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Abstract The kernel idea for this paper came from our more recent development of a mass spectrometric model equation, based on stochastic dynamics. It treats quantitatively the experimental intensity of analytes and their fragment ions under soft ionization conditions. The effort has resulted to exact universally applicable and empirically testable relationship, between mass spectrometric stochastic dynamic diffusion and the intensity. A linear correlation at high level of statistical significance occurs between D SD and the corresponding quantum chemical diffusions, obtained within the Arrhenius' approximation. It provides bridge between experimental MS parameters and 3D structure of analyte ions. Furthermore, we have claimed that the total intensity of the ions is proportional to their D SD parameter according to our model equation; or I tot ~ D SD. As evident from the small–scale of our contributions, so far, the simplistic theoretical concept and corresponding model equation need to be translated into a broad practical employment, because of; there is extended the capability of mass spectrometry beyond its routine application as irreplaceable method for quantitative analysis to the analytical practice. The superior features of the mass spectrometric instrumentation can offer us a new perspective of looking at the implementation of the method to exact 3D structural analysis in condense phase. As far as any such statement should be strongly quantified from the point of view of the chemometrics, this work deals with application of our stochastic dynamic concept of mass spectrometric diffusion to structural analysis of complex ions of CuII–ion with glycylhomopentapeptide and its dimeric associates. The large difference in the coordination fashion of oligopeptides, and competitive fragment paths together with the variety of the coordination modes of CuII–ion; and accounting, in parallel, for the different oxidation states of copper allows for us to demonstrate the great capability of our theoretical concept, studying so challenging research area. The experimental design is based on high resolution electrospray ionization mass spectrometric data in positive operation mode. High accuracy ab initio and methods based on theory on functional of density are used. Both static and molecular dynamic methods are employed. Graphical abstract Unlabelled Image Highlights • Electrospray ionization mass spectrometric quantification of diffusion parameters • Stochastic dynamic approach for quantification of the mass spectrometric intensity • Complexes of CuII–ion with glycylhomopentapeptide and its oligomeric associates • 3D structural analysis [ABSTRACT FROM AUTHOR]

Abstract The focus on this paper is on to continue the research line taken in our more recent studies of mass spectrometric approaches treating quantitatively the intensity of analyte fragment peaks with respect to time within the own model equation, based on stochastic dynamics, and correlating between experimental diffusion parameters of ions and their 3D structures, when this approach is used complementary with high accuracy methods of quantum chemistry. Accordingly, the aims at the work will be undeniably presented. First, we will explore ESI–MS in solution, operating under positive mode and crystallographic data of a CuII–complex of glycine (cis –{[CuII(Gly) 2 ].H 2 O} (1)) in determining experimental MS diffusions of ions according to the aforementioned methodology. The correlative analysis to quantum chemical diffusions will be carried out, using the Arrhenius' approximation to the theoretical diffusion of charged species under soft–ionization MS conditions. Second, on the base on experimentally observed complex isotope shape of coordination species of ions of copper, a theoretical description of redox processes under ESI–MS conditions will be detailed. There is nothing irreconcilable between both goals, as far as, the experimental data convincingly argued that the relation to MS stochastic dynamic diffusions ⇔ quantum chemical diffusion parameters has direct bearing on how the analysis of the MS intensity of isotope sub–peaks within the aforementioned method can provide direct information about experimental 3D structure of the analyte in condense phase. The cis/trans isomerization of {[CuII(Gly) 2 ]} complex is discussed in detail correlating crystallographic data of (1) with ESI(+)–MS ones. A process of isomerization cis –{[CuII(gly) 2 ]0} → trans –{[CuII(gly) 2 +H]+} is proposed on the base on crystallographic and mass spectrometric data on (1). Graphical abstract Stochastic dynamic mass spectrometric diffusion as a tool for 3D structural determination of metal-organics. Image 1 [ABSTRACT FROM AUTHOR]

Abstract The issue of this work focuses on development of quantitative model equations connecting experimental mass spectrometric (MS) parameters, for instance, MS intensity, of analyte peaks with thermodynamic, kinetic and diffusion parameters of the corresponding ions with their 3D molecular and electronic structures. Our more recent contribution to this field has convincingly argued that equation D = 1.3194.10 − 17. A. I 2 ¯ − (I ¯) 2 (I − I ¯ ) 2 , obtained on the base on stochastic dynamics, is applicable to electrospray ionization (ESI), collision induced dissociation (CID) and matrix–assisted laser desorption/ionization (MALDI) mass spectrometric (MS) methods, respectively. It connects MS diffusion parameters of ions with the intensities of their peaks in the MS spectrum. There has been evidenced, that experimental diffusion parameters correspond quantitatively to theoretical quantum chemical diffusion coefficients, obtained on the base on Arrhenius' formalism. If next research effort continues to confirm the validity of the shown above quantitative relation to the behavior of the MS intensity of the analyte, with respect to time, this might imply that the mass spectrometry represents not only an irreplaceable method for quantification in the analytical practice, but it provides exact experimental information about the 3D structure of the analytes. According to the latter line of research, the first aspect of this study is an experimental and theoretical MS quantification of diffusion parameters and 3D structural determination of ions of L-tryptophyl– l –tryptophan (H–Trp–Trp–OH) under ESI(+)–MS conditions. Another issue details experimentally and theoretically the process of molecular cyclization of H–Trp–Trp–OH. This aspect of the chemical reactivity of the dipeptide has provided very important insights into major reaction paths, yielding to permuted oxazolone. Taking a step into a broad application of our model relationship stated above to different areas of science, we should underline that, no doubt, the paper contributes significantly to methodological development of mass spectrometric based methods for 3D structural analysis, exploiting herein a nontrivial case of MS fragment behavior of the peptide H–Trp–Trp–OH under ESI–MS conditions. Graphical abstract Image 1 Highlights • Electrospray ionization mass spectrometry. • Diffusion parameters. • Quantum chemistry. • 3D structural analysis. • Dipeptide. [ABSTRACT FROM AUTHOR]

This paper provides experimental and theoretical study of reaction of [2 + 2] cycloaddition of substituted α–unsaturated isophorone dyes, involving high resolution electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) tandem mass spectrometric (MS/MS) analysis in solution and in gas–phase (GP) of substituted 3-[2-(X-substituted-phenyl)-vinyl]-5,5-dimethyl-cyclohex-2-enone and configurationally locked polyenes (CLP). The ab initio and density functional theoretical (DFT) examining provides information about molecular geometry, thermodynamics, kinetics and ionization potentials of sixty six isomers of dimeric dyes, including corresponding cis -anti- cis and cis -syn- cis head-to-tail and head-to-head forms. The comparative collision induced dissociation (CID) or collision activated MS and theoretical analyses carried out bring light into the mechanisms of competitive dimerization within the frame of 3-[2-(X-substituted-phenyl)-vinyl]-5,5-dimethyl-cyclohex-2-enone; molecular and environmental factors governing regioselectivity of reaction. The analyses involve both qualitative and quantitative kinetics and thermodynamics of experimental MS data along with corresponding theoretical examining of CLP dimers. As far as 3-[2-(X-substituted-phenyl)-vinyl]-5,5-dimethyl-cyclohex-2-enone and CLP dyes have already found an industrial scale application as non-linear optical materials (NLO) for THz wave generation and detection as well as pharmaceutics for treatment of and preventing of neurodegenerative diseases, this study has a strong transdisciplinary impact to many research fields as well as to still not well understood, but crucial to fields of organic synthesis and catalysis, molecular level fundamentals of chemical reactivity in gas– and condense phases. Following the latter lines of contributions of the work, we might hopefully expect that the prospective highlighted in this study should inspired further research effort devoted to correlative quantitative thermodynamic and kinetic CID mass spectrometric and quantum chemical analyses, which allow to improve the reaction effectiveness depending on the complexity of the wanted CLP scaffolds. [ABSTRACT FROM AUTHOR]

