- Self-Assembled Fluorescent Pt(II) Metallacycles as Artificial Light-Harvesting Systems
-
Light-harvesting is one of the key steps in photosynthesis, but developing artificial light-harvesting systems (LHSs) with high energy transfer efficiencies has been a challenging task. Here we report fluorescent hexagonal Pt(II) metallacycles as a new platform to fabricate artificial LHSs. The metallacycles (4 and 5) are easily accessible by coordination-driven self-assembly of a triphenylamine-based ditopic ligand 1 with di-platinum acceptors 2 and 3, respectively. They possess good fluorescence properties both in solution and in the solid state. Notably, the metallacycles show aggregation-induced emission enhancement (AIEE) characteristics in a DMSO-H2O solvent system. In the presence of the fluorescent dye Eosin Y (ESY), the emission intensities of the metallacycles decrease but the emission intensity of ESY increases. The absorption spectrum of ESY and the emission spectra of the metallacycles show a considerable overlap, suggesting the possibility of energy transfer from the metallacycles to ESY, with an energy transfer efficiency as high as 65% in the 4a+ESY system.
- Acharyya, Koushik,Bhattacharyya, Soumalya,Sepehrpour, Hajar,Chakraborty, Shubhadip,Lu, Shuai,Shi, Bingbing,Li, Xiaopeng,Mukherjee, Partha Sarathi,Stang, Peter J.
-
-
Read Online
- Phosphine-based push-pull AIE fluorophores: Synthesis, photophysical properties, and TD-DFT studies
-
Herein, we report the design and characterization of a novel series of four push-pull fluorophores using diphenylphosphino as an electron-donating terminal group (P-chromophores). The spectroscopic properties in solution, the aggregation-induced emission
- Andraud, Chantal,Bretonnière, Yann,Colinet, Pauline,Jeanneau, Erwan,Le Bahers, Tangui,Rémond, Maxime
-
-
- Palladium-Catalyzed C-P(III) Bond Formation by Coupling ArBr/ArOTf with Acylphosphines
-
Palladium-catalyzed C-P bond formation reaction of ArBr/ArOTf using acylphosphines as differential phosphination reagents is reported. The acylphosphines show practicable reactivity with ArBr and ArOTf as the phosphination reagents, though they are inert to the air and moisture. The reaction affords trivalent phosphines directly in good yields with a broad substrate scope and functional group tolerance. This reaction discloses the acylphosphines' capability as new phosphorus sources for the direct synthesis of trivalent phosphines.
- Chen, Xingyu,Wu, Hongyu,Yu, Rongrong,Zhu, Hong,Wang, Zhiqian
-
p. 8987 - 8996
(2021/06/30)
-
- Targetable and fixable rotor for quantifying mitochondrial viscosity of living cells by fluorescence lifetime imaging
-
It is meaningful to accurately quantify the changes in local viscosity within the mitochondria of living cells, because viscosity influences mitochondrial network organization and metabolite diffusion. Although many molecular probes targeting mitochondria have been reported, almost all of them are not fixed to the mitochondria. Thus, they may not be suitable for sensing in abnormal mitochondria with lowered potential. In order to monitor viscosity in all mitochondria, no matter their working or health status, we develop the first fixable BODIPY (boron-dipyrromethene) rotor, named Vis-A. Vis-A contains an aldehyde group as an anchor to react with amino groups of proteins, which make it immobilizable in mitochondria. Vis-B, the reference compound without such anchor unit, is also synthesized. Both Vis-A and Vis-Bshow excellent mitochondrial targetability, as good as the commercially available mitochondrial dye (Mito Tracker Deep Red). However, when cells are chemically treated to decrease the mitochondrial potential, only Vis-A continues emitting strong fluorescence in mitochondria, but the signals of Vis-B and Mito Tracker Deep Red completely disappear. This comparison confirms that Vis-A not only specifically localizes in mitochondria, but also can be stably retained there. Then, Vis-A is applied to detect the mitochondrial viscosity of living cells by Fluorescence Lifetime Imaging (FLIM). Especially, with the aid of Vis-A, the changes in viscosity under typical pathological conditions (i.e., treatment with rotenone and carbonylcyanide-m-chlorophenylhydrazone (CCCP)) for mitochondria are monitored by FLIM.
- Song, Xinbo,Li, Ning,Wang, Chao,Xiao, Yi
-
p. 360 - 368
(2017/01/16)
-
- Chemoselective Reduction of Phosphine Oxides by 1,3-Diphenyl-Disiloxane
-
Reduction of phosphine oxides to the corresponding phosphines represents the most straightforward method to prepare these valuable reagents. However, existing methods to reduce phosphine oxides suffer from inadequate chemoselectivity due to the strength of the P=O bond and/or poor atom economy. Herein, we report the discovery of the most powerful chemoselective reductant for this transformation to date, 1,3-diphenyl-disiloxane (DPDS). Additive-free DPDS selectively reduces both secondary and tertiary phosphine oxides with retention of configuration even in the presence of aldehyde, nitro, ester, α,β-unsaturated carbonyls, azocarboxylates, and cyano functional groups. Arrhenius analysis indicates that the activation barrier for reduction by DPDS is significantly lower than any previously calculated silane reduction system. Inclusion of a catalytic Br?nsted acid further reduced the activation barrier and led to the first silane-mediated reduction of acyclic phosphine oxides at room temperature.
- Buonomo, Joseph A.,Eiden, Carter G.,Aldrich, Courtney C.
-
supporting information
p. 14434 - 14438
(2017/10/23)
-
- Polyethyleneimine-Supported Triphenylphosphine and Its Use as a Highly Loaded Bifunctional Polymeric Reagent in Chromatography-Free One-Pot Wittig Reactions
-
A polyethyleneimine-supported triphenylphosphine reagent has been synthesized and used as a highly loaded bifunctional homogeneous reagent in a range of one-pot Wittig reactions that afforded high yields of the desired products after simple purification procedures. The approach also served efficiently in tandem reaction sequences involving a one-pot Wittig reaction followed by conjugate reduction of the newly formed alkene product in situ. In these transformations, the phosphine oxide groups generated in the Wittig reaction served as the catalyst for activating trichlorosilane in the subsequent reduction reaction.
- Xia, Xuanshu,Toy, Patrick H.
-
p. 1737 - 1743
(2015/07/20)
-
- Arene-ruthenium(II) complexes containing amino-phosphine ligands as catalysts for nitrile hydration reactions
-
Three different series of novel mononuclear arene-ruthenium(II) complexes containing amino-phosphine ligands, namely, [RuCl2{κ 1(P)-2-Ph2PC6H4CH 2NHR}(η6-arene)], [RuCl2{κ 1(P)-3-Ph2PC6H4CH 2NHR}(η6-arene)], and [RuCl2{κ 1(P)-4-Ph2PC6H4CH 2NHR}(η6-arene)] (arene = C6H6, p-cymene, 1,3,5-C6H3Me3, C6Me 6; R = iPr, tBu; all combinations), have been synthesized and fully characterized. These readily accessible species are efficient catalysts for the selective hydration of organonitriles into amides under challenging reaction conditions, i.e., pure aqueous medium in the absence of any cocatalyst, being much more active than their corresponding nonfunctionalized triphenylphosphine counterparts [RuCl2(PPh 3)(η6-arene)]. The results obtained in this study indicate that the (amino-phosphine)ruthenium(II) complexes operate through a "bifunctional catalysis" mechanism in which the ruthenium center acts as a Lewis acid, activating the nitrile molecule, and the P-donor ligand acts as a Brnsted base, the pendant amino group generating the real nucleophile of the hydration process, i.e., the OH- group.
- Garcia-Alvarez, Rocio,Diez, Josefina,Crochet, Pascale,Cadierno, Victorio
-
scheme or table
p. 3955 - 3965
(2010/12/25)
-
- Synthesis of aryl phosphines via phosphination with triphenylphosphine by supported palladium catalysts
-
The palladium catalyzed phosphination of functionalized aryl bromides, triflates, and chlorides with triphenylphosphine to yield aryldiphenylphosphines was catalyzed by thermally stable palladium catalysts supported on charcoal and aluminia. The addition
- Wang, Yanchun,Lai, Chi Wai,Kwong, Fuk Yee,Jia, Wen,Chan, Kin Shing
-
p. 9433 - 9439
(2007/10/03)
-
- Application of palladium-catalyzed Pd-aryl/P-aryl exchanges: Preparation of functionalized aryl phosphines by phosphination of aryl bromides using triarylphosphines
-
Palladium-catalyzed Pd-aryl/P-aryl interchange reaction was applied in the synthesis of various functionalized arylphosphines. This phosphination used inexpensive, readily available and air stable triarylphosphines as the phosphinating agents. Broad functional groups were compatible including keto, aldehyde, ester, nitrile, ether, chloride, pyridyl and thiophenyl groups. Halides were found to be good promoter for the rates and yields of the reaction.
