TY - JOUR A1 - Flores, E. A1 - Idrees, F. A1 - Moussay, P. A1 - Viallon, J. A1 - Wielgosz, R. A1 - Fernández, T. A1 - Rojo, A. A1 - Ramírez, S. A1 - Aoki, N. A1 - Kato, K. A1 - Jeongsoon, L. A1 - Moon, D. A1 - Kim, J.-S. A1 - Harling, A. A1 - Milton, M. A1 - Smeulders, D. A1 - Guenther, F.R. A1 - Gameson, L. A1 - Botha, A. A1 - Tshilongo, J. A1 - Ntsasa, N.G. A1 - Valková, M. A1 - Konopelko, L. A1 - Kustikov, Y.A. A1 - Ballandovich, V. S. A1 - Gromova, E.V. A1 - Tuma, Dirk A1 - Kohl, Anka A1 - Schulz, Gert T1 - Final report of the pilot study CCQM-P110-B1: A comparison of nitrogen dioxide (NO2) in nitrogen standards at 10 µmol/mol by Fourier transform infrared spectroscopy (FT-IR) N2 - This pilot study compares the performance of participants in analyzing gas mixtures of nitrogen dioxide in nitrogen by comparison with in-house gravimetric standards using Fourier transformed infrared spectroscopy (FT-IR). In this study the same gas mixtures were used as in the key comparison CCQM-K74, which was designed to evaluate the level of comparability of National Metrology Institutes' measurement capabilities for nitrogen dioxide (NO2) at a nominal mole fraction of 10 µmol/mol. In the comparison CCQM-K74 most of the participants used chemiluminescence, with a small number using UV absorption or FT-IR spectroscopy, and thus it is of interest to improve understanding of the comparative performance of these techniques because they do not exhibit any cross-sensitivity to nitric acid (HNO3), which was known to be present in the mixtures used for the comparison. The results of this pilot study indicate good consistency and a level of agreement similar to that reported in the comparison CCQM-K74, demonstrating that FT-IR can be operated as a comparison method when calibrated with appropriate gas standards and can achieve similar measurement uncertainties to chemiluminescence and UV absorption techniques. An additional pilot study, CCQM-P110-B2, was conducted on the same gas mixtures in parallel with this pilot study. The second study addressed FT-IR spectroscopy when used to measure the gas mixtures with respect to reference spectra. The results of this second study will be reported elsewhere. Main text. To reach the main text of this paper, click on Final Report. The final report has been peer-reviewed and approved for publication by the CCQM-GAWG. DatesIssue 1A (Technical Supplement 2012) KW - Ringversuch KW - NO2 KW - Spurenverunreinigungen KW - FT-IR-Spektroskopie PY - 2012 DO - https://doi.org/10.1088/0026-1394/49/1A/08006 SN - 0026-1394 SN - 1681-7575 VL - 49 IS - 08006 SP - 1 EP - 76 PB - Inst. of Physics Publ. CY - Bristol AN - OPUS4-25928 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ermilov, Eugeny A. A1 - Liu, J.-Y. A1 - Menting, R. A1 - Huang, Y.-S. A1 - Röder, B. A1 - Ng, D. K. P. T1 - An artificial photosynthetic model based on a molecular triad of boron dipyrromethene and phthalocyanine N2 - A boron dipyrromethene (BDP) unit and its monostyryl derivative (MSBDP) were introduced at the axial positions of a silicon(IV) phthalocyanine (SiPc) core. The absorption spectrum of this compound virtually covered the entire visible region (300-700 nm) and could be interpreted as a superposition of the spectra of individual components. The intramolecular photoinduced energy and charge transfer processes of this triad were studied using steady-state and time-resolved spectroscopic methods in polar and nonpolar solvents. Upon BDP-part excitation, a fast and highly efficient excitation energy transfer (EET) occurred resulting in strong quenching of its fluorescence and the formation of the first excited singlet state of SiPc or MSBDP. It was found that both EET and charge transfer (CT) processes competed with each other in the depopulation of the first excited singlet state of the MSBDP moiety. The former strongly superseded CT in nonpolar toluene, whereas the latter was dominant in a polar environment. Direct or indirect (via EET) excitation of the SiPc-part of the triad was followed by CT yielding the charge-separated (CS) species BDP-SiPc center dot--MSBDP center dot+. The energy gap between the CS state and the S-1-state of the SiPc moiety was found to be only 0.06 eV in toluene, which facilitated the back CT process and resulted in the appearance of thermally activated delayed fluorescence. With increasing solvent polarity, the energy of the CS state reduced resulting in the disappearance of the delayed fluorescence in CHCl3, tetrahydrofuran or N,N-dimethylformamide. The charge recombination rate, k(CR), was very fast in polar DMF (3.3 x 10(10) s(-1)), whereas this process was two-orders of magnitude slower in nonpolar toluene (k(CR) = 4.0 x 10(8) s(-1)). KW - Photoinduced electron-transfers KW - Zinc phthalocyanine KW - Solar-energy KW - Charge separation KW - Solvent polarity KW - Porphyrin KW - Excitation KW - Fullerene KW - Recombination KW - Carotenoids PY - 2016 DO - https://doi.org/10.1039/c6cp00920d VL - 18 IS - 16 SP - 10964 EP - 10975 PB - Royal Soc Chemistry CY - Cambridge, UK AN - OPUS4-36271 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -