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The mechanisms behind the faceting of vesicles in polymer-catanionic vesicles are investigated where the polymer is oppositely charged to the vesicle and bears a grafted chain. The results show that the faceting involves different mechanisms depending on polymer architecture.

The degenerate electron exchange (DEE) reaction involving radical cations (RCs) of n-nonane, n-dodecane, and n-hexadecane in n-hexane solution is analyzed by using the method of time-resolved magnetic field effect in recombination fluorescence of spin-correlated radical ion pairs. The influence of the interaction between RC and a neutral molecule in an encounter complex on DEE rate constant is examined.

A systematic investigation of the Cu(I) and Cu(II) cation interactions with biologically important types of ligands at the density functional theory level was performed. The results provide in-depth insight into the Cu-binding properties and could be used for calibration of bioinorganic force fields.

The fundamental photophysics and photochemistry of a cationic dye rhodamine 800 (R800) in water studied using steady-state and ultrafast time-resolved spectroscopies shows that the pure dimer spectrum obtained indicates a nonparallel H-dimer and the steady-state fluorescence spectra do not show concentration dependence. The S1 dimer dissociates to produce the S1 monomer or relaxes to the S0 dimer with a short time constant, resulting in the absence of dimer fluorescence.

The differences between the Gibbs free energies of association of the p-sulfonatocalix[4]arene with the tetramethylammonium cations in acidic aqueous solution are reported. The relative importance of the potential of mean force (pmf) bond correction and of the van der Waals and electrostatic contributions to the total change in the Gibbs free energy of complexation is presented.

The aggregation properties of single-chain cationic surfactants bearing one, two and three pyridinium headgroups are studied by using detailed small-angle neutron scattering (SANS). The critical micellar concentration (cmc) of these surfactants is estimated by measuring the specific conductance of the aqueous solution of the surfactants.

The synthesis and structural characterization, determined by H1 and C13 NMR, for a new tetraester calix[4] arene derivative containing mixed pendant arm in its lower rim are reported. The medium effect on the binding process of tetraester calix[4]arene for metal cations are examined to establish the sites of interaction of the ligand with the metal cation, the composition of complex formed and the strength of ligand-cation interaction in different media.

The ability of the effective fragment potential (EFP) method is assessed to describe the hydration of simple cations, calculations are carried out on alkali metal/alkaline earth cation water clusters containing up to six water molecules. Model chemistry is suggested that is based upon EFP/6-31+G optimizations and Hessians and single-point energies at the MP2/aug-cc-p VDZ level of theory.

Excited-state twisting and relaxation of triarylpyrylium cations is studied with various substituents attached to different parts of the molecule by means of femtosecond pump-probe absorption spectroscopy. The modeling shows that a broad population distribution along the twisting angle in the ground state is transferred to the excited state, causing strong fluorescene broadening, while competition between the excited-state twisting and solvation determines a subsequent reaction path.

Guided ion beam mass spectrometry is used to examine threshold collision-induced dissociation of M(super +)(C6H5CH3)(sub x) with XE, where M(super +) includes alkali metal ions, both with mono- and bis-complexes, (x=1 and 2). The bond dissociation energies of metal cation-toluene complexes are determined theoretically and experimentally to identify the influence of the methyl substituents on the binding energies, and the factors that control the strength of cation-pi interactions.

Theoretically the general formula for cations H(sub 3)(super +)Ar(sub n)(H2)m (n=0,m=0,6; and, n+m=6) is used to study the structures and consecutive energies and enthalpies of dissociation reactions. The vibrational frequencies for the H(sub 3)(super +) modes are examined.

The beta-carotene radical cation is studied using the hybrid density functional theory method B3LYP. The way in which the rotation of the headgroups can affect the properties of the radical are discussed.

Formation of intra molecular sigma three-electron-bonded 2 sigma/1sigma* radical cations upon reduction of dialkylsulfinyl sulfides by H-atoms in strongly acidic aqueous medium were studied. The findings indicate that this reaction leads to the formation of an S(super .+) radical cation entity, which coordinates, with the original sulfide moiety to yield the three-electron-bonded 2sigma/1sigma radical cation.

The structure of a single crystal of fully dehydrated K+ exchange zeolite X was determined by x-ray defraction methods in the cubic space group. The remaining 36 K+ ions are found at one III and two III'sites, these appear to be close in energy for K+ ions so that no single site is preferred.

Research into the stability of radical cations of three series of carotenoids substituted with terminal ester, cyano and aldehyde groups and with different numbers of backbone double bonds is presented. Radical cation stability is connected with the change in dipole moment between radical cations and the neutral species.

It has been possible to produce the radical cation of trimethylenemethane and a derivative, 2-isopropylidenecyclopentane-1,3-diyl. These two radical cations show significant reactivity differences.

The thermodynamics of ionic association of tetraphenylphosphonium and tetraphenylarsonium cations is examined using FT-Raman spectroscopy.

It has been possible to optimize the geometrical structures of unprotonated (NH3)n+ (n = 1-6), protonated NH4+(NH3)n-1 (n = 1-6) and proton-transferred (NH4+-NH2)(NH3)n-2 (n = 3-7) ammonia cluster cations. The harmonic vibrational frequencies were assessed.

Research into the structural and conformational behaviour of the sugar-diphosphate linkage is presented. It was established that interactions of the diphosphate group with the Mg2+ cation alter the conformational preferences around the diphosphate linkage.

Research into the impact of charge balancing cations on encapsulation of CO in the pores of Y-zeolite is presented. It is concluded that CO or CO2 molecules entrapped in narrow zeolitic cages undergo a dipole-dipole or van der Waals type weak interaction.

An investigation of the thermochemistry of tungsten hexafluoride and its singly charged cations and anions is presented. Density functional theory performs quite well, but the maximum errors are relatively large.

