The solid state structures and the physical, solution magnetic, solid state magnetic, and spectroscopic (NMR and UV/Vis) properties of a range of oxygen- and nitrogen-free dialkylmanganese(II) complexes are reported, and the solution reactivity of these complexes towards H2 and ZnEt2 is described. The dialkyl compounds investigated are [{Mn(μ-CH2SiMe3)2}∞] (1), [{Mn(CH2CMe3)(μ-CH2CMe3)2}2{Mn(μ-CH2CMe3)2Mn}] (2), [Mn(CH2SiMe3)2(dmpe)] (3) (dmpe = 1,2-bis(dimethylphosphino)ethane), [{Mn(CH2CMe3)2(μ-dmpe)}2] (4), [{Mn(CH2SiMe3)(μ-CH2SiMe3)}2(μ-dmpe)] (5), [{Mn(CH2CMe3)(μ-CH2CMe3)}2(μ-dmpe)] (6), [{Mn(CH2SiMe3)(μ-CH2SiMe3)}2(μ-dmpm)] (7) (dmpm = bis(dimethylphosphino)methane), and [{Mn(CH2CMe3)(μ-CH2CMe3)}2(μ-dmpm)] (8). Syntheses for 1-4 have previously been published, but the solid state structures and most properties of 2-4 had not been described. Compounds 5 and 6, with a 1:2 dmpe:Mn ratio, were prepared by reaction of 3 and 4 with base-free 1 and 2, respectively. Compounds 7 and 8 were accessed by reaction of 1 and 2 with 0.5 or more equivalents of dmpm per manganese atom. An X-ray structure of 2 revealed a tetrametallic structure with two terminal and six bridging alkyl groups. In the solid state, bis(phosphine)-coordinated 3-8 adopted three distinct structural types: (a) monometallic [LMnR2], (b) dimetallic [R2Mn(μ-L)2MnR2], and (c) dimetallic [{RMn(μ-R)}2(μ-L)] (L = dmpe or dmpm). Compound 3 exhibited particularly desirable properties for an ALD or CVD precursor, melting at 62-63 °C, subliming at 60 °C (5 mTorr), and showing negligible decomposition after 24 h at 120 °C. Comparison of variable temperature solution and solid state magnetic data provided insight into the solution structures of 2-8. Solution reactions of 1-8 with H2 yielded manganese metal, demonstrating the thermodynamic feasibility of the key reaction steps required for manganese(II) dialkyl complexes to serve, in combination with H2, as precursors for metal ALD or pulsed-CVD. By contrast, the solution reactions of 1-8 with ZnEt2 yielded a zinc-manganese alloy with an approximate 1:1 Zn:Mn ratio. Wilkinson’s manganese(I) ethylene hydride complex trans-[(dmpe)2MnH(C2H4)] (10) can react as a source of a low-coordinate manganese(I) ethyl complex. This is illustrated in the reactivity of 10 towards a variety of reagents in this work (vide infra). The proposed low-coordinate intermediate, [(dmpe)2MnEt] (13), was not observed spectroscopically, but could be trapped using isonitrile ligands; reaction of 10 with CNR (R = tBu, o-xylyl) afforded the manganese(I) ethyl complexes [(dmpe)2MnEt(CNR)] (14a: R = tBu, 14b: R = o-xylyl). Ethyl complex 14a did not react further with CNtBu at 80 °C. By contrast, complex 14b reacted with excess o-xylyl isonitrile to form 1,1 insertion products, including the iminoacyl complex [(dmpe)Mn(CNXyl)3{C(=NXyl)CEt(=NXyl)}] (15, Xyl = o-xylyl). Complexes 14a-b and 15, as well as previously reported 10, were crystallographically characterized, and DFT calculations were employed to probe the accessibility of cis ethylene hydride and ethyl isomers of 10. Reaction of the ethylene hydride complex trans-[(dmpe)2MnH(C2H4)] (10) with H2SiEt2 at 20 °C afforded the silylene hydride [(dmpe)2MnH(=SiEt2)] (16Et2) as the trans isomer. By contrast, reaction of 10 with H2SiPh2 at 60 °C afforded [(dmpe)2MnH(=SiPh2)] (16Ph2) as a mixture of the cis (major) and trans (minor) isomers, featuring a Mn–H–Si interaction in the former. The reaction to form 16Ph2 