Luminescence and simulation of mixed metal nanoclusters of dicyanoargentate(I) and dicyanoaurate(I) in alkali halides

Welch, David; Baril-Robert, François; Li, Xiaobo; Patterson, Howard H.

doi:10.1016/j.ica.2011.01.076

Cited by 11 publications

(12 citation statements)

References 32 publications

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“…Only in solutions containing both [Cu(CN) 2 − ]/[Ag(CN) 2 − ] do we observe a low energy emission band at 500 nm. The energy of this band is consistent with a MC heterometallic charge transfer between Cu/Ag metal centers as reported in other d 10 /d 8 analogs and as observed in the IR …”

Section: Methodssupporting

confidence: 90%

Nanoclusters of Dicyanocuprate(I) Anions in Aqueous Solutions: Investigating Cuprophilic Interactions

et al. 2019

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The oligomerization of cyanocuprate(I) ions in aqueous solutions lacking and containing alkali cyanide salts (NaCN/ KCN) has been investigated by infrared, Raman, and low temperature luminescence spectroscopy. In solution metallophilic interactions between Cu(I) metal centers bind the ions together into ∼ 1D chains. The structure and luminescence assignment of these nanoclusters was determined using simple Group Theory and Density Functional Theory calculations. Measurements show that the presence of KCN and NaCN in solution drives oligomerization of CuCN 2 À ions to higher order nanoclusters. Calculations of dimer and trimer clusters with K + and Na + ions indicate that alkali metals favor the formation of linear clusters as opposed to those that are bent. These findings fill an important gap in the understanding of d 10 cyanometallate oligomers given the prevalence of cyanocuprate(I) in metal-organic frameworks.Spontaneous oligomerization of d 10 cyanometallates in solution was first reported for aqueous solutions of Ag(CN) 2 À and Au (CN) 2 À ions. [1][2][3][4] Interest in these systems was driven by the prevalence of Au(I) and Ag(I) metals in photoactive materials. These nanoclusters display strong photoluminescence properties at extremely low concentrations. Measurements revealed that absorbance and emission energies are heavily dependent on the oligomer size, as clearly demonstrated by the red shift of the UV-vis absorption edge within increasing ion concentration. The culprit for the formation of these clusters is ground state aurophilic and argentophilic interactions between metal centers. The strong interaction significantly stabilizes the ion cluster permitting the formation of large clusters of size n > 4. An investigation of the excited states of [Au(CN) 2 À ] n clusters was later performed by Iwamura and others using pico-and femtosecond spectroscopy. [5][6][7][8] In all cases it was concluded that these oligomers exist as loosely bound close-shelled clusters in the ground state but become tightly bound in the open-shelled excited state. For those of n � 3, this results in ground state structures, Scheme 1, that are bent in nature but contract to form a linear AuÀ Au-Au upon photoexcitation.Curiously, despite the importance of this work and its prevalence throughout the literature, there has been no similar investigation of the cyanocuprate(I) analog. Presumably this system behaves in a similar manner to Au(CN) 2 À and Ag(CN) 2 À due to their similar electronic configurations. The need for this investigation comes at a time when researchers are actively seeking cheaper, more abundant alternatives to precious metals such as Pt, Ag, and Au. [9][10][11] To address this discrepancy we have prepared solutions of CuCN 2 À in DI water with and without the alkali cyanide salts KCN and NaCN. It has been demonstrated that coexisting simple cations (i.e Li + , K + , Rb + , Cs + ) are capable of stabilizing larger [Au(CN) 2 À ] n oligomers. [6,8] [a] Dr.

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Section: Methodssupporting

confidence: 90%

Nanoclusters of Dicyanocuprate(I) Anions in Aqueous Solutions: Investigating Cuprophilic Interactions

et al. 2019

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“…[99] Pioneering work has also included salts with bulky cations, as in NBu 4 [Au(CN) 2 ], which separate the anions in the crystals [100] such that the photophysical characteristics of isolated [Au(CN) 2 ] À anions could be studied in the same way as in crystal matrices doped with traces of M[Au(CN) 2 ]. [101][102][103] In crystals of salts with very bulky cations such as bis(triphenylphosphoranylidene)ammonium [(Ph 3 P) 2 N] + also no aggregation of the anions occurs. [104] Early studies of the vibrational spectra of dicyanoaurates(I) provided no evidence for as pecific influence of the Au•••Auc ontacts on the fundamental characteristics of the anion in solids,a nd solution IR and 13 CNMR spectra (with 13 C-labeled cyanide) at various concentrations (in water and dichloromethane at room temperature) did not indicate any major effects of anion aggregation.…”

