0000000000332310
AUTHOR
Pi-tai Chou
showing 29 related works from this author
Millimeter wave absorption by confined acoustic modes in CdSe/CdTe core-shell quantum dots
2007
International audience; Taking advantage of the specific core-shell charge separation structure in the CdSe/CdTe core-shell Type-II quantum dots (QDs), we experimentally observed the resonant-enhanced dipolar interaction between millimeter-wave (MMW) photons and their corresponding (l = 1) confined acoustic phonons. With proper choice of size, the absorption band can be tuned to desired frequency of MMW imaging. Exploiting this characteristic absorption, in a fiber-scanned MMW imaging system, we demonstrated the feasibility of CdSe/CdTe QDs as the contrast agents of MMW imaging.
Harnessing Fluorescence versus Phosphorescence Branching Ratio in (Phenyl)n-Bridged (n = 0–5) Bimetallic Au(I) Complexes
2013
We have designed and synthesized a series of Au(I) complexes bearing either an alkynyl–(phenylene)n–diphosphine (A-0–A-3) or a (phenylene)n–diphosphine (B-1–B-5) bridge, among which the effective distance between Au(I) and the center of the emitting ππ* chromophore can be fine-tuned via the insertion of various numbers of phenylene spacers. We then demonstrated for the first time in a systematic manner the decrease of rate constant for S1 → T1 intersystem crossing (ISC) kisc as the increase of the effective distance. The results also unambiguously showed that the phosphorescence could be harvested via higher S0 → Sn (n > 1) electronic excitation, followed by fast Sn → Tm ISC and then the po…
Fluorescence Probes Exhibit Photoinduced Structural Planarization: Sensing <i>in vitro</i> and <i>in vivo</i> Microscopic Dyn…
2019
We demonstrate the construction of wavelength λ-ratiometric images that allow visualizing the distribution of microscopic dynamics within living cells and tissues by using the newly developed principle of fluorescence response. The bent-to-planar motion in the excited state of incorporated fluorescence probes leads to elongation of the π-delocalization, resulting in microviscosity-dependent but polarity-insensitive interplay between well-separated blue and red bands in emission spectra. This allows constructing the exceptionally contrasted images of cellular dynamics. Moreover, the application of probes with increased affinity towards biological membranes allowed detecting the differences i…
Phosphorescent Pt II Systems Featuring Both 2,2′‐Dipyridylamine and 1,3,5‐Triazapentadiene Ligands
2014
The treatment of cis-[Pt(dpa)(RCN)2][SO3CF3]2 {dpa = 2,2′-dipyridylamine, R = Me, Et, CH2Ph, Ph; [2a–d](OTf)2} (OTf = SO3CF3) with 2 equiv. of N,N′-diphenylguanidine [NH=C(NHPh)2] in CH2Cl2 solutions at room temp. for 16 h gives [Pt(dpa){NH=C(R)NC(NHPh)=NPh}][SO3CF3] {[3a,b,d](OTf)} as the addition products and [Pt(dpa){NH=C(R)NHC(R)=NH}][SO3CF3]2 {[4a,b](OTf)2} as the tailoring products. The formulation of complexes [3a,b,d](OTf) and [4a,b](OTf)2 was supported by satisfactory C, H, and N elemental analyses and agreeable high-resolution ESI-MS, IR, and 1H (including 1H–1H COSY experiments) and 13C{1H} NMR data. The structures of all of the platinum species were determined by single-crystal …
Solid-state luminescence of Au-Cu-alkynyl complexes induced by metallophilicity-driven aggregation.