also yielded [(dmpe)2MnH2(SiHPh2)] (18Ph2); [(dmpe)2MnH2(SiHR2)] {R = Et (18Et2) and Ph (18Ph2)} were accessed cleanly by reaction of 16R2 with H2. Both 16Et2 and 16Ph2 engaged in unique reactivity with ethylene, generating the silene hydride complexes cis-[(dmpe)2MnH(R2Si=CHMe)] {R = Et (19Et2) and Ph (19Ph2)}. Compounds trans-16Et2, cis-16Ph2, and 19Ph2 were crystallographically characterized, and bonding in 16Et2 and 19Et2 was probed computationally. trans-[(dmpe)2MnH(C2H4)] (10) reacted with primary hydrosilanes H3SiR (R = Ph, nBu) at 60 °C to afford ethane and the manganese disilyl hydride complexes [(dmpe)2MnH(SiH2R)2] (20Ph: R = Ph, 20Bu: R = nBu). 20R reacted with ethylene to form silene hydride complexes [(dmpe)2MnH(RHSi=CHMe)] (19Ph,H: R = Ph, 19Bu,H: R = nBu). Compounds 19R,H reacted with a second equivalent of ethylene to generate [(dmpe)2MnH(REtSi=CHMe)] (19Ph,Et: R = Ph, 19Bu,Et: R = nBu), resulting from apparent ethylene insertion into the silene Si–H bond. Furthermore, in the absence of ethylene, silene complex 19Bu,H slowly isomerized to the silylene hydride complex [(dmpe)2MnH(=SiEtnBu)] (16Bu,Et). Reactions of 20R with ethylene likely proceed via low-coordinate silyl {[(dmpe)2Mn(SiH2R)] (17Ph: R = Ph, 17Bu: R = nBu)} or silylene-hydride {[(dmpe)2MnH(=SiHR)] (16Ph,H: R = Ph, 16Bu,H: R = nBu)} intermediates accessed from 20R by H3SiR elimination. DFT calculations and high temperature NMR spectra support the accessibility of these intermediates, and reactions of 20R with isonitriles or N-heterocyclic carbenes yielded the silyl isonitrile complexes [(dmpe)2Mn(SiH2R)(CNR')] (21a-d: R = Ph or nBu; R' = o-xylyl or tBu), and NHC-stabilized silylene-hydride complexes [(dmpe)2MnH{=SiHR(NHC)}] (22a-d: R = Ph or nBu; NHC = 1,3-diisopropylimidazolin-2-ylidene or 1,3,4,5-tetramethyl-4-imidazolin-2-ylidene), respectively, all of which were crystallographically characterized. Manganese silyl dihydride complexes [(dmpe)2MnH2(SiHR2)] {R = Ph (18Ph2) or Et (18Et2)} and [(dmpe)2MnH2(SiH2R)] {R = Ph (18Ph) or nBu (18Bu)} were generated by exposure of silylene hydride complexes, [(dmpe)2MnH(=SiR2)] (16R2), and disilyl hydride complexes, [(dmpe)2MnH(SiH2R)2] (20R), respectively, to H2 at room temperature. In solution, 18R and 18R2 exist as an equilibrium mixture of a central isomer with a meridional H–Si–H arrangement of the silyl and hydride ligands {this isomer may be considered to contain an η3-coordinated silicate (H2SiR3–) anion}, and a transHSi isomer with trans-disposed hydride and nonclassical hydrosilane ligands (the latter is the result of significant but incomplete hydrosilane oxidative addition). Additionally, DFT calculations indicate the thermodynamic accessibility of lateralH2 and transH2 isomers with cis- and trans-disposed silyl and dihydrogen ligands, respectively. Compounds 18Ph2 and 18Ph crystallized as the central isomer, whereas 18Bu crystallized as the transHSi isomer. Bonding in the central and transHSi isomers of 18R and 18R2 was further investigated through 29Si_edited 1H–1H COSY solution NMR experiments to determine both the sign and magnitude of J29Si,1H coupling (negative and positive values of J29Si,1H are indicative of dominant 1-bond and 2-bond coupling, respectively). These experiments afforded J29Si,1H coupling constants of –47 Hz for η3-(H2SiR3) in the central isomer of 18Et2 (calcd. –40 to –47 for 18R and 18R2), –38 to –54 Hz for η2-(R3Si–H) in the transHSi isomer of 18R and 18R2 (calcd. –26 to –47 Hz), and 5 to 9 Hz for the terminal manganese hydride ligand in the transHSi isomer of 18Et2, 18Ph, and 18Bu (calcd. 