title: Tri-[Pt2Tl]3- and polynuclear chain [Pt-Tl]infinity- complexes based on nonbridged Pt(II)-Tl(I) bonds: solid state and frozen solution photophysical properties.
abstract: Treatment of (NBu4)2[PtR4] (R = C6F5) with 1 or 0.5 equiv of TlNO3 in EtOH/H(2)O produces colorless crystals of trinuclear complex (NBu4)3[Tl{PtR4}2], 1, in which the Tl+ center is complexed by two [PtR4]2- fragments (Pt-Tl = 2.9777(4) and 3.0434(4) A). The expected mixed complex with a Pt/Tl composition of 1:1, 2, is generated as an orange microcrystalline solid by treating [PtR4]2- with a large excess of TlNO3 (approximately 8 equiv). Crystallographic analysis of 2 reveals the formation of a novel one-dimensional (1D) heterometallic linear chain (NBu4)(infinity)[Tl{PtR4}](infinity), 2, formed by alternating a [PtR4]2- fragment and a Tl+ center with a uniform Pt-Tl bond separation along the chain of 3.0321(2) A. Surprisingly, treatment of (NBu4)2[PtR4] with 1 equiv of TlPF6 in EtOH yields pale greenish-yellow needles of an unusual adduct, 2.{(NBu4)(PF6)}(infinity) (3), which was found to form a similar extended linear chain, {TlPtR4}(infinity), constructed by two alternating Pt-Tl separations, a shorter (3.1028(6) A) one and a longer (3.2306(6) A) one. The solid state and solution photophysical properties have been examined. While complex 1 shows a high-energy MM'CT blue phosphorescence (450 nm), the extended chain in 2 exhibits a lower-energy emission (582 nm) than that in adduct 3 (505 nm). For products 2 and 3, interesting luminescence thermochromism is observed in frozen solutions. The emissions are found to be strongly dependent on the solvent, concentration, and excitation wavelength.
authors.affiliation: Departamento de Química Inorganica, Instituto de Ciencia de Materiales de Aragón, Universidad de Zaragoza-Consejo Superior de Investigaciones Científicas, 50009 Zaragoza, Spain.
authors.forename: Larry R
authors.initials: LR
authors.lastname: Falvello
authors.forename: Juan
authors.initials: J
authors.lastname: Forniés
authors.forename: Raquel
authors.initials: R
authors.lastname: Garde
authors.forename: Ana
authors.initials: A
authors.lastname: García
authors.forename: Elena
authors.initials: E
authors.lastname: Lalinde
authors.forename: M Teresa
authors.initials: MT
authors.lastname: Moreno
authors.forename: Alexander
authors.initials: A
authors.lastname: Steiner
authors.forename: Milagros
authors.initials: M
authors.lastname: Tomas
authors.forename: Isabel
authors.initials: I
authors.lastname: Usón