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Resume The authors checked resistance of different populations of Chenopodium album L. to heavy doses of atrazine. In the presence of different triazines, diazine and urea, they compared the behaviour of susceptible and resistant populations. Measured by whole leaves fluorescence, electron transfer of susceptible and resistant plants is respectively stopped or not by the different herbicides. Furthermore, with low doses of herbicides, about 1 % of tolerant plants have been selected from susceptible plants. In the presence of the same herbicides, leaves of tolerant plants present intermediate and variable reactions.

As reported previously, the treatment of aryl(4-pyridazinyl)methanols of type (I) with TosOH leads unexpectedly to a rearranged pyrazole like (II) along with dismutation products (III).

The reaction of N-phenyl-N′-trimethylsilyl sulphur di-imide with sulphur dichloride yields benzo-1,3-dithia-2,4-diazine, a novel twelve π-electron heterocycle.

Nonenzymatic oxidation of several amine homologs was carried out under mild conditions. Aliphatic amines were efficiently oxidized by PQQ in CTAB micellar system. In the case of ω, ω’-diamines, length of the carbon chain was significant; the reaction rate became larger with the increase in the carbon number. On the contrary ethylenediamine showed competitive inhibition forming the cyclic adduct, a fused diazine. Carbonyl reagents such as hydrazines and aminoguanidine were also oxidized by PQQ, but the latter compound deactivated PQQ by forming the 1,2,4-triazine derivative under catalytic conditions or at lower pH region.

Publisher Summary This chapter presents evidence for an early sulfhydryl reagent sensitive step during lymphocyte activation. In a study described in the chapter, human peripheral blood lymphocytes were prepared from heparinized blood by dextran sedimentation and isopycnic centrifugation on Ficoll/Hypaque gradients. In the study, 2 × 105 lymphocytes were cultured in 0.2 ml in microtitre plates with mitogenic concentrations of phytohemagglutinin (PHA) or ConA. Diamide [diazine dicarboxylic acid bis (N,N-dimethylamide)] was added at the initiation of the culture or at various times thereafter. Activation was assayed by adding 0.1 μCi of 3H thymidine to each well at 68 h of culture, and the lymphocytes were harvested at 72 h using an automated multiple sample harvester. When diamide was added coincidentally with lectin, there was a dose-related inhibition of activation with no decrease in 3H thymidine incorporation at 10−5 M and complete suppression of activation at 10−3 M or greater. If diamide (2 × 10−4 M) was added to culture at various times after PHA or ConA, there was complete inhibition of activation up to 30 min and progressively less suppression at longer times.

In order to investigate the generality of a chain-elongation reaction observed in the metabolism of fusaric acid (5-butyl-2-pyridinecarboxylic acid) and its derivatives, various heteroaromatic (diazine, 1, 3-azole, and 1, 2-azole) carboxylic acids with a normal alkyl side-chain were synthesized.

Umsetzung von Pyridin mit Cyclopropyllithium (1) fuhrt zu Mono-, Di- und Tricyclopropyl-pyridinen 3–7. Der Primarangriff erfolgt ausschlieslich in 2-Stellung. Die Reaktion last sich auf substituierte und anellierte Pyridinsysteme (8–12) sowie auf Diazine (14–20) ubertragen. Auch Cyclopropylmagnesiumbromid reagiert mit Pyridin bzw. Chinolin nur zu 2-Substitutions-produkten (3 bzw. 12), wahrend mit Cyclopropylbromid/Magnesium Gemische aus 2- und 4- cyclopropylsubstituierten Verbindungen (3, 5, 12, 23) neben mehrfach substituierten Pyridinen (4, 6, 7) entstehen. Dies spricht fur einen zumindest partiell radikalischen Reaktionsverlauf, da bei definierter radikalischer Cyclopropylierung ein analoges Produktspektrum erhalten wird. Synthesis of Cyclopropylsubstituted Azines and Diazines By reaction of pyridine with cyclopropyllithium (1), mono-, di-, and tricyclopropyl pyridines 3–7 are formed. Primarily, 1 attacks exclusively in the 2 position. The procedure is applicable also to substituted and anellated pyridines and to diazines. – Exclusively 2-substituted product is also obtained from cyclopropylmagnesium bromide and pyridine or quinoline (3, 12) whereas cyclopropylbromide/magnesium afford a mixture of 2- and 4-cyclopropylsubstituted compounds (3, 5, 12, 23) besides polysubstituted pyridines (4, 6, 7). This indicates a reaction mechanism proceeding, at least partially, via radicals since cyclopropylation by an established radical process results in an analogous product mixture.