12 to 14 Hz for 18R and 18R2), experimentally supporting the nonclassical nature of bonding in the central and transHSi isomers. Exposure of disilyl hydride complexes 20R to diisopropylcarbodiimide {C(NiPr)2} afforded manganese(I) amidinylsilyl complexes [(dmpe)2Mn{κ2-SiHR(NiPrCHNiPr)}] {R = Ph (25Ph,H) or nBu (25Bu,H)}. DFT calculations and analysis of XRD bond metrics suggest that the structure of 25R,H involves a contribution from a resonance structure featuring a neutral base-stabilized silylene and an anionic amido donor on manganese. Reactions of 20R, as well as the silylene hydride complex 16Et2, with CO2 yielded the manganese(I) formate complex trans-[(dmpe)2Mn(CO)(κ1-O2CH)] (26), with a polysiloxane byproduct. Compound 26 was found to undergo reversible CO2 elimination at room temperature, and was only stable under an atmosphere of CO2. Complexes 25R,H and 26 were crystallographically characterized. Silyl, silylene, and silene complexes in this work were accessed via reactions of [(dmpe)2MnH(C2H4)] (10) with hydrosilanes, in some cases followed by ethylene. Therefore, ethylene (C2H4 and C2D4) hydrosilylation was investigated using [(dmpe)2MnH(C2H4)] (10) as a pre-catalyst, resulting in stepwise conversion of primary to secondary to tertiary hydrosilanes. Various catalytically active manganese-containing species were observed during catalysis, including silylene and silene complexes, and a catalytic cycle is proposed. The proposed catalytic cycle is unusual due to the involvement of silylene hydride and silene hydride complexes, potentially as on-cycle species. The reaction of [(dmpe)2MnH(C2H4)] (10) with H2 at 60 °C afforded ethane and the dihydrogen hydride complex [(dmpe)2MnH(H2)] (11), which has previously been prepared by an alternative route. Complex 10 reacted with hydroborane reagents 9-BBN or HBMes2 at 60 °C to afford EtBR2 and Mn(I) borohydride complexes [(dmpe)2Mn(μ-H)2BR2] (29: R2 = C8H14, 30: R = Mes); two intermediates were observed in each of these reactions. Deuterium labelling experiments using the deuterated hydroborane DBMes2 suggest that this reaction proceeds via the 5-coordinate ethyl isomer of 10; [(dmpe)2MnEt] (13). By contrast, exposure of 10 to BH3∙NMe3 required a higher temperature (90 °C) to yield [(dmpe)2Mn(μ-H)2BH2] (28), and ethylene was formed as the reaction byproduct; this reaction presumably proceeded by ethylene substitution. Deuterium incorporation into both the MnH and BH environments of 28 was observed under an atmosphere of D2 at 90 °C. Reactions of 10 with free dmpe yielded ethylene and a mixture of [{(dmpe)2MnH}2(μ-dmpe)] (31) and [(dmpe)2MnH(κ1-dmpe)] (32), which could be isolated by washing/recrystallization or sublimation, respectively. Similar reactivity was observed between 10 and HPPh2, which afforded ethylene and [(dmpe)2MnH(HPPh2)] (33) at 90 °C. Exposure of 10 to HSnPh3 yielded the manganese(II) stannyl hydride complex [(dmpe)2MnH(SnPh3)] (34) along with ethylene and, presumably, additional unidentified products. However, the mechanism for formation of 34 is unclear, it could not be isolated in pure form due to decomposition to form various species including SnPh4, and the mechanism of the decomposition process remains obscure. Previously reported complex 11, along with new complexes 28-31 and 33-34, were crystallographically characterized. This work