2012
A new series of homoleptic alkynyl complexes, [{Au2Cu2(C2R)4}n] (R=C3H7O (1), C6H11O (2), C9H19O (3), C13H11O (4)), were obtained from Au(SC4H8)Cl, Cu(NCMe)4PF6, and the corresponding alkyne in the presence of a base (NEt3). Complexes 1-4 aggregate upon crystallization into polymeric chains through extensive metallophilic interactions. The cluster that contains fluorenolyl functionalities, C13H9O (5), crystallizes in its molecular form as a disolvate, [Au2Cu2(C2C13H9O)4]·2THF. The substitution of weakly bound THF molecules with pyridine molecules leads to the complex [Au2Cu2(C2C13H9O)4]·2py (6), thus giving two polymorphs in the solid state. Such structural diversity is established through …
Triphosphine-supported bimetallic Au(I)-M(I) (M = Ag, Cu) alkynyl clusters.
2014
The reactions of gold acetylides (AuC2R)n with triphosphine ligands PPh2-(CH2)n-PPh-(CH2)2-PPh2 (n = 1, dpmp; 2, dpep) in the presence of M(+) ions (M = Cu, Ag) lead to an assembly of the heterometallic clusters, the composition of which is determined by the steric bulkiness of the alkynyl groups and the flexibility of the phosphine motifs. For R = Ph, an unprecedented hexanuclear complex [Au5Cu(C2R)4(dpmp)2](2+) (1) was isolated, while for the aliphatic alkynes (R = 1-cyclohexanolyl, 2-borneolyl, 2,6-dimethyl-4-heptanolyl) a family of compounds based on a tetrametallic framework was prepared, [Au3Cu(C2R)3(dpmp)](+) (2, R = 1-cyclohexanolyl), [Au3M(C2R)3(dpep)]2(+2) (3, M = Cu, R = 1-cycloh…
Harvesting Fluorescence from Efficient Tk -> Sj (j, k > 1) Reverse Intersystem Crossing for ??* Emissive Transition-Metal Complexes
2013
Using a bimetallic Au(I) complex bearing alkynyl-(phenylene)3-diphosphine ligand (A-3), we demonstrate that the fluorescence can be exquisitely harvested upon T1 → Tk (k > 1) excitation followed by Tk → Sj (j, k > 1) intersystem crossing (ISC) back to the S1 state. Upon S0 → S1 355 nm excitation, the S1 → T1 intersystem crossing rate has been determined to be 8.9 × 108 s–1. Subsequently, in a two-step laser pump–probe experiment, following a 355 nm laser excitation, the 532 nm T1 → Tk probing gives the prominent blue 375 nm fluorescence, and this time-dependent pump–probe signal correlates well with the lifetime of the T1 state. Careful examination reveals the efficiency of Tk → Sj (j, k > …
Fluorescence Probes Exhibit Photoinduced Structural Planarization: Sensing In Vitro and In Vivo Microscopic Dynamics of Viscosity Free from Polarity …
2020
We demonstrate the construction of wavelength λ-ratiometric images that allow visualizing the distribution of microscopic dynamics within living cells and tissues by using the newly developed principle of fluorescence response. The bent-to-planar motion in the excited state of incorporated fluorescence probes leads to elongation of the π-delocalization, resulting in microviscosity-dependent but polarity-insensitive interplay between well-separated blue and red bands in emission spectra. This allows constructing the exceptionally contrasted images of cellular dynamics. Moreover, the application of probes with increased affinity toward biological membranes allowed detecting the differences in…
Ambipolar Phosphine Derivatives to Attain True Blue OLEDs with 6.5% EQE