Density functional theory ab inito quantum chemical techniques and Hartree-Fock, second-order Moller-Plesset perturbation theory have been used to investigate the energies, structures and charges of uranyl cation complexes with nitrate ion, water molecules and carbonate ions. It is vital to take into account charge transfer and polarization effects when seeking to study complex formation.

It has been established that secondary C-H protonation is energetically favoured over protonation of C-C and primary C-H bonds in n-alkanes. Proton transfer from decane radical cations to decane molecules in gamma-irradiated CCl3F/decane leads to the selective formation of secondary C-H protonated decanes.

The impact of vinyl cations substituted at the alpha-position (H2C=C(+)R) with R = H, CH=CH2, Ch3, F and Cl and their neutral precursors (H2C=CHR) on the thermodynamic stability and electronic properties is considered. Stabilization of the vinyl cations is provided by most of the alpha-substituents, and also by hyperconjugation of the hydrogen atom at C-beta.

Pulse radiolysis at 133 K with methylcyclohexane as solvent has been used to investigate the radical cation of quadricyclane (Q). Attention is given to the precursor cations M+* and Q+*.

A combined time-of-flight secondary ion mass spectrometry (ToF-SIMS) and theoretical investigation of the impact of metal cationization on the molecular weight distribution of Surfynol 465 (S465) is presented. It is demonstrated that ToF-SIMS is an effective way of measuring the molecular weight distribution of an oligomer series.

Research designed to analyze the cation distribution in the crystal structure of fully dehydrated partially Pd2+-exchanged zeolite X is presented. It was possible to identify 30 Pd cations at sites I, I', another I' and III'.

Multireference second-order perturbation theory has been used to study the mechanism for the reaction of Co+ with propane on the triplet ground electronic state potential energy surface. Reasonable agreement with the experimental energetics was obtained.

It can be states that, for a large class of molecules, M, there is a straightforward link among the calculated values of bond lengths in its ground singlet state, its first excited triplet state, the ground-state doublet of its radical anion and the ground-state doublet of the related radical cation.

The quantum theory of atoms in molecules has been used to obtain further proof that the 2-norbornyl cation has a T-structure. The 13C shifts of C1, C2 and C6 on the 165 pm geometry are seen to differ substantially from the experimental values.

Research is presented demonstrating the use of diffuse reflectance spectroscopy and electron spin resonance to study the photoionization yields of ultra violet irradiation generated N-alkylphenothiazine cation radicals.

Research designed to establish the sequential thermochemistry of the di-iron carbonyl cluster cations, Fe2(CO)y+ (y = 1-9), is presented. Elimination of one CO molecule was observed as the primary fragmentation pathway.

Extended X-ray absorption fine structure and X-ray absorption near edge structure spectroscopies have been used to analyze the solvation structure of the yttrium(III) cation in aqueous dilute and concentrate solutions.

An investigation of the ionization process of the lowest four conformers of glycine is presented. Attention is given to the intramolecular proton-transfer process of the second conformer in the ground and first excited states of glycine radical cation.

Valence bond theory has been used to investigate the transition metal hydride cations TMH+. It was established that modern valence bond methods are valuable for studies involving transition metals.

Pulse radiolysis has been used to measure absolute rate constants for the reaction of sulfur-sulfur [>S..SS..NH2R]+) three-electron bonded sulfide radical cation complexes with superoxide and carbon dioxide radical anion.

FT-ICR mass spectrometry can be used to assess the reactions of hydrated metal cations Ag+(H2O)n, n = 11-26, and Na+(H2O)n, n = 12-28, with HCl. It was established that an analogue to bulk precipitation reaction arises on a molecular level in clusters.

It has been possible to establish 300 K rate constants and product branching fractions for reactions of NO+, O2+, O+, N+ and N2+ with the alkylbenzenes ethylbenzene, toluene, m-xylene and n-propylbenzene.

Pulse radiolysis, steady-state methods and laser flash photolysis techniques have been used to characterize two different tautomeric types of radical cations produced from 1,8-acridinediones.

Pulse radiolysis can be used to analyze sequential electron-proton addition to various NAD+ model compounds. A stepwise electron-proton-electron transfer in NADH-NAD+ type transformations involves two tautometic types of the NADH radical cation.

Density functional theory can be used to analyze the neutral, cationic and anionic charge states of the B13 cluster. Throughout the various charge states, planar or quasi-planar structures are preferred to three-dimensional isomers.

A new study provides experimental evidence for the structure and rearrangement of the phenylcyclopropane radical cation.

Results of photodissociative experiments on Cu+-C5H5N and Ag+-C5H5N complexes in the gas phase are presented.

An analysis of the mechanism of C-H activation at a cationic platinum (II) complex with a bidentate nitrogen ligand using quantum chemical density functional theory methods is presented. The main impact of a Lewis basic solvent is to stabilize platinum (IV) series relative to platinum (II).

Free energy perturbation molecular dynamics simulations of the relative binding free energies of three spherands and alkali metal ions are presented. It was found that relative free energies of binding calculated in water are in better agreement with experiment than those calculated in chloroform.

Anisole has been identified as an ambidentate ligand. Two clear modes for cation binding involve coordination mainly through the arene ring or the ether oxygen.

An analysis of the transition metal molecular cation Sc[BO]+ is presented. It is suggested that the study of the Sc[BO]+ species can be used as a model system to allow the investigation of more complex boron oxide-metal systems.

It has been possible to identify evidence that the structure of arginine-alkali metal ion complexes (Arg.M+), M = H, Li, Na, K, Rb, and Cs, depends on the size of the cation. Salt-bridge structures become more stable compared with the charge-solvated structures as the metal ion size increases.