Diarylsulfoxide 4 reagieren mit Stickstoffwasserstoffsaure in Gegenwart von Schwefelsaure zu 1.2.4-Benzothia(IV)diazin-1-oxiden 7. 3-Chlormethyl-1-aryl-1.2.4-benzothia(IV)diazin-1-oxide 7a–d erfahren unter dem Einflus von Hydroxidionen eine Ringerweiterung zu 1-Aryl-4-oxo-4.5-dihydro-3H-1.2.5-benzothia(IV)diazepin-1-oxiden 9, einem neuen heterocyclischen Ringsystem. Reaktion von 7a–d mit primaren Aminen in alkoholischer Losung fuhrt zu normaler Substitution. 1.2.4-Benzothia(IV)diazines and 1.2.5-Benzothia(IV)diazepines, Ring Enlargement of Some Chloromethyl-1.2.4-benzothia(IV)diazine 1-oxides Diarylsulfoxides 4 react with hydrazoic acid in the presence of sulfuric acid to form 1.2.4-benzothia(IV)diazine 1-oxides 7. On treatment of 3-chloromethyl-1-aryl-1.2.4-benzothia(IV)-diazine 1-oxides 7a–d with sodium hydroxide a novel rearrangement occurs affording 1-aryl-4-oxo-4.5-dihydro-3H-1.2.5-benzothia(IV)diazepine 1-oxides 9. Reaction of 7a–d with primary amines in alcoholic solution proceeds without rearrangement.

