Syntheses, Molecular Structures, and Spectroscopy of Gold(III) Dithiolate Complexes

Mansour, Michael; Lachicotte, Rene J.; Gysling, Henry J.; Eisenberg, Richard

doi:10.1021/ic980032b

Cited by 75 publications

(75 citation statements)

References 41 publications

(37 reference statements)

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“…On the other hand, variation of the cyclometalating C^N ligands would cause a change in the absorption energies. With reference to such sensitivity to the nature of the cyclometalating C^N ligands, together with previous reports on the dichlorogoldA C H T U N G T R E N N U N G (III) precursors and the related goldA C H T U N G T R E N N U N G (III) ppy [10,11] and alkynylgoldA C H T U N G T R E N N U N G (III) complexes, [8] the electronic ab- sorption band of these dialkynylgoldA C H T U N G T R E N N U N G (III) complexes is suggested to be assigned as a metal-perturbed p-p* intraA C H T U N G T R E N N U N G liA C H T U N G T R E N N U N G gand (IL) transition of the C^N ligand, with charge-transfer character from the aryl ring to the pyridyl or isoquinoline moiety, probably mixed with some alkynyl-to-cyclometalating ligand LLCT character, given the non-reducing nature of the goldA C H T U N G T R E N N U N G (III) metal center, which eliminates the possibility of a metal-to-ligand charge-transfer (MLCT) transition. Attachment of electron-donating methyl, tert-butyl, and the strongly electron-donating methoxy groups on the phenyl ring in complexes 6-13 has generally resulted in red shifts in the electronic absorption compared with complexes 1-5 that contain the unsubstituted ppy ligand.…”

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confidence: 90%

“…[10,11] It is envisaged that the use of cyclometalating C^N-type ligands in combination with alkynyl ligands would result in interesting organogoldA C H T U N G T R E N N U N G (III) complexes with rich luminescence behaviors. In addition, by the judicious selection of the bidentate cyclometalating ligand, the emission color of the goldA C H T U N G T R E N N U N G (III) complexes can be readily tuned.…”

Section: Introductionmentioning

confidence: 99%

“…[10] The dichlorogoldA C H T U N G T R E N N U N G (III) complex showed moderately intense absorption bands at 224, 292, and 334 nm, whereas the free ligand peaked at 234 and 290 nm. Because there was insignificant shift in the electronic absorption bands upon complexation, the high-energy bands of the dichlorogoldA C H T U N G T R E N N U N G (III) precursor were assigned as intraA C H T U N G T R E N N U N G liA C H T U N G T R E N N U N G gand pp* transitions of the ppy ligand.…”

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confidence: 99%

“…These results were found to resemble those of the dichlorogoldA C H T U N G T R E N N U N G (III) precursors and related complexes reported in the literature. [10,11] A detailed study has previously been conducted by Eisenberg and co- …”

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confidence: 99%

“…, which is reported to be non-emissive at room temperature and is only emissive at low-temperature glass, [10] incorporation of the strong electron-donating alkynyl ligands into goldA C H T U N G T R E N N U N G (III) has led to the enhancement of the photoluminescence properties of these cyclometalated goldA C H T U N G T R E N N U N G (III) complexes through the enlargement of the d-d ligand-field splitting. This concept has also been demonstrated in other relat-…”

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confidence: 99%

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Luminescent Cyclometalated Dialkynylgold(III) Complexes of 2‐Phenylpyridine‐Type Derivatives with Readily Tunable Emission Properties

Wong

Zhu

et al. 2010

Chemistry A European J

112

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A novel class of luminescent dialkynylgold(III) complexes containing various phenylpyridine and phenylisoquinoline-type bidentate ligands has been successfully synthesized and characterized. The structures of some of them have also been determined by X-ray crystallography. Electrochemical studies demonstrate the presence of a ligand-centered reduction originating from the cyclometalating C^N ligand, whereas the first oxidation wave is associated with an alkynyl ligand-centered oxidation. The electronic absorption and photoluminescence properties of the complexes have also been investigated. In dichloromethane solution at room temperature, the low-energy absorption bands are assigned as the metal-perturbed π-π* intraligand (IL) transition of the cyclometalating C^N ligand, with mixing of charge-transfer character from the aryl ring to the pyridine or isoquinoline moieties of the cyclometalating C^N ligand. The low-energy emission bands of the complexes in fluid solution at room temperature are ascribed to originate from the metal-perturbed π-π* IL transition of the cyclometalatng C^N ligand. For complex 4 that contains an electron-rich amino substituent on the alkynyl ligand, a structureless emission band, instead of one with vibronic structures as in the other complexes, was observed, which was assigned as being derived from an excited state of a [π(C≡CC(6) H(4) NH(2) )→π*(C^N)] ligand-to-ligand charge-transfer (LLCT) transition.

