No description available.

No description available.

No description available.

<p>The thermal azide-alkyne cycloaddition using electron deficient alkynes was used to functionalize polysiloxanes at low temperatures and without the need of a metal catalyst. We observed that the temperature at which cycloaddition began can be attributed to the identity of the alkyne's substituents (Chapter 2). We propose that the location of functionalization can be controlled by the specific introduction of electron deficient alkynes on terminal or pendant points on the polysiloxane. Polysiloxanes, each containing two electronically different alkynes, were prepared to show preferential functionalization of the more reactive alkyne without consuming the less reactive alkyne. The alkyne's reactivity can be modified by our choice of substituents. The extension of these results led to polysiloxane difunctionalization where the more reactive alkyne was consumed by a small azide followed by consumption of the less reactive alkyne with a bisazide siloxane. Thermal cycloaddition was used to introduce carbohydrates onto polysiloxanes without complicated protection/deprotection schemes and without catalysts (Chapter 3). The process was successful as propiolate-functionalized siloxane and azide-functionalized gluconamide reacted to produce a trisiloxane-functionalized gluconamide. Trisiloxane-functionalized gluconamide gelled diethyl ether at 3.0% gelator/solvent volume ratio becoming one of the few siloxane-based gelling agents.</p> / Master of Science (MSc)

Biofouling is an ongoing problem in the development and usage of biomaterials for biomedical implants, microfluidic devices, and water-based sensors. Antifouling coatings involving surface modification of biomaterials is widely utilized to reduce unwanted protein adsorption and cell adhesion. Surface modification strategies, however, are reliant on the working material’s chemical properties. Thus, published procedures are often not applicable to a wide range of material classes. This constitutes a serious limitation in using surface modification on assembled multi-material devices, i.e on whole device modification. The objective of this research is to develop an antifouling coating with non-aggressive reaction conditions that can universally modify polymers and other material classes. Two strategies using polydopamine (PDA) as an anchor for polyethylene glycol (PEG) surface attachment were investigated: (1) PDA-PEG backfilled with bovine serum albumin (BSA), and (2) PDA-PEG with light activated perfluorophenyl azide (PFPA) conjugated to the PEG. Three materials varying in surface wettability were studied to evaluate the coatings for multi-material applications: porous polycarbonate membrane (PC), polydimethyl siloxane (PDMS), and soda lime glass cover slips. Atomic force microscopy (AFM) and ellipsometry studies revealed substantial structural differences of PDA. Differences in PDA surface roughness affected PEG grafting in solution (the first method), with higher PEG coverage achieved on PC with intermediate surface roughness to PDMS and glass. Radiolabeled Fg adsorption and E. coli adhesion experiments showed reduced fouling on all PDA-PEG modified materials when backfilled with BSA. The ability for BSA to penetrate the PEG layer indicated that low PEG grafting densities were achieved using this grafting-to approach. The use of a photoactive labeling agent, PFPA, to tether PEG was proposed to improve PEG grafting on PDA. The PFPA-PEG modification protocol was optimized by quantifying Fg adsorption. Two treatments of PFPA-PEG were required to fully block PDA active sites. Fg adsorption was not significantly improved on PFPA-PEG modified PC and glass when backfilled with BSA, indicating sufficient PEG coverage of PDA. High Fg adsorption on PFPA-PEG surfaces indicate that high density PEG brushes were still not achieved with this method. PDMS surfaces were damaged with this procedure due to increased surface handling in the protocol. This is the first, to our knowledge, successful demonstration of PFPA modification on PDA surfaces. Photopatterning of polymer-based materials can be achieved, providing opportunities for utilising new materials in cell patterned platforms. Due to low PEG coverage on PDA surfaces from solution and using PFPA, ultra-low protein adsorption cannot be achieved using these aqueous-based methods. Antifouling modifications using PDA and PEG should be applied for short-term cell studies. / Thesis / Master of Applied Science (MASc)

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.

