bluuebunny/crossref_metadata_2025_split huggingface dataset:
Der Stoffwechsel von Verbindungen mit Dreifachbindung V. Der Abbau von Diincarbonsäuren und Kohlenwasserstoffen in vivo
Authors: Bernhard Karl , Kaempf Ekkehard 
Published: December 2004

Abstract10,12‐Heneicosadiynoic acid (I), 5,7‐hexadecadiynoic acid (IV), and 10,12‐docosadiynedioic acid (VI) were fed to rats. As metabolites 4,6‐undecadiynedioic acid (II), 5,7‐dodecadiynedioic acid (V), and 4,6‐decadiynedioic acid (VII) respectively were isolated from the urine. 10,12‐Heptadecadiynoic acid (III) also yielded metabolite II. Furthermore 9,11‐eicosadiyne (X) and for comparison purposes eicosane (XI), hexadecanedioic acid (VIII), and docosanedioic acid (IX) were fed. X and XI were incorporated into depot fat and liver lipids to a cetain degree. The diynes I, II, IV, and X are new compounds.
Steric Rate‐Retardation in the Chromium Trioxide Oxidation of 4,6‐Dimethyl‐benzocyclobutenol
Authors: Müller Paul 
Published: December 2004

AbstractThe rate of oxidation of 4, 6‐dimethyl‐benzocyclobutenolThis nomenclature is preferred in the literature [1] [2] to the more systematic name (7‐hydroxy‐3, 5‐dimethyl‐bicyclo [4.2.0] octa‐1,3,5‐triene).
(1) with chromium trioxide has been measured. After correction for the influence of the two methyl substituents the rate of oxidation of 1 is lower than that of 1‐tetralol (9) and 1‐indanol (10) by factors of 3 and 5 respectively. The lower oxidation rate of 1 as compared to 9 and 10 is interpreted in terms of a steric rate retardation arising from angle strain in the developing carbonyl function of 4, 6‐dimethylbenzocyclobutenone (4).
Stabilité des carboxylates de terres, III. Maléates, méthylsuccinates et malates
Authors: Roulet R. , Feuz J. , Vu Duc T. 
Published: December 2004

AbstractThe stability constants of maleates, methylsuccinates and malates of rare earths have been determined at 25.0 °C and at ionic strength 0,100 (NaClO4) by a potentiometric method. Each ligand forms 1 : 1 and 1 : 2 complexes in aqueous solution, the malates being the most stable. The first and the second dissociation constants of the ligand acids were also measured. The 1 : 2 maleates of La, Pr, Nd, Sm, and Eu have been isolated.
Reaction of Isocyanates and Isothiocyanates with Butyraldazine; Formation of 1‐Substituted 2‐Pyrazolines
Authors: Zirngibl Ludwig , Tam S. W. 
Published: December 2004

AbstractPhenyl isothiocyanate reacts with butyraldazine in presence of acidic catalysts to form a 2‐pyrazoline (IV) whereas phenyl or benzyl isocyanates under similar conditions yield a mixture of the two isomeric 2‐pyrazolines XIa and XII. On reaction with Ac2O, IV gave the 1‐acetyl derivative V. Reduction with LiAlH4 led to the corresponding pyrazolidines. Reexamination of Kost's three step preparation of a 1‐phenylthiocarbamoyl 2‐pyrazoline [19] such as X via formic acid cyclization [18] of butyraldazine revealed that his first step product was apparently a mixture of two stereoisomeric 1‐formyl‐2‐pyrazolines VIIIa and VIIIb. A mechanism for the formation of these pyrazolines is proposed.
Preparation of a 2‐Methylcyclodopa Derivative
Authors: Fischer Nikolaus , Dreiding André S. 
Published: December 2004

