scholarly journals Gold nanoclusters with bright near-infrared photoluminescence

Nanoscale ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 3792-3798 ◽  
Author(s):  
Goutam Pramanik ◽  
Jana Humpolickova ◽  
Jan Valenta ◽  
Paromita Kundu ◽  
Sara Bals ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Quantum Yield ◽  
Near Infrared ◽  
Gold Nanoclusters ◽  
Ligand Charge Transfer

Triphenylphosphonium cations strongly enhance the PL quantum yield of the near infrared photoluminescent gold nanoclusters by metal-to-ligand charge transfer.

Os(II) Phosphors with Near-Infrared Emission Induced by Ligand-to-Ligand Charge Transfer Transition

2014 ◽  
Vol 53 (17) ◽  
pp. 9366-9374 ◽  
Author(s):  
Jia-Ling Liao ◽  
Yun Chi ◽  
Shih-Hung Liu ◽  
Gene-Hsiang Lee ◽  
Pi-Tai Chou ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Near Infrared ◽  
Infrared Emission ◽  
Charge Transfer Transition ◽  
Ligand Charge Transfer ◽  
Near Infrared Emission

Implementing Metal-to-Ligand Charge Transfer in Organic Semiconductor for Improved Visible-Near-Infrared Photocatalysis

2016 ◽  
Vol 28 (32) ◽  
pp. 6959-6965 ◽  
Author(s):  
Yanrui Li ◽  
Zhaowu Wang ◽  
Tong Xia ◽  
Huanxin Ju ◽  
Ke Zhang ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Organic Semiconductor ◽  
Near Infrared ◽  
Ligand Charge Transfer

Luminescence of a New Ru(II) Polypyridine Complex Controlled by a Redox-Responsive Protonable Anthra[1,10]phenanthrolinequinone

2005 ◽  
Vol 70 (11) ◽  
pp. 1891-1908 ◽  
Author(s):  
František Hartl ◽  
Sandrine Vernier ◽  
Peter Belser
Keyword(s):  
Charge Transfer ◽  
Quantum Yield ◽  
Emission Intensity ◽  
Luminescence Quenching ◽  
Luminescence Quantum Yield ◽  
Ligand Charge Transfer ◽  
Redox Responsive ◽  
Electron Reduction ◽  
Mlct State

Redox-controlled luminescence quenching is presented for a new Ru(II)-bipyridine complex [Ru(bpy)2(1)]2+ where ligand 1 is an anthra[1,10]phenanthrolinequinone. The complex emits from a short-lived metal-to-ligand charge transfer, 3MLCT state (τ = 5.5 ns in deaerated acetonitrile) with a low luminescence quantum yield (5 × 10-4). The emission intensity becomes significantly enhanced when the switchable anthraquinone unit is reduced to corresponding hydroquinone. On the contrary, chemical one-electron reduction of the anthraquinone moiety to semiquinone in aprotic tetrahydrofuran results in total quenching of the emission.

Synthesis and Photochemical Properties of Re(I) Tricarbonyl Complexes Bound to Thione and Thiazole-2-ylidene Ligands

2020 ◽  
Author(s):  
Matthew Stout ◽  
Brian Skelton ◽  
Alexandre N. Sobolev ◽  
Paolo Raiteri ◽  
Massimiliano Massi ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Excited States ◽  
Ligand Exchange ◽  
Ligand Substitution ◽  
Bidentate Ligand ◽  
The Other ◽  
Ligand Exchange Reaction ◽  
Multiple Products ◽  
Ligand Charge Transfer ◽  
Photochemical Properties

<p>Three Re(I) tricarbonyl complexes, with general formulation Re(N^L)(CO)<sub>3</sub>X (where N^L is a bidentate ligand containing a pyridine functionalized in the position 2 with a thione or a thiazol-2-ylidene group and X is either chloro or bromo) were synthesized and their reactivity explored in terms of solvent-dependent ligand substitution, both in the ground and excited states. When dissolved in acetonitrile, the complexes bound to the thione ligand underwent ligand exchange with the solvent resulting in the formation of Re(NCMe)<sub>2</sub>(CO)<sub>3</sub>X. The exchange was found to be reversible, and the starting complex was reformed upon removal of the solvent. On the other hand, the complexes appeared inert in dichloromethane or acetone. Conversely, the complex bound to the thiazole-2-ylidene ligand did not display any ligand exchange reaction in the dark, but underwent photoactivated ligand substitution when excited to its lowest metal-to-ligand charge transfer manifold. Photolysis of this complex in acetonitrile generated multiple products, including Re(I) tricarbonyl and dicarbonyl solvato-complexes as well as free thiazole-2-ylidene ligand.</p>