Hinweis: Zur optimalen Darstellung des Dokumentes bitte die Schriftart „ArnoPro“ installieren. Die vorliegende Arbeit beschäftigt sich mit der Synthese und den Reaktionen von heteroatomgebundenen Aziden. Im Speziellem werden vier verschiedene Gruppen untersucht, diese umfassen: Die Synthese von N-Azido-Aminen u. a. mittels nucleophiler Substitution und Diazotransfer-Reaktion, die Synthese von N-Azido-Iminen mittels nucleophiler Substitution und Addition-Reaktion von Azid an Iminium-aktivierte Azide, die Synthese von N4O/N4O2 durch Addition von Azid-Ion an Nitrosyl/Nitronium-Salze und die Synthese von Iod(III)aziden als Iod(III)mono-, -di- und triazid(e) mittels nucleophiler Substitution. Ein besonderes Augenmerk liegt in der Untersuchung der neu etablierten Reaktion zur Synthese von N-Amidino-Pentazolen und N-Azido-Amidinen ausgehend von Chlor-Iminium-Salzen. Es konnte hierbei gezeigt werden, dass nach einer ersten Substitutionsreaktion die neu eingeführte Azid-Gruppe durch die Nachbarschaft zur Iminium-Struktur aktiviert wird und so ein weiteres Azid-Ion an der Azid-Gruppe angreifen kann. Die sich im Folgenden bildenden N-Amidino-Pentazole und N-Azido-Amidine lassen sich mit Hilfe von 15N-Isotopenmarkierungen eindeutig, ohne unterstützende quantenchemische Rechnungen, bei tiefer Temperatur NMR-spektroskopisch nachweisen und belegen. Der Zerfall dieser Verbindungen bei Raumtemperatur liefert neben drei Äquivalenten Distickstoff ein nucleophiles Carben, welches diversen Folgereaktionen unterliegt und u. a. zu Azidomethylenaminen und Triazenium-Derivaten führt.:I. Inhaltsverzeichnis vi II. Abkürzungsverzeichnis ix 1. Einleitung 1 1.1. Azide - explosiv und vielfältig 1 1.1.1. Allgemeines 1 1.1.2. Heteroatomgebundene Azide in der Literatur 4 1.1.2.1. Überblick und bekannte Reagenzien 4 1.1.2.2. N-Azido-Amine 41 7 1.1.2.3. N-Azido-Imine 67 12 1.2. Stickstoff-haltige Heterocyclen 13 1.3. Zielsetzung 17 2. Ergebnisse und Diskussion 19 2.1. Synthese von N-Azido-Aminen 41 19 2.1.1. Synthese mittels nucleophiler Substitution 20 2.1.1.1. Reaktion von 43a mit NaN3: Die Reaktionsprodukte A und B 20 2.1.1.2. Reaktion von 43a mit NaN3: Aufklärung des Reaktionsmechanismus 22 2.1.1.3. Reaktion von 43a mit NaN3: Variation der Reaktionsbedingungen 26 2.1.1.4. Reaktion von 43a mit NaN3: Variation des Azid-Reagenzes 27 2.1.1.5. Variationen der Abgangsgruppe 29 2.1.2. Synthese mittels Diazotransfer 36 2.1.3. Synthese mittels Azid-Gruppen-Übertragung 43 2.1.4. Synthese über Tetrazenium-Salze 45 2.1.5. Synthese über N-Diazonium-Salze 47 2.2. Synthese von N-Azido-Iminen 67 52 2.2.1. Synthese mittels nucleophiler Substitution 53 2.2.2. Synthese mittels Additionsreaktion 55 2.2.2.1. Vorversuche 56 2.2.2.2. Reaktionssystem nach BALLI et al. 59 2.2.2.3. Weitere Formamid-Derivate 79 2.2.2.4. Weitere Systeme 90 2.3. Synthese von N4O (213) und N4O2 (216) 100 2.4. Synthese von Iod(III)aziden 108 2.4.1. Synthese von Iod(III)monoaziden 108 2.4.2. Synthese von Iod(III)diaziden 110 2.4.3. Synthese von Iod(III)triazid (242) 115 3. Zusammenfassung und Ausblick 120 4. Experimenteller Teil 124 4.1. Arbeitsweisen 124 4.1.1. Sicherheitshinweise zum Umgang mit Aziden 124 4.1.2. Arbeiten unter Inertgas 124 4.1.3. Arbeiten bei tiefer Temperatur 125 4.1.4. Verwendung/Trocknung von Lösungsmitteln 125 4.1.5. NMR-Spektroskopie 125 4.1.6. FT-IR-Spektroskopie 126 4.1.7. in-situ-IR-Spektroskopie 126 4.1.8. HRMS 127 4.1.9. Elementaranalyse 127 4.1.10. Schmelzpunkt 127 4.1.11. Synthese von Methylmethylenimin (117) 127 4.1.12. Synthese von N4O (213) und N4O2 (216) 129 4.2. Synthese der Edukte/Reagenzien 130 4.3. Genutzte, kommerziell verfügbare Chemikalien 131 4.4. Synthesevorschriften 135 