Synthesis and Properties of Pentaamminepyridinenthenium ( 11) and Related Pentaammineruthenium Complexes of Aromatic Nitrogen Heterocycles P. Ford,l* De F. P. Rudd,lb R. Gaunder, and H. Taube Contribution from the Department of Chemistry, Stanford University, Stanford, California 94305. Received September 11, 1967 Abstract: The syntheses of pentaammineruthenium(I1) and pentaammineruthenium(II1) complexes of pyridine and analogous aromatic nitrogen heterocycles are reported here. The pentaammineruthenium(I1) complex of each of these heterocyclic ligands has an intense absorption band in the visible region which, on the basis of evidence presented below, is assigned to a metal-to-ligand charge-transfer transition. The pentaamminepyrazineruthenium- (11) complex ion can be protonated in a reversible fashion, presumably at the noncoordinated nitrogen of the 1,4- diazine. The pK, of this complex demonstrates that the dipositive ion is approximately two orders of magnitude more basic than the free ligand. This result and related data are interpreted in terms of ground-state ir back-bonding from the ruthenium(I1) to the aromatic ligand. W e undertook the present work in the hope that com- parison of the reactivity of various ruthenium- (111) complexes, which have low-spin d5 electronic con- figurations, to analogous cobalt(II1) complexes (low- spin d6) would improve our understanding of the role of electronic configuration in the mechanism of reductions of these complexes. Pentaammineruthenium(II1) com- plexes of nitrogen heterocycles such as pyridine deriva- tives are of special interest because it is reported that reductants such as chromium(I1) can attack at ligand sites remote from the metal ion center in certain Co(II1) analogs. Remote attack may require transfer of the reducing electron through the conjugated n orbitals of the aro- matic ligand. It has been suggested that the ruthenium- (111) complexes having a n-symmetry (t2,) acceptor orbital might demonstrate dramatically different re- activity characteristics in reductions by remote attack from Co(II1) analogs having u-symmetry (or e,) acceptor orbitals. In the course of investigating these problems, we have synthesized a number of pentaammineru- thenium(I1) and pentaammineruthenium(II1) complexes of aromatic nitrogen heterocycles. These have been found to have interesting physical and spectral proper- ties; their description and interpretation form the sub- ject of this paper. Results Spectral Characteristics. The spectrum of penta- amminepyridineruthenium(I1) perchlorate in aqueous solution is shown in Figure 1. Characteristic of the spectrum of this complex and of the pentaammine- ruthenium(I1) complexes of related aromatic nitrogen heterocycles is an intense absorption band in the visible range having an extinction coefficient approximately lo4 M-’cm-’. Comparison ofthe spectrum in the visible range for pentaammineruthenium(I1) perchlorate in aqueous solution to the spectra of pentaamminepyridine- ruthenium(II1) perchlorate (Figure 1) and of hexaam- mineruthenium(I1) perchlorate (Table I) in aqueous (1) (a) NSF Postdoctoral Research Associate, Stanford University; (b) NSF Science Faculty Fellow and Visiting Scholar at Stanford University. (2) F. R. Nordmeyer and H. Taube, J . Am. Chem. Soc., 88, 4745, solutions demonstrates that among these the band occur- ring at 407 mp is unique to the Ru(I1)-pyridine species. Somewhat analogous absorptions have been observed in the spectra of other pyridine complexes with d6 metal ions. For example, the spectra of pyridine complexes of chloroiridium(II1) show intense visible range absorp- tions which are suggested by Jorgensen3 to arise from metal-to-ligand charge transfers. Table I. Spectra of Pentaammineruthenium Complexes Complex Lax, m r (log emax) (NH3)eRu2+ a ( N H ~ ) ~ R u ~ + ~ 320 (2.00) ( N H ~ ) ~ R U ( ~ Y ) 407 (NH~)~Ru(PY)~+ Pyridineb Pyridine (H+) T. Meyer, Ph.D. Dissertation, Stanford University, 1966, p 30. band of pyridine spectrum: H. H. Jaff6 and M. Orchin, “Theory and Application of Ultraviolet Spectroscopy,” John Wiley and Sons, Inc., New York, N. Y., 1962, p 363. “0,O) The only other high-intensity absorption apparent in the electronic spectrum of the pentaamminepyridine- ruthenium(I1) complex occurs in the ultraviolet region of the spectrum at 244 mp. The position of this band and its intensity, E 4.6 X lo3 M-’ cm-I, are similar to those for free pyridine and for protonated pyridine (Table I) implying that this transition is essentially localized in the aromatic ligand and is presumably analogous to the T absorption seen in the free ligand. Similar n* bands occur in the spectrum of pentaamminepyridine- ruthenium(II1); on the other hand, transitions in this region for hexaammineruthenium(I1) and the hexa- ammineruthenium(II1) are of much lower intensity (Table I). The absorption bands for pyridine, when it is free, when it is protonated, and when it is bound to ruthen- ium(III), are close in energy while the analogous band for the pyridine bound to ruthenium(I1) is shifted to higher energy. (3) C. K. Jprgensen, Acta Chem. Scand., 11, 151 (1957). Ford, Rudd, Gaunder, Taube 1 Pentaamminepyridineruthenium(II)