The problematic that we consider in this paper treats the quantitative correlation model equations between experimental kinetic and thermodynamic parameters of coupled electrospray ionization (ESI) mass spectrometry (MS) or atmospheric pressure chemical ionization (APCI) mass spectrometry with collision induced dissociation mass spectrometry, accounting for the fact that the physical phenomena and mechanisms of ESI– and APCI–ion formation are completely different. There are described forty two fragment reactions of three analytes under independent ESI– and APCI–measurements. The developed new quantitative models allow us to study correlatively the reaction kinetics and thermodynamics using the methods of mass spectrometry, which complementary application with the methods of the quantum chemistry provide 3D structural information of the analytes. Both static and dynamic quantum chemical computations are carried out. The object of analyses are [2,3-dimethyl-4-(4-methyl-benzoyl)-2,3-di-p-tolyl-cyclobutyl]-p-tolyl-methanone (1) and the polycyclic aromatic hydrocarbons derivatives of dibenzoperylen (2) and tetrabenzo [ a,c,fg,op ]naphthacene (3) , respectively. As far as (1) is known to be a product of [2π+2π] cycloaddition reactions of chalcone (1,3-di-p-tolyl-propenone), however producing cyclic derivatives with different stereo selectivity, so that the study provide crucial data about the capability of mass spectrometry to provide determine the stereo selectivity of the analytes. This work also first provides quantitative treatment of the relations ‘ 3D molecular/electronic structures ’–‘ quantum chemical diffusion coefficient ’–‘ mass spectrometric diffusion coefficient ’, thus extending the capability of the mass spectrometry for determination of the exact 3D structure of the analytes using independent measurements and computations of the diffusion coefficients. The determination of the experimental diffusion parameters is carried out within the ‘ current monitoring method ’ evaluating the translation diffusion of charged analytes, while the theoretical modelling of MS ions and computations of theoretical diffusion coefficients are based on the Arrhenius type behavior of the charged species under ESI– and APCI–conditions. Although the study provide certain sound considerations for the quantitative relations between the reaction kinetic–thermodynamics and 3D structure of the analytes together with correlations between 3D molecular/electronic structures–quantum chemical diffusion coefficient–mass spectrometric diffusion coefficient, which contribute significantly to the structural analytical chemistry, the results have importance to other areas such as organic synthesis and catalysis as well. [ABSTRACT FROM AUTHOR]

This paper aims at filling the gap of governing forces leading to bonded charged Ag I –ion to unsaturated hydrocarbons comparing with its coordination ability in metal–organics, in particular, carboxylic acids, describing a new, first reported in the literature, very rare case of cation-π–complex of Ag I –ion with 1H-indole-5-carboxylic acid ([Ag I (η 2 -C 9 H 7 NO 2 ) 3 (NO 3 )]) ( 1 ). Correlation between bonding fusion of Ag I –ion, examining four interaction modes (π–complex to ethene fragment (I); π–complex to phenyl fragment (II); M–N bond formation (III); and M–O bond formation (IV)) and the energetics of the interacting complex system is carried out. The energetics of M–L bonds is studied using topologic charge density analysis at bond critical points ( bcps ) using experimental crystallographic electron densities. The bond energies are correlated to theoretical quantum chemical bond dissociation energies. The methods of single crystal X-ray diffraction and computational quantum chemistry such as ‘atoms in molecules’ (AIM); ‘natural bond orbital analyses’ (NBO) and electrostatic potentials are used. The research takes dual steps associated with: ( i ) increasing the understanding about the molecular forces causing for preferred cation-π–interactions of Ag I –ions even in presence of classical ligand like a carboxylic acid; and ( ii ) provides a thermodynamic explanation about bonding affinity of Ag I –ion towards polydentate molecular systems. Clearly then, the paper has fundamental importance for the organometallic and inorganic chemistry. Owing the great significance of the cation-π–interactions in the folding of proteins; neurological signaling in living cells, and many more phenomena in the biological systems, our paper also has an underlined interdisciplinary impact. [ABSTRACT FROM AUTHOR]

The present paper deals with quantitative kinetics and thermodynamics of collision induced dissociation (CID) reactions of piperazines under different experimental conditions together with a systematic description of effect of counter-ions on common MS fragment reactions of piperazines; and intra-molecular effect of quaternary cyclization of substituted piperazines yielding to quaternary salts. There are discussed quantitative model equations of rate constants as well as free Gibbs energies of series of m –independent CID fragment processes in GP, which have been evidenced experimentally. Both kinetic and thermodynamic parameters are also predicted by computational density functional theory (DFT) and ab initio both static and dynamic methods. The paper examines validity of Maxwell–Boltzmann distribution to non–Boltzmann CID processes in quantitatively as well. The experiments conducted within the latter framework yield to an excellent correspondence with theoretical quantum chemical modeling. The important property of presented model equations of reaction kinetics is the applicability in predicting unknown and assigning of known mass spectrometric (MS) patterns. The nature of “GP” continuum of CID–MS coupled scheme of measurements with electrospray ionization (ESI) source is discussed, performing parallel computations in gas–phase (GP) and polar continuum at different temperatures and ionic strengths. The effect of pressure is presented. The study contributes significantly to methodological and phenomenological developments of CID–MS and its analytical implementations for quantitative and structural analyses. It also demonstrates great prospective of a complementary application of experimental CID–MS and computational quantum chemistry studying chemical reactivity, among others. To a considerable extend this work underlies the place of computational quantum chemistry to the field of experimental analytical chemistry in particular highlighting the structural analysis. [ABSTRACT FROM AUTHOR]

The fundamental goal of this work in applying high resolution crystallographic X-ray measurements of single crystals as well as ab initio and density functional computational methods is to provide a correlation between the experimental electron densities and valence states of atoms with the theoretically predicted ones by methodological approaches of quantum chemistry. In order to test the reliability of the data, we chose to examine statistically the crystallographic datasets of nine metal-organics with Zn 2+ , Ag + and Cu 2+ ions. There are several premises to the argument for this choice: (i) the different nature of M–L interactions, (ii) various geometries of the chromophores and (iii) distinguishable chemical behavior of the dentate atoms in the inner coordination sphere (L = O, N, Cl). New insights about the nature of the M–L interactions are gained for the following bonding fashions: (a) bonded Ag I –X(Y) fragments (X, Y = O and/or N) in tetrahedral (T d ) and square planar AgX 2 Y 2 symmetries, (b) bonded Zn II –X(Y) cores (X, Y = O and/or N; or Cl) in T d Zn II X 2 Y 2 or Zn II X 2 chromophores, (c) Zn II –OH 2 interactions in the discrete octahedral {[Zn II (H 2 O)] 2+ } charged complex and (d) bonded Cu II –X(Y) systems (X, Y = O and/or N) in square planar AgX 2 Y 2 chromophores as comparative examples of complexes with the d 9 configurations of the metal ion. The methods of ‘atoms in molecules’ (AIM), ‘natural bond orbital analyses’ (NBO) and electrostatic potentials were employed. The analyses include employment of the bond valence (BV) methodology and non-covalent interaction (NCI) analysis. Quantum chemical prediction of multi-pole moments, orbital population and charge transfer effects (CT), bond covalence, iconicity, different bond order methodologies (BOs); electron density distribution and Laplacian of the total electron density (ED) were carried out. The energetics of the M–L bonds were treated using topological charge density analysis at the bond critical points (bcps). The foci of the presented theoretical and experimental designs allow us to answer our main research questions: Is the nature of the M–L bond with ions having an identical electronic configuration, d 10 , interacting with one and the same type dentate-ligands the same? and is there a quantitative statistically significant correlation between the theoretically predicted dissociation energetic of the complexes and their experimental topological crystallographic M–L bond energies? The presented comprehensive analyses of this problematic provide crucial new information of both fundamental and applied importance to the field of structural chemistry and the properties of metal–organic molecules. Such results seek to shed light on whether the theoretical models extracting information about the molecular electronic properties of the species in the crystalline state on the base on crystallographic measurements and the corresponding topological, electron density and orbital based methods of computational quantum chemistry are able to enable a common conceptualization about the relationship between ‘crystal structure’–‘molecular structure’–‘electronic structure’–‘M–L bonding type’. The low temperature redetermination of the crystal structure and new description of the structure of the Ag I complex of 2-hydroxy-5-sulfo-benzoic acid ( 1 ) is reported as well. [ABSTRACT FROM AUTHOR]

