Bright Luminescence in Three Phases—A Combined Synthetic, Spectroscopic and Theoretical Approach

Abstract

Combining phase‐dependent photoluminescence (PL) measurements and quantum chemical calculations is a powerful approach to help understand the influence of the molecular surroundings on the PL properties. Herein, a phosphine functionalized amidinate was used to synthesize a recently presented bimetallic gold complex, featuring an unusual charge separation. The latter was subsequently used as metalloligand to yield heterotetrametallic complexes with an Au‐M‐M‐Au “molecular wire” arrangement (M=Cu, Ag, Au) featuring metallophilic interactions. All compounds show bright phosphorescence in the solid state, also at ambient temperature. The effect of the molecular environment on the PL was studied in detail for these tetrametallic complexes by comparative measurements in solution, in the solid state and in the gas phase and contrasted to time‐dependent density functional theory computations.

Cooperativity in luminescent heterobimetallic diphosphine-β-diketiminate complexes

“…The distance is shorter than in other conventionally known literature examples (2.7 Å–3.0 Å). 38,49,50 The resonance in the 31 P{ 1 H} NMR spectrum at 27.1 ppm is only marginally shifted compared to the mononuclear Au I complex 1 (28.6 ppm). The NMR spectra of 3 show persistent peaks of some decomposition products.…”

“…35,36 In particular, coinage metals are known for their different behaviour towards hard and soft coordination sites. [37][38][39][40][41] In this manner, gold as the "softest" cation prefers "soft" donors, while copper as a "hard" metal ion has great affinity for "hard" donors. The bis(diphenyl) phosphine-functionalised β-diketiminato ligand system [HC {(CH 3 )C} 2 {(o-[P(C 6 H 5 ) 2 ] 2 C 6 H 4 )N} 2 ] − (PNac) might be a perfect candidate to achieve heterobimetallic systems (Fig.…”

Phase‐Dependent Long Persistent Phosphorescence in Coumarin‐Phosphine‐Based Coinage Metal Complexes

“…In contrast to zinc compounds, the phosphorescence lifetimes of numerous known coinage metal complexes are typically limited to a microseconds to milliseconds range, both at low and ambient temperatures [12–20] . In general, coinage metal phosphine complexes have attracted significant attention due to the ease of coordination of phosphine donors with metal centers, as well as to their potential to support metallophilic interactions, which often lead to supramolecular architectures with fascinating optical properties [21–23] . In this context, diphosphine ligands have been elaborated as especially useful because of their ability to act as chelates, monodentate or bridging ligands, allowing for the spatial proximity of the metal centers and thereby resulting in stabilization of homo‐ and hetero‐nuclear metal complexes [24,25] …”

“…[12][13][14][15][16][17][18][19][20] In general, coinage metal phosphine complexes have attracted significant attention due to the ease of coordination of phosphine donors with metal centers, as well as to their potential to support metallophilic interactions, which often lead to supramolecular architectures with fascinating optical properties. [21][22][23] In this context, diphosphine ligands have been elaborated as especially useful because of their ability to act as chelates, monodentate or bridging ligands, allowing for the spatial proximity of the metal centers and thereby resulting in stabilization of homo-and hetero-nuclear metal complexes. [24,25] It has been well established that the introduction of additional, photophysically "active" groups into a ligand backbone can significantly alter optical properties of the related metal complexes, in particular their photoluminescence (PL).…”