4.4.1. Synthese von 1,3,5-Trimethyl-2,3,4,5-tetrahydro-1,3,5-triazinium- chlorid (116a) 135 4.4.2. Synthese von Methylmethylenimin (117) 136 4.4.3. Synthese von N-Brom-N,N-dimethylamin (121a) 137 4.4.4. Synthese von N,N-Dichlormethylamin (125a) 138 4.4.5. Synthese von Benzoesäuremethylester (131) 139 4.4.6. Synthese von N-Chlor-N-methyl-N-prenylamin (43q) 140 4.4.7. Synthese von 1,1-Dibenzyl-2-tosylhydrazin (137) 141 4.4.8. Synthese von N-Methyl-N-(3-methylbut-2-en-1-yl)hydrazin (54q) 142 4.4.9. Synthese von (E)-1-Methyl-2-(1,1-dimethylprop-2-en-1-yl)diazen (132r) 143 4.4.10. Synthese von 1-((2,4,6-Triisopropylphenyl)sulfonyl)-4,5,6,7,8,9-hexahydro-1H-cycloocta[d]-1,2,3-triazol (141) und 2-((2,4,6-Triisopropylphenyl)sulfonyl)-4,5,6,7,8,9-hexahydro-2H-cycloocta[d]-1,2,3-triazol (142) 144 4.4.11. Synthese von 1,1,1,4,4-Pentamethyltetrazenium-triflat (145a) 146 4.4.12. Synthese von 1-Methyl-4,5,6,7,8,9-hexahydro-1H-cycloocta[d]-1,2,3- triazol (152) 147 4.4.13. Synthese von N-Thiocyanato-cyclohexylimin (181u) 148 4.4.14. Synthese von 5-Chloro-1-methyl-3,4-dihydro-2H-pyrrol-1-ium chlorid (185n) 149 4.4.15. Synthese von N-Cyano-N,N-dimethylamin (122) 150 4.4.16. Synthese von N-Azidomethyl-N,N-dimethylamin (48) 151 4.4.17. Synthese von N-Azido-3-ethylbenzothiazol-2-imin (71a) 152 4.4.18. Synthese von 3-Ethyl-N-(4,5,6,7,8,9-hexahydro-1H-cycloocta[d]-1,2,3-triazol-1-yl) benzothiazol-2-imin (196a) 154 4.4.19. Synthese von N'-Azido-N,N-dimethylformamidin (15N4-67a) und N,N-Dimethyl-N'-pentazolyl)formamidin (15N6-199a) 157 4.4.20. Synthese von N-(Azidomethylen)-N-methylmethanaminium- salzen (15N3-186a) 160 4.4.21. Allgemeine Synthesevorschrift zu den N-Azido-formamidinen (15N3-67), Azido-Iminium-Salzen (15N2-186), Diaziden (15N2-187) und N-Amidino-Pentazolen (15N4-199) 161 4.4.22. Synthese von 1-Ethyl-2-(4,5,6,7,8,9-hexahydro-2H-cycloocta[d]-1,2,3-triazol-2-yl)pyridin-1-iumsalzen (210q) 168 4.4.23. Synthese von 2-((1,3-Dimethylimidazolidin-2-yliden)triaz-1-en-1-yl)-1,3-dimethyl-4,5-dihydro-1H-imidazol-3-ium-hexafluorophosphat (208s) 170 4.4.24. Synthese von Ethyl-2-(azido(phenyl)iodanyl)-2-diazoacetat (227a) 171 4.4.25. Synthese von 2-Ethoxy-2-oxo-acetonitril (232a) 172 4.4.26. Synthese von Phenyl((trimethylsilyl)oxy)iodanyl-triflat (239a) 173 5. Literaturverzeichnis 174 6. Danksagung 186 7. Anhang 188 7.1. Teil I 189 7.2. Teil II 199 8. Selbstständigkeitserklärung 294 9. Lebenslauf 295

The work centersaround perfluoroaryl azides (PFAAs), and theirability to undergo certain fast and robusttransformations. The chemistry was furtherappliedfor biomedical applications. The first section focuses on the azide-aldehyde-amine cycloaddition using PFAAs. Experimental and computational investigations uncovered a fast azide-enamine cycloaddition to form triazolines, which spontaneously rearrange into stable amidine products. In addition, this transformation was explored in the formulation of pure nanodrugs. Because this reaction can introduce a phenyl and a perfluoroaryl moiety enabling supramolecular interactions near the antibiotic drug, the resulting ciprofloxacin derivatives formed nano-sized aggregates by precipitation, which displayed aggregation-induced emission for bacterial imaging as well as enhanced size-dependent antibacterial efficacy. In the second section, the high electrophilicity of PFAAs was explored to transform azides to aryl amides. The reactivity of PFAAs in the thioacid/azide reaction was studied. In addition, PFAAs were discovered to react with phenylacetaldehyde to form aryl amidesviaan azide-enol cycloaddition, similar tothe perfluoroaryl azide-aldehyde-amine reaction.This strategyof amide synthesiswas furthermoregeneralized through a combination of base-catalyzed azide-enolate cycloaddition reaction and acid-or heat-promoted rearrangement of triazolines. The last section describes a type of azide fluorogens whose fluorescence can be switched on by alight-initiated intramolecular nitrene insertion intoa C-H bond in the neighboring aromaticring. These fluorogenic structures were efficiently accessed via the direct nucleophilic aromatic substitution of PFAAs. / <p>QC 20150903</p>