An essential part of molecular scaffolds of organosilver(I) catalysing reactions of C–H bond activation and C–X (X = C or O) bond formation of polysubstituted benzoic acids in polar medium represent biphenyls, 6H-benzo-[ c ]-chromene[6]-one, chromeno[5,4,3-cde]chromene-5,10-dione, and 4,10-dioxa-pyrene-5,9-diones. A second strand of catalytic activity is in promoting synthesis of substituted quanterphenyls. This paper is a an extend of the systematic examining of catalytic activity of Ag I –containing intermediates of substituted benzoic acids, gaining insights by synthesis of oligomers, studying benzene-1,2,4-tricarboxylic acid (124BA) and benzene-1,3,5-tricarboxylic acid (135BA). Arguably, the optimization of the latter reactions need further effort in order to achieve the standard characteristics allowing their effective implementation as routine routs in the field of organic synthesis. The purpose of this part of the research is mass spectrometric (MS) quantitative kinetic and thermodynamic treatment of collision induced dissociation (CID) reactions comparing experimental reaction kinetics and energetics with quantum chemical modelling of MS fragment processes. Analyses - experimental and theoretical - include deuterium labelled oligomers as the most useful technique studying MS reaction mechanisms. More specifically we treat eight substituted quaterphenyls both experimentally and theoretically along with a set of one hundred twenty 3D molecular models of MS fragment species. Importantly, the detail understanding of the molecular mechanistic aspects of the reactions causing for obtaining of high functionalized oligomers allows an efficient optimization of synthetic roads studying polyfunctional derivatives. This knowledge is the kay to understanding why the obtaining of the oligomer derivatives depends on the positional isomerism of the starting reagents as clearly evidenced in this study. In this context the study is relevant to the fields of organometallic synthesis and catalysis as well as the polymers' chemistry. [ABSTRACT FROM AUTHOR]

The research draws on experimental and theoretical data about energetics and kinetics of mass spectrometric (MS) reactions of glycyl homopenta- ( G5) and glycyl homohexapeptides ( G6). It shows the great applicability of the methods of quantum chemistry to predict MS profile of peptides using energetics of collision induced dissociation (CID) fragment species. Mass spectrometry is among irreplaceable methods, providing unambiguous qualitative, quantitative and structural information about analytes, applicable to many scientific areas like environmental chemistry; food chemistry; medicinal chemistry; and more. Our study could be considered of substantial interdisciplinary significance, where MS proteomics is widely used. The experimental design involves electrospray ionization (ESI) and CID MS/MS. Theoretical design is based on ab initio and density functional theory (DFT) methods. Experimental MS and theoretical free Gibbs energies as well as rate constants of fragment reactions are compared. The thermodynamic encompasses gas-phase and polar continuum analysis, including polar protic and aprotic solvents within temperature T = 10-500 K; dielectric constant ε = 0-78, pH, and ionic strengths μ = 0.001-1.0 mol dm−1. There are computed and discussed 39 protonated forms of peptides at amide N- and -(NHC)= O centers; corresponding fragment ions studying their thermodynamic stability depending on experimental conditions. A correlation analysis between molecular conformations of parent ions and fragment species; their proton accepting ability and internal energy distribution is carried out. Data about ionization potentials (IPs) and electron affinities (EAs) are discussed, as well. [ABSTRACT FROM AUTHOR]

The paper provides a comprehensive study of lanthanide and actinide complexes to a matter of key area in the field of the chemistry, i.e. environmental analytical chemistry. The content has involved: ( i ) solution and sorption behaviour of lanthanides (Ln n+ , Ln = Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Py, Ho, Er, Tm, Yb and Lu) onto Y(O)O(H) minerals (Y = Fe, Mn or Si); ( ii ) ligand exchange processes with participation of inorganic OH − , F − , Cl − , Br − , SO 4 2− , SO 3 2− , IO 3 − , NO 3 2− , CO 3 2− and/or HCO 3 − ligands as well as mixed ligand complexes, including solvent molecules such as {[LnOR] 2+ }, {[Ln(OR) 2 ] + } (R = CH 3 OH, CH 3 CH 2 CH 2 OH) and {[Ln(CH 3 CN) x (H 2 O) z ] 3+ } ( x = 6–8, z = 0–4); ( iii ) the actinide speciation has involved different oxidation states (+4)–(+6) and ions {[UOH] 3+ }, {[UX] 3+ } (X = F or Cl), {[UF x ] y+/- } ( x = 2–6, y = 0–2), {[U(CO 3 ) x ] y- } (x = 4 or 5, y = 4 or 6), {[U(SO 4 )] 2+ ], {[U(NO 3 )] 3+ }, {[U(NO 3 ) 2 ] 2+ }, [[UO 2 (CO 3 ) 3 ] 5- }, {[(UO 2 ) x (OH) z ] y+/- } ( x = 1–4, y = 1 or 2, z = 1–7), {[UO 2 F x ] y+/- } ( x = 1–4, y = 1 or 2), {[UO 2 (CO 3 ) x ] y- } ( x = 2, or 3, y = 2, or 4), {[(UO 2 ) 2 (CO 3 )(OH) 3 ] - }, {[(UO 2 ) 3 O(OH) 2 (HCO 3 )] + }, {[(UO 2 ) 11 (CO 3 ) 6 (OH) 12 ] 2- }, {[UO 2 (SO 4 ) x ] y- }, ( x = 2 or 3, y = 2 or 4), {[UO 2 SiO(OH) 3 ] + }, {[AnC x ] y+/- } (x,y = 1 and 2), {[CAnH] +/− }, {[C x An y ] 0 } (x,y = 2 and 3), {[AnH x ] y+ } (x = 1–3, y = 0–5), {[AnX n ] m+/- } (n = 1–6, m = 1–4, X = F − , Br − , I − ), {[AnO x F z ] y+/- } (x, z = 1 or 2, y = 0, 1 and 2), {[AnN x ] y+ } (x = 1 and 2), {[An x O z (OH) n ] y+/- } (x = 1–3, z = 1–4, y = 0, 1 or 2, n = 0 or 1) and An n+ (n = 0–6) at An = Th, Pa, U, Np, Pu, Am, Cm, Bk, Cf, Es, Fm, Md, No and Lr, respectively. Correlation analysis between thermodynamic parameters, accounting for different surface interactions of adsorbed species and experimental mass spectrometric data, including liquid, semi–liquid and solid–state measurements in a large set of experimental conditions such as pH = 2–13, low and intermediate ionic strength, solvent type, ε = 0–78.0, variety of solvent proton accepting and donating numbers and T = 25–400 °C has carried out. [ABSTRACT FROM AUTHOR]

