain platinum complexes with short Pt···Pt contacts. Time-dependent density-functional theory calculations on complex 5 and the X-ray diffraction study on compound [K(OCMe2)2][Pt(ppy)(CN)2] (4c) are also included.

Idioma: Inglés

DOI: 10.1021/ic800265q

Año: 2008

Publicado en: Inorganic Chemistry 47, 16 (2008), 7166-7176
ISSN: 0020-1669

Factor impacto JCR: 4.147 (2008)

Categ. JCR: CHEMISTRY, INORGANIC & NUCLEAR rank: 4 / 43 = 0.093 (2008) - Q1 - T1

Financiación: info:eu-repo/grantAgreement/ES/DGA/E17-20R
Financiación: info:eu-repo/grantAgreement/ES/MEC/CTQ2005-06807-BQU
Financiación: info:eu-repo/grantAgreement/ES/MEC/CTQ2005-08606-C02-01

Tipo y forma: Article (PostPrint)

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