AbstractDie Herstellung von O,O‐Diacetyl‐S‐2‐methylcyclodopa‐methylester (7) durch Oxydation von S‐2‐Methyldopa‐methylester (4) und anschliessende Reduktion und Acetylierung ist beschrieben. Im Gegensatz zu Cyclodopa (2) wird 2‐Methylcyclodopa‐methylester (6) am Stickstoff durch Acetanhydrid und Pyridin nicht acetyliert.
Organische Phosphorverbindungen 40. Methoden zur Herstellung von Pentamethylen‐1,5‐bis‐(dihydroxyphosphonylmethyl‐phosphinsäure) [1]
Authors: Maier Ludwig 
Published: December 2004

AbstractAlkyl‐pentamethylene‐1,5‐bis‐(dialkyloxyphosphonylmethyl‐phosphinates) (VII) are formed in high yield by heating alkyl pentamethylene‐1,5‐diphosphonites, (RO)2P(CH2)5P(OR)2, with alkyl chloromethylphosphonates, ClCH2P(O)(OR)2, at 170° for several hours until evolution of alkyl halides ceases. Hydrolysis to the corresponding acid (VIII) is effected by refluxing with conc. HCl for 40 h.The synthesis and properties of some other 1,5‐diphosphorus‐substituted pentanes, i.e., H2P(CH2)5PH2, Cl2P(CH2)5PCl2, (Et2N)2P(CH2)5P(NEt2)2, (EtO) (HO)P(CH2)5P(OH)(OEt), and (HO)2P(CH2)5P(OH)2, are also reported.
Ligandenverdrängungsreaktionen von Kobalt‐dicyclopentadienyl mit tertiären Phosphiten – Darstellung und Eigenschaften der Komplexe C5H5Co[P(OR)3]2
Authors: Harder V. , Müller J. , Werner H. 
Published: December 2004

AbstractThe reaction of Co(C5H5)2 with tertiary phosphites mainly gives the half‐sandwich type compounds C5H5Co[P(OR)3]2 (R = CH3, C2H5, C6H5), which are characterised by means of their IR., UV., and NMR. spectroscopic data. The mass spectra of the new compounds are discussed.
Crystallographic Studies of Synthetic Corrinoids. II. Molecular structure of a C/D‐seco‐corrinoid nickel(II) complex
Authors: Dobler M. , Dunitz J. D. 
Published: December 2004

AbstractAn X‐ray crystal structure analysis of the perchlorate salt of the C/D‐seco‐corrinoid nickel(II) complex I is reported. The structural transformations that occur in the base‐catalysed iminoester‐enamine condensation of I leading to the corrin complex II are discussed.
Der Mechanismus der Hydrolyse von Chlortriazinen in protischen Lösungsmitteln. II. Mitteilung Über nukleophile uromatische Substitutionen
Authors: Rys P. , Schmitz A. , Zollinger H. 
Published: December 2004

AbstractThe complex kinetics found for the hydrolysis of 1, 3, 5‐trichloro‐s‐triazine in 9/91% (v) acetone/water at 10.0°C have been evaluated as a function of the hydroxyl ion and the acetate ion concentration using an analogue computer. The kinetics are consistent with a nonsteady state mechanism in which the primary intermediate anion is protonated giving a neutral species whose concentration goes through a maximum during the course of the reaction. This secondary intermediate forms the final product by deprotonation and release of a chloride ion. The product itself can undergo a second (reversible) deprotonation.In dimethylsulfoxide the analogous intermediate of the hydrolysis of 1, 3‐dimethoxy‐5‐chloro‐s‐triazine can be identified by analysis of the NMR. and UV. spectra.
Komplexone VL. Reaktionsenthalpie und ‐entropie bei der Bildung der 1 : 1‐Komplexe der Seltenen Erdionen mit 1,3‐Diaminopropan‐N, N, N′, N′‐tetraacetat
Authors: Anderegg G. , Wenk F. 
Published: December 2004