1. 1. The effects of diazine® green (Janus green), a specific vital stain for mitochondria, on the total number of bull spermatozoa moving normally and on their mean velocity and velocity distributions were studied, using the photo-electric equipment described by Rikmcnspoel [12] and by Rikmenspoel and Van Herpen [14]. 2. 2. In the absence of light diazine green has no measurable effect on living bull spermatozoa in concentrations up to 200 p.p.m. (4 × 10 −7 M ). 3. 3. Under illumination, diazine green acts as a powerful photosensitizer, decreasing the total number of normally moving spermatozoa as well as their mean swimming velocity. Both effects may be attributed to one single site of attack. 4. 4. The photosensitizing effect is strictly proportional to the number of dye molecules adsorbed per unit of susceptible area. The quantitative relationships are in agreement with a simple adsorptive process, following the empirical Freundlich equation and also the theoretically founded Langmuir adsorption isotherm. 5. 5. The velocity frequency distributions are not only shifted to lower values, but their shape is altered too. The top value of the normalised frequency curves rises and the standard deviation of the distribution is significantly decreased.

Sulfadimethoxine (2,4-dimethoxy-6-sulfanilamido-1,3-diazine) is a new sulfonamide having low toxicity after single oral administration to rats and dogs. Chronic toxicity studies of sulfadimethoxine [Madribon (Ro-4-0517)] were conducted in rats at dose levels of 25, 50, 100, and 200 mg/kg and in dogs at 20, 40, 80, and 160 mg/kg. As the results of these studies do not indicate a direct toxic effect of sulfadimethoxine upon the tissues studied, the question of whether or not this new sulfonamide will produce hypersensitivity reactions awaits further evaluation in man. After oral administration to rats the tissue concentrations of sulfadimethoxine are, in decreasing order: blood, kidney, liver, muscle and brain. Repeated daily doses increase the concentration on the second or third day, but there is no further cumulative action. After single doses, the sulfonamide is present in tissues for at least 4 days. The half-life in blood is 48 hours. After a single dose, 59% was excreted in the urine in 48 hours. After multiple doses, 48–53% was excreted daily. A large proportion is excreted in the bound form in rats.

Pyridazine, pyrazine and substituted pyridazines have been studied by proton magnetic resonance spectroscopy. The spectra of pyridazine and pyrazine were analyzed completely with the aid of information obtained from the C13-satellites (in natural isotopic abundance), whereas the spectra of substituted pyridazines were analyzed easily by the usual treatments. The proton magnetic resonance parameters of diazines were discussed in connection with the electronegativity of the nitrogen atoms. Effects of some substituents upon the ring proton shifts of pyridazine were discussed. The total methyl effect on the ring protons of pyridazine (0.54 p.p.m.) falls in the normal aromatic range. Electronic charge distributions in diazine molecules were discussed by comparing the π-electron densities calculated by the Huckel MO method with those obtained from the ring proton chemical shifts. Discrepancies in these electronic densities were ascribed to the possible paramagnetic anisotropy effect arising from the n-π* transition of the lone-pair electrons of the nitrogen atoms.

The trinuclear copper(II) complex [Cu3(saltag)(py)6]ClO4 (H5saltag = tris(2-hydroxybenzylidene)triaminoguanidine) was synthesized and characterized by experimental as well as theoretical methods. This complex exhibits a strong antiferromagnetic coupling (J = −298 cm−1) between the copper(II) ions, mediated by the N–N diazine bridges of the tritopic ligand, leading to a spin-frustrated system. This compound shows a T2 coherence time of 340 ns in frozen pyridine solution, which extends to 591 ns by changing the solvent to pyridine-d5. Hence, the presented compound is a promising candidate as a building block for molecular spintronics.

Trotz vieler möglicher Techniken zur Konservierung von Lebensmitteln landen derzeit 20% aller hochwertigen Fleischprodukte durch ineffiziente Konservierung und Lagerung im Müll. Im Gegensatz zu herkömmlichen Konservierungstechniken, wie Erhitzen oder Gefrieren, könnten Diazinderivate es möglich machen, Fleisch ohne Textur- oder Geschmacksveränderungen länger lagerfähig zu machen. Das Ziel der vorliegenden Arbeit war es, effiziente Strategien zu entwickeln, um die Haltbarkeit von Fleischprodukten zu erhöhen und dabei den Anteil an konservierenden Substanzen zu verringern. Durch Kombination von kultivierungs-abhängigen mikrobiologischen Methoden, Konfokaler Laser-scanning Mikroskopie und einer Hochdurchsatz Empfindlichkeitsprüfung wurden Basisinformationen gesammelt, um eine Diazinformulierung mit erhöhter Wirksamkeit zu entwickeln. Des Weiteren wurde die praktische Anwendbarkeit von Diazinen in Kombination mit Maltodextrin erforscht. Es konnte gezeigt werden, dass in Abhängigkeit von der Substituierung der Diazinderivate, verschiedene knockout Mutanten unterschiedliche Empfindlichkeiten zeigten. Ebenfalls konnte gezeigt werden, dass Diazin die antimikrobielle Wirksamkeit von Maltodextrin synergistisch erhöht. In Abhängigkeit der zugesetzten Menge an Wirkstoff konnte die bakterielle Belastung in verarbeiteten Fleischprodukten um bis zu 99,9% reduziert werden. Mittels einer neuen Methode, mit welcher Mikroorganismen von Fleischsteifen auf Textilfasern transferiert, gefärbt und mikroskopiert wurden, konnte der antimikrobielle Effekt des Maltodextrin/Diazin-Gemisches bestätigt werden. Die Gesamtergebnisse zeigten, dass eine Mischung aus Diazinderivaten in Kombination mit Maltodextrin die Haltbarkeit von Fleischprodukten erhöht und dabei die Menge an Konservierungsmittel reduziert. Nowadays many different techniques for the preservation of food are used, but statistics shows, that 20% of produced meat, which is fastidious in production, gets lost due to inappropriate handling during production process or storage afterwards. Diazine derivatives could overcome storage problems without changing the texture and flavor of meat while other preservation techniques like cooking or canning change those probabilities. The main objective of this study was to find efficient strategies, which enable to increase the shelf life of meat products and thereby reduce the dose of preserving ingredients. Cultivation-dependent methods, confocal laser scanning microscopy and a high-throughput susceptibility testing method on an Escherichia coli KEIO knockout collection delivered basic informations for the development of a diazine formula. Furthermore the practical application of diazine in combination with maltodextrin was explored. It was shown, that depending on the side chains of the diazine derivatives, distinct mutants of the knockout collection show different susceptibility to them. Furthermore, it was shown, that diazine synergistically increased the antimicrobial effect of maltodextrin. Depending on the added amount of active ingredient, a 99.9% reduction of colony forming units in processed meat was reached. A novel approach including the transfer of bacteria from meat strips, followed by differential staining confirmed the antimicrobial effect of a maltodextrin/diazine mixture. The overall results provided evidence that diazine derivatives in combination with maltodextrin could increase the shelf life of meat products and simultaneously decrease the amount of required preservatives. Matthias Schöck, BSc Zusammenfassungen in Deutsch und Englisch Masterarbeit Karl-Franzens-Universität Graz 2017 7612

The synthesis, structural, electrochemical, optical, and electronic structure properties of a new azine-thiophene semiconductor family are reported and compared to those of analogous oligothiophenes. The new molecules are: 5,5'-bis(6-(thien-2-yl)pyrimid-4-yl)-2,2'-dithiophene (1), 5,5'-bis(6-(5-hexylthien-2-yl)pyrimid-4-yl)-2,2'-dithiophene (3), and 5,5'-bis(6-(thien-2-yl)pyridazin-3-yl))-2,2'-dithiophene (2). Electrochemical experiments demonstrate that introduction of electron-poor heteroaromatic rings into the oligothiophene core significantly enhances electron affinity. Thin-film transistors were fabricated with these materials and evaluated both in vacuum and in air. We find that although diazine substitution is important in tuning oligothiophene orbital energetics, these oligomers are p-channel semiconductors and the field-effect transistor (FET) charge transport properties are remarkably similar to these of unsubstituted oligothiophenes. The combined computational-experimental analysis of the molecular and thin film properties indicates that these diazine-containing oligothiophenes essentially behave as pi-extended bithiophenes. Interestingly, despite strong intermolecular interactions, high solid-state fluorescence efficiencies are observed for these new derivatives. Such emission characteristics suggest that these materials behave as more extended pi systems, which should be advantageous in light-emitting transistors.

Various quinazolin-4(3H)-ones and quinazolines were successfully lithiated using different lithiating reagents at low temperature. Reactions of the lithio reagents thus obtained with a variety of electrophiles afforded the corresponding substituted derivatives in very good yields.

Methods for the preparation of a wide variety of pyridazine-containing bi- and tricyclic ring systems, starting from appropriately substituted pyridazines are reviewed. The compilation comprises pyridazine-fused five-, six-, and seven-membered carbo- and heterocyclic systems. Particular interest is focused on compounds bearing no additional substituents in the 1,2-diazine moiety. In the syntheses discussed, diaroylpyridazines, aroylpyridazinecarboxylic acids, alkylpyridazinecarboxylic acids, aminopyridazinyl aryl ketones, and chloro- or alkylpyridazinecarbonitriles represent the key intermediates

The Raman spectra of three diazines adsorbed on silicas have been measured. Spectra changes upon adsorption are interpreted as the result of hydrogen-bond formation between the surface OH group and the N atom of diazine. The order of the shifts of the Raman bands between three diazines is: 1,3-diazine>1,4-diazine>1,2-diazine.

The synthesis of benzo[h]cinnolin (3) is reported. Its spectroscopic properties (uv, luminescence, pmr, ms) are similar to the other diazaphenanthrenes containing a diazine ring. The lowering of the basicity of 3 compared with a monoazaphenanthrene like other diaza-aromatic compounds appears to be due to an electrostatic field effect and not to an inductive effect.

The reaction of N-phenyl-N′-trimethylsilyl sulphur di-imide with sulphur dichloride yields benzo-1,3-dithia-2,4-diazine, a novel twelve π-electron heterocycle.

The binuclear, hydroxo-bridged, five-co-ordinate copper(II) complex of a hexadentate (N6) phthalazine ligand, the crystal structure of which has been determined, exhibits very strong antiferromagnetic exchange (–2J= 990 ± 50 cm–1) and very intense visible absorption (610 nm, Iµ 18 400 I mol–1 cm–1) and unlike comparable (N4) diazine complexes undergoes two-electron oxidation at 0.50 V (vs. standard calomel electrode) to produce a stable binuclear copper(III) derivative.

A recent analysis of the nuclear magnetic resonance spectra of the diazine mono N-oxides has shown that the meta coupling across the nitrogen in pyrazine N-oxide is positive in contrast to all other known cases, where the coupling is negative. In order to obtain further information on the magnitude and sign of the meta couplings across nitrogen nuclei, the authors have examined the spectra of the analogous N-methyldiazinium iodides. (Author)

CONSIDERABLE discussion of the structure of proteins, especially in relation to the cyclol hypothesis, has recently appeared in NATURE1,2,3. This theory assumes that globular proteins consist of a spaceenclosing arrangement of diazine and triazine rings. Most of the evidence produced (including the X-ray diagrams2,3) is, however, not specific for the cyclol theory; many of the points made by Langmuir4 could be equally well used as an argument in favour of any regular geometrical structure which joins peptide chains to form a globular molecule. It is indeed possible to suggest bonds between peptide chains of types already known to exist; thus we are familiar with compounds containing the linkages S—S; CO—S, NH—S or CO—NH—CO, all of which might occur in proteins; in addition, the possibility exists of linkages between hydroxyl groups of hydroxy-amino acids and free carboxyl groups.