This thesis contains investigations in the area of polymers herein propellants binders are modified functionally to meet the requirements of future energetic propellants. Chapter 1 contains a broad introduction to the area of recent advances in solid propellants and the numerous applications of ‘Click Chemistry’. Chapters 2 details the materials, characterization tools and the experimental techniques employed for the studies. This is followed by Chapter 3, 4, and 5 which deals with functional modification of various propellants binders, their characterisation and evaluation in propellant formulations. Chapter 6 details with the thermal decomposition of diazides and its reaction with alkenes. The advent of modern rockets has opened a new era in the history of space exploration as well as defence applications. The driving force of the rocket emanates from the propellant – either solid or liquid. Composite solid propellants find an indispensable place, in today’s rockets and launch vehicles because of the inherent advantages such as high reliability, easy manufacturing, high thrust etc. The composite propellant consisting of inorganic oxidiser like ammonium perchlorate, (AP), ammonium nitrate (AN) etc), metallic fuel (aluminium powder, boron etc) and polymeric fuel binder (hydroxyl terminated polybutadiene-HTPB, polybutadiene-acrylic acid-acrylonitrile PBAN, glycidyl azide polymer (GAP), polyteramethylene oxide (PTMO) etc. is used in igniters, boosters, upper stage motors and special purpose motors in large launch vehicles. Large composite solid propellant grains or rocket motors in particular, demand adequate mechanical properties to enable them to withstand the stresses imposed during operation, handling, transportation and motor firing. They should also have a reasonably long ‘potlife’ to provide sufficient window for processing operations such as mixing and casting which makes the selection of binder with appropriate cure chemistry more challenging. In all composite solid propellants currently in use, polymers perform the role of a binder for the oxidiser, metallic fuel and other additives. It performs the dual role of imparting dimensional stability to the composite, provides structural integrity and good mechanical properties to the propellant besides acting as a fuel to impart the required energetics. Conventionally, the terminal hydroxyl groups in the binders like GAP, PTMO and HTPB are reacted with diisocyanates to form a polyurethane network, to impart the necessary mechanical properties to the propellant. A wide range of diisocyantes such as tolylene diisocyanate (TDI) and isophorone diisocyanate (IPDI) are used for curing of these binders. However, the incompatability of isocyanates with energetic oxidisers like ammonium dinitramide (ADN), hydrazinium nitroformate (HNF), short ‘potlife’ of the propellant slurry and undesirable side reactions with moisture are limiting factors which adversely affect the mechanical properties of curing binders through this route. The objective of the present study is to evolve an alternate approach of curing these binders is to make use of the 1,3 dipolar addition reactions between azide and alkyne groups which is a part of ‘Click chemistry’. This can be accomplished by