Recent strategies in molecular drugs-design shift efforts to nanomedicine . Large supra-molecular inclusion systems are implemented as therapeutics. The sophistication of design is based on major advances of cyclodextrins (CDs) as host molecules. They are friendly towards biological environment. CDs have good (bio)compatibility as well. CDs can form host–guest macromolecular systems incorporating small molecules with suitable shapes due to non–covalent interactions. Innovative strategies yield to polymeric nano-particles; micelles; linear polymers and/or CDs-functionalized dendrimeric nanostructures; nanofibers as well as hydrogels. Attractive are phosphorous containing ( bio )matrerials, having high selectivity toward biological active molecules. The non–covalent interactions in aquatic CD-systems contribute to stability of host–guest systems under physiological conditions, determining conformational preferences of host-CD macromolecule and guest small molecular template. In this paper we have reported complementation application of mass spectrometric (MS) and quantum chemical analysis of phosphorous chemically substituted γ-cyclodextrin hydrates γ-CDPO/nH 2 O (n ∊ [0–14]), studying neutral and polynegatively charged molecules as an effort to describe realistic a representative scale of physiological conditions. The binding affinity and molecular conformations are discussed. The 250 neutral and charged systems (γ-CDPOH m /nH 2 O, n ∊ [10][0,14], m ∊ [0,15], γ-CDPOH -8 /nH 2 O.8Na + , and γ-CDPOH -16 /nH 2 O.16Na + ) in four main domains of non–covalent hydrogen bonding interactions are studied. [ABSTRACT FROM AUTHOR]

• Quantitative matrix-assisted laser desorption/ionization mass spectrometry. • Solid-state 3D structural analysis of analytes in mixture via MALDI-MS method. • Strustural analysis of tautomers of guanine and guanosine in solid-state mixtures. • Stochastic dynamics mass spectrometry for structural analysis in condensed phases. • Complementary quantum chemistry and mass spectrometry for 3D analysis of tautomers. The paper tackles issue of solid-state 3D structural analysis by means of matrix assisted laser desorption/ionization mass spectrometry with a view of our innovative stochastic dynamic new simplistic formula D" SD = 2.6388.10−17.(–_I_2). It represents a universal law, which is obeyed by temporal behavior of experimental variable intensity of any analyte peak of ion, measured in solution under soft-ionization electrospray ionization, collision induced dissociation and atmospheric pressure chemical ionization conditions, respectively. The equation connects between so-called stochastic dynamic diffusion parameter , D" SD , and variable intensity , I, determined per any span of scan time of a measurement. So far, it has been proven empirically, that D" SD parameters of MS ions reflect exactly analyte concentration in solution — a claim independently verified via chromatography — and provide exact information about 3D molecular and electronic structure of molecular species in liquid phase. Herein, we urge that this simplistic formula is a fundamental law also valid to MALDI-MS phenomena; thus, providing exact quantitative and 3D molecular structural information about analytes in solid-state; or, mass spectrometric phenomena in condensed phases are governed by one and the same stochastic dynamic law, which is applicable both to quantitative and 3D analyses of analytes. The latter statement underlines a crucial advantage of the functional relation and emphasizes on incapability of other known fundamental MS theories and equation to deal with simultaneous exact quantitative and 3D structural analyses in the two condensed phases. A body of new empirical evidence is directed to favor the view of application of the model equation to MALDI-MS processes, examining guanosine (1) in mixture of N(2),N(2)-dimethyl guanosine, quantitatively and 3D structurally, with respect to different experimental conditions without, and involving different sample matrix components. The ultra-high accuracy mass spectrometric outcomes are treated by chemomerics. The same is true for utilizing high accuracy quantum chemical static and molecular dynamics in order to correlate experimental mass spectrometric with theoretical quantum chemical data on 3D molecular and electronic structures of nucleosides, their fragment species and energetics in gas and condensed phases. There are detailed subtle electronic effects on various tautomers, ionization processes, radical-ion formation MS reactions, chemical rearrangement, charge and (doubly) proton transfer effects; if any. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Quantitative mass spectrometry of enantiomers of steroids in mixture in solution. • Stochastic dynamics atmospheric pressure chemical ionization mass spectrometry. • Quantum chemical and mass spectrometric stereoselective 3D analysis of mixtures. • Mass sectrometric 3D molecular structural analysis of steroids in mixture. There is explored, herein, functional relation: Experimental mass spectrometric phenomenon, obeying a certain scientific law ⇔ 3D molecular conformations and electronic structures of analytes obtained for quantum chemical theories. The paper answers to questions: (a) What evidence claims these actual relations among measurable and theoretical parameters, experimental factors and molecular properties; (b) how the provided evidence is collected and used; and (c) how empirical proof relates to assign and explain mass spectrometric phenomena of steroids afforded by our innovative stochastic dynamic mass spectrometric formula, D″ SD = 2.6388.10−17.(–_I_2), quantum chemical 3D conformations, electronic structures and energetics of molecules, respectively. The paper address issue concerning empirical evidence at very high-to-exact level of assignment of 3D molecular conformations of steroids to experimental mass spectrometric fragment ions, accounting precisely for (i) effect of protonation; (ii) intramolecular rearrangement for A–D rings of steroidal skeleton and proton transfer effect, if any; in addition to (iii) examination of enantiomers of steroids in mixture with different stereochemistry, (R) and (S), of a set of six atoms of the molecular backbone of hydrocortisone (1), deoxycorticosterone (2), progesterone (3) and methyltestosterone (4), respectively. Results from testosterone (5) are discussed, as well. There are used ultra-high resolution atmospheric pressure chemical ionization mass spectrometric data on analytes (1)–(4) at ng.(mL)-1 concentration levels in mixtures in solution obtained for positive operation mode. High accuracy static and molecular dynamic quantum chemical computations and chemometrics are also utilized. Experimental 3D structural parameters of steroids obtained for stochastic dynamic diffusion theory are correlated with available crystallographic data. [ABSTRACT FROM AUTHOR]

The study encompassed experimental mass spectrometric and theoretical quantum chemical studies on adsorption of uranium species in different oxidation states of the metal ion, and oxides of U x O y n+ type, where x = 1 or 3, y = 2 or 8, and n = 0, 1 or 2 onto nanosize-particles of saltrock oxides MO (M = MgII, CaII, NiII, CoII, SrII or BaII), M2O y (M = AuIII or AgI, y = 3 or 1) silicates 3Al2O3.2SiO2, natural kaolinite (Al2O2·2SiO2·2H2O), illite (K0.78Ca0.02Na0.02(Mg0.34Al1.69FeIII 0.02)[Si3.35Al0.65]O10(OH)2·nH2O), CaSiO3, 3MgO·4SiO2,H2O, and M1M2(SiO4)X2 (M1 = M2 = Al or M1 = K, M2 = Al, X = F or Cl), respectively. The UV-MALDI-Orbitrap mass spectrometry was utilized in solid-state and semi-liquid colloidal state, involving the laser ablation at λ ex = 337.2 nm. The theoretical modeling and experimental design was based on chemical-, physico-chemical, physical and biological processes involving uranium species under environmental conditions. Therefore, the results reported are crucial for quality control and monitoring programs for assessment of radionuclide migration. They impact significantly the methodology for evaluation of human health risk from radioactive contamination. The study has importance for understanding the coordination and red-ox chemistry of uranium compounds as well. Due to the double nature of uranium between rare element and superconductivity like materials as well as variety of oxidation states ∈ (+1)–(+6), the there remain challenging areas for theoretical and experimental research, which are of significant importance for management of nuclear fuel cycles and waste storage. [ABSTRACT FROM AUTHOR]

