Publications by authors named "Elizabeth Suk-Hang Lam"

Gold(III) alkynyl complexes with dianionic tridentate pincer ligands have received growing attention recently because of their rich luminescence behavior and their potential applications in areas such as optoelectronics and sensors. In this study, density functional theory (DFT) and time-dependent DFT (TDDFT) calculations have been performed to investigate the radiative and nonradiative processes for the gold(III) alkynyl complexes with different dianionic tridentate ligands, [Au(C^N^C)(C≡CC6H5)] (1; C^N^C = 2,6-diphenylpyridine), [Au(C(Np)^N^C(Np))(C≡CC6H5)] [2; C(Np)^N^C(Np) = 2,6-di(2-naphthyl)pyridine], [Au(N^N^N)(C≡CC6H5)] [3; N^N^N = 2,6-bis(benzimidazol-2'-yl)pyridine], and [Au(C^C^N)(C≡CC6H5)] [4; C^C^N = 3-(2-pyridyl)biphenyl]. It has been found that the electronic properties of the tridentate ligand could have a significant impact on the radiative and nonradiative processes.

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A novel class of alkynylgold(III) complexes of the dianionic ligands derived from 2,6-bis(benzimidazol-2'-yl)pyridine (H2bzimpy) derivatives has been synthesized and characterized. The structure of one of the complexes has also been determined by X-ray crystallography. Electronic absorption studies showed low-energy absorption bands at 378-466 nm, which are tentatively assigned as metal-perturbed π-π* intraligand transitions of the bzimpy(2-) ligands.

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Platinum(II) alkynyl complexes of various tridentate pincer ligands, [Pt(trpy)(C≡CR)](+) (trpy = 2,2':6',2″-terpyridine), [Pt(R'-bzimpy)(C≡CR)](+) (R'-bzimpy = 2,6-bis(N-alkylbenzimidazol-2'-yl)pyridine and R' = alkyl), [Pt(R'-bzimb)(C≡CR)] (R'-bzimb = 1,3-bis(N-alkylbenzimidazol-2'-yl)benzene and R' = C4H9), have been found to possess rich photophysical properties. The emission in dilute solutions of [Pt(trpy)(C≡CR)](+) originated from a triplet alkynyl-to-tridentate pincer ligand-to-ligand charge transfer (LLCT) excited state, with mixing of a platinum-to-tridentate pincer ligand metal-to-ligand charge transfer (MLCT) excited state, while that of [Pt(R'-bzimb)(C≡CR)] originated from a triplet excited state of intraligand (IL) character of the tridentate ligand mixed with a platinum-to-tridentate ligand MLCT character. Interestingly, both emissions were observed in [Pt(R'-bzimpy)(C≡CR)](+) in some cases.

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A series of luminescent cyclometalated platinum(II) complexes of N^C^N ligands [N^C^N=2,6-bis(benzoxazol-2'-yl)benzene (bzoxb), 2,6-bis(benzothiazol-2'-yl)benzene (bzthb), and 2,6-bis(N-alkylnaphthoimidazol-2'-yl)benzene (naphimb)] has been synthesized and characterized. Two of the platinum(II) complexes have been structurally characterized by X-ray crystallography. Their electrochemical, electronic absorption, and luminescence properties have been investigated.

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A series of cholesterol-/estradiol-appended alkynylplatinum(II) complexes with tridentate N-donor ligands, based on 2,6-bis(1-alkylpyrazol-3-yl)pyridine, has been synthesized and characterized by (1)H NMR spectroscopy, FAB-mass spectrometry, and elemental analysis. Their photophysical properties have also been investigated. Computational studies have been performed to provide insights into the nature of the electronic transitions.

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A new class of luminescent alkynylplatinum(II) complexes with a tridentate pyridine-based N-heterocyclic carbene (2,6-bis(1-butylimidazol-2-ylidenyl)pyridine) ligand, [Pt(II)(C^N^C)(C≡CR)][PF6], and their chloroplatinum(II) precursor complex, [Pt(II)(C^N^C)Cl][PF6], have been synthesized and characterized. One of the alkynylplatinum(II) complexes has also been structurally characterized by X-ray crystallography. The electrochemistry, electronic absorption and luminescence properties of the complexes have been studied.

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A series of luminescent platinum(II) complexes of tridentate 1,3-bis(N-alkylbenzimidazol-2'-yl)benzene (bzimb) ligands has been synthesized and characterized. One of these platinum(II) complexes has been structurally characterized by X-ray crystallography. Their electrochemical, electronic absorption, and luminescence properties have been investigated.

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A luminescent cyclometalated platinum(II) complex has been shown to sandwich a silver ion, which demonstrates intense luminescence with appreciable photoluminescence quantum yield. Computational studies have been performed to provide insights into the nature of the photophysical properties.

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