title: New dicyano cyclometalated compounds containing Pd(II)-Tl(I) bonds as building blocks in 2D extended structures: synthesis, structure, and luminescence studies.
abstract: New mixed metal complexes [PdTl(C^N)(CN)(2)] [C^N = 7,8-benzoquinolinate (bzq, 3); 2-phenylpyridinate (ppy, 4)] have been synthesized by reaction of their corresponding precursors (NBu(4))[Pd(C^N)(CN)(2)] [C^N = bzq (1), ppy (2)] with TlPF(6). Compounds 3 and 4 were studied by X-ray diffraction, showing the not-so-common Pd(II)-Tl(I) bonds. Both crystal structures exhibit 2-D extended networks fashioned by organometallic "PdTl(C^N)(CN)(2)" units, each one containing a donor-acceptor Pd(II)-Tl(I) bond, which are connected through additional Tl···N≡C contacts and weak Tl···π (bzq) contacts in the case of 3. Solid state emissions are red-shifted compared with those of the precursors and have been assigned to metal-metal'-to-ligand charge transfer (MM'LCT [d/s σ*(Pd,Tl) → π*(C^N)]) mixed with some intraligand ((3)IL[π(C^N) → π*(C^N)]) character. In diluted solution either at room temperature or 77 K, the Pd-Tl bond is no longer retained as confirmed by mass spectrometry, NMR, and UV-vis spectroscopic techniques.
authors.affiliation: Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC - Universidad de Zaragoza, Departamento de Química Inorgánica, Escuela de Ingeniería y Arquitectura de Zaragoza, Campus Río Ebro, Edificio Torres Quevedo, 50018 Zaragoza, Spain. sicilia@unizar.es
authors.forename: Violeta
authors.initials: V
authors.lastname: Sicilia
authors.forename: Juan
authors.initials: J
authors.lastname: Forniés
authors.forename: Sara
authors.initials: S
authors.lastname: Fuertes
authors.forename: Antonio
authors.initials: A
authors.lastname: Martín