Abstract: Despite that among non-camptothecin natural products promising anticancer therapeutics are evodiamine derivatives, involved into mechanism of physiological function of topoisomerase-I. But, more recent findings have been shown that substituted quinazole alkaloids act as transient receptor potential vanilloid 1 agonists. The TRP(V1) is a calcium ion channel, activated by pH, heat and inflammatory activators. I is implicated in pain sensing. TRPV1 agonist is capsaicine (1). Both 1 and evodiamine (2), therefore, produce same physiological response, but are structurally unrelated from chemical viewpoint. Furthermore precise mechanistic aspects of drugs receptor interactions are still not fully understood. This study is the first one, which provides assessment of molecular factors contributing significantly to selectivity of 2 and rutaecarpine (3) as well as their twenty-two new functionalized derivatives towards (TRP)V1. The suggested new functionalization type of molecular skeleton, which is completely different one in respect the known derivatives, which is implicated in treatment of variety of cancer cell lines interacting preferably with topoisomerase-I. It resulted to increasing of the binding affinity and selectivity of the functionalized derivatives specifically to (TRP)V1∈1.36–1.72 and ∈2.50–3.16 higher than 1–3. [Copyright &y& Elsevier]

Highlights: [•] Mass spectrometry (ESI, APCI and MALDI), crystallography and quantum chemistry of cyclodextrins. [•] Macroscopic complex CDs/n stability (n ∈0–12): self-assembly of non-covalent bonding interactions. [•] Non-covalent interactions in CDs crystals and physical gas-phase phenomena. [ABSTRACT FROM AUTHOR]

The paper highlighted the molecular docking drug design and analysis of eighteen 1-18 substituted benzo[ i]phenanthridines as promising non-camptothecin topoisomerase-I-targeting agents for anticancer therapeutics. Although antitumor camptothecin-based drugs such as topotecan and irinotecan are successfully implemented into clinical practice, prevent their lower solubility CPTs the widespread clinical use of naturally occurring products of the same class. Synthetic chemicals that have benzo[ i]phenanthridine core to be an active as antitumor Top-I-therapeutics in vivo. Therefore, the search for new effective drugs with the same molecular framework is a successful strategy of the state of exception that is of great interest to the border, the anticancer drug research. Therefore, the Top-I/drugs docking analysis is compared to Top-I/topotecan data. All substances 1- 18 had higher binding affinity and thermodynamic stability (Δ G ∈ (−16.59) − (−64.08) kcal mol). Top-I/topotecan complex showed positive Δ G = 30.21 kcal mol value. In the series of successfully isolated fifteen derivatives, most promising for in vivo assay is 17 (Δ G = −57.95 kcal mol), issuing a dipole moment (μ) of 11.1007 Debye. The value is different of Δ μ = |2.6859| Debye, than the topotecan ( μ = 8.4148 Debye) one. Thus, the higher solubility of 17 is under physiological conditions. The 16 and 18 have higher dipole moments Δ μ of |2.2528| and |2.6023| Debye than topotecan. The Δ G = −16.59 and −20.51, kcal mol values are lower than 17. However, since the quantities remain negative, the substances would also be promising therapeutic candidates. The 6 revealed the lowest Δ G (−64.08 kcal mol) but μ of 3.8204 Debye. The simple synthetic roads, which are produced the substances ∈ 47.3-73.6 % yields are additional benefits for the potential pharmaceutical industrial manufacturing. The mechanistic aspects of the photo- and thermal cyclization processes greatly affect the products are evaluated by theoretical quantum chemical methods for first time. The mass spectrometric data obtained from different ionization stresses because the method provided highly accurate structural information on analyte fg g concentrations and direct imaging bioassay. For this reason, the molecular fragmentation of the isolated derivatives is a comprehensively debate. [ABSTRACT FROM AUTHOR]

Highlights: [•] ESI-MS/MS and quantum chemical study of SnIVCl4 catalyzing coupling reaction of benzaldehydes. [•] Redox SnIV/SnII catalyzing process explaining the complex MS fragmentation scheme of the products. [•] Binuclear SnII-organometallic precursor with thermodynamics ΔG =−52996.80kcal/mol. [•] Mechanistic aspects of the coupling process, improving significantly the reaction effectiveness. [ABSTRACT FROM AUTHOR]

Abstract: The paper highlighted the capability of the UV-MALDI mass spectrometry, employing the Orbitrap analyzer for solid-state assay of halogenated phenyl–pesticides in mixtures. It is successfully applied for the analysis of eighteen (1)–(18) molecular objects of Fenarimol (1) type and their condensation products (P5)–(P12). The full method and technique validation is performed using the dried droplet sample preparation technique on embedded analytes in novel organic matrix crystals of N-(1H-benzoimidazol-2-yl)-guanidine (M4) and (E)-phenyl-2-pyridyl ketone oxime (M5), resulting to successful ionization of the analytes. Since the sampling technique in the UV-MALDI method is a key step in the overall process impacting significantly the metrology through the reproducibility of the data, the crystallization of M4, M5 and matrix–analyte in situ morphology of the samples is controlled by single crystal X-ray diffraction. The achieved promising metrology of LODs, of 0.46ngkg−1 (1.53ngkg−1 LOQs), is several orders of magnitude lower than the reported ecotoxicological effect values of studied pesticides. It is confirmed by the partial validated protocol based on ESI-MS. Inasmuch that LC-MS/MS is a method of choice for foodstuffs monitoring of organic contaminations, due to its routine quantitative analytical procedures, it is often characterized with the difficulties of the chromatographic separation of the closely structured analytes at a large scale of experimental conditions, complex multi-step sampling pretreatments, which inevitably alert the variables through the systematic and random errors. In this respect, notwithstanding the complex quantitative UV-MALDI-Orbitrap-MS procedure, conceptually different from the LC-MS/MS one, its high resolving power, capability for achieving meaningful analytical qualitative, quantitative and structural information of low-molecular weight analytes, its instrumental and sampling operation flexibility, applicable for a large scale of foodstuff matrices, and operating at the analyte concentrations of up to fgg−1 make UV-MALDI-Orbitrap-MS a perspective method of choice for an extensive implementation in the foodstuffs monitoring practice for control of the most essential task related to the assessment of the human health risks from environmental and foodstuff contaminations. [Copyright &y& Elsevier]

Abstract: The paper studied factors of the gas phase (GP) ionic stabilization of molecular organic crystals of salts. The single crystal X-ray diffraction, electrospray ionization (ESI) and matrix-assisted laser desorption/ionization (MALDI) mass spectrometric (MS) methods are employed. The GP phenomena are explained by the comprehensive quantum-chemical theoretical models, providing significant information for the electronic structures and thermodynamics of the observed MS species. The n-chloro-alkyl aliphatic heterocyclic 5-sulfosalicylates i.e. 1-(2-chloroethyl) pyrrolidinium 5-sulfosalicylicilate (1), 1-(2-chloroethyl)-piperidinium 5-sulfosalicylicilate (2), and 1-(3-chloropropyl) piperidinium 5-sulfosalicylicilate (3) are examined. The ionic systems that contain N+H-heterocyclic fragments, a complex MS image variety of monocations, quaternary ammonium dications and hydrogen bonded molecular complexes revealed. Their stabilization is explained by proton transfer (PT), charge-transfer (CT) and Jahn–Teller (JT) effects. The 4-(2-chloroethyl) morpholinium hydrochloride crystals (4) yielded quaternary ammonium adduct which structure is crystallographically determined. In parallel the GP stabilized ions of 4 are analyzed. The complementary application of the single-crystal X-ray diffraction and MS methods provided unique structural evidences in condenses and in the GP able to understand the competitive intramolecular and environmental factors contributing to the thermodynamics stability of the ionic species. Therefore, the data reported are helped for more comprehensive knowledge of the basic mass spectrometric GP and phase transition phenomena with both its methodological development and used robust analytical technique application. [Copyright &y& Elsevier]

