Combining hard- and soft-modelling to solve kinetic problems

Juan, Anna de; Maeder, Marcel; Martínez, M.; Tauler, Romà

doi:10.1016/s0169-7439(00)00112-x

Cited by 297 publications

(206 citation statements)

References 24 publications

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“…Reactant and product ion relationships, and their general kinetic behavior, were determined using the MCR method SIMPLISMA [44]. Next, a hard-modeling approach that used an alternating least squares (ALS) regression [45,46] was employed to generate concentration profiles starting from the MCR-derived kinetic model. Finally, a set of kinetic rate equations were fit to the concentration profiles obtained from ALS using the MATLAB 6.1 (Mathworks, Inc, Natick, MA) function FMINSEARCH, which uses a non-linear simplex optimization [47].…”

Section: Calculation Of Rate Constantsmentioning

confidence: 99%

Ion-molecule reactions of gas-phase chromium oxyanions: Cr_xO_yH_z⁻ + O₂

Gianotto¹,

Hodges²,

Harrington

et al. 2003

J. Am. Soc. Mass Spectrom.

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Section: Calculation Of Rate Constantsmentioning

confidence: 99%

Ion-molecule reactions of gas-phase chromium oxyanions: Cr_xO_yH_z⁻ + O₂

Gianotto¹,

Hodges²,

Harrington

et al. 2003

J. Am. Soc. Mass Spectrom.

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“…Special attention should be paid to this latter point when dealing with difference data as non-negativity constraint does not hold for the spectra. For this reason, the integration of convoluted kinetic models in hybrid hard-and soft-MCR procedure [17] to resolve ultrafast spectrokinetic data is currently under investigation.…”

Section: Discussionmentioning

confidence: 99%

“…To perform component resolution of unknown reactions, soft-modeling MCR methods [13,14] may provide powerful alternative to parametric methods more conventionally applied in the field of femtochemistry [15]. Furthermore, MCR methods can be extended to include refinement of the time-dependent concentration profiles (more generally any profiles) fitting them with a kinetic model (hard-model) to assess reaction constants and increase the robustness of the resolution [16,17]. The potential of this kind of approach mixing hard-and soft-modeling has been shown in time-resolved spectroscopy [7,9,10,18].…”

Section: Introductionmentioning

confidence: 99%

Deconvolution of femtosecond time‐resolved spectroscopy data in multivariate curve resolution. Application to the characterization of ultrafast photo‐induced intramolecular proton transfer

Mouton

Sliwa

Buntinx

et al. 2010

Journal of Chemometrics

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In femtosecond absorption spectroscopy, deconvolution of the measured kinetic traces is still an important issue as photochemical processes that may possess shorter characteristic times than the time resolution of the experiment are usually considered. In this work, we propose to perform deconvolution of the time-dependent concentration profiles extracted from multivariate curve resolution (MCR) applied to spectrokinetic data. The profiles are fitted with a model function including a description of the instrumental response function (IRF) of the experiment. The method combines the potential benefits of soft-modeling data analysis with the ones of hard-modeling for parameter estimation. The potential of the method is demonstrated first analyzing five synthetic data sets for which IRF of different widths are simulated. It is then successfully applied to resolve femtosecond UV-visible transient absorption spectroscopy data investigating the photodynamics of salicylidene aniline, a photochromic molecule of wide interest. Considering a time resolution of 150 fs for the IRF, a characteristic time of 45 fs is recovered for the first step of the photo-induced process which consists of an ultrafast intramolecular proton transfer. Our results also confirm the existence of an intermediate species with a characteristic time of 240 fs.

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“…[5][6][7][8][9][10][11] Only a limited number of studies include the second order reactions of the form U + V → W, [12][13][14] which are industrially important. Second order consecutive reactions,…”

Section: Introductionmentioning

confidence: 99%