The Experts below are selected from a list of 19539 Experts worldwide ranked by ideXlab platform
Vivian Wing Wah Yam - One of the best experts on this subject based on the ideXlab platform.
-
Design and synthesis of calixarene-based bis-alkynyl-bridged dinuclear AuI isonitrile complexes as luminescent Ion Probes by the modulatIon of Au⋯Au interactIons
Chemistry - A European Journal, 2009Co-Authors: Xiaoming He, Wai Han Lam, Nianyong Zhu, Vivian Wing Wah YamAbstract:Two calixarene-based bis-alkynyl-bridged Au(I) isonitrile complexes with two different crown ether pendants, [{calix[4]arene-(OCH(2)CONH-C(6)H(4)C[triple bond]C)(2)}{Au(CNR)}(2)] (R=benzo[15]crown-5 (1); R=benzo[18]crown-6 (2)), together with their related crown-free analogue 3 (R=C(6)H(3)(OMe)(2)-3,4) and a mononuclear gold(I) complex 4 with benzo[15]crown-5 pendant, have been designed and synthesized, and their photophysical properties have been studied. The X-ray structure of the ligand, calix[4]arene-(OCH(2)CONH-C(6)H(4)C[triple bond]CH)(2) has been determined. The catIon-binding properties of these complexes with various metal Ions have been studied using UV/Vis, emissIon, (1)H NMR, and ESI-MS techniques, and DFT calculatIons. A new low-energy emissIon band associated with AuAu interactIon could be switched on upon formatIon of the metal Ion-bound adduct in a sandwich fashIon.
-
molecular design of luminescence Ion Probes for various catIons based on weak gold i gold i interactIons in dinuclear gold i complexes
Inorganic Chemistry, 2004Co-Authors: Keith Manchung Wong, Nianyong Zhu, C W Chan, Vivian Wing Wah YamAbstract:A series of luminescent dinuclear gold(I) complexes with different crown ether pendants, [Au(2)(PwedgeP)(S-B15C5)(2)] [S-B15C5 = 4'-mercaptobenzo-15-crown-5, P(wedge)P = bis(dicyclohexylphosphino)methane (dcpm) (1), bis(diphenylphosphino)methane (dppm) (2)] and [Au(2)(P(wedge)P)(S-B18C6)(2)] [S-B18C6 = 4'-mercaptobenzo-18-crown-6, P(wedge)P = dcpm (3), dppm (4)], and their related crown-free complexes, [Au(2)(P(wedge)P)(SC(6)H(3)(OMe)(2)-3,4)(2)] [P(wedge)P = dcpm (5), dppm (6)], were synthesized. The low-energy emissIon of the mercaptocrown ether-containing gold(I) complexes are tentatively assigned as originated from states derived from a S --> Au ligand-to-metal charge transfer (LMCT) transitIon. The crown ether-containing gold(I) complexes showed specific binding abilities toward various metal catIons according to the ring size of the crown pendants. Spectroscopic evidence was provided for the metal-Ion-induced switching on of the gold...gold interactIons upon the binding of particular metal Ions in a sandwich binding mode.
Yubai Bai - One of the best experts on this subject based on the ideXlab platform.
-
luminescent cdte quantum dots and nanorods as metal Ion Probes
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2005Co-Authors: Dongsheng Bao, Xia Hong, Yubai BaiAbstract:Abstract Water-soluble luminescent thiol-capped CdTe QDs and nanorods have been synthesized and used to investigate the effect on their photoluminescence (PL) responses to divalent metal Ions, such as zinc, calcium, magnesium, manganese, nickel, and cobalt Ions. The change trends of PL were nearly similar for both CdTe QDs and nanorods. The zinc Ions enhanced the photoluminescence, while the manganese, nickel, and cobalt Ions quenched the PL. The effect on the PL response of CdTe QDs to divalent metal Ions could be described by Langmuir-type binding model or Stern–Volmer-type equatIon. The CdTe nanorods were more sensitive to metal catIons than QDs, and their enhancement mechanisms are different. CdTe QDs and nanorods maybe used as selective Ion Probes and developed as fluorescence sensors.