Abstract: The paper presented a comprehensive theoretical and experimental study on the molecular drugs-design, synthesis, isolation, physical spectroscopic and mass spectrometric elucidation of novel functionalization derivatives of Cytisine (Cyt), using nucleosidic residues. Since these alkaloids have established biochemical profile, related the binding affinity of the nicotinic acetylcholine receptors (nAChRs), particularly α7 sub-type, the presented correlation between the molecular structure and properties allowed to evaluated the highlights of the biochemical hypothesises related the Schizophrenia. The anticancer activity of α7 subtype agonists and the crucial role of the nucleoside-based medications in the cancer therapy provided opportunity for further study on the biochemical relationship between Schizophrenia and few kinds of cancers, which has been hypothesized recently. The physical electronic absorptions (EAs), circular dichroic (CD) and Raman spectroscopic (RS) properties as well as mass spectrometric (MS) data, obtained using electrospray ionization (ESI) and atmospheric-pressure chemical ionization (APCI) methods under the positive single (MS) and tandem (MS/MS) modes of operation are discussed. Taking into account reports on a fatal intoxication of Cyt, the presented data would be of interest in the field of forensic chemistry, through development of highly selective and sensitive analytical protocols. Quantum chemical method is used to predict the physical properties of the isolated alkaloids, their affinity to the receptor loop and gas-phase stabilized species, observed mass spectrometrically. [Copyright &y& Elsevier]

Abstract: The relationship between the molecular structure and physical properties of functionalized naturally occurred Ergot-alkaloids as potential dopamine D3 receptor agonists is presented. The molecular modeling of the ergoline-skeleton is based on the comprehensive theoretical study of the binding affinity of the isolated chemicals towards the active sites of the D3 sub-type receptor (D3R) loops. The studied proton accepting ability under physiological conditions allows classifying four types of monocationics, characterizing with the different binding modes to D3R involving selected amino acid residues to the active sites. These results marked the pharmaceutical potential and clinical usage of the reported compounds as antipsychotic drugs for Schizophrenia treatment, since they allowed evaluating the highlights of the different hypothesizes of the biochemical causes the illness. The applied complex approach for theoretical and experimental elucidation, including quantum chemistry method, electrospray ionization (ESI) and matrix assisted laser desorption/ionization (MALDI) mass spectrometric (MS) methods, nuclear magnetic resonance and vibrational IR and Raman spectroscopy on the isolated fifteen novel derivatives (1)–(15) and their different protonated forms (1a)–(15a) evidenced a strong dependence of molecular conformation, physical properties and binding affinity. Thus, the semi-synthetic functionalization of the naturally occurred products (NPs), provided significant possibilities to further molecular drugs-design and development of novel derivatives with wanted biological function, using the established profile of selected classes/families of NPs. The work described chiefly the non-linear (NL) approach for the interpretation of the mass chromatograms on the performed hybrid high performance liquid chromatography (HPLC) tandem MS/MS and MS/MS/MS experiments, discussing the merits and great diversity of instrumentation flexibility, thus achieving fundamental structural information, indispensable for the analysis of Ergot-alkaloid derivatives, which under the physiological conditions easily converted to d-lysergic acid (LSD). [Copyright &y& Elsevier]

Abstract: Electronic absorption (EAs), circular dichroic (CD), vibrational IR- and Raman-spectroscopy, nuclear magnetic resonance (NMR), electrospray ionization (ESI) and matrix assisted laser desorption/ionization (MALDI) mass spectrometry (MS) were utilized to investigate the coordination ability of bradykinin (1) with the metal ions ZnII and AgI. The experimental data were supported by the theoretical quantum chemical calculations of the electronic structures and physical properties of the isolated complexes. Since the main aim of the study is related to the design of new artificial catalysts and angiotensin converting enzyme (ACE) inhibitors, the model interactions with the active center of ACE are also designed, taking into account the coordination mode of the ZnII-ion, crystallographically determinate in the enzyme. The role of the macromolecular conformation, the enzyme cavity around the metal ion, the coordination ability of the His383.A, His353.A and Glu411.A amino acid residues, and the competitive salt-bridged processes typical for the Arg-containing ligands are discussed with a view to explain the preferred untypical C-terminus coordination mode. The data were discussed and compared with those of the angiotensin I and II (Ang-I, Ang-II). Comprehensively were described the gas-phase stabilized complex species and fragmentation modes of the complexes by the MS methods, including the imaging mass spectrometric (IMS) techniques, representing a background for the further molecular design on the base of small synthetic, semi-synthetic and naturally occurred peptides, as well as discovery of new ACE-inhibitors, since the in vivo mapping using IMS methods, provided unique opportunity for the single experiment study of the localization of molecules, including metal complexes, achievement of the important semi-quantitative, quantitative and structural information within the frame of cells, tissues, organs and whole systems. [Copyright &y& Elsevier]

Crystal structures, theoretical, and experimental physical properties of six coordination compounds of violuric and 5-sulfosalicylic acid (5SSA) with silver and potassium ions (1–6) are reported. The correlation between crystallographic data of the potassium violurate methanol solvate (2), potassium 5-sulfosalicylicilate salts (3 and 4), the redeterminated structure for the potassium violurate dihydrate (1), and the already reported complexes of silver(I) with 5SSA (5 and 6) as well as the optical properties in the condensed phase was performed using the electronic-absorption, diffuse reflectance and fluorescence spectroscopies. The vibration characteristics of the crystals were studied by solid-state Raman spectroscopy. Special attention is focused on elucidation of the specific excitation phenomena within the THz-region, allowing unambiguously defining of the metal–organic polymorphs. The physical behavior and related processes under soft electrospray ionization (ESI) and matrix-assisted laser desorption/ionization (MALDI) mass spectrometric conditions are elucidated by corresponding methods, including imaging mass spectrometry (MS). A discussion on the stabilization of complex species and adducts in the gas phase depending on the type of metal ion was performed, with a view to their further application as matrices in the MALDI-Orbitrap MS method. The thermal properties were elucidated using the thermogravimetric and differential scanning calorimetric methods. Quantum chemical DFT calculations of the optical properties and selected thermodynamic quantities in solid-state were performed, supporting and elucidating some of the observed phenomena. [ABSTRACT FROM PUBLISHER]

This article deals with the experimental and theoretical study of the coordination ability and processes of glycyl-penta and hexahomopeptides and corresponding cyclic derivatives with the AgI, ZnII, and CuII. Special attention is focused on the observed cyclic small peptide analogues as well as corresponding complexes. These phenomena are studied experimentally by electrospray ionization and matrix-assisted laser desorption ionization mass spectrometric methods. Considering the physical and chemical properties of gas-phase stabilized systems, precisely calculated thermodynamic parameters, physical properties, and structures by the quantum chemical DFT methods are performed. Conformational preferences of the obtained peptide species as well as the complexes are presented. The coordination ability is elucidated in condense phase by electronic absorption, infrared, and Raman spectroscopies, nuclear magnetic resonance, and thermal methods. The AgI/AgIII redox process observed during the interaction with the peptides is discussed. [ABSTRACT FROM PUBLISHER]