the reaction of azide groups of GAP with triple bonds of alkynes and reactions of functionally modified HTPB/PTMO (azide/alkyne) to yield 1,2,3 -triazole based products. This offers an alternate route for processing of solid propellants wherein, the cured resins that have improved mechanical properties, better thermal stability and improved ballistic properties in view of the higher heat of decomposition resulting from the decomposition of the triazole groups. GAP is an azide containing energetic polymer. The azide groups can undergo reaction with alkynes to yield triazoles. In, Chapter 3 the synthesis and characterisation of various alkynyl compounds including bis propargyl succinate (BPS), bis propargyl adipate (BPA), bis propargyl sebacate (BPSc.) and bis propargyl oxy bisphenol A (BPB) for curing of GAP to yield triazoles networks are studied. The mechanism of the curing reaction of GAP with these alkynyl compounds was elucidated using a model compound viz. 2-azidoethoxyethane (AEE). The reaction mechanism has been analysed using Density Functional Theory (DFT) method. DFT based theoretical calculations implied marginal preference for 1, 5 addition over the 1, 4 addition for the uncatalysed cycloaddition reaction between azide and alkyne group. The detailed characterisation of these systems with respect to the cure kinetics, mechanical properties, dynamic mechanical behaviour and thermal decomposition characteristics were done and correlated to the structure of the network. The glass transition temperature (Tg), tensile strength and modulus of the system increased with crosslink density which in turn is, controlled by the azide to alkyne molar stoichiometry. Thermogravimetic analysis (TGA) showed better thermal stability for the GAP-triazole compared to GAP based urethanes. Though there have been a few reports on curing of GAP with alkynes, it is for the first time that a detailed characterisation of this system with respect to the cure kinetics, mechanical, dynamic mechanical, thermal decomposition mechanism of the polymer is being reported. To extent the concept of curing binders through 1,3 dipolar addition reaction, the binder HTPB as chemically transformed to propargyloxy carbonyl amine terminated polybutadiene (PrTPB) with azidoethoxy carbonyl amine terminated polybutadiene (AzTPB) and propargyloxy polybutadiene (PTPB). Similarly, PTMO was convnerted to propargyloxy polytetramethylene oxide (PTMP). Triazole-triazoline networks were derived by the reaction of the binders with alkyne/azide containing curing agents. The cure characteristics of these polymers (PrTPB with AzTPB, PTPB with GAP and PTMP with GAP) were studied by DSC. The detailed characterisations of the cured polymers for were done with respect to the, mechanical, dynamic mechanical behaviour and thermal decomposition characteristics were done. Propellant level studies were done using the triazoles derived from GAP, PrTPB-AzTPB, PTPB and PTMP as binder, in combination with ammonium perchlorate as oxidiser. The propellants were characterised with respect to rheological, mechanical, safety, as well as ballistic properties. From the studies, propellant formulations with improved energetics, safety characteristics, processability and mechanical properties as well defect free propellants could be developed using novel triazole crosslinked based binders. Chapter 6, is aimed at understanding the mechanism of thermal decomposition of diazido compounds in the first section. For this, synthesis and characterisation of a diazido ester 1,6 –bis (azidoacetoyloxy) hexane (HDBAA) was done. There have been no reports on the thermal decomposition mechanism of diazido compounds, where one