Pratima R Solanki - One of the best experts on this subject based on the ideXlab platform.
-
l cysteine and 3 mercaptopropIonic acid capped cadmium selenide quantum dots based metal Ion Probes
Journal of Luminescence, 2017Co-Authors: Reena K Sajwan, Yana Bagbi, Purnima Sharma, Pratima R SolankiAbstract:Abstract Herein, a report on the synthesis of 3-mercaptopropIonic acid (MPA) and L cysteine (Cyst) capped luminescent cadmium selenide (CdSe) quantum dots (QDs) was studied. The MPA-CdSe and Cyst-CdSe QDs were conducted with different physiologically important metal Ions such as Cu 2+ , Fe 2+ , Zn 2+ , Co 2+ , Pb 2+ , Mg 2+ , Ni 2+ and Ag + Ions in aqueous solutIon using fluorescence spectroscopic technique. It was found that the MPA-CdSe QDs, categorically sensitive to only Cu 2+ Ions only. However, other metal Ions such as Zn 2+ , Co 2+ , Pb 2+ , Mg 2+ , Ni 2+ and Ag + , did not exhibit measurable quenching. On the other hand, Cyst-CdSe QDs were very selective and sensitive to Zn 2+ Ions only, which showed fluorescence enhancement while for other Ions no such behavior was noticed. Thus, MPA-CdSe and Cyst-CdSe QDs have successfully detected Cu 2+ and Zn 2+ Ions in the linearity range from 4 to 160 µM, respectively. The effect of fluorescence response of QDs towards metals Ions were described by Langmuir-type binding model or Stern–Volmer-type equatIon.
Dongsheng Bao - One of the best experts on this subject based on the ideXlab platform.
-
luminescent cdte quantum dots and nanorods as metal Ion Probes
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2005Co-Authors: Dongsheng Bao, Xia Hong, Yubai BaiAbstract:Abstract Water-soluble luminescent thiol-capped CdTe QDs and nanorods have been synthesized and used to investigate the effect on their photoluminescence (PL) responses to divalent metal Ions, such as zinc, calcium, magnesium, manganese, nickel, and cobalt Ions. The change trends of PL were nearly similar for both CdTe QDs and nanorods. The zinc Ions enhanced the photoluminescence, while the manganese, nickel, and cobalt Ions quenched the PL. The effect on the PL response of CdTe QDs to divalent metal Ions could be described by Langmuir-type binding model or Stern–Volmer-type equatIon. The CdTe nanorods were more sensitive to metal catIons than QDs, and their enhancement mechanisms are different. CdTe QDs and nanorods maybe used as selective Ion Probes and developed as fluorescence sensors.
Andrey L Rogach - One of the best experts on this subject based on the ideXlab platform.
-
luminescent cdte nanocrystals as Ion Probes and ph sensors in aqueous solutIons
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2006Co-Authors: Andrei S Susha, Almudena Munoz Javier, Wolfgang J Parak, Andrey L RogachAbstract:CdTe nanocrystals capped by short-chain thiol molecules can easily be prepared in aqueous solutIon, possess a single narrow emissIon band and can potentially be used as luminescence sensors and Ions Probes. We report the effect of pH and various Ions, including physiology important catIons such as calcium(II), manganese(II) and iron(III), on the luminescence intensity of CdTe nanocrystals capped by thioglycolic acid. Quenching of luminescence of CdTe nanocrystals by Ag(I)-catIons points out their use in cellular studies as fluorescent labels and quenching agents, respectively. Micromolar amounts of Hg2+ Ions caused quenching of the emissIon of CdTe nanocrystals, while at increasing Hg2+ concentratIon alloyed CdxHg1−xTe nanocrystals were formed, followed by appearance of a near-infrared luminescence band. Luminescence of both bare CdTe nanocrystals and CdTe nanocrystals embedded into polymer microcapsules was found to be pH sensitive within the pH range of 4–6.