- Kwong, Fuk Yee,Lai, Chi Wai,Yu, Michael,Chan, Kin Shing
-
p. 5635 - 5645
(2007/10/03)
-
- Nickel-catalyzed reductive coupling of chlorodiphenylphosphine with aryl bromides into functionalized triarylphosphines
-
Functionalized triarylphosphines are obtained with good yields in a one-step reaction of an equimolar mixture of chlorodiphenylphosphine and an aromatic bromide in NMP or DMF at 110°C in the presence of zinc dust and a catalytic amount of NiBr2
- Le Gall, Erwan,Troupel, Michel,Nédélec, Jean-Yves
-
p. 7497 - 7500
(2007/10/03)
-
- Palladium-catalyzed phosphination of functionalized aryl triflates
-
Catalytic user-friendly approach to the syntheses of various functionalized aromatic phosphines from their corresponding substituted aryl triflates and triarylphosphines was accomplished. This method is carried out in neutral media and compatible with man
- Kwong, Fuk Yee,Lai, Chi Wai,Yu, Michael,Tian, Yuan,Chan, Kin Shing
-
p. 10295 - 10305
(2007/10/03)
-
- Solvent-free palladium-catalyzed phosphination of aryl bromides and triflates with triphenylphosphine
-
Palladium-catalyzed phosphination of substituted aryl bromides and triflates using triphenylphosphine as the phosphinating agent was developed using solvent-free conditions. This operationally simple method tolerates ketone, aldehyde, ester, nitrile and e
- Kwong, Fuk Yee,Lai, Chi Wai,Chan, Kin Shing
-
p. 3537 - 3539
(2007/10/03)
-
- Acetonyltriphenylphosphonium bromide and its polymer-supported analogues as catalysts in protection and deprotection of alcohols as alkyl vinyl ethers
-
Both acetonyltriphenylphosphonium bromide (ATPB, 1) and poly-p-styryldiphenylacetonylphosphonium bromide (A) were effective catalysts in the protection of alcohols as THP, THF, and EE ethers as well as the cleavage of THP, THF, and EE ethers to the corresponding alcohols. They could be applied to 1°, 2° and 3° alcohols, phenol and acid-labile alcohols. Both ATPB and catalyst A are excellent catalysts in the present study. It needed only 1×10-2-1.25×10-2 mol equiv. of the polymer-supported catalyst A in the reactions.
- Hon, Yung-Son,Lee, Chia-Fu,Chen, Rong-Jiunn,Szu, Ping-Hui
-
p. 5991 - 6001
(2007/10/03)
-
- Synthesis of aryl phosphines by phosphination with triphenylphosphine catalyzed by palladium on charcoal
-
The palladium-catalyzed phosphination of aryl bromides and triflates by phosphination with triphenylphines to yield aryl phosphines was catalyzed by the thermally stable catalyst palladium on charcoal.
- Lai, Chi Wai,Kwong, Fuk Yee,Wang, Yanchun,Chan, Kin Shing
-
p. 4883 - 4885
(2007/10/03)
-
- A general synthesis of aryl phosphines by palladium catalyzed phosphination of aryl bromides using triarylphosphines
-
Palladium catalyzed phosphination of substituted aryl bromides using triarylphosphines as the phosphinating agents has been developed; this method tolerates ketone, aldehyde, ester, nitrile, ether and chloride functional groups.
- Kwong, Fuk Yee,Chan, Kin Shing
-
p. 1069 - 1070
(2007/10/03)
-
- A novel synthesis of functionalised tertiary phosphines by palladium catalysed phosphination with triarylphosphines
-
The palladium catalysed Pd-aryl/P-aryl exchange was applied in the synthesis of various functionalised phosphines from their corresponding substituted aryl triflates using triarylphosphines as the phosphinating agents. This method tolerated many functional groups including ketone, aldehyde, ester, nitrile, methyl ether, pyridyl and chloride groups. (C) 2000 Elsevier Science Ltd.
- Kwong, Fuk Yee,Lai, Chi Wai,Tian, Yuan,Chan, Kin Shing
-
p. 10285 - 10289
(2007/10/03)
-
- Preparation of a Polymer-supported Diol and Its Use in isolating Aldehydes and Ketones from Mixtures and as a Protecting Group for Aldehydes and Ketones
-
Reaction of cross-linked chloromethylated polystyrenes with 3-mercaptopropane-1,2-diol and sodium hydroxide under phase-transfer conditions gave polymers containing diol residues.A range of aldehydes and ketones were successfully bound to these polymers via acetal formation.The aldehydes and ketones were released by treating the products with aqueous dioxane in the presence of toluene-p-sulphonic acid.The polymer-supported diol could be used to isolate aldehydes or ketones from mixtures with other compounds and to separate a 3-oxosteroid from a 17- or a 20- oxosteroid.The supported diol was successfully used to protect the aldehyde group of undec-10-enal whilst the terminal vinyl group was transformed into -CH2CH2OCOPh.Attempts to monoprotect dicarbonyl compounds were unsuccessful.
- Hodge, Philip,Waterhouse, Janette
-
p. 2319 - 2323
(2007/10/02)
-