Dinuclear and tetranuclear copper(I) iodide complexes with P and P^N donor ligands: Structural and photoluminescence studies. (1st November 2018)

• Record Type: Journal Article
• Authors: Neshat, Abdollah; Aghakhanpour, Reza Babadi; Mastrorilli, Piero; Todisco, Stefano; Molani, Farzad; Wojtczak, Andrzej
• Is Part Of: Polyhedron. Volume 154(2018)
• Page Start: 217
• Page End: 228
• Publication Date: 2018-11-01
• Subjects: Copper(I) complexes -- Luminescent -- DFT -- Phosphine ligands -- Copper cluster; Chemistry, Inorganic -- Periodicals; Chimie inorganique -- Périodiques; Organometaalverbindingen; Anorganische chemie; 546.05
• DOI: 10.1016/j.poly.2018.07.045
• Languages: English
• ISSNs: 0277-5387

Abstract

Graphical abstract: The dependence of the solid state blue photoluminescence intensity in1 upon its poly- or single-crystallinity. Dimer1 in polycrystalline form is a stronger blue light emitter under 254 nm light irradiation than in 365 nm. Abstract: In order to investigate photophysical properties and crystallization medium effects, three Cu complexes, [CuI(PCy3 )]2 (1 ), [Cu(I)(PPh2 Me)]4 (2 ), and [Cu4 (I)4 (PPh2 py)2 ] (3 ) were prepared and characterized using single crystal X-ray crystallography, solid state NMR, UV–Vis, and IR spectroscopy. In1, as previously reported, Cu2 I2 core is a square dimer with alternating copper and iodides positioned in the corners. Each copper atom is surrounded by two bridging iodides and a terminal tricyclohexylphosphine ligand. The cluster2 adopts a cubane-like Cu4 I4 core, while in cluster3 (as thf solvate) a Cu4 I2 distorted octahedral core is decorated with two bridging iodides and two chelating P^N ligands. The solid state 31 P NMR analysis showed the presence in the powder of several polymorphs, the most abundant of which being, in the case of2, the cubane-like structure resolved by XRD methods, and in the case of3, a butterfly structure, different from that found for3 ·thf. The solid state blue photoluminescence intensity in1 is dependent upon its poly- or single-crystallinity. While dimer1 in polycrystalline form is a stronger blue light emitter under 254 nm light irradiation than in 365 nm, in single crystalline phase it shows a similar higher intensity blue luminescence under lower energy light (365 nm) irradiation. On the other hand, clusters2 and3 do not show phase-dependent luminescence intensity variation. Time-dependent Density Functional Theory (TD-DFT) showed that the emission in1 and3 is assigned to a mixed metal to ligand and halide to ligand charge transfer, (X + M)LCT. In2, a dual emission band at low temperature was observed which was attributed to 3 CC (LE band) and 3 XLCT (HE band). Thermochromism and mechanochromism of complexes1 –3 were also investigated.