Luminescent Chains Formed from Neutral, Triangular Gold Complexes Sandwiching Tl^I and Ag^I. Structures of {Ag([Au(μ-C²,N³-bzim)]₃)₂}BF₄·CH₂Cl₂, {Tl([Au(μ-C²,N³-bzim)]₃)₂}PF₆·0.5THF (bzim = 1-Benzylimidazolate), and {Tl([Au(μ-C(OEt)═NC₆H₄CH₃)]₃)₂}PF₆·THF, with MAu₆ (M = Ag⁺

Abstract

It has been found that several trinuclear complexes of AuI interact with silver and thallium salts to intercalate Ag+ and Tl+ cations, thereby forming chains. The resulting sandwich clusters center the cations between the planar trinuclear moieties producing structures in which six AuI atoms interact with each cation in a distorted trigonal prismatic coordination. The resultant (B3AB3B3AB3)infinity pattern of metal atoms also shows short (approximately 3.0 A) aurophilic interactions between BAB molecular centers. These compounds display a strong visible luminescence, under UV excitation, which is sensitive to temperature and the metal ion interacting with the gold. X-ray crystal structures are reported for Ag([Au(mu-C2,N3-bzim)]3)2BF4CH2Cl2 (P1, Z = 2, a = 14.4505(1) A; b = 15.098(2)A; c = 15.957(1)A; alpha = 106.189(3) degrees; beta = 103.551(5) degrees; gamma = 101.310(5) degrees); Tl([Au(mu-C2,N3-bzim)]3)2PF(6)05C4H8O (P1, Z = 2, a = 15.2093(1)A; b = 15.3931(4)A; c = 16.1599(4)A; alpha = 106.018(1) degrees; beta = 101.585(2) degrees; gamma = 102.068(2) degrees); and Tl([Au(mu-C(OEt)=NC6H4CH3)]3)2PF6.C4H8O (P2(1)/n, Z = 4, a = 16.4136(3)A; b = 27.6277(4)A; c = 16.7182(1)A; beta = 105.644(1) degrees). Each compound shows that the intercalated cation, Ag+ or Tl+, coordinates to a distorted trigonal prism of six AuI atoms. The counteranions reside well apart from the cations between the cluster chains.

A Dinuclear Gold(I)–Silver(I) Derivative of 2‐Cyclopentylidene‐2‐sulfanylacetic Acid and Related Complexes: Synthesis, Crystal Structures, Properties and Antitumor Activity

“…However, equivalent and shorter metal–metal distances were described for the dinuclear complexes [AuAg{CH 3 im(CH 2 py)} 2 ](BF 4 ) 2 [CH 3 im(CH 2 py) = 1‐methyl‐3‐(2‐pyridinylmethyl)imidazole]20 and [(dpim) 3 AuAg](BF 4 ) 2 [dpim = 2‐(diphenylphosphanyl)‐1‐methylimidazole], respectively 21. Shorter distances were also found in the trinuclear complex [AuAg 2 {(pyCH 2 ) 2 im} 2 (NCCH 3 ) 2 ](BF 4 ) 3 [(pyCH 2 ) 2 im = 1,3‐bis(2‐pyridylmethyl)imidazole],22 in the tetranuclear cation [{(Ph 3 P)Au(μ‐mes)Ag(thz)} 2 ] 2+ ,23 in the clusters [Au 6 Ag{μ‐C 6 H 2 (CHMe 2 ) 3 } 6 ] + ,24 [Au 3 Ag(μ 3 ‐O)(PPh 2 py) 3 ] 2+ ,25 [Au 5 Ag 8 (μ‐dppm) 4 {1,2,3‐C 6 (C 6 H 5 ) 3 }(C≡CC 6 H 5 ) 7 ] 3+[26] and (Bu 4 N) 2 [Au(3,5‐C 6 F 3 Cl 2 ) 2 Ag 4 (CF 3 COO) 5 ],27,28 and in polymers such as [{Au(μ‐mes)AsPh 3 } 2 Ag](ClO 4 ),29 [AgAu(mtp) 2 ] (mtp = diphenylmethylenethiophosphinato),30 {[AuAg(Meimpy) 2 (L)](BF 4 ) 2 } n , {[AuAg(Meimpy) 2 (NO 3 )]NO 3 } n (Meimpy = methylimidazolepyridine; L = CH 3 CN, C 6 H 5 CN, C 6 H 5 CH 2 CN),31 [Au 2 Ag 2 (C 6 F 5 ) 4 (OCMe 2 ) 2 ] n ,32 [Au 2 Ag 2 (C 6 F 5 ) 4 (NCCH 3 ) 2 ] n ,33 or Ag([Au(μ‐C 2 ,N 3 ‐bzim)] 3 ) 2 · BF 4 · CH 2 Cl 2 ,34,35 [AuAg 4 (mes)(CF 3 CO 2 ) 4 (tht)] n , [AuAg 4 (mes)(CF 3 CF 2 CO 2 ) 4 (tht)] n , [AuAg 4 (mes)(CF 3 CF 2 CO 2 ) 4 (tht) 3 ] n , {[AuAg 4 (mes)(CF 3 CO 2 ) 4 (tht)(H 2 O)] · H 2 O · CH 2 Cl 2 } n ,17 [AuAg 3 (C 6 F 5 )(CF 3 CO 2 ) 3 (CH 2 PPh 3 )] n ,36 [AgAu(C 6 F 5 )(CF 3 CO 2 )(tht)] n , [Ag 2 Au(C 6 Cl 2 F 3 )(CF 3 CO 2 ) 2 (tht)] n , and [AgAu(C 6 Cl 5 )(CF 3 CO 2 )(tht)] n 18…”