Abstract: The molecular architecture design and physical properties of seven camptothecin (CPT) alkaloids, structurally related to irinotecan (CPT-11), substituted with the cyclic bulk N-aliphatic substituents at A-ring as well as their different protonated forms were studied. The correlation between the molecular geometry and physical properties of the neutral lactone form and different possible cationic forms was elucidated, using the electronic absorptions (EAs), circular dichroic (CD) and Raman spectroscopy within the far-IR region as well as electrospray ionization and matrix-assisted laser desorption/ionization mass spectrometry and nuclear magnetic resonance methods. The electronic structures, and properties of the neutral CPTs, their mono- and diprotonated forms as well as molecular ion fragments, obtained by the mass spectrometric data are predicted theoretically using the DFT method. [Copyright &y& Elsevier]

Abstract: The conformational analysis, determination of absolute configurations (ACs) as well as elucidation of the electronic absorption and CD spectra of chiral molecules 2′,3′-O-isopropylideneadenosine (1), 5′-carboxy-2′,3′-O-isopropylidene-D-adenosine (2), 2-chloro-2′,3′-O-isopropylideneadenosine-5′-N- ethylcarboxamide (3) and 1-[6-(6-Amino-2-methyl-purin-9-yl)-2,2-dimethyl-tetrahydro-furo[3,4-d][1,3]dioxol-4-ylmethyl]-3-carbamoyl-pyridinium chloride (4), 9-(6-aminomethyl-2,2-dimethyl-tetrahydro-furo[3,4-d][1,3]dioxol-4-yl)-9H-purin-6-ylamine (5) and acetic acid 6-(6-amino-purin-9-yl)-2,2-dimethyl-tetrahydro-furo[3,4-d][1,3]dioxol-4-ylmethyl ester (6) are performer. The methods such as electronic absorption (EAs), diffuse reflectance (DSs) spectroscopy as well as electronic circular dichroism (ECD) are applied. The theoretical density functional theory (DFT) calculations are carried out to evaluate the optical phenomena of isolated molecules as well as dimeric associates. We are demonstrated the significance and the advances of the stereo chemical experimental and theoretical characterization of natural products and their functional synthetic derivatives, vitha a view to further elucidation of unknown extracts of same chemical class. Special attention is devoted to the role of intermolecular interactions in condense phases on the theoretical and experimental optical properties, studying the corresponding dimeric associates. These results are a key in the drug discovery, and structure-based design of functionalized nucleosides. The methods as single crystal X-ray diffraction and MALDI Orbitrap mass spectrometric imaging (MALDI Orbitrap MSI) are also applied. [Copyright &y& Elsevier]

Abstract: A discussion on the possible application of the organic 5-sulfosalicylates as organic materials with tunable optical and non-linear-optical (NLO) properties is performed on the basis of the experimental crystallographic and spectroscopic methods such as single crystal X-ray diffraction, electronic absorption, diffuse reflectance and fluorescence spectroscopy in condense phase, conventional and linear-polarized IR- and Raman spectroscopy in solid-state. The model systems 5-sulfosalicylic acid dihydrate (1), 4-aminobenzamidinium bis(5-sulfosalicylicilate) monohydrate (2) and 5-sulfosalicylicilate salt of glycinamide (3), comparing with the as well as theoretical quantum chemical calculations of the systems neutral 5-sulfosalicylic acid (I), its mono-(Ia) and dianion (Ib), respectively. [Copyright &y& Elsevier]

• Atypical octahedral complex zinc(II) bis ((1R,2R)−1,2-diaminocyclohexane) dinitrate. • Crystallographic electron density analysis. • Theoretical topology of the electron density and its correlation with the experiment. • Charge transfer phenomena and their effect on the geometry of the metal chromophore. The topic of the study is crystallographic experimental and theoretical electron density analyses of entitled complex zinc(II) bis ((1R,2R)-1,2-diaminocyclohexane) dinitrate (1) , showing an atypical of ZnII-ion octahedral geometry of the metal chromophore (ZnO 2 N 4.) The ligand 1,2-diaminocyclohexane (L) is characterized by a diversity of coordination modes with transition metal ions. Also, it has been broadly used to design of new metal-organic anticancer medications, for instance, looking at its PtII-complex (oxaliplatin) at clinical trials. Its coordination capability of ZnII-ion reveals mainly complexes with a distorted T d * geometry of the metal chromophore, including cases of complexes of simply N-substituted derivatives of the ligand. These empirical arguments arise a very important question: What are the governing molecular and environmental factors causing for the observed geometry of the chromophore in complex (1) ? In order to address this question, we shed light on correlation among molecular structure ⇔ electronic structure ⇔ nature of metal-to-ligand bond (M L) ⇔ energetics of M L bond ⇔ thermodynamics of ZnII–metal organics of 1,2-diaminocyclohexane. A comparative analysis between octahedral complex (1) and classical tetrahedral coordination compounds of ZnII–ion with 1,2-diaminocyclohexane and ethylenediamine (en) is carried out. High resolution crystallographic data are used. Static and molecular dynamics ab initio methods and those based on density functional theory are employed. The methods of atoms in molecules (AIM) and natural bond orbital (NBO) are utilized, as well. [Display omitted] [ABSTRACT FROM AUTHOR]

Twelve new Au(III), Pt(II) and Pd(II) complexes with glycyl-containing homopeptides glycyl-glycine (G2), glycyl-glycyl-glycine (G3), glycyl-glycyl-gycyl-glycine (G4), glycyl-glycyl-glycyl-glycyl-glycine (G5) and glycyl-glycyl-glycyl-glycyl-glycyl-glycine (G6) have been synthesized, isolated and characterized spectroscopically and structurally by means of solid-state linear-dichroic infrared (IR-LD) spectroscopy of oriented colloids in nematic liquid crystal host, 1H- and 13C-NMR, TGA and DSC, UV-Vis spectroscopy, EPR, ESI- and FAB mass spectrometry and HPLC tandem mass spectrometry (HPLC-MS/MS). Quantum chemical calculations are carried out with a view to obtain the structures and spectroscopic properties of the ligand and newly synthesized metal complexes. [ABSTRACT FROM AUTHOR]

The potential energy surface of curcumin [1,7‐bis(4‐hydroxy‐3‐methoxyphenyl)‐1,6‐heptadiene‐3,5‐dione] was explored with the DFT correlation functional B3LYP method using 6‐311G* basis. The single‐point calculations were performed at levels up to B3LYP/6‐311++G**//B3LYP/6‐311G*. All isomers were located and relative energies determined. According to the calculation the planar enol form is more stable than the nonplanar diketo form. The results of the optimized molecular structure are presented and compared with the experimental X‐ray diffraction. In addition, harmonic vibrational frequencies of the molecule were evaluated theoretically using B3LYP density functional methods. The computed vibrational frequencies were used to determine the types of molecular motions associated with each of the experimental bands observed. Our vibrational data show that in both the solid state and in all studied solutions curcumin exists in the enol form. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005 [ABSTRACT FROM AUTHOR]