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confidence: 90%

Section: Introductionmentioning

confidence: 99%

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confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 3 more Smart Citations

Luminescent Cyclometalated Dialkynylgold(III) Complexes of 2‐Phenylpyridine‐Type Derivatives with Readily Tunable Emission Properties

Wong

Zhu

et al. 2010

Chemistry A European J

112

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Structure and Properties of d ⁸ Metal–Dithiolene Complexes

Deplano

Mercuri

Serpe

et al. 2010

Patai's Chemistry of Functional Groups

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Luminescence of Supramolecular Gold‐Containing Materials

López‐de‐Luzuriaga

2008

Modern Supramolecular Gold Chemistry

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In addition to the characteristics that make gold a unique element, such as the lowest electrochemical potential of all metals, its high electronegativity, or the fact that it may have a mononegative oxidation state, perhaps the most intriguing characteristic is the tendency of many gold complexes to aggregate into oligomers or supramolecular assemblies through metal-metal interactions. This fact, far from being a chemical curiosity, has become an object of study because of the associated properties. One of the most studied properties and that which involves many groups all over the world is the luminescence displayed by many gold-containing complexes. In fact, after the discovery of the luminescence of the three-coordinate complex [AuCl(PPh 3 ) 2 ] by Dori and coworkers in 1970 [1], the number of groups that have studied this topic has increased rapidly in recent years, together with the number of synthesized luminescent gold molecules. At the same time, the large number of studies performed in this area has provided knowledge of the conditions that gold complexes require to display luminescence. For instance, luminescence can originate from ligands, assigned to certain geometries around the gold atom or from the presence of metal-metal interactions in the complexes. More specifically, it can be produced by transitions between orbitals of the metal center exclusively, in orbitals of the ligands, usually among p orbitals, or in transitions involving both metal and ligands, where these can act as donors or acceptors of electronic density (charge transfer transitions). In gold (I), with a d 10 closed shell configuration, the ground state is 1 S 0 , while the excited states are 3 D 2 , 3 D 1 , 3 D 0 and 1 D 0 (see Figure 6.1) [2].Of all these, the only permitted electronic transition is 1 D 0 1 S 0 , while the rest are forbidden according to the spin rule, leading to phosphorescent emissions. However, these are precisely the ones responsible for the emissions found in many luminescent gold complexes, appearing in a range between 500 and 700 nm (665 nm in the gaseous ion). j347Another very important factor that should be considered is the expected large spin-orbit effect promoted by a heavy atom such as gold. This effect produces a relaxation of the spin rule and makes orbital forbiddenness instead of the spin rule the key factor for determining whether a gold complex will show luminescence. For instance, phosphorescence is generally not observed for linear molecules (where the ligands are not involved in the transitions), since the mixing of s, p z and d z 2 of gold form a HOMO of S þ symmetry, while the LUMO orbital is formed mainly from p x and p y leading to a P symmetry, consequently, there is no orbital forbiddenness in the transition and phosphorescence is not observed [3]. Another possible coordination environment at gold is the tetrahedral one. In that case, the HOMO and the LUMO are 1 T 2 in symmetry and the transition is allowed according to Laportes rule; therefore, phosphorescence is not observed in thes...

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Syntheses, Molecular Structures, and Spectroscopy of Gold(III) Dithiolate Complexes

Cited by 75 publications

References 41 publications

Luminescent Cyclometalated Dialkynylgold(III) Complexes of 2‐Phenylpyridine‐Type Derivatives with Readily Tunable Emission Properties

Luminescent Cyclometalated Dialkynylgold(III) Complexes of 2‐Phenylpyridine‐Type Derivatives with Readily Tunable Emission Properties

Structure and Properties of d ⁸ Metal–Dithiolene Complexes

Luminescence of Supramolecular Gold‐Containing Materials

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Syntheses, Molecular Structures, and Spectroscopy of Gold(III) Dithiolate Complexes

Cited by 75 publications

References 41 publications

Luminescent Cyclometalated Dialkynylgold(III) Complexes of 2‐Phenylpyridine‐Type Derivatives with Readily Tunable Emission Properties

Luminescent Cyclometalated Dialkynylgold(III) Complexes of 2‐Phenylpyridine‐Type Derivatives with Readily Tunable Emission Properties

Structure and Properties of d 8 Metal–Dithiolene Complexes

Luminescence of Supramolecular Gold‐Containing Materials

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Structure and Properties of d ⁸ Metal–Dithiolene Complexes