AbstractThe stability constants of the 1 :1 complexes of trimethylenediamine‐N, N, N′ N′ tetraacetate ‘TMTA’ with rare earth trivalent cations have been checked. The heats involved in complex formation have been determined.The thermodynamic data show a similar trend as for those of the EDTA complexes, but the discontinuities in the plots ΔH vs. 1/r and ΔS vs. 1/r are displaced towards lower values of 1/r.A change of the coordination number and of the number of coordinated water molecules for the complexes along the series La3+ – Lu3+ is suggested. The simultaneous presence in solution of species differing only in the number of bonded H2O for some members of the series has been confirmed by spectrophotometric measurements in the temperature range 2 to 70°.All facts support the conclusion that in dilute solution all SEIII aquo ions exhibit the same coordination number.
Organische Phosphorverbindungen 44 Darstellung und Eigenschaften von Bis‐(ß‐chloräthyl)‐phosphinsäure‐Derivaten [1]
Authors: Maier Ludwig 
Published: December 2004

AbstractReaction of ClCH2CH2PCl2 with ethylene oxide gives the phosphonous acid ester ClCH2CH2P (OCH2CH2Cl)2 which on heating to 120° rearranges to the phosphinic acid ester (ClCH2CH2)2P(O)OCH2CH2Cl (3). Chlorination of 3 with PCl5 in CCl4‐solution yields the phosphinic chloride (ClCH2CH2)P(O)Cl (4), which on treatment with P2S5 at 170° produces the thioderivative, (ClCH2CH2)2P(S)Cl, (5). Treatment of 4 and 5 with alcohols, mercaptanes, or amines in the presence of an acid binding agent leads to the corresponding phosphinic and thiophosphinic acid derivatives, (ClCH2CH2) P (X)Y, (X = O, S; Y = OR, SR, NR2) (6). Reaction of 6 with excess base yields the corresponding divinylphosphinic and divinylthiophosphinic acid derivatives (CH2 = CH)2P (X) Y (X = O, S; Y = OR, SR, NR2) (7).Bis‐(ß‐chloroethyl)‐phosphinates, e. g. (ClCH2CH2)2P (O) OEt, undergo a Michaelis‐Arbuzov reaction when heated with phosphites to 160–170° to give bis‐(phosphonylethyl)‐phosphinates, e.g. (EtO) (O)P[CH2CH2CH2P(O)(OEt)2]2 (8), which on hydrolysis with conc. HCl under reflux yield the corresponding acid HO2P(CH2CH2PO3H2)2.
Über Ketoxime der 9,10‐Dihydro‐4H‐benzo[4,5]cyclohepta[1,2‐b]thiophene und ihre Umlagerungen zu 4,5,10,11‐Tetrahydro‐benzothienoazocinen. Untersuchungen über synthetische Arzneimittel, 18. Mitteilung [1]
Authors: Bastian J. M. , Ebnöther A. , Jucker E. 
Published: December 2004

AbstractLes oximes des dihydro‐9,10‐4 H‐benzo [4,5] cyclohepta [1, 2‐b] thiophénones‐4 et leurs dérivés ont été synthétisés et transposés selon Beckmann en benzo [b] thiéno [2, 3‐f] azocines et benzo [c] thiéno‐[2,3‐g]azocines. Des dérivés basiques de ces nouveaux composés tricycliques ont été synthétisés.
Thermisches Verhalten von Cyclopropa[c]chromenen
Authors: Hug R. , Fráter Gy. , Hansen H.‐J. , Schmid H. 
Published: December 2004

AbstractThe Cyclopropa[c]chromenes 14, trans‐and cis‐15, trans‐and cis‐16 and 17 rearrange on heating > 200° in N, N‐diethylaniline to give 2‐alkyl‐2H‐chromenes 7, 8, 21, 22. The rate determining step of this rearrangement is the ‘homoelectrocyclic’ ring opening of the cyclopro‐pa[c]chromenes to give ω‐allyl‐quinomethanes of type 4. These intermediates show fast [1,5s] and [1,7a] H‐shifts, followed by electrocyclic ring closure. Deuterium labelling experiments are in agreement with this mechanism. The remarkable dependence of the rates of rearrangement with respect to the stereochemistry of the cyclopropa[c]chromenes (cf. table 2) suggests that in the first step only one of the two possible disrotatory modes of ring opening is involved.
Über den Verteilungssatz der Auxochrome bei Azokörpern, I. Di‐ und Tetramethoxy‐xobenzole
Authors: Kokkinos K. , Wizinger R. 
Published: December 2004

AbstractThe validity of the rule of repartition of the auxochromes is examined for some symmetric tetramethoxy‐azobenzenes, dimethoxy‐azobenzenes, and dimethoxy‐4′‐nitro‐azobenzenes whose methoxy groups are in 2,4‐, 3,4‐ and 2,5‐position. The rule is confirmed with 2,4‐and 2,5‐derivatives. The long wave lengths absorption maxima of 3,4,3′,4′‐tetramethoxy‐azobenzene and of 3,4‐dimethoxy‐4′‐nitro‐azobenzene are situated at shorter wave lengths than expected.
Neue alkaloide aus Adhatoda vasica Nees
Authors: Johne S. , Gröger D. , Hesse M. 
Published: December 2004

AbstractIn addition to the known alkaloid peganine (1) from young plants of the Acanthacea Adhatoda vasica, the base anisotine (7) and the three new alkaloids vasicoline (4), adhatodine (5), and vasicolinone (6) were isolated and analysed. Mainly on the basis of spectral properties (UV., IR., NMR. and mass spectrometry) the structures were assigned. By atmospheric oxygen the bases vasicoline and adhatodine are oxidized in position 7; it is therefore remarkable that these bases are present as such in the plant.
Etude de Composés d'Addition d'acides de Lewis‐XXXII [1]. Composés d'addition d'aldéhydes aliphatiques et aromatiques et de diverses cétones
Authors: Filippini Franchino , Susz Bernard‐P. 
Published: December 2004

AbstractTreize composés d'addition d'aldéhydes et de cétones ont été préparés avec divers acides de Lewis (HgCl2, ZnCl2, CdCl2, SbCl5 et NbCl5). A l'état solide, ils possèdent une stoechiométrie bien définie. Pour tous ces composés d'addition, la fréquence de vibration ω(CO) de la base de Lewis (1600–1700 cm−1) subit un abaissement marqué Δω, allant de −15 cm−1 (HgCl2) à −167 cm−1 (NbCl5), ce qui prouve que leur formation est due à l'établissement d'une liaison de coordination entre l'atome d'oxygène donneur et l'acide de Lewis.Il existe une bonne corrélation linéaire entre ω(CO) des aldéhydes aromatiques ou entre Δω de leurs composés d'addition avec SbCl5 et la constante ωr du type de Hammett ou le potentiel de demi‐vague de la réduction polarographique.Les auteurs ont calculé les constantes de force de H2CO·SbCl5 en se référant aux valeurs expérimentales des fréquences de vibration, en appliquant la méthode FG à un modèle plan de 5 masses. L'abaissement de FCO est d'environ 7%, alors que Δω/ω vaut environ −5%. La variation de longueur de la liaison carbonyle contribue pour 55,7% à l'énergie potentielle de ω(CO) de H2CO et pour 56,4% à celle de H2CO·SbCl5.
Die Valenzisomerisierung des trans‐15, 16‐Dimethyl‐dihydropyrens ‐ ein beitrag zur frage nach der aktivierungsenergie symmetrie‐verbotener prozesse. Vorläufige mitteilung
Authors: Schmidt W. 
Published: December 2004

AbstractConcerted electrocyclic processes which are forbidden according to the symmetry conservation rules of Woodward & Hoffmann, may nevertheless take place at low activation energies. The necessary conditions are exemplified by the unique case of the trans‐15, 16‐dimethyl‐dihydropyrene ⇌ 15, 16‐dimethyl‐[2.2]metacyclophane‐4,9‐diene system.
Über die Bedeutung des Histidins im «Thyrotropin‐releasing» Hormon (TRH)
Authors: Gillessen D. , Studer R. O. , Piva F. , Steiner H. 
Published: December 2004

AbstractThe syntheses and biological activities of 4 analogues of the thyrotropin‐releasing hormone (TRH) are described. In these analogues the histidine residue has been replaced by L‐lysine, L‐α,γ‐diaminobutyric acid, β‐(3‐pyrazolyl)‐L‐alanine, and L‐arginine. All analogues exhibited the characteristic biological responses of TRH. For the β‐(3‐pyrazolyl)‐L‐alanine analogue as well as for TRH the bioassays suggest an induction of a strong and rapid resynthesis of thyrotropin (TSH) in higher (μg) concentrations.
Notiz zur Konstitution des Laurepukins. 8. Mitteilung über natürliche und synthetische Isochinolin‐Derivate
Authors: Weiss Ek. , Bernauer Karl , Girardet A. 
Published: December 2004

AbstractThe alkaloid (−)‐laurepukine is shown to possess one of the epimeric N‐oxide structures 4 or 5. Oxidation of (−)‐pukateine (3) by hydrogen peroxide gives (−)‐laurepukine and, as a second product, 6‐epi‐laurepukine.
Die Komplexbildung der neutralen Amidgruppe mit Cu2+ in wässeriger Lösung
Authors: Kaden Th. , Zuberbühler A. 
Published: December 2004

AbstractThe interaction between Cu2+ and the terdentate ligands N‐picolinoyl‐ethylenediamine, glycine‐2‐pyridylmethylamide, Nα‐(2‐pyridylmethyl)‐glycinamide and Nα‐(2‐pyridylmethyl)‐glycine‐ethylamide, respectively, has been studied by spectrophotometry and potentiometry. At high pH values the ionised amide group undergoes complex formation and the resulting chelates have similar structures and stabilities. In slightly acidic solution however, each ligand gives rise to a different species. These facts are explained by assuming that the neutral amide group coordinates through its carbonyl oxygen atom. The stability constant and the absorption spectrum of each complex have been calculated by computer programmes.
Strahlungschemie von Kohlenwasserstoffen. 19. Mitteilung. Die Deuteriumabspaltung in isotop‐isomeren Cyclohexanen
Authors: Ballenegger M. , Ruf A. , Gäumann T. 
Published: December 2004

AbstractThe G‐value for D2 production has been measured for C6D12 and for gem‐, cis‐, and trans‐C6H10D2. The G‐values for the unimolecular process are 0.24, 0.023, 0.010 and 0.004, resp. In C6D12 two bimolecular processes can be distinguished: one includes ‘hot’ D‐atoms, e. g. a species that shows no isotope effect for the hydrogen abstraction yielding D2 and HD, resp.; its G‐value is 1.22. The other process goes via thermal D‐atoms, it has a G‐value of 1.97 and gives an isotope effect for abstraction: kD/kH = 0.075 (10°C). In the partially deuteriated cyclohexanes, only the former process can be observed. Its G‐value depends on the irradiation temperature and phase, is independent of the position of the D‐atoms in the molecule and amounts to 0.035 (10°C), 0.028 (−40°C solid), 0.040 (−40°C liquid with 25% hexane). The following conclusions can be drawn: the unimolecular detachment shows no intramolecular isotope effect in partially deuteriated molecules and comes only from the gem‐, cis‐ and trans‐positions. Most of the G‐values for the D2 and HD production by different reaction paths can be cross‐checked by G‐values from different mixtures. The agreement between these values is excellent.
Etude de la séparation de traces de mercure ionique par adsorption, en milieu aqueux, sur verre sodocalcique. Application à la séparation Hg2+‐organomercuriels
Authors: Haerdi W. , Gorgia E. , Lakhoual N. 
Published: December 2004

AbstractThe separation conditions of traces of ionic mercury from aqueous solution on microbeads of soda lime are studied theoretically and established experimentally. The formation of a stable complex of the ion with ethylene diamine allows to operate at pH 7–8. The efficiency of the exchange is close to 96%. The methods allows the separation and essay of ionic mercury in presence of various organomercuric compounds.
Struktur von Coleon C, einem neuen Blattfarbstoff aus Coleus aquaticus Gürcke
Authors: Rüedi P. , Eugster C. H. 
Published: December 2004

AbstractFrom the yellow glands on the leaves and inflorescences of Coleus aquaticus Gürcke (Labiatae) a new, yellow diterpenoid hydroquinone, coleon C, C20H26O6, was isolated and its structure elucidated as 1. The compound contains a novel 1‐hydroxyprop‐2‐yl‐side chain at C(13).
Synthese und Eigenschaften von Thiazolo[3,2‐a]pyrimidinen und Thiazolo [3,2‐a] pyrrolo [2,3‐d]pyrimidinen
Authors: Bormann G. , Troxler F. 
Published: December 2004

AbstractFrom the alkali‐catalysed reaction of thiouracil with bromoacetaldehyde diethyl acetal three products are isolated in nearly the same quantity: 2‐(2, 2‐diethoxyethylthio)‐uracil (2) and two cyclization products: 3, a thiazolo[3, 2‐a]pyrimidin‐5‐one, and 4, athiazolo[3, 2‐a]pyrimidin7‐one. By warming with acid both 2 and 4 yield 3. Rearrangement of 4 to 3 proceeds also by heating the hydrochloride. Similar cyclizations leading to thiazolo[3, 2‐d]pyrrolo[2, 3‐d]pyrimidin‐5‐ones are also described. Bromine substitutes 3 in position 6. The bromo derivative 6 on treatment with primary or secondary amines affords 7‐amino compounds.
Structure of boromycin
Authors: Dunitz J. D. , Hawley D. M. , Mikloš D. , White D. N. J. , Berlin Yu. , Marušić R. , Prelog V. 
Published: December 2004

AbstractThe structure II of boromycin C45H74BNO15 (cf. [2]) has been established by combination of chemical evidence with X‐ray analysis. The antibiotic is a D‐valine ester of a Böeseken‐complex of boric acid with a macrodiolide of a new type.
Farbstoffsensibilisierte Photo‐Oxygenierung von(−)‐cis‐Pulegol und (+)‐Pulegon. Zur Addition von O2(1Δg) an Doppelbindungen mit allylständiger. Hydroxyl‐ oder Carbonyl‐Gruppe
Authors: Schulte‐Elte K. H. , Gadola M. , Müller B. L. 
Published: December 2004

Abstract(−)‐cis‐Pulegol (1) and (+)‐pulegone (2) readily add one mole of oxygen on dyesensitized photo‐oxygenation in solution, forming almost exclusively allyl hydroperoxides.The product distributions and structures of the peroxides (B–E) have been derived from analysis of their reduction products. Compound 1 yielded only the diols 4, 5 and 6, besides the epoxyketones 7 and 8 formed directly from the hydroperoxide C (proportions of 4–8, ∼21:56:13:4:6), while 2 gave the keto‐alcohols 9,10 and 11 (∼80:6:14) as the sole products.The course of addition of O2(1Δg) on 1 and 2 was found in all cases to be independent of solvent and photosensitizer.
Recherches sur les arǒmes, 18e communication Sur l'arǒme de viande de boeuf grillée, I. Pyrazines
Authors: Flament I. , Ohloff G. 
Published: December 2004

AbstractA combined gas chromatography‐mass spectrometry analysis of roasted meat flavor prepared by pyrolysis of water‐soluble components of fresh beef has yielded 17 alkylpyrazines (5 already found in heated beef fat), one being a new flavor compound. The mass spectrum of this compound is given.
Rates of Chromium(VI)‐Oxidation of Benzocyclenols
Authors: Müller Paul 
Published: December 2004

AbstractThe oxidation rate of benzocyclobutenol (6) and of the homologous alcohols up to 1‐benzocyclo‐octenol (7) with chromium (VI) has been determined in 90% acetic acid. The rate profile for the oxidation reaction is similar to that obtained for the solvolysis of the corresponding chlorides, and clearly shows a low reactivity for the benzocyclobutenyl skeleton, for reactions in which the hybridization changes from sp3 to sp2. On the other hand, semicarbazone formation occurs faster with benzocyclobutenone (6a) than with the homologous ketones. The implication of these results for the oxidation mechanism is discussed.
Totalsynthese von Steroiden. 1. Mitteilung. rac‐17β‐Hydroxydes‐A‐androst‐9‐en‐5‐on
Authors: Saucy G. , Borer R. , Fürst A. 
Published: December 2004

AbstractIn connection with earlier work on the synthesis of 9β, 10α‐steroids, a new and practical synthesis of rac‐17α‐hydroxy‐des‐A‐androst‐9‐en‐5‐one (19) has been developed, based on a novel stereoselective condensation of 7‐hydroxy‐1‐nonen‐3‐one (3) with 2‐methyl‐cyclopentane‐1, 3‐dione (9) and subsequent transformations of the resulting tricyclic diene ether 12.
Silbermercaptide und ‐mercaptokomplexe
Authors: Tunaboylu K. , Schwarzenbach G. 
Published: December 2004

AbstractThe complex formation of silver(I) has been studied with the anions of simple mercaptans RSH which have been rendered soluble by replacing some H in the substituent R by OH. All equilibria constants refer to a solvent of ionic strength μ = 0,1 and 20°C.Monothioglycol HOCH2CH2SH (pK = 9.48) forms an amorphous insoluble mercaptide {AgSR} (s), ionic product [Ag+] [SR−] = 10−19.7. The solution in equilibrium with the solid contains the molecule AgSR at a constant concentration of 10−6.7 M which furnishes the formation constant of the 1:1‐complex: K1 = 1013. 0. The solid is soluble in excess of mercaptide (AgSR+SR− → Ag(SR)2−: K2 = 104. 8) as well as in an excess of silver ion (AgSR + Ag+ → Ag2SR+K ≈︁ 106).With the bulky monothiopentaerythrite (HOCH2)3CCH2SH (pK = 9.89) no precipitation occurs with silver when the mercaptan concentration is below 10−3. 2M. A single polynuclear Ag10(SR)9+ (β10.9 = 10175) is formed in acidic solutions which breaks up with the formation of Ag2SR+ (β2.1 = 1019.0) when an excess of silver ion is added. Below the mononuclear wall ([RS]total < 10−6) Ag2SR+ is formed via the mononuclear AgSR (K1 = 1013). At higher mercaptan concentrations ([RS]tot > 10−3.2) an amorphous precipitate is formed which has almost the same solubility product as silver thioglycolate ([Ag+] [SR−] = 10−19.1).Apparently silver(I) forms with mercaptans always the complexes Ag2SR+, AgSR and Ag(SR)2−. Above the mononuclear wall, these species condense to chain‐like polynuclears which are cations Ag(SRAg)n+ in presence of an excess of Ag+, and anions SR (AgSR)n− when the concentration [RS−] is larger than [Ag+]. Usually n becomes rapidly very large as soon as the condensation starts (n → ∞: precipitate). The decanuclear Ag(SRAg)9+ formed with thiopentaerythrit is somewhat more stable than the shorter chains (n < 9) and larger chains (n > 9), because it can tangle up to a ball by coordination of bridging mercapto‐sulfur to the terminal silver ions (figure 12, page 2179). This ball seems to be further stabilized by hydrogen bonds between the many alcoholic OH groups of the substituent R = (HOCH2)3CCH2. The stability of the bonds AgS, however, is little influenced by the substituent R which carries the mercaptide sulfure.