The Experts below are selected from a list of 148716 Experts worldwide ranked by ideXlab platform
Michael R Detty - One of the best experts on this subject based on the ideXlab platform.
-
Longer Wavelength absorbing extended chalcogenorhodamine dyes
Organometallics, 2016Co-Authors: Mark W Kryman, Theresa M Mccormick, Michael R DettyAbstract:Extended rhodamines were prepared by inserting an additional fused benzene ring into the rhodamine xanthylium core. The synthesis of “bent” dyes 4-E (E = S, Se, Te) began with regioselective lithiation of the 1-position of N,N-diisopropyl 6-dimethylamino-2-naphthamide (11b) with n-BuLi/TMEDA (≥25:1 1- vs 3-lithiation) followed by addition of a dichalcogenide electrophile. The synthesis of “linear” dyes 5-E (E = S, Se, Te) began with regioselective lithiation of the 3-position of N,N-diethyl 6-dimethylamino-2-naphthamide (11a) with lithium tetramethylpiperidide (≥50:1 3- vs 1-lithiation) followed by addition of a dichalcogenide electrophile. Dyes 4-E and 5-E have absorption maxima in the 633–700 nm range. Dyes 4-E generate singlet oxygen upon irradiation while dyes 4-S and 5-S are highly fluorescent, with quantum yields for fluorescence of 0.47 and 0.18, respectively. DFT calculations were performed on the 4-E and 5-E chromophores. For the dyes 4-E, the lowest energy excitation is due solely to the HOMO–LU...
-
water soluble core modified porphyrins as novel Longer Wavelength absorbing sensitizers for photodynamic therapy
Journal of Medicinal Chemistry, 2000Co-Authors: Corey E Stilts, Marina I Nelen, David G Hilmey, Sherry R Davies, Sandra O Gollnick, Allan R Oseroff, Scott L Gibson, Russell Hilf, Michael R DettyAbstract:Water-soluble, core-modified 5,10,15,20-tetrakis(4-sulfonatophenyl)-21,23-dithiaporphyrin (1) and 5,10,15,20-tetrakis(4-sulfonatophenyl)-21,23-diselenaporphyrin (2) were prepared as the tetrasodium salts by the sulfonation of 5,10,15,20-tetraphenyl-21,23-dithiaporphyrin (3) and -21,23-diselenaporphyrin (4), respectively, with sulfuric acid. Compounds 3 and 4 were prepared by the condensation of pyrrole with either 2,5-bis(phenylhydroxymethyl)thiophene (5) or 2,5-bis(phenylhydroxymethyl)selenophene (6) in propionic acid. The addition of benzaldehyde to 2,5-dilithiothiophene or 2,5-dilithioselenophene gives 5 or 6, respectively, as a nearly equimolar mixture of meso- and d,l-diastereomers. Careful crystallization of 5 gives a single diastereomer by removing the crystalline product from the equilibrating mixture of diastereomers in solution. Photodynamic therapy (PDT) with 1 has an LD50 of less than 25 μg/mL against Colo-26 cells in culture and exhibits a lethal dose for 90% or more at concentrations greater...
Marc Sciamanna - One of the best experts on this subject based on the ideXlab platform.
-
Leader-laggard relationship of chaos synchronization in mutually coupled vertical-cavity surface-emitting lasers with time delay
Physical Review E : Statistical Nonlinear and Soft Matter Physics, 2009Co-Authors: Mitsutoshi Ozaki, Atsushi Uchida, Hiroyuki Someya, Shigeru Yoshimori, Krassimir Panajotov, Takaya Mihara, Marc SciamannaAbstract:We experimentally and numerically observe synchronization of chaos in two mutually coupled vertical-cavity surface-emitting lasers (VCSELs) with time delay. We observe in-phase and antiphase synchronization of polarization-resolved chaotic temporal wave forms under the condition of Wavelength matching. We investigate leader-laggard relationship between two chaotic wave forms of mutually coupled VCSELs and find that the laser with Longer Wavelength becomes the leader.
-
Synchronization of chaos in mutually coupled vertical-cavity surface-emitting lasers with time delay
2009Co-Authors: Atsushi Uchida, Hiroyuki Someya, Mitsutoshi Ozaki, Kazuya Tanaka, Shigeru Yoshimori, Krassimir Panajotov, Marc SciamannaAbstract:We experimentally observe in-phase and anti-phase synchronization of chaos in two mutually-coupled vertical-cavity surface-emitting lasers. We investigate leader-laggard relationship between two chaotic waveforms and find that the laser with Longer Wavelength becomes the leader.
Allan R Oseroff - One of the best experts on this subject based on the ideXlab platform.