Section: The Case Of the Dicyanoaurate(i) Anionmentioning

confidence: 99%

“…Pioneering work has also included salts with bulky cations, as in NBu 4 [Au(CN) 2 ], which separate the anions in the crystals such that the photophysical characteristics of isolated [Au(CN) 2 ] − anions could be studied in the same way as in crystal matrices doped with traces of M[Au(CN) 2 ] . In crystals of salts with very bulky cations such as bis(triphenylphosphoranylidene)ammonium [(Ph 3 P) 2 N] + also no aggregation of the anions occurs …”

Section: Relevant Aspects Of Aurophilic Aui−aui Bondingmentioning

confidence: 99%

Excimer and Exciplex Formation in Gold(I) Complexes Preconditioned by Aurophilic Interactions

Schmidbaur

Raubenheimer

2020

Angew Chem Int Ed

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Excimers and exciplexes are defined as assemblies of atoms or molecules A/A′ where interatomic/intermolecular bonding appears only in excited states such as [A2]* (for excimers) and [AA′]* (for exciplexes). Their formation has become widely known because of their role in gas‐phase laser technologies, but their significance in general chemistry terms has been given little attention. Recent investigations in gold chemistry have opened up a new field of excimer and exciplex chemistry that relies largely on the preorganization of gold(I) compounds (electronic configuration AuI(5d10)) through aurophilic contacts. In the corresponding excimers, a new type of Au⋅⋅⋅Au bonding arises, with bond energies and lengths approaching those of ground‐state Au−Au bonds between metal atoms in the Au0(5d106s1) and AuII(5d9) configurations. Excimer formation gives rise to a broad range of photophysical effects, for which some of the relaxation dynamics have recently been clarified. Excimers have also been shown to play an important role in photoredox binuclear gold catalysis.

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“…In richtungsweisenden Arbeiten wurden auch Salze mit raumfüllenden Kationen wie in NBu 4 [Au(CN) 2 ], untersucht, welche die Anionen in den Kristallen voneinander trennen, sodass die photophysikalischen Eigenschaften isolierter [Au(CN) 2 ] − ‐Anionen untersucht werden konnten, genauso wie in mit Spuren von M[Au(CN) 2 ] dotierten Kristallmatrizes . In Kristallen von Salzen mit sehr sperrigen Kationen wie Bis(triphenylphosphoranyliden)ammonium, [(Ph 3 P) 2 N] + , kommt es ebenfalls zu keiner Aggregation der Anionen …”

Section: Relevante Aspekte Der Aurophilen Aui‐aui‐bindungunclassified

Excimer‐ und Exciplex‐Bildung in durch aurophile Wechselwirkungen präkonditionierten Gold(I)‐ Komplexen

Schmidbaur

Raubenheimer²

2020

Angewandte Chemie

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Excimere und Exciplexe sind definiert als Aggregate von Atomen oder Molekülen A/A′, in denen es nur in angeregten Zuständen [A2]* und [AA′]* zu interatomaren/‐molekularen Bindungen kommt. Ihre Bildung wurde weithin bekannt durch ihre Bedeutung in Gasphasen‐Lasertechnologien. Jüngste Untersuchungen in der Goldchemie haben der Excimer‐ und Exciplex‐Chemie ein neues Gebiet eröffnet, das hauptsächlich durch die Aggregation von Gold(I)‐Verbindungen (AuI(5d10)) über aurophile Kontakte bedingt wird. In den zugehörigen Excimeren entstehen Au–Au‐Bindungen mit Bindungsenergien und ‐abständen, die denen im Grundzustand von Au0(5d106s1)‐ und AuII(5d9)‐Verbindungen entsprechen. Der aktuelle Kenntnisstand über Excimere und Exciplexe in der Goldchemie wird hier vorgestellt, vorwiegend an einfachen Beispielen wie der Assoziation von [Au(CN)2]−‐Anionen in Festkörpern und in Lösung. Die Excimer‐Bildung führt zu einem breiten Spektrum an photophysikalischen Effekten, deren Relaxationsdynamik in einigen Fällen kürzlich aufgeklärt wurde. Excimere sind aktuell auch von großer Bedeutung auf dem Gebiet der “photoredox binuclear gold catalysis”.

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Luminescence and simulation of mixed metal nanoclusters of dicyanoargentate(I) and dicyanoaurate(I) in alkali halides

Cited by 11 publications

References 32 publications

Nanoclusters of Dicyanocuprate(I) Anions in Aqueous Solutions: Investigating Cuprophilic Interactions

Nanoclusters of Dicyanocuprate(I) Anions in Aqueous Solutions: Investigating Cuprophilic Interactions

Excimer and Exciplex Formation in Gold(I) Complexes Preconditioned by Aurophilic Interactions

Excimer‐ und Exciplex‐Bildung in durch aurophile Wechselwirkungen präkonditionierten Gold(I)‐ Komplexen

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