Tunable Trimers: Using Temperature and Pressure to Control Luminescent Emission in Gold(I) Pyrazolate‐Based Trimers

“…Intermolecular aurophilic interactions have been shown to be highly sensitive to conditions such as temperature with several examples of gold(I) trimers displaying thermochromism 2. 5 The triazolate‐based trimer investigated by Coppens and Omary et al 2. displays a shift in emission wavelength upon cooling from approximately 725 nm at 280 K ( λ ex =280 nm) to 755 nm at 90 K. The shift in emission can be attributed to a reduction in intermolecular aurophilic interaction length from 3.42 Å at room temperature to 3.19 Å at 90 K. Time resolved photocrystallographic studies of the copper analogue have observed similar structural distortions in the excited state, confirming the temperature induced structural distortion is directly linked to the change in emission spectrum 6.…”

Metal‐Ion Permeation in Congested Nanochannels: The Exposure Effect of Ag+ Ions on the Phosphorescent Properties of a Gold(I)–Pyrazolate Complex that is Confined in the Nanoscopic Channels of Mesoporous Silica

“…), which was characteristic of a Au I Ag I heterometallic interaction,11a, 12 in addition to the original, less‐intense phosphorescence at 693 nm. The same phosphorescence properties were also observed when EtOH and water were used as solvents.…”

“…Moreover, we have not yet observed any phosphorescence color changes upon exposure of [Au 3 Pz 3 ]/silica hex to other metal ions, such as Cu I , Ir I , Rh I , and Re I , owing to the selective interactions of Ag I to the trinuclear gold(I)–pyrazolate complex in the congested silicate nanochannels 11a. 12 The initial phosphorescence intensity and red emission could be recovered by using the same concentration of cetyltrimethylammonium chloride (CTAC) in CHCl 3 as AgOTf 11a. These observations indicated that the nanoscopic channel of hexagonal mesoporous silica played an essential role in the immobilization of the 1D columnar assembly of [Au 3 Pz 3 ] for the permeation of metal ions.…”

“…On the other hand, the excitation spectra for emission at 486 nm showed a peak maximum at 276 nm with a small peak at 390 nm (Figure 3 b) and the intensity of these two peaks simultaneously became more‐intense with longer dipping time. Interestingly, upon excitation at 396 nm, the resulting Ag@[Au 3 Pz 3 ]/silica hex film displayed a single luminescence center at 486 nm (Figure 1 b),11a, 12 whilst excitation at 276 nm resulted in emissions at both 486 and 693 nm (Figure 1 a). Comparison of the emission spectra upon excitation at 276 nm after dipping for 30 and 60 min (Figure 1 a) showed that the emission owing to a Au I Au I metallophilic interaction was mostly lost in both spectra, whilst that owing to a Au I Ag I heterometallic interaction became much more intense between 30 and 60 min.…”