The paper draws on our stochastic dynamic approach providing exact analytical procedure to quantify experimental mass spectrometric outcome intensity " I " via the so–called mass spectrometric diffusion parameter "D SD." A small–scale research, so far, has taken a closer look at the functional relation between D SD parameters and quantum chemical diffusion parameters "D QC " according to the Arrhenius's approximation, underlying an excellent linear correlation. Straightforward facts about the latter statement have shown excellent coefficients of linear correlations r = 0.9557 5 –0.9956. This work continues the problematization of the issues relevant to this concept that affect the field of structural analytical chemistry, in particular, looking at experimental 3D molecular and electronic structures of analytes, and the catalysis. As a corollary, the application of the model equations, so far, only covers few examples of analysis of complexes of CuII– and AgI–ions with small organic molecules and oligopeptides. Herein, we move on to a thorny problematic dealing with 3D structural analysis of isomers and tautomers of benzaldehydes, benzoic acids and their products of homocoupling reactions of C–C bond formation leading to 6H-benzo-[ c ]-chromene[6]-one, chromeno[5,4,3-cde]chromene-5,10-dione, and 4,10-dioxa-pyrene-5,9-dione derivatives, amongst others. We account for the excellent capability of our method, studying quantitatively subtle electronic effects. The analysis encompasses one hundred thirty seven molecular species. Against the backdrop that mass spectrometry appears inapplicable to 3D structural analysis, we demonstrate persuasively its great applicability to exact multidimensional structural study of molecular objects by means of a highly selective quantification of D SD parameters and high accuracy ab initio and DFT D QC parameters of analytes and their fragment ions. A deeper experimental proof of dependence on D SD parameter with respect to experimental factor "temperature" is presented. In spite of, formulas are embedded within the general framework of stochastic dynamic the two equations provide different analytical information. Therefore, by means of our innovative functional relations we not only exactly determine 3D molecular structures by mass spectrometry, but also can quantitatively account for the effect of experimental factor temperature on them. Image 1 • Mass spectrometric stochastic dynamics. • Benzoic acids, benzaldehydes and their conjugated products of interactions. • Multidimensional structural analysis. • Tautomerizm and isomerism – quantification. [ABSTRACT FROM AUTHOR]

• Carbohydrates. • Quantification. • HPLC-MS. • Stochastic dynamics. • Diffusion. The paper addressed shortcoming with highly precise and selective 3D structural analysis of native cyclodextrins in mixture using ions observable at low m / z –region by ESI– and APCI–mass spectrometry. Because of, the quantitative and structural analyses of CDs, in general, are vexed by a set of complications. The study outlines our own stochastic dynamic approaches to the latter issues based on new model relations, quantifing the measurable MS outcome intensity. They introduce the so–called stochastic dynamic mass spectrometric diffusion "D SD " parameter, exhibiting high accuracy, precision, sensitivity and selectivity, respectively. It is linearly connected with the so–called quantum chemical diffusion parameter "D QC " according to Arrhenius's theory. The most important upshot is that statistical parameters r = 0.99 639 –0.99 981 has been obtained correlating between D SD and D QC parameters. Therefore, we determine high accurately 3D molecular and electronic structures of analytes by mass spectrometry. Fragment peaks at m / z 313, 279, 272, 252, 231, 214, 198, 171, 158 and 141 are examined. Mixtures of CDs and monomeric and acyclic oligomer carbohydrates glucose (1), sucrose (2), raffinose (3), melezitose (4) and cellotriose (5) are also studied. Our method is able to account precisely for the effect of the temperature under ESI– and APCI–MS conditions, as well. Correlative analysess between D SD parameters of ESI– and APCI–MS measurements under different temperatures is also shown. Chemometric tests are used. Another important results and conclusions, among others, to draw from this research are: (i) excellent linear correlation between D SD and D QC parameters of r = 0.99 636 is found looking at common ions at m / z 141, 158 and 171, belonging to 2-formyl-3,4-dihydroxy-pyranylium, 4,5,6-trihydroxy-6H-pyran-2-carbaldehyde and 3,4,5-trihydroxy-6-oxo-6H-pyran-2-ylmethylidyne-oxonium ions. Thus, we distinguish precisely between the last structure and 3-formyl-4,5-dihydroxy-2,7-dioxa-8-oxonia-bicyclo[4.2.0]octa-1(8),3,5-triene cation. In the case of ion at m / z 141 subtle electronic effects are distinguished between the mentioned structure and the charged 3,4-dihydroxy-6H-pyran-2-carbaldehyde one. The method determines precisely very similar structurally poly–OH–substituted derivatives. Because of, (ii) absolute reproducibility (r = 1) of D SD parameters of ESI–MS spectra is obtained studying the shown in point (i) MS peaks of β-CD between jth and jth numbers of experiments. The statistical equation is Di SD = (0.51 ± 3.1.10−5) × Dj SD ; (iii) the APCI– and ESI–MS provide identical results studying common MS ions of CDs and the correlation between DAPCI SD and DESI SD parameters excludes from error, due to, experiment; and (iv) The correlation between theory and experiment accounting for the factor temperature within our model equations shows r = 0.98 28 looking at the MS peaks at m / z 313 280, 279, 274 and 252, respectively. The effect of the temperature under both ESI– and APCI–MS conditions on the 3D molecular and electronic structures of CDs is precisely studied, respectively. [ABSTRACT FROM AUTHOR]

The paper deals with determination of mass spectrometric diffusion parameters (D SD) based on our stochastic dynamic approach to treat quantitatively the experimental variable " intensity " of observable peaks of analyte ions with respect to different spans of the scan time. There has been derived, more recently, the following model equation Dtot SD = Sum/i n (Di SD) = Sum/i n {1.3194.10−17 · Ai · (( − 2) / <(I i − )2>)}. Our next interpretation of the mutual relations among mass spectrometric D SD parameter according to the equation written above, the experimental outcome " intensity " and the temperature " T " results in new model equation ln{<(I i − )2>} = −ln{−(ln(k B · T / m))3 · ((2 · Δt · T · k B) / (m · D SD))}, which is applied to metal organics for the first time in the literature in this paper. Therefore, the ultimate goal of this study is twofold. First, we examine how empirical arguments of electrospray ionization mass spectra of metal–organics of AgI–ion of mandelic acid (1) and (3) as well as 2-hydroxy-4-sulfo-benzoic (2) acid support for validity of the new theoretical model, which is tested on metal–organics for the first time in the literature. Second, one of the aims is to provide a reliable approach to quantify exactly the isotope MS shape of complexes of AgI–ion allowing for an unambiguous determination of such analytes in mixture. Thus, we detail the intensity ration of the mass spectrometric isotope shapes over the time within different experimental conditions, making correlation among diffusion parameters based on the equations written above and the " quantum chemical diffusion parameter " (D QC) of ions obtained within the Arrhenius's approximation. Our model equations have ambition of providing exact methodological tool to determine experimentally the 3D molecular and electronic structures of the analytes on the base on a correlative study between D SD and D QC parameters or by a complementary use to high resolution mass spectrometric and high accuracy theoretical quantum chemical methods. In this context, we tackle the problematic on the correlation between the intensity ratio of the isotope sub peaks and the multidimensional molecular structure of complex species with each of the isotopes of 107,109Ag–ion. As a corollary, our research shows excellent coefficient of statistical correlation among the mentioned above theoretical models. The contribution provides, therefore, very important insights into the mutual connections among experimental measurable mass spectrometric outcomes; experimental factors, for instance, the temperature, as among the most important factor determining the ionization efficiency of the analyte ions; and 3D molecular conformational and electronic structure of AgI–containing metal–organics. The contribution, therefore, addresses serious shortcomings with the applicability of the mass spectrometry to exact multidimensional structural analysis and to quantify the intensity of the isotope shapes, unambiguously. Because of, the model equations written above and universally applicable, empirically testable and credible models applicable to not only different mass spectrometric methods, but also to different analytes and a broad spectrum of experimental parameters. Unlabelled Image • Metal–organics • Organometallics • Mass spectrometry • Stochastic dynamics • 3D structural analysis [ABSTRACT FROM AUTHOR]