Browsing by Author "Satapathy, Rudrakanta"

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Novel dithieno-benzo-imidazole-based Pb2+ sensors: substituent effects on sensitivity and reversibility
(2012)
Satapathy, Rudrakanta
;
Wu, Yen-Hsing
;
Lin, Hong-Cheu
;
材料科學與工程學系
;
Department of Materials Science and Engineering
Two novel dithieno-benzo-imidazole-based compounds (M2 and A2) showed remarkable sensitivities towards Pb2+ by 12-fold enhancement and 10-fold decay of fluorescence, respectively, in aqueous solutions. Substituent effects of different dithieno-benzo-imidazole-based moieties (M1, M2, A1 and A2) on the quantum yields, fluorescence lifetimes and sensitivities to Pb2+ along with the reversibilities by S2- were investigated.
Novel metallo-dendrimers containing various Ru core ligands and dendritic thiophene arms for photovoltaic applications
(2014)
Satapathy, Rudrakanta
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Ramesh, Mohan
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Padhy, Harihara
;
Chiang, I. -Hung
;
Chu, Chih-Wei
Three series of supramolecular mono-(i.e., Ru1G1, Ru1G2 and Ru1G3), bis-(i.e., BTRu2G1, BTRu2G2 and BTRu2G3) and tris-(i.e., TPARu3G1, TPARu3G2 and TPARu3G3) Ru-based dendritic complexes were synthesized. Their photophysical and electrochemical properties were investigated. These metallo-dendritic complexes covered a broad absorption range of 250-750 nm with optical bandgaps of 1.51-1.86 eV. The energy levels of the metallo-dendrimers can be effectively adjusted not only by different generations of dendritic thiophene arms but also by their pi-conjugated core ligands bearing various electron donor (i.e., triphenylamine) and acceptor (i.e., benzothiadiazole) moieties. Due to the donor-acceptor effect, the bis-Ru-based dendrimers containing a benzothiadiazole electron-acceptor core ligand showed the highest power conversion efficiency (PCE) among these three series of metallo-dendrimers. The tris-Ru-based architecture with a triphenylamine electron-donor core ligand revealed moderate photovoltaic performance. Among the different generations (G1-G3) of dendrimers, the third generation (G3) possessed the highest PCE values in each series of Ru-based dendrimers. Hence, the third generation bis-\'Ru\'-based dendrimer BTRu2G3 blended with PC70BM (1 : 3 w/w) showed the highest PCE value of 0.77% (without the aid of additives or annealing), which is the highest efficiency among all bulk hetero-junction (BHJ) solar cells containing metallo-dendrimers reported to date.
Novel Thieno-imidazole Based Probe for Colorimetric Detection of Hg2+ and Fluorescence Turn-on Response of Zn2+
(2012-05-18)
Satapathy, Rudrakanta
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Wu, Yen-Hsing
;
Lin, Hong-Cheu
;
材料科學與工程學系
;
Department of Materials Science and Engineering
Novel thieno-imidazole based polymer P showed both colorimetric and ratiometric detections of Hg2+ as well as fluorometric detection of Zn2+ via fluorescence turn-on response with augmented lifetime. Its model polymer M did not show any such sensing capability under similar conditions, which further confirmed the unique sensitivity of P toward Hg2+ and Zn2+ via the chelation of metal ions to both "S" and "N" heteroatoms.
Synthesis and Characterization of Reversible Chemosensory Polymers: Modulation of Sensitivity through the Attachment of Novel Imidazole Pendants
(2012-12-01)
Satapathy, Rudrakanta
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Padhy, Harihara
;
Wu, Yen-Hsing
;
Lin, Hong-Cheu
;
材料科學與工程學系
Three novel electron donoracceptor conjugated polymers (P1P3) bearing various imidazole pendants have been synthesized. Their excellent photophysical and electrochemical properties make them suitable transduction materials for chemosensing applications. Indeed, polymers P1P3 have been found to show remarkable sensing capabilities towards H+ and Fe2+ in semi-aqueous solutions. Upon titration with H+, polymers P1 and P2 showed hypsochromic shifts of their absorptions and photoluminescence (PL) maxima with enhanced fluorescence intensities. However, P3 showed diminished absorption and fluorescence intensities under similar conditions due to static quenching. The anomalous behavior of P3 compared with P1 and P2 has been clarified in terms of electronic distributions through computational analysis. Furthermore, P3 (KSV=1.03x107) showed a superior sensing ability towards Fe2+ compared with P1 (KSV=2.01x106) and P2 (KSV=4.12x106) due to its improved molecular wire effect. Correspondingly, the fluorescence lifetime of P3 was greatly decreased (almost 11-fold) compared to those of polymers P1 (4.6-fold) and P2 (6.2-fold) in the presence of Fe2+. By means of a fluorescence on-off-on approach, chemosensing reversibilities in protonationdeprotonation and metallationdemetallation have been achieved by employing triethylamine (TEA) and the disodium salt of ethylenediaminetetraacetic acid (Na2-EDTA)/phenanthroline, respectively, as suitable counter ligands. 1H NMR titrations have revealed the unique behavior of P3 compared with P1 and P2. To the best of our knowledge, there have been no previous reports of Fe2+ sensors based on single imidazole receptors conjugated to a main-chain polymer showing such a diverse sensitivity pattern depending on their attached substituents.
Synthesis of Main-Chain Metallo-Copolymers Containing Donor and Acceptor Bis-Terpyridyl Ligands for Photovoltaic Applications
(2012-04-13)
Padhy, Harihara
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Ramesh, Mohan
;
Patra, Dhananjaya
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Satapathy, Rudrakanta
;
Pola, Murali Krishna
Two random (ZnII-based P1P2) and two alternating (RuII-based P3P4) metallo-copolymers containing bis-terpyridyl ligands with various central donor (i.e., fluorene or carbazole) and acceptor (i.e., benzothiadiazole) moieties were synthesized. The effects of electron donoracceptor interactions with metal (ZnII and RuII) ions on their thermal, optical, and electrochemical properties were investigated. Because of the strong ICT transitions between donor and acceptor ligands in both ZnII- and RuII-based metallo-coplymers and MLCT transitions in RuII-based metallo-coplymers, the absorption spectra covered a broad range of 260750 nm with the band gaps of 1.571.77 eV. In addition, the introduction of RuII-based metallo-coplymer P4 mixed with PC60BM as an active layer of the BHJ solar cell device exhibited the highest PCE value up to 0.90%.