2016
A family of new branched phosphine derivatives {Ph2N-(C6H4)n-}3P → E (E = O 1-3, n = 1-3; E = S 4-6, n = 1-3; E = Se 7-9, n = 1-3; E = AuC6F5 4-6, n = 1-3), which are the donor-acceptor type molecules, exhibit efficient deep blue room temperature fluorescence (λem = 403-483 nm in CH2Cl2 solution, λem = 400-469 nm in the solid state). Fine tuning the emission characteristics can be achieved varying the length of aromatic oligophenylene bridge -(C6H4)n-. The pyramidal geometry of central R3P → E fragment on the one hand disrupts π-conjugation between the branches to preserve blue luminescence and high triplet energy, while on the other hand provides amorphous materials to prevent excimer form…
Harnessing Fluorescence versus Phosphorescence Ratio via Ancillary Ligand Fine-Tuned MLCT Contribution
2016
A series of gold(I) alkynyl-diphosphine complexes (XC6H4C2Au)PPh2—spacer—PPh2(AuC2C6H4X); spacer = —C2(C6H4)nC2— (A1, n = 2, X = CF3; A2, n = 2, X = OMe; A3, n = 3, X = CF3; A4, n = 3, X = OMe), —(C6H4)n— (B5, n = 3, X = OMe; B6, n = 4, X = OMe) were prepared, and their photophysical properties were investigated. The luminescence behavior of the titled compounds is dominated by the diphosphine spacer, which serves as an emitting ππ* chromophore. The complexes exhibit dual emission, comprising low and high energy bands of triplet (phosphorescence) and singlet (fluorescence) origins, respectively. The electron-donating characteristics of ancillary groups X significantly affect the LLCT/MLCT c…
CCDC 916957: Experimental Crystal Structure Determination
2013
Related Article: Igor O. Koshevoy, Yuh-Chia Chang, Antti J. Karttunen, Julia R. Shakirova, Janne Jänis, Matti Haukka, Tapani Pakkanen, Pi-Tai Chou|2013|Chem.-Eur.J.|19|5104|doi:10.1002/chem.201204611
CCDC 916956: Experimental Crystal Structure Determination
2013
Related Article: Igor O. Koshevoy, Yuh-Chia Chang, Antti J. Karttunen, Julia R. Shakirova, Janne Jänis, Matti Haukka, Tapani Pakkanen, Pi-Tai Chou|2013|Chem.-Eur.J.|19|5104|doi:10.1002/chem.201204611
CCDC 962935: Experimental Crystal Structure Determination
2014
Related Article: Ilya S. Krytchankou, Dmitry V. Krupenya, Antti J. Karttunen, Sergey P. Tunik, Tapani A. Pakkanen, Pi-Tai Chou, Igor O. Koshevoy|2014|Dalton Trans.|43|3383|doi:10.1039/C3DT52658E
CCDC 986952: Experimental Crystal Structure Determination
2014
Related Article: Ivan I. Eliseev, Pavel V. Gushchin, Yi-An Chen, Pi-Tai Chou, Matti Haukka, Galina L. Starova, Vadim Yu. Kukushkin|2014|Eur.J.Inorg.Chem.||4101|doi:10.1002/ejic.201402364
CCDC 986953: Experimental Crystal Structure Determination
2014
Related Article: Ivan I. Eliseev, Pavel V. Gushchin, Yi-An Chen, Pi-Tai Chou, Matti Haukka, Galina L. Starova, Vadim Yu. Kukushkin|2014|Eur.J.Inorg.Chem.||4101|doi:10.1002/ejic.201402364
CCDC 962936: Experimental Crystal Structure Determination
2014
Related Article: Ilya S. Krytchankou, Dmitry V. Krupenya, Antti J. Karttunen, Sergey P. Tunik, Tapani A. Pakkanen, Pi-Tai Chou, Igor O. Koshevoy|2014|Dalton Trans.|43|3383|doi:10.1039/C3DT52658E
CCDC 916958: Experimental Crystal Structure Determination
2013
Related Article: Igor O. Koshevoy, Yuh-Chia Chang, Antti J. Karttunen, Julia R. Shakirova, Janne Jänis, Matti Haukka, Tapani Pakkanen, Pi-Tai Chou|2013|Chem.-Eur.J.|19|5104|doi:10.1002/chem.201204611
CCDC 986955: Experimental Crystal Structure Determination
2014
Related Article: Ivan I. Eliseev, Pavel V. Gushchin, Yi-An Chen, Pi-Tai Chou, Matti Haukka, Galina L. Starova, Vadim Yu. Kukushkin|2014|Eur.J.Inorg.Chem.||4101|doi:10.1002/ejic.201402364
CCDC 916959: Experimental Crystal Structure Determination
2013
Related Article: Igor O. Koshevoy, Yuh-Chia Chang, Antti J. Karttunen, Julia R. Shakirova, Janne Jänis, Matti Haukka, Tapani Pakkanen, Pi-Tai Chou|2013|Chem.-Eur.J.|19|5104|doi:10.1002/chem.201204611
CCDC 916955: Experimental Crystal Structure Determination
2013
Related Article: Igor O. Koshevoy, Yuh-Chia Chang, Antti J. Karttunen, Julia R. Shakirova, Janne Jänis, Matti Haukka, Tapani Pakkanen, Pi-Tai Chou|2013|Chem.-Eur.J.|19|5104|doi:10.1002/chem.201204611
CCDC 962938: Experimental Crystal Structure Determination
2014
Related Article: Ilya S. Krytchankou, Dmitry V. Krupenya, Antti J. Karttunen, Sergey P. Tunik, Tapani A. Pakkanen, Pi-Tai Chou, Igor O. Koshevoy|2014|Dalton Trans.|43|3383|doi:10.1039/C3DT52658E
CCDC 1583379: Experimental Crystal Structure Determination
2017
Related Article: Ilya Kondrasenko, Kun-you Chung, Yi-Ting Chen, Juha Koivistoinen, Elena V. Grachova, Antti J. Karttunen, Pi-Tai Chou, Igor O. Koshevoy|2016|J.Phys.Chem.C|120|12196|doi:10.1021/acs.jpcc.6b03064
CCDC 962933: Experimental Crystal Structure Determination
2014
Related Article: Ilya S. Krytchankou, Dmitry V. Krupenya, Antti J. Karttunen, Sergey P. Tunik, Tapani A. Pakkanen, Pi-Tai Chou, Igor O. Koshevoy|2014|Dalton Trans.|43|3383|doi:10.1039/C3DT52658E
CCDC 962934: Experimental Crystal Structure Determination
2014
Related Article: Ilya S. Krytchankou, Dmitry V. Krupenya, Antti J. Karttunen, Sergey P. Tunik, Tapani A. Pakkanen, Pi-Tai Chou, Igor O. Koshevoy|2014|Dalton Trans.|43|3383|doi:10.1039/C3DT52658E
CCDC 962937: Experimental Crystal Structure Determination
2014
Related Article: Ilya S. Krytchankou, Dmitry V. Krupenya, Antti J. Karttunen, Sergey P. Tunik, Tapani A. Pakkanen, Pi-Tai Chou, Igor O. Koshevoy|2014|Dalton Trans.|43|3383|doi:10.1039/C3DT52658E
CCDC 986951: Experimental Crystal Structure Determination
2014
Related Article: Ivan I. Eliseev, Pavel V. Gushchin, Yi-An Chen, Pi-Tai Chou, Matti Haukka, Galina L. Starova, Vadim Yu. Kukushkin|2014|Eur.J.Inorg.Chem.||4101|doi:10.1002/ejic.201402364
CCDC 986954: Experimental Crystal Structure Determination
2014
Related Article: Ivan I. Eliseev, Pavel V. Gushchin, Yi-An Chen, Pi-Tai Chou, Matti Haukka, Galina L. Starova, Vadim Yu. Kukushkin|2014|Eur.J.Inorg.Chem.||4101|doi:10.1002/ejic.201402364
CCDC 916953: Experimental Crystal Structure Determination
2013
Related Article: Igor O. Koshevoy, Yuh-Chia Chang, Antti J. Karttunen, Julia R. Shakirova, Janne Jänis, Matti Haukka, Tapani Pakkanen, Pi-Tai Chou|2013|Chem.-Eur.J.|19|5104|doi:10.1002/chem.201204611
CCDC 916954: Experimental Crystal Structure Determination
2013
Related Article: Igor O. Koshevoy, Yuh-Chia Chang, Antti J. Karttunen, Julia R. Shakirova, Janne Jänis, Matti Haukka, Tapani Pakkanen, Pi-Tai Chou|2013|Chem.-Eur.J.|19|5104|doi:10.1002/chem.201204611