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311.
Guijarro N Campiña JM Shen Q Toyoda T Lana-Villarreal T Gómez R 《Physical chemistry chemical physics : PCCP》2011,13(25):12024-12032
Among the third-generation photovoltaic devices, much attention is being paid to the so-called Quantum Dot sensitized Solar Cells (QDSCs). The currently poor performance of QDSCs seems to be efficiently patched by the ZnS treatment, increasing the output parameters of the devices, albeit its function remains rather unclear. Here new insights into the role of the ZnS layer on the QDSC performance are provided, revealing simultaneously the most active recombination pathways. Optical and AFM characterization confirms that the ZnS deposit covers, at least partially, both the TiO(2) nanoparticles and the QDs (CdSe). Photoanodes submitted to the ZnS treatment before and/or after the introduction of colloidal CdSe QDs were studied by electrochemical impedance spectroscopy, cyclic voltammetry and photocurrent experiments. The corresponding results prove that the passivation of the CdSe QDs rather than the blockage of the TiO(2) surface is the main factor leading to the efficiency improvement. In addition, a study of the ultrafast carrier dynamics by means of the Lens-Free Heterodyne Detection Transient Grating technique indicates that the ZnS shell also increases the rate of electron transfer. The dual role of the ZnS layer should be kept in mind in the quest for new modifiers for enhancing the performance of QDSCs. 相似文献
312.
Masao Kato Hiroshi Urabe Yoshinao Oosawa Taro Saito Yukiyoshi Sasaki 《Journal of organometallic chemistry》1976,121(1):81-91
Cationic palladium(II) and platinum(II) complexes with chelate ylides and neutral ligands of the type, [MCl (Y) (L)]+BPh4? (M Pd or Pt; Y bdep or bdmp*; L = 4-methylpyridine, 3,5-dimethylpyrazole, PPh3, PCy3, PMePh2, P(OMe)3, AsPh3 or SbPh3) and [M(bdep) (4-methylpyridine)2] (BPh4)2 (M = Pd or Pt) were prepared and characterized by means of infrared and 1H NMR spectra. 相似文献
313.
Taro Asaba Yuki Katoh Dr. Daisuke Urabe Prof. Dr. Masayuki Inoue 《Angewandte Chemie (International ed. in English)》2015,54(48):14457-14461
The complex ABC‐tricyclic structure of crotophorbolone, a derivative of the tigliane diterpenoids, was assembled by coupling of simple fragments. The six‐membered C‐ring fragment, having five contiguous stereocenters, was stereoselectively constructed from (R)‐carvone. After attachment of the five‐membered A‐ring through the π‐allyl Stille coupling reaction, the α‐alkoxy bridgehead radical reaction effected the endo‐cyclization of the seven‐membered B‐ring by forming the sterically congested bond at C9 and C10 stereospecifically and stereoselectively, respectively. Finally, the functional groups on the 5/7/6‐membered ring system were manipulated by rhodium‐catalyzed C2 olefin isomerization, C13 decarboxylative oxidation, and C4 hydroxylation, thus completing the first total synthesis of crotophorbolone. 相似文献
314.
Let A be a finite group acting on a finite group G via automorphisms. Assume that
$$(|A|,|G|)=1$$
. We prove that if
$$C_G(A)$$
is a Hall
$$\pi $$
-subgroup of G, then G has a normal
$$\pi $$
-complement. 相似文献
315.
316.
The thermal reaction of methyl 2-oxo-2H-pyran-5-carboxylates with substituted styrenes in the presence of 10% palladium on activated carbon afforded directly the corresponding methyl 4-biphenylcarboxylates in good yields. By the similar procedure, methyl 4-heteroaryl- and 4-alkyl-substituted benzoates were obtained from heteroaromatic olefins and alkenes, respectively. 相似文献
317.
Blue pulses with durations of 8.5 fs are generated by broadband frequency doubling of subterawatt Ti:sapphire laser systems at 1-5-kHz repetition rates. The average powers are 1.6 W at 5 kHz and 1.9 W at 1 kHz. The peak power is 0.16 TW with a duration of 12 fs at 1 kHz. 相似文献
318.
Circularly Polarized Luminescence of Chiral Pt(pppb)Cl (pppbH=1‐pyridyl‐3‐(4,5‐pinenopyridyl)benzene) Aggregate in the Excited State 下载免费PDF全文
Saori Tanaka Dr. Kyohei Sato Kyoko Ichida Dr. Taichi Abe Prof. Taro Tsubomura Prof. Takayoshi Suzuki Prof. Kazuteru Shinozaki 《化学:亚洲杂志》2016,11(2):265-273
We prepared enantiomers of chiral PtII complexes, Pt(pppb)Cl and Pt(pppb)CN (pppbH=1‐pyridyl‐3‐(4,5‐pinenopyridyl)benzene), and measured their CPL (circularly polarized luminescence) spectra for excimer and trimer emission. The contribution of the pinene moiety to CPL was considerably low for the π–π* emission of the monomer but large for MMLCT (metal‐metal‐to‐ligand charge‐transfer) of the excimer and trimer which had a helical structure induced in a face‐to‐face stacking fashion. The trimer CPL for (+)‐Pt(pppb)Cl was larger in intensity than that of excimer CPL; on the other hand, that for (+)‐Pt(pppb)CN was opposite in sign compared with that of excimer CPL. We conclude that differences in the excited‐state structure of the aggregate between Pt(pppb)Cl and Pt(pppb)CN account for the variation in the CPL spectra. By the aid of TD‐DFT calculations it was predicted that the dihedral angle θ(Cl‐Pt‐Pt‐Cl) was 50–60° or 110–140° for Pt(pppb)Cl aggregates and 160° for Pt(pppb)CN aggregates. 相似文献
319.
Onoda A Kakikura Y Uematsu T Kuwabata S Hayashi T 《Angewandte Chemie (International ed. in English)》2012,51(11):2628-2631
All connected: a protein-immobilized electrode comprising hierarchical assemblies of photoactive cytochrome b(562) reconstituted with zinc protoporphyrin IX exhibits remarkably enhanced photocurrent generation relative to an electrode bearing a single zinc-substituted hemoprotein layer. The protein oligomers, which bear a covalently linked protoporphyrin group, assemble by a supramolecular heme/heme pocket interaction. 相似文献
320.