provides valuable insights to unusual metal–ligand bonding motifs and reactions, and as such contributes to the fundamental understanding of organometallic chemistry. / Dissertation / Doctor of Philosophy (PhD) / The focus of this work is the synthesis and investigation of manganese-containing complexes with Mn–P, Mn–C, Mn–H, and/or Mn–Si linkages. Many of these complexes feature unusual bonding motifs, including the first group 7 complexes bearing an unstabilized silylene (:SiR2) ligand and the first 1st row transition metal complexes bearing an unstabilized silene (R2Si=CR2) ligand. Variable temperature Nuclear Magnetic Resonance (NMR) spectroscopy and X-ray crystallography were employed to investigate the structures of these complexes, while Density Functional Theory (DFT) calculations and trapping experiments were employed to understand the mechanisms for various unusual chemical transformations. Some of the complexes were evaluated for activity towards catalytic hydrosilylation of ethylene. This work provides valuable insights to unusual metal–ligand bonding motifs and reactions, and as such contributes to the fundamental understanding of organometallic chemistry.

京都大学 / 新制・課程博士 / 博士(工学) / 甲第24627号 / 工博第5133号 / 新制||工||1981(附属図書館) / 京都大学大学院工学研究科材料化学専攻 / (主査)教授 中尾 佳亮, 教授 松原 誠二郎, 教授 杉野目 道紀 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

The effect of wine matrix ingredients and conditions on the headspace (HS) sampling of 3-alkyl-2-methoxypyrazines was investigated with solid-phase microextraction (SPME) and capillary gas chromatography, using a nitrogen phosphorus detector. Changes in the recovery of 3-ethyl-, isopropyl-, sec-butyl-, and isobutyl-2-methoxypyrazines from the static headspace of synthetic wine matrices spiked with 5mg/L of each analyte were investigated and reported as a function of SPME fiber type, extraction time, and temperature. The influence of pH, ethanol, phenolics, and ground oak was studied. DVB/Carboxen?/PDMS SPME fibers at an extraction temperature of 50°C for 30 minutes with 30% (w/v) added sodium chloride resulted in the highest analyte recoveries. Although, PDMS (100 micron) SPME fibers at an extraction temperature of 35°C for 30 minutes with 30% (w/v) added sodium chloride resulted in the lower analyte recoveries, the fiber remained functional after 50 to 75 analyses after other coatings deteriorated. Changing the sample ethanol concentration from 0 to 20% (v/v) resulted in an exponential decrease in the recovered analytes. Below pH 2, there was extensive loss of the analytes in the headspace. No measurable impact on alkylmethoxypyrazine headspace concentrations was observed with exposures to selected phenolics and to ground oak. / Master of Science

Les Liquides Ioniques [LI] à température ambiante forment une nouvelle classe de matériaux, prometteurs dans des applications diverses. Les avantages que les LI soulèvent par rapport aux autres liquides moléculaires ou sels fondus résident dans la facilité à changer leurs propriétés intrinsèques en jouant sur la nature chimique de la combinaison [cation-anion]. Cependant, on n’est pas encore près à prédire les propriétés d’un LI en connaissant uniquement sa composition chimique. Par conséquent, nous avons fait des expériences de diffraction de rayons-x et de neutrons, complétées par une série de simulations de dynamiques moléculaires sur une famille de LI à bases de cations d’alkyl-methylimidazolium et d’anion Bromure. Ainsi, en changeant