Vapochromic Gold(I)–Silver(I) Cluster Protected by Alkynyl and Phosphine Ligands

Abstract

Intensely luminescent coinage metal cluster [Au12Ag14(C≡CPh)20(mdppz)4(CH3OH)8](BF4)6 {1, mdppz = 2‐(3‐methylpyrazinyl)diphenylphosphine} was synthesized and structurally characterized. Twenty alkynyl ligands (PhC≡C–), four mdppz ligands, and eight methanol molecules were found to co‐stabilize the metal cluster. Interestingly, when the weakly ligated methanol molecules were removed, the green luminescence of 1 significantly redshifted to yellow; exposing the resulting yellow sample in methanol vapor immediately restores the green luminescence. Thus reversible luminescence response can be observed by removing and restoring methanol. Other small solvent molecules with weak coordination ability such as Me2CO, MeCN, and C2H5OH were also found to be good agents to trigger the vapochromism.

Innovative Molecular Design Strategies in Materials Science Following the Aurophilicity Concept

“…Reversible luminescence of 150 . Reproduced with permission from ref . Copyright 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.…”

“…Complex 150 exhibits reversible luminescence (365 nm excitation) from green to yellow upon loss of coordinated methanol; the green luminescence is restored in the presence of methanol vapor (Figure 39). 177 Blue-emissive crystals of…”

Two-way vapochromism of a luminescent platinum(ii) complex with phosphonic-acid-functionalized bipyridine ligand

“…Other promising approaches recently developed involve the use of host-guest interactions between the adsorbing material and vapour molecules [23][24][25][26][27][28] or the use of ligand substitution reactions at metal centres. [29][30][31][32][33][34][35][36][37] Most of the vapochromic behaviour reported so far is essentially based on the colour differences between vapouradsorbed and vapour-released phases. Although many vapochromic materials have been reported to date, there are few examples that exhibit switching vapochromic behaviour.…”

Theoretical Analysis of Optical Absorption and Emission in Mixed Noble Metal Nanoclusters

“…Properties of solution-phase noble metal clusters in the size regime of 1–3 nm have drawn significant interest in the last few year because of unique properties dependent on the structure, where more than 100 such clusters have been synthesized and characterized so far (ref and references therein). Clusters of noble metal atoms can have light absorption and emission properties useful for applications, including photodynamic therapy, − photovoltaics, − optical memory, − imaging, − sensors, − and biolabels. − Noble metal clusters demonstrate strong luminescence, − tunability in the absorption wavelength, and also a large two-photon absorption (TPA) cross-section. ,, Materials that exhibit TPA have advantages in tighter spatial confinement, as well as in accessing electronic excitation of twice the incident photon energy, and can be particularly useful in photodynamic therapy, − imaging, − and optical memory, , as well as in confocal microscopy , and microfabrication. − The possible applications of noble metal clusters are being expanded by using them as building blocks to form superclusters. , We have investigated one-photon absorption (OPA) and TPA spectra of [Au 25 (SR) 18 ] −1 by applying density functional theory (DFT) and time-dependent DFT (TDDFT). The large TPA cross-section was explained in terms of resonance enhancement .…”