Multiple-state emission from platinum(II) diimine dithiolate complexes. Solvent and temperature effects

Zuleta, Juan A.; Bevilacqua, Joanne M.; Rehm, Julie M.; Eisenberg, Richard

doi:10.1021/ic00034a009

Cited by 77 publications

(82 citation statements)

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“…[49] [50] The role of the metal ion, dithiolate and diimine ligands in the tuning of the optical and nonlin-solvatochromic intramolecular charge-transfer transition, whereas that of the metallocenylvinyl bipyridines 14 exhibear optical properties was investigated. Negative β values in the range 0 to Ϫ40 ϫ 10 Ϫ30 esu were found.…”

Section: Metal-to-ligand Charge-transfer Transitionsmentioning

confidence: 99%

Dipolar and Non-Dipolar Pyridine and Bipyridine Metal Complexes for Nonlinear Optics

Bozec

Renouard

2000

Eur. J. Inorg. Chem.

187

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Metal complexes of pyridine and bipyridine‐type ligands represent an important class of nonlinear optical (NLO) materials: (i) They can incorporate a variety of functionalised ligands with a wide range of metals which can give rise to tuneable NLO properties; (ii) they are generally associated with intense low‐lying charge‐transfer excitations such as metal to ligand charge‐transfer (MLCT) or intraligand charge‐transfer (ILCT); (iii) bipyridyl ligands are also good building blocks that allow the construction of octupolar complexes with a defined geometry and symmetry. This review describes the recent developments in the design of such dipolar and octupolar chromophores for second‐order nonlinear optics.

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Section: Metal-to-ligand Charge-transfer Transitionsmentioning

confidence: 99%

Dipolar and Non-Dipolar Pyridine and Bipyridine Metal Complexes for Nonlinear Optics

Bozec

Renouard

2000

Eur. J. Inorg. Chem.

187

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“…The cycloplatinated complexes 1 and 2 also show a small blue shift of ca. 5 nm on cooling to 77 K. This observation could be attributed to the increased rigidity in the frozen state, which has usually been described as rigidochromism (seeFigure 3andTable 2) 27,[52][53][54][55][56]. Due to combination of strong-fields of aryl and C ˄ N cyclometalating ligands, the complexes…”

mentioning

confidence: 93%

Photophysical and DFT studies on cycloplatinated complexes: modification in luminescence properties by expanding of π-conjugated systems

et al. 2015

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To investigate the factors influencing the luminescent properties of cycloplatinated complexes containing aryl and SMe 2 ligands, a detailed study of the photophysical and structural properties of the complexes [Pt(p-MeC 6 H 4 )(C^N)(SMe 2 )], (C^N= benzo[h]quinolate (bzq), 1, or 2-phenylpyridinate (ppy), 2), was conducted in solution and solid state at different temperatures. Density functional theory (DFT) and Time-dependent density functional theory (TD-DFT) investigations were carried out on both the singlet (S 0 , ground) and triplet (T 1 , excited) states of these complexes for explanation of the electronic structures, absorption and emission spectra. In the solid state, these complexes display an intense phosphorescence emission which was red-shifted from 2 to 1 due to expanding of π conjugated system in cyclometalated bzq ligand. These complexes are strongly emissive in 77 K, giving emission peaks similar to those observed at ambient temperature. The complex 1 in deoxygenated CH 2 Cl 2 solution (at low concentration) gave a phosphorescence band which 2 was accompanied by a higher-energy fluorescence band (ascribed to 1 LC transition, centered on bzq ligand), and these bands were disappeared when a concentrated solution or glassy state (77 K) of the complex is in use. On the basis of theoretical calculations, the HOMO level is a mixture of platinum center and ligand orbitals, while the LUMO level is predominantly C^N ligand based. Lowest-lying excited state responsible for the phosphorescence emission (with a significantly long lifetime) is originated from mixed 3 ILCT/ 3 MLCT with some 3 L'LCT excited state and the emission is red shifted to corresponding free cyclometallating ligand.

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“…11 As such, dithiolene ligands exhibit “non-innocent” behavior and metal-dithiolenes are among a limited number of inorganic systems that display extensive metal-ligand redox interplay making them useful as key components of donor-acceptor molecules. 12,13 From a valence bond perspective, dithiolene ligands can be viewed as existing somewhere between the extremes of the neutral dithione/dithiete and dianionic dithiolate ligand forms. (Fig.…”

Section: Introductionmentioning

confidence: 99%

Study of Molybdenum(4+) Quinoxalyldithiolenes as Models for the Noninnocent Pyranopterin in the Molybdenum Cofactor

et al. 2011

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A model system for the molybdenum cofactor has been developed that illustrates the non-innocent behavior of a N-heterocycle appended to a dithiolene chelate on molybdenum. The pyranopterin of the molybdenum cofactor is modeled by a quinoxalyl-dithiolene ligand (S2BMOQO) formed from reaction of a molybdenum tetrasulfide and a quinoxalyl alkyne. The resulting complexes TEA[Tp*MoX(S2BMOQO)] (1, X = S; 3, X = O; TEA = tetraethylammonium; Tp* = hydrotris(3,5-dimethylpyrazolyl)borate) undergo a dehydration-driven intramolecular cyclization within the quinoxalyl-dithiolene forming Tp*MoX(pyrrolo-S2BMOQO) (2, X= S; 4, X= O). 4 can be oxidized by one electron to produce the Mo(5+) complex 5. In a preliminary report of this work evidence from X-ray crystallography, electronic absorption and resonance Raman spectroscopies, and DFT bonding calculations revealed that 4 possesses an unusual asymmetric dithiolene chelate with significant thione-thiolate character. The results described here provide a detailed description of the reaction conditions that lead to formation of 4. Data from cyclic voltammetry, additional DFT calculations and several spectroscopic methods (infrared, electronic, resonance Raman, electron paramagnetic resonance) have been used to characterize the properties of members in this suite of five Mo(S2BMOQO) complexes and further substantiate the highly electron-withdrawing character of the pyrrolo-S2BMOQO ligand in 2 and 4. This study of the unique non-innocent ligand S2BMOQO provides examples of the roles that the N-heterocycle pterin can play as an essential part of the molybdenum cofactor. The versatile nature of dithiolene appended by heterocycles may aid in modulating the redox processes of the molybdenum center during the course of enzyme catalysis.

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Multiple-state emission from platinum(II) diimine dithiolate complexes. Solvent and temperature effects

Cited by 77 publications

References 1 publication

Dipolar and Non-Dipolar Pyridine and Bipyridine Metal Complexes for Nonlinear Optics

Dipolar and Non-Dipolar Pyridine and Bipyridine Metal Complexes for Nonlinear Optics

Photophysical and DFT studies on cycloplatinated complexes: modification in luminescence properties by expanding of π-conjugated systems

Study of Molybdenum(4+) Quinoxalyldithiolenes as Models for the Noninnocent Pyranopterin in the Molybdenum Cofactor

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