Mononuclear cycloplatinated complexes derived from 2-tolylpyridine with N-donor ligands: Reactivity and structural characterization

Rodríguez‐Castro, Antonio; Fernández, Alberto; López‐Torres, Margarita; Vázquez‐García, Digna; Naya, Leticia; Vila, José M.; Fernández, Jesús J.

doi:10.1016/j.poly.2011.11.055

Cited by 10 publications

(6 citation statements)

References 54 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is notable that the formation of 1 proceeded with the amidine-induced cleavage of dinuclear [Pt(pypm)(μ-Cl)] 2 . Similar donor-induced dissociation of dimers has been well documented in the literature. − …”

Section: Results and Discussionsupporting

confidence: 75%

Near-Infrared Emission Induced by Shortened Pt–Pt Contact: Diplatinum(II) Complexes with Pyridyl Pyrimidinato Cyclometalates

Wang

Wei

et al. 2019

Inorg. Chem.

View full text Add to dashboard Cite

Four diplatinum(II) complexes with the formula [Pt(pypm)(μ-F n )] 2 (2, 3a−c) bearing both a pyridine-pyrimidinate chelate and formamidinate bridge, where (pypm)H and F n H stand for 5-(pyridin-2-yl)-2-(trifluoromethyl)pyrimidine and functional formamidines with various substituents of i Pr (n = 1), Ph (n = 2), C 6 H 4 t Bu (n = 3), and C 6 H 4 CF 3 (n = 4), were synthesized en route from a mononuclear intermediate represented by [Pt(pypm)Cl-(F 1 H)] (1). Single-crystal X-ray diffraction studies confirmed the structure of 1 and 3a comprised of an individual "Pt(pypm)" unit and two "Pt(pypm)" units with a Pt•••Pt distance of 2.8845(2) Å, respectively. Therefore, in contrast to the structured emission of mononuclear 1 with the first vibronic peak wavelength at 475 nm, all other diplatinum complexes with shortened Pt•••Pt separation exhibited greatly red shifted and structureless metal−metal to ligand charge transfer (MMLCT) emission that extended into the near-infrared region in solid states. Their photophysical characteristics were measured under three distinctive morphological states (i.e., crystals, sublimed powders, and vacuum-deposited thin films) by steady-state UV−vis spectroscopy, while retention of Pt•••Pt interactions in deposited thin films of 2 and 3a−c was confirmed using Raman spectroscopy, demonstrating lowered Pt•••Pt stretching at 80−200 cm −1 . Most importantly, complexes 3a−c exhibited a gradual red shift with the trends crystals < sublimed powders < vacuum-deposited thin films, a result of increased intermolecular π−π stacking interactions and Pt•••Pt interactions, while crystalline samples exhibited the highest luminescence among all three morphological states due to the fewest defects in comparison to other morphologies. Finally, 3b was selected as a nondoped emitter for the fabrication of NIR-emitting OLEDs, giving an electroluminescence peak at 767 nm and a maximum external quantum efficiency of 0.14% with negligible roll-off.

show abstract

Section: Results and Discussionsupporting

confidence: 75%

Near-Infrared Emission Induced by Shortened Pt–Pt Contact: Diplatinum(II) Complexes with Pyridyl Pyrimidinato Cyclometalates

Wang

Wei

et al. 2019

Inorg. Chem.

View full text Add to dashboard Cite

show abstract

“…Two isomers of complexes [Pt(ppy)X( L )] may exist in solution. , Based on the established order of a kinetic trans effect, it would be expected that the halo ligand trans to the carbon donor would be more labile and that the monodentate ligand would be located trans to the carbon. However, the most published cyclometalated platinum complexes [Pt(ppy)X( L )] are presented by cis (N,X) isomers and there are only few representatives of trans (N,X) complexes. − To get an idea about the preferred molecular structure of complexes 1 – 8 in solution and to identify spectral features that could be used to analyze their isomeric structures in solution, quantum-chemical (DFT) calculations were carried out. According to the calculations, the cis (N,X) isomer is substantially more preferable in terms of energy than the trans (N,X) isomer (by 8–9 kcal/mol) for both halo ligands (Table S1).…”

Section: Resultsmentioning

confidence: 99%

“…Two isomers of complexes [Pt(ppy)X(L)] may exist in solution. 29,30 Based on the established order of a kinetic trans effect, it would be expected that the halo ligand trans to the carbon donor would be more labile and that the monodentate ligand would be located trans to the carbon. However, the most published cyclometalated platinum complexes [Pt(ppy)X(L)] are presented by cis(N,X) isomers and there are only few representatives of trans(N,X) complexes.…”

Section: ■ Introductionmentioning

confidence: 99%

Cyclometalated Platinum(II) Complexes with 10-(Aryl)phenoxarsine Ligands: Synthesis, Structure, and Photophysical Properties

et al. 2023

View full text Add to dashboard Cite

A series of C^N-cyclometalated platinum(II) complexes [Pt(ppy)X(L)] (ppy = 2-phenylpyridinate, X = Cl and I) with 10-(aryl)phenoxarsines, namely 10-(p-tolyl)phenoxarsine (L1), 10-(p-fluorophenyl)phenoxarsine (L2), 10-(m-fluorophenyl)phenoxarsine (L3), and 10-(phenyl)phenoxarsine (L4), was synthesized. The structure of the complexes was determined by in-dept NMR spectroscopy, mass spectrometry, and X-ray analysis. The UV/vis absorption and emission properties were studied and rationalized by DFT and time-dependent DFT calculations. In the solid state, under UV irradiation, platinum complexes with chloro ligands exhibit an intense green emission, which was attributed to a 3IL/3(X,M)LCT triplet state.

show abstract

Section: Resultsmentioning

confidence: 99%

“…As a consequence, the donor properties of py 2CF 3 , and hence of the corresponding nitrogen in bpy 6CF 3 , are expected to be poor. A survey of literature data showed only one result for coordination of py 2CF 3 , 23 versus 888 results for py 2CH 3 . 24 A clue concerning the electronic influence of these substituents on the pyridine ring is also given by comparison of Hammett σ values: CF 3 has a marked electron-attracting effect, both inductive and mesomeric, whereas the opposite effect is provided by CH 3 : σ m (CF 3 ) = +0.43, σ m (CH 3 ) = −0.07; σ p (CF 3 ) = +0.54, σ p (CH 3 ) = −0.17.…”

Section: ■ Introductionmentioning

confidence: 99%

Electronic and Steric Effects in Rollover C–H Bond Activation

et al. 2015

View full text Add to dashboard Cite

Steric and electronic factors in rollover C−H bond activation of substituted 2,2′-bipyridines, mediated by platinum(II), have been investigated by comparing the influence of two substituents, CH 3 and CF 3 , on the progress of the reaction. The substituents were chosen to have similar steric hindrance but different electronic effects and were placed in position 6 (i.e., near one of the nitrogen atoms) or in position 5, which allows, in part, electronic and steric influence to be distinguished. The ligands studied, 6-methyl-2,2′-bipyridine, 5-methyl-2,2′-bipyridine, 6-trifluoromethyl-2,2′-bipyridine, and 5-trifluoromethyl-2,2′-bipyridine, were compared to unsubstituted 2,2′-bipyridine in the reaction with the electron-rich complex [Pt(Me) 2 (DMSO) 2 ]. The electron-withdrawing CF 3 group was found to have a significant effect in accelerating the cyclometalation reaction. The substituent in position 6 influences the stability of the intermediate adduct [Pt(N,N)(Me) 2 ] (N,N = chelated bipyridine), as indicated by density functional theory calculations. The steric hindrance of substituted bipyridines was also evaluated by defining and measuring the angle ζ in [Pt(N,N)(Me) 2 ] adducts. The presence of a substituent in position 6 causes destabilization of the adduct, acceleration of the cyclometalation reaction, and regioselectivity of C−H bond activation.

show abstract

Mononuclear cycloplatinated complexes derived from 2-tolylpyridine with N-donor ligands: Reactivity and structural characterization

Cited by 10 publications

References 54 publications

Near-Infrared Emission Induced by Shortened Pt–Pt Contact: Diplatinum(II) Complexes with Pyridyl Pyrimidinato Cyclometalates

Near-Infrared Emission Induced by Shortened Pt–Pt Contact: Diplatinum(II) Complexes with Pyridyl Pyrimidinato Cyclometalates

Cyclometalated Platinum(II) Complexes with 10-(Aryl)phenoxarsine Ligands: Synthesis, Structure, and Photophysical Properties

Electronic and Steric Effects in Rollover C–H Bond Activation

Contact Info

Product

Resources

About