Highly Fluorescent Au25-xAgx Nanoclusters Protected with Poly(ethylene glycol) - and Zwitterion-Modified Thiolate Ligands

2018 ◽  
Author(s):  
Dinesh Mishra ◽  
Sisi Wang ◽  
Zhicheng Jin ◽  
Eric Lochner ◽  
Hedi Mattoussi
Keyword(s):  
Quantum Yield ◽  
Near Infrared ◽  
Small Diameter ◽  
Binding Energies ◽  
Thiolate Ligands ◽  
Nir Emission ◽  
Thiolate Complexes ◽  
Long Lifetime ◽  
Poly Ethylene

<p>We describe the growth and characterization of highly fluorescing, near-infrared-emitting nanoclusters made of bimetallic Au<sub>25-x</sub>Ag<sub>x</sub> cores, prepared using various monothiol-appended hydrophobic and hydrophilic ligands. The reaction uses well-defined triphenylphosphine-protected Au<sub>11</sub> clusters (as precursors), which are reacted with Ag(I)-thiolate complexes. The prepared nanoclusters are small (diameter < 2nm, as characterized by TEM) with emission peak at 760 nm and long lifetime (~12 µs). The quantum yield measured for these materials was 0.3 - 0.4 depending on the ligand. XPS measurements show the presence of both metal atoms in the core, with measured binding energies that agree with reported values for nanocluster materials. The NIR emission combined with high quantum yield, small size and ease of surface functionalization afforded by the coating, make these materials suitable to implement investigations that address fundamental questions and potentially useful for biological sensing and imaging applications.<br></p>

Emergence of intense near-infrared photoluminescence by photoactivation of silver nanoclusters

2021 ◽  
Author(s):  
Wataru Ishii ◽  
Shohei Katao ◽  
Yoshiko Nishikawa ◽  
Yasuo Okajima ◽  
Atsuya Hatori ◽  
...  
Keyword(s):  
Quantum Yield ◽  
Near Infrared ◽  
Silver Nanoclusters ◽  
Pyridine Solution

Photoirradiation to a pyridine solution of Ag29 nanoclusters (NCs) with red photoluminescence (PL) at 680 nm activated intense PL in the near infrared (NIR) region, giving a PL quantum yield...

scholarly journals Tuning π-Acceptor/σ-Donor Ratio of the 2-Isocyanoazulene Ligand: Non-Fluorinated Rival of Pentafluorophenyl Isocyanide and Trifluorovinyl Isocyanide Discovered

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 981
Author(s):  
Mason D. Hart ◽  
John J. Meyers ◽  
Zachary A. Wood ◽  
Toshinori Nakakita ◽  
Jason C. Applegate ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Coordination Chemistry ◽  
Single Crystal ◽  
13C Nmr ◽  
Quantitative Assessment ◽  
X Ray ◽  
New Class ◽  
Linear Relationships ◽  
Ligand Charge Transfer ◽  
Donor Characteristics

Isocyanoazulenes (CNAz) constitute a relatively new class of isocyanoarenes that offers rich structural and electronic diversification of the organic isocyanide ligand platform. This article considers a series of 2-isocyano-1,3-X2-azulene ligands (X = H, Me, CO2Et, Br, and CN) and the corresponding zero-valent complexes thereof, [(OC)5Cr(2-isocyano-1,3-X2-azulene)]. Air- and thermally stable, X-ray structurally characterized 2-isocyano-1,3-dimethylazulene may be viewed as a non-benzenoid aromatic congener of 2,6-dimethyphenyl isocyanide (2,6-xylyl isocyanide), a longtime “workhorse” aryl isocyanide ligand in coordination chemistry. Single crystal X-ray crystallographic {Cr–CNAz bond distances}, cyclic voltametric {E1/2(Cr0/1+)}, 13C NMR {δ(13CN), δ(13CO)}, UV-vis {dπ(Cr) → pπ*(CNAz) Metal-to-Ligand Charge Transfer}, and FTIR {νN≡C, νC≡O, kC≡O} analyses of the [(OC)5Cr(2-isocyano-1,3-X2-azulene)] complexes provided a multifaceted, quantitative assessment of the π-acceptor/σ-donor characteristics of the above five 2-isocyanoazulenes. In particular, the following inverse linear relationships were documented: δ(13COtrans) vs. δ(13CN), δ(13COcis) vs. δ(13CN), and δ(13COtrans) vs. kC≡O,trans force constant. Remarkably, the net electron withdrawing capability of the 2-isocyano-1,3-dicyanoazulene ligand rivals those of perfluorinated isocyanides CNC6F5 and CNC2F3.

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