azide group may influence the decomposition of the other. The thermal decomposition mechanism of the diazido ester were theoretically predicted by DFT method and corroborated by pyrolysis-GC-MS studies. In the second section of this chapter, the cure reaction of the diazido ester with the double bonds of HTPB has been investigated. The chapter 6B reports the mechanism of Cu (I) catalysed azide-alkene reaction validated using density functional theory (DFT) calculations in isomers of hexene (cis-3-hexene, trans-3-hexene and 2-methy pentene: model compound of HTPB) using HDBAA. This the first report on an isocyanate free curing of HTPB using an azide. Chapter 7 of the thesis summarizes the work carried out, the highlights and important findings of this work. The scope for future work such as development of high performance eco-friendly propellants based on triazoles in conjunction with chlorine-free oxidizer like ADN, synthesis of compatible plasticisers and suitable crosslinkers have been described. This work has given rise to one patent, three international publications and four papers in international conferences in the domain.

Foram estudados os equilíbrios dos complexos de Mn (II) com íons azoteto, em meio aquoso, por método potenciométrico indireto, através de medidas de pH, em meio de azoteto 0 a 1,8 M, e a 25,0 ºC, utilizando força iônica 2,00 M mantida com perclorato de sódio. Nas diferentes concentrações de íon metálico empregadas, 20, 40, 60, 80 e 100 mM, obteve-se uma mesma curva de formação de número médio de ligantes vs. concentração de ligante livre, o que configura a inexistência de complexos polinucleares nessas condições experimentais. Os valores de número médio de ligantes n&#175;, e de concentração de ligante livre, [L], foram utilizados para a integração de função de Bjerrum, obtendo-se a função de Fronaeus, F0(L), a partir da qual calcularam-se, por métodos gráficos e matemáticos, as quatro sucessivas constantes globais de equilíbrio: &#946;1 = 4,15 &#177; 0,02 M-1 , &#946;2 = 6,61 &#177; 0,04 M-2 , &#946;3 = 3,33 &#177; 0,02 M-3 , &#946;4 = 0,63 &#177; 0,01 M-4 . Avaliando os valores das constantes, observa-se que os complexos formados são fracos e, em obediência à regra de Irving e Williams, são menos estáveis que os complexos de cobalto (II) e de níquel (II). Em concentrações de ligante superiores a 1M há condições para lenta oxidação espontânea dos complexos de manganês(II) a manganês(III) com significativas mudanças espectrais. / The equilibria of complex formation between manganese(II) cations and azide anions were studied in aqueous medium by an indirect potentiometric method, at 25°C and ionic strengh 2.0 M (NaClO4). The equilibrium data were based on pH measurements of Mn(II) in N3&#175;/HN3 buffers. Metal ion concentration changing from 20 to 100 mM have defined one single formation curve of n_ (Bjerrum function) vs. [N 3 &#175; ] which is an evidence that only mononuclear species ara present in the working solutions. Integration of the formation curve from the best n&#175;vs. [N3&#175;] data leads to Fronaeus function data. They were properly treated to obtain the formation by a variety of methods (graphic and mathematical). The best set formed is: &#946;1 = 4,15 &#177; 0,02 M-1 , &#946;2 = 6,61 &#177; 0,04 M-2 , &#946;3 = 3,33 &#177; 0,02 M-3 , &#946;4 = 0,63 &#177; 0,01 M-4 . The complex are weaks and are is agreement with the Irving and Williams rule, i. e., less stable than the corresponding complexes of Ni(II) and Co(II). At ligand concentration higher t than 1,0 M there were conditions for a slow spontaneous oxidation of manganese(II) complexes to manganese to manganese(III), with remarkable spectral changes.