la longueur de la chaine alkyl, nous avons comparé la structure et la dynamique de trois LI de chaines ethyl, butyl et hexyl. La comparaison des résultats structuraux obtenus par la simulation avec ceux des rayons-x donnèrent complète satisfaction. Des résultats intéressants ont été obtenus, spécialement ceux issus de la comparaison de la structure et la dynamique du LI 1-ethyl-3-methylimidazolium Bromide en phase cristalline et liquide. Par ailleurs, l’hétérogénéité en phase volumique a pu être quantifiée ce qui a permis de déterminer que la ségrégation augmente avec la longueur de la chaine alkyl cationique. / Room temperature ionic liquids constitute a class of materials with many promising applications in very diverse fields. Their potentiality stems from the fact that their properties are very different from those of typical molecular solvents and furthermore they can be tailored by modifying the combination of ions forming the liquid. However it is not yet possible to predict which species will produce a particular set of properties. Therefore we have done a systematic computer simulation study on a series of three room temperature ionic liquids based on the alkyl-methylimidazolium cation combined with the bromium anion. The length of the alkyl chain of the cation and the anions has been increased progressively, going from ethyl to butyl and hexyl, in order to explore the structural and dynamical changes brought about by such change. Simulation results are also compared satisfactorily to high-energy x-ray diffraction and quasi elastic neutron scattering data obtained by us. Our results show that the structure of liquid 1-ethyl-3methylimidazolium Bromide presents large similarities with the crystal one. This resemblance appears also when the local dynamics of the ethyl chain is investigated using neutron spectroscopy. Moreover we have quantified the heterogeneity found in the bulk state, finding that segregation is favored by the length of the cation’s alkyl chain.

Pyrazoles have been studied for over a century as an important class of heterocyclic compounds and continue to attract considerable interest due to the broad range of biological activities they possess. The incorporation of the essential structural features of pyrazoles with a ferrocene moiety could provide new derivatives with unexpected and/or enhanced biological activities since several ferrocene derivatives have already been shown to be active against a number of tumors. For this reason, we investigated the synthesis of ferrocenyl-substituted pyrazoles, such as 1-alkyl/aryl-5-ferrocenylpyrazoles, by employing the reaction between (2-formyl-1-chlorovinyl)ferrocene and hydrazine derivatives. Although this reaction is known, it was not studied in much detail and the low yields of ferrocenyl pyrazoles were obtained. Thus, we have reinvestigated this reaction and improved the yields of pyrazoles by optimizing the reaction conditions. (2-Formyl-1-chloro vinyl)ferrocene was first reacted with the excess amount (3 equivalents) of hydrazine derivative at 25 0C in dioxane under argon for 2 hours, and the resulting mixture was then heated at 100 0C for 6 hours in the same solvent. Under our optimized conditions, these reactions afforded 1-alkyl/aryl-5-ferrocenylpyrazole derivatives in moderate to good yields as a single or major product of the reaction. In some cases, 1-alkyl/aryl-3-ferrocenylpyrazole derivatives resulted from these reactions as very minor products.

