Bücher von Michael Spiteller

Academic Paper from the year 2021 in the subject Chemistry - Analytical Chemistry, University of Dortmund (Institute of Environmental Research), language: English, abstract: In this work we discuss certain consideration for quantum chemical and chemometric assessing in the crystallographic polymorphism. It is aimed primarily at researchers in ¿Analytical chemistry¿ and is designed to help readers¿ understanding of the implications of the different quantum chemical theories in the chemical crystallography.The term ¿polymorphism¿ reflects molecular ability to crystalize in more than one structure. Since, properties of polymorphs can vary, their quantification becomes an important task to manufacturing pharmaceutics. It affects packing properties via molar volume and crystal density; optical properties and refractive index; electrical and thermal properties; conductivity; hydroscopicity; other differences associated with thermodynamics; kinetics; surface and mechanical properties, and more. In order to make a complex prediction of correlation among ¿molecular structure¿¿¿electronic structure¿¿¿energetics¿ using crystallographic and quantum chemical data it should be taken into consideration various polymorph modifications.

Research Paper (postgraduate) from the year 2019 in the subject Chemistry - Analytical Chemistry, University of Dortmund (Institut für Umweltforschung), language: English, abstract: The major aim of this work is to introduce our new model equation connecting among the söcalled stochastic dynamic diffusion coefficient ¿DSD,¿ the experimental mass spectrometric outcome intensity ¿I¿ and the experimental parameter temperature ¿T,¿ respectively. A closer review of our contributions, so far, to the domain of the ¿stochastic dynamic mass spectrometry¿ has shown that we have developed a functional relationship between the DSD parameter and the mass spectrometric intensity. It is . Its universal applicability to a set of soft¿ionization mass spectrometric methods has been evidenced within a small¿scale research on correlation between theory and experiment, which has been tested by chemometrics. As a corollary, there has been concluded that the temporal behaviour of the experimental mass spectrometric intensity obeys a certain law and this law is the equation shown above. The fundamental differences in the functional relationship written before and our new innovative model lies in that we account for the effect of the temperature on the DSD parameter and the experimental mass spectrometric measurable variable. The roots of the latter model are again to stochastic plausibility theories, focusing the attention on the Gillespie¿s exact numerical solution of the Ornstein¿Uhlenbeck process according to the forward Fokker¿Planck equation (or the forward Kolmogorov equation) and the theory of continuous Markov processes. We shall not only introduce, a new functional relation, but also we shall provide persuasive empirical proofs of that the new formula is true. The contribution explores our own experimental mass spectrometric data. The discussion, herein, provides sufficient justification, that the content of the work would be of interest in MSc students specializing in ¿Advanced methods for the Analytical Chemistry¿ or ¿Environmental Chemistry;¿ students specializing in ¿Theoretical and computational chemistry;¿ and PhD students or researchers developing the mass spectrometric methodology.

Research Paper (postgraduate) from the year 2019 in the subject Chemistry - Analytical Chemistry, University of Dortmund (Institute of Environmental Research, Department of Analytical Chemistry), language: English, abstract: Throughout the chapters in this book we argue that the temporal behaviour of the experimental mass spectrometric intensity of analyte ions obeys a certain and universal law based on a stochastic dynamic approach. The content of the book evidences convincingly through a selected series of examples to molecular systems of metal¿organic complexes of transition metal ions with electronic configuration d10, for instance, AgI¿ and ZnII¿ions, the validity of our model equation reported, more recently. It needs to be underlined that, the comprehensive study that is provided, herein, is published, for first time in the literature. The book, therefore, represents monograph containing results from our research work, detailing correlatively experimental and theoretical mass spectrometric analyses of metal¿organics using ultrahigh accuracy electrospray ionization and collision induced dissociation mass spectrometry. An enormous amount of effort is concentrated on a quantitative description of the relationships between experimental measurable parameter ¿intensity¿ and diffusion or kinetic parameters of analyte ions.

Academic Paper from the year 2020 in the subject Chemistry - Analytical Chemistry, grade: Second author Michael Spiteller, University of Dortmund (Institut für Umweltforschung), language: English, abstract: The idea for this contribution has its root in exact formulas connecting between measurable variable intensity of mass spectrometric peak of analyte ion and its stochastic dynamic diffusion parameter introduced, more recently in our works devoted to quantitative mass spectrometry. Herein, we present innovative functional relations connecting among not only DSD- and I-parameters, but also the experimental factor temperature and the concentration of analyte in solution. The temperature is one of the most important parameter determining the ionization efficiency of analytes under soft-ionization mass spectrometric conditions.The focus of the work is not only on outlining quantitative conjunctions among experimental factors, respectively, parameters; measurable outcomes; and molecular properties, but also to help readers achieve in-depth understanding of governing factors determining the ionization efficiency of analyte ions with respect to temperature at a molecular level. Another important aspect for studying is that, all theoretical proposals introduced, so far, are based on stochastic dynamics. The latter field, however, is very broad. It encompasses a large set of mathematical methods applicable to explain diverse phenomena not only in the Chemistry, but also in the Physics, Astronomy, Economy, and many more research areas.The methodology used to our principle theory behind the derivation of model functional relations; our innovative empirical modification of known relationship; and corresponding definition of the DSD parameter as a function of the measurable variable intensity are based on Box-Müller method, Einstein¿s concept of diffusion within his molecular kinetic theory of heat; the forward Fokker-Planck equation (or the forward Kolmogorov equation,) where we empirically modify the characteristic function diffusion and its (their) application to Ornstein-Uhlenbeck process; approximations to a Wiener process; Gillespie¿s interpretation of Ornstein-Uhlenbeck process and its exact numerical solution, respectively.Due to, complexity of many of the soft-ionization mass spectrometric phenomena and the interconnection of different concepts behind our stochastic dynamic theory of exact quantification of the variable intensity, we hope that the readers will be able to gain the background to the different mass spectrometric phenomena and theories to more advanced primary literature sources, which can be found in the corresponding reference sections.

Research Paper (postgraduate) from the year 2018 in the subject Chemistry - Analytical Chemistry, grade: Mass spectrometry, University of Dortmund (Institut für Umweltforschung, Lehrstuhl für Analytische Chemie), language: English, abstract: The goal of this work is to describe more recent developments in the quantitative mass spectrometry and to illustrate how our new model equations based on the stochastic dynamics relate to the determining the 3D molecular and electronic structures of analytes. It is aimed at researchers in Chemistry who would like to find out about what is going on in mass spectrometric methodological contributions more recently. The work could also be used to MSc and PhD students in the field of Chemistry, in particular, highlighting the ¿Analytical chemistry¿, ¿Physicöchemistry¿ and/or ¿Computational and theoretical chemistry¿, respectively.