-
water soluble core modified porphyrins as novel Longer Wavelength absorbing sensitizers for photodynamic therapy ii effects of core heteroatoms and meso substituents on biological activity
Journal of Medicinal Chemistry, 2002Co-Authors: David G Hilmey, Corey E Stilts, Marina I Nelen, Sherry R Davies, Sandra O Gollnick, Masako Abe, Gary A Baker, Sheila N Baker, Frank V Bright, Allan R OseroffAbstract:Water-soluble, core-modified porphyrins were prepared and evaluated as sensitizers for photodynamic therapy (PDT). The addition of an aromatic aldehyde to 2,5-dilithiothiophene or -selenophene gave diol 3 as a nearly equimolar mixture of meso and d,l diastereomers, which gave a single diastereomer following careful recrystallization. The condensation of pyrrole with a diol 3 using catalytic BF3-etherate gave bispyrrolochalcogenophenes (4). Condensation of a diol 3 with 4 in the presence BF3-etherate gave 21,23-dichalcogenaporphyrins (5). 21-Thiaporphyrins (6) were prepared by condensation of a diol 3 with excess pyrrole and benzaldehyde in the presence of tetrachlorobenzoquinone and catalytic BF3-etherate. Sulfonation of 5 and 6 with concentrated sulfuric acid at 100 °C gave sulfonated derivatives 7−15. Bis-4-methoxy-21,23-dithiaporphyrins 5h and 5l were demethylated with BBr3, and the resulting phenols were alkylated with ethyl bromoacetate. Saponification gave 21,23-dithiaporphyrin dicarboxylate salts 1...
-
water soluble core modified porphyrins as novel Longer Wavelength absorbing sensitizers for photodynamic therapy
Journal of Medicinal Chemistry, 2000Co-Authors: Corey E Stilts, Marina I Nelen, David G Hilmey, Sherry R Davies, Sandra O Gollnick, Allan R Oseroff, Scott L Gibson, Russell Hilf, Michael R DettyAbstract:Water-soluble, core-modified 5,10,15,20-tetrakis(4-sulfonatophenyl)-21,23-dithiaporphyrin (1) and 5,10,15,20-tetrakis(4-sulfonatophenyl)-21,23-diselenaporphyrin (2) were prepared as the tetrasodium salts by the sulfonation of 5,10,15,20-tetraphenyl-21,23-dithiaporphyrin (3) and -21,23-diselenaporphyrin (4), respectively, with sulfuric acid. Compounds 3 and 4 were prepared by the condensation of pyrrole with either 2,5-bis(phenylhydroxymethyl)thiophene (5) or 2,5-bis(phenylhydroxymethyl)selenophene (6) in propionic acid. The addition of benzaldehyde to 2,5-dilithiothiophene or 2,5-dilithioselenophene gives 5 or 6, respectively, as a nearly equimolar mixture of meso- and d,l-diastereomers. Careful crystallization of 5 gives a single diastereomer by removing the crystalline product from the equilibrating mixture of diastereomers in solution. Photodynamic therapy (PDT) with 1 has an LD50 of less than 25 μg/mL against Colo-26 cells in culture and exhibits a lethal dose for 90% or more at concentrations greater...
Mitsutoshi Ozaki - One of the best experts on this subject based on the ideXlab platform.
-
Leader-laggard relationship of chaos synchronization in mutually coupled vertical-cavity surface-emitting lasers with time delay
Physical Review E : Statistical Nonlinear and Soft Matter Physics, 2009Co-Authors: Mitsutoshi Ozaki, Atsushi Uchida, Hiroyuki Someya, Shigeru Yoshimori, Krassimir Panajotov, Takaya Mihara, Marc SciamannaAbstract:We experimentally and numerically observe synchronization of chaos in two mutually coupled vertical-cavity surface-emitting lasers (VCSELs) with time delay. We observe in-phase and antiphase synchronization of polarization-resolved chaotic temporal wave forms under the condition of Wavelength matching. We investigate leader-laggard relationship between two chaotic wave forms of mutually coupled VCSELs and find that the laser with Longer Wavelength becomes the leader.
-
Synchronization of chaos in mutually coupled vertical-cavity surface-emitting lasers with time delay
2009Co-Authors: Atsushi Uchida, Hiroyuki Someya, Mitsutoshi Ozaki, Kazuya Tanaka, Shigeru Yoshimori, Krassimir Panajotov, Marc SciamannaAbstract:We experimentally observe in-phase and anti-phase synchronization of chaos in two mutually-coupled vertical-cavity surface-emitting lasers. We investigate leader-laggard relationship between two chaotic waveforms and find that the laser with Longer Wavelength becomes the leader.
Shumin Wang - One of the best experts on this subject based on the ideXlab platform.
-
novel type ii ingaas gaasbi quantum well for Longer Wavelength emission
Journal of Alloys and Compounds, 2017Co-Authors: Li Yue, Yuxin Song, Xiren Chen, Qimiao Chen, Wenwu Pan, Juanjuan Liu, Liyao Zhang, Jun Shao, Shumin WangAbstract:We propose a new type II InGaAs/GaAsBi quantum well structure to extend light emission Wavelength on GaAs and demonstrate the effect experimentally. Type II InGaAs/GaAsBi QWs were grown using molecular beam epitaxy. Room temperature photoluminescence confirms Wavelength extension to 1230 nm, 82 and 208 nm Longer than that of the type I GaAsBi and InGaAs QW with the same Bi or In content, respectively. The PL intensity is enhanced by more than ten times than the GaAsBi QW. Our results show that the type II dilute bismide QW has potentials for making telecom lasers on GaAs.