L'objectif de ces travaux était d'utiliser certains aspects de l'activité chimique et photochimique de télomères fluorés porteurs de fonctions azides, dans le but de promouvoir les synthèses de polymères thermostables et de nouveaux matériaux photoréticulés. En premier lieu, nous avons développé et caractérisé une nouvelle classe de poly(alkyl-aryl) éthers par une promotion de la compétition de la réaction de « Click » et de couplage de Hay. Par la suite, l'activité photochimique de ces composés fluorés a été étudiée et utilisée pour élaborer des matériaux photoréticulés. Les énergies libres des surfaces des films obtenus ont été calculées en utilisant le modèle d'Owens et Wendt. Les rugosités et les compositions de ces surfaces présentant des mouillabilités singulières ont été investiguées par le biais d'analyses par profilométrie, AFM et EDX. En dernier lieu, les synthèses et caractérisations de réseaux photoréticulés sont abordées. La post sulfonation de ces matériaux a conduit à la préparation de nouveaux électrolytes pour l'application pile à combustible dont les microstructures et propriétés physico-chimiques ont été étudiées. / This work aims at using both chemical and photochemical activities of fluorinated telomers bearing azido end groups, to promote the synthesis of thermostable macromolecules and original photocrosslinked networks. In a first part, we have prepared and characterized a novel class of linear poly(alkyl aryl) ethers by the promotion of competitive “Click” reaction and Hay coupling. Then, the photolysis under UV irradiation of these fluorinated polymers was studied and used to generate photocrosslinked materials. The surface free energies of the resulting films were established using the Owens-Wendt model. The roughness and composition of the surfaces were investigated by profilometry, AFM and EDX analysis. Finally, the preparation under UV irradiation of original polymer networks was performed. The post-sulfonation of these materials allowed to prepare new proton exchange membranes for fuel cells application. The microstructures, physical and chemical properties of these electrolytes were investigated.

Ribonucleotide reductases (RNR) are essential enzymes that catalyze the reduction of ribonucleotides to 2'-deoxyribonucleotides, which is a critical step that produces precursors for DNA replication and repair. The inactivation of RNR, logically, would discontinue producing the precursors of the DNA of viral or cancer cells, which then would consequently end the cycle of DNA replication. Among different compounds that were found to be inhibitors of RNR, 2'-azido-2'-deoxynucleotide diphosphates (N3NDPs) have been investigated in depth as potent inhibitors of RNR. Decades of investigation has suggested that the inactivation of RNR by N3NDPs is a result of the formation of a nitrogen-centered radical (N•) that is covalently attached to the nucleotide at C3' and cysteine molecule C225 [3'-C(R-S-N•-C-OH)]. Biomimetic simulation reactions for the generation of the nitrogen-centered radicals similar to the one observed during the inactivation of the RNR by azionuclotides was investigated. The study included several modes: (i) theoretical calculation that showed the feasibility of the ring closure reaction between thiyl radicals and azido group; (ii) synthesis of the model azido nucleosides with a linker attached to C3' or C5' having a thiol or vicinal dithiol functionality; (iii) generation of the thiyl radical under both physiological and radiolysis conditions whose role is important in the initiation on RNR cascades; and (iv) analysis of the nitrogen-centered radical species formed during interaction between the thiyl radical and azido group by electron paramagnetic resonance spectroscopy (EPR). Characterization of the aminyl radical species formed during one electron attachment to the azido group of 2'-azido-2'-deoxyuridine and its stereospecifically labelled 1'-, 2'-, 3'-, 4'- or 5,6-[2H2]-analogues was also examined. This dissertation gave insight toward understanding the mechanism of the formation of the nitrogen-centered radical during the inactivation of RNRs by azidonucleotides as well as the mechanism of action of RNRs that might provide key information necessary for the development of the next generation of antiviral and anticancer drugs.

This thesis deals with the conformation and phase-transitions in anchored alkyl chain bilayer assemblies in organic-inorganic hybrids. The alkyl chain bilayers in organic-inorganic hybrids bear a striking resemblances to the lipid bilayers that are an integral part of biomembranes. However, unlike the lipid bilayer where individual lipid molecules can undergo the total absence of translational mobility. The anchored bilayer are, therefore, the simplest model system for understanding the structure, organization and thermal behaviour of alkyl-chain assemblies. The anchored bilayer in the organic-inorganic hybrids also offer the advantage that unlike the lipid bilayers that are essentially fluid like, these are solids and therefore, amenable to study by a variety of solid-state spectroscopic techniques. The objective of the present works was to determine the organization, conformation and thermal behaviour of alkyl chains in these class of materials- the alkyl ammonium layered pervoskites and in zinc soaps of saturated and unsaturated fatty acids. The preparation, conformation and orientation of alkyl chains assemblies in the layered(CH3CH2)nNH3)2PbI4 is described in chapter 2 and the phase-transitions and associated changes in conformation in presented in chapter 3. In chapter 4 the preparation, structure, conformation and phase-transitions of alkyl chains in the m = 2 member of the layered (CH3NH3)m-1(CH3CH2)nNH3)2PbmI3m+1 Ruddleson-Popper series is discussed. The thermal behavior of zinc soaps of saturated fatty acids is discussed in chapter 5 and formation and phase-transitions in solid solution between saturated zinc soaps of differing chain lengths, zinc stearate and zinc myristate is presented in chapter 6. The effect of a rigid link or double bond on the evolution of conformational disorder and phase-transitions of other-wise flexible hydrocarbon chains is explored in chapter 7 by comparing the thermal behavior of zinc oleate and zine elaidate with that of zinc stearate. A unique feature of the zinc soaps is that they form solid solutions over the entire composition range feature of the zinc soaps is that they form solid solutions over the entire composition range between soaps of saturated and unsaturated fatty acids. The formation and conformation of alkyl chains in the solid solution of zinc stearate and zinc oleate is discussed in chapter 8.

<p>Adsorption on solid surfaces from solution is a fundamental property of a surfactant. It might even be the most important aspect of surfactant behavior, since it influences many applications, such as cleaning, detergency, dispersion, separation, flotation, and lubrication. Consequently, fundamental investigations of surfactant adsorption are relevant to many areas.</p><p>The main aim of this thesis has been to elucidate the adsorption properties, primarily on the solid/water interface, of a particular class of polyhydroxyl based surfactants: the alkyl glucosides. By the use of ellipsometry, the equilibrium and kinetic aspects of adsorption on titanium dioxide with respect to structural effects has been studied. Furthermore, the effects of small amounts of cationic surfactant additives on the adsorption on silica have been investigated. The results have been compared with similar studies for other nonionic surfactants.</p><p>We have found that the surfactant structure has a strong effect on the adsorption properties. An increase in the surfactant chain length increases the cooperativity of the system. An increase in the head group polymerization decreases the cooperativity and the plateau adsorbed amount at equilibrium. The effect of surfactant structure on the adsorption kinetics depends on the concentration relative to the cmc, while the there is a decrease in the rate of desorption with increasing hydrophobic chain length independent of the concentration. The adsorption/desorption process is concluded to be diffusion driven, as suggested by the model used. When comparing these results with studies on ethylene oxide based surfactants, we conclude that the two types of surfactants exhibit similar trends on surfaces onto which they adsorb.</p><p>Adsorption from binary surfactant solutions is even more interesting than adsorption from single surfactant solutions, since it brings us one step closer to the systems used in applications. In addition, adsorption from a mixture can be very different from adsorption from any of the single surfactants in the mixture. Alkyl glucosides alone do not adsorb on silica, but addition of small amounts of a cationic surfactant to the alkyl glucoside solution allows for adsorption on silica. A comparison between the adsorption and bulk properties has shown that mixed micellization explains most, but not all, effects of the coadsorption properties. Changing the pH in the mixed systems reveals that a surfactant with a pH-dependent charge and the ability to adapt its charge to the environment, e.g. a surface, enhances the adsorbed amount over a wider range of pH values than a purely cationic surfactant.</p><p>It is well known that alkyl glucosides and ethylene oxides adsorb differently on different types of hydrophilic surfaces. As a consequence, replacing ethylene oxides with alkyl glucosides might not be all straight-forward; however, we have shown that the effect of the surface can be eliminated by the use of a cosurfactant.</p>

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