1,2-Alkylsubstituierte Phenanthrene und Dihydrophenanthrene

Zusammenfassung Die Synthese von 1,2-Diäthylphenanthren und 1,2-Diäthyl-3,4-dihydrophenanthren wird beschrieben. Weiters werden die UV- und die IR-Spektren der genannten Verbindungen sowie von 1-Methyl-2-äthylphenanthren und 1-Methyl-2-äthyl-3,4-dihydrophenanthren angeführt.Mit 2 Abbildungen     

Lichtabsorption und konstitution heterocyclischer 1,2-endiole

The symmetrical direction of two donor and acceptor groups around a central CC-double bond has been found out as the chromophore of the heterocyclic 1,2-enedioles. Non-bonded interactions are jointly responsible for the position of the longest-wavy π-π^*-transition. Several substituents in different positions of the molecule affect the electronic spectra in a different way.     

Vernetzung und Oxidation von 1,2-Polybutadien durch UV-Bestrahlung

Ohne Zusammenfassung     

Synthese und Charakterisierung von Metallocen-Chelaten heterocyclischer 1,2-Diselenolate

Synthesis and Characterization of Metallocene Chelates of Heterocyclic 1,2-Diselenolates Synthesis and properties of metallocen diselenolates Cp₂^RML (Cp^R = η⁵-C₅H₄CH₃ (Cp′); η⁵-C₅(CH₃)₄ C₂H₅ (Cp^o)) of titanium(IV) and vanadium(IV) with L = dsit (1,3-dithiole-2-thione-4,5-diselenolate), dsise (1,3-dithiole-2-selone-4,5-diselenolate) dsitse (1,3-thiaselenole-2-selone-4,5-diselenolate) and dsis (1,3-diselenole-2-selone-4,5-diselenolate) are described. The structures of these compounds in solution are discussed using ¹H, ¹³C, ⁷⁷Se NMR and EPR data. Their voltammetric behaviour is investigated in dichloromethane. The activation parameters of the chelate ring inversion of the titanocene diselenolates (Cp₂^RTiL) and the x-ray structures of Cp₂′Ti(dsit), Cp₂^oTi(dsit); Cp₂^oTi(dsise) (2 modifications) and Cp₂^oTi(dsis) are reported.     

Nachweis und Bestimmung von Kobalt mittels 1,2-Nitro-naphthols

Ohne Zusammenfassung     

Vernetzung und Oxidation von 1,2-Polybutadien durch UV-Bestrahlung

Ohne Zusammenfassung     

Synthese und Charakterisierung von Metallocen-Chelaten heterocyclischer 1,2-Dithiolate

Synthesis and Characterization of Metallocene Chelates of Heterocyclic 1,2-Dithiolates Synthesis and properties of metalocene dithiolene chelates Cp₂ML with metal(IV) ions (M) of group IVA (Ti, Zr, Hf) and of vanadium with L = dmit (1,3-dithiole-2-thione-4,5-dithiolate), dmt (1,2-dithiole-3-thione-4,5-dithiolate), dmid (1,3-dithiole-2-one-4,5-dithiolate) and dmise (1,3-dithiole-2-selone-4,5-dithiolate) are described. The structures of these compounds were discussed using IR-, UV/VIS-, ¹H-NMR-, ¹³C-NMR- and EPR data. The activation parameters of the chelate ring inversion of titanocene dithiolenes (Cp₂TiL) and the x-ray structure of Cp₂Ti(dmid) are given.     

Schwingungsspektren und Kraftkonstanten des Monothio-, 1,1-Dithio-, 1,2-Dithio- und Trithiooxalat-Ions

The i.r. and Raman spectra of the monothio-, 1,1-dithio-, 1,2-dithio- and trithio-oxalate ion in the solid state and in solution are reported. The fundamentals are assigned on the basis of normal coordinate analyses and of Raman polarisation data. Force constants for identical internal coordinates can be transferred without change within this series. In all ions the carboxylic groups are in a staggered conformation. A possible exception is the monothio-oxalate ion in the barium and lead salt.     

1,2-Dimethyl-3,5-dioxopyrazolidin und seine Kondensations-produkte mit Aldehyden

Zusammenfassung 1,2-Dimethyl-3,5-dioxopyrazolidin wird durch direkte Umsetzung von Malonsäuredimethylester und sym-Dimethylhydrazin erhalten. Kondensation dieser Verbindung mit aliphatischen und aromatischen Aldehyden liefert elektrisch neutrale organische Lewissäuren, die in bezug auf die UV-Absorption weitestgehend den entsprechenden cyclischen Isopropylidenacylalen von Alkylund Aryl-methylenmalonsäuren gleichen.1,2-Dimethyl-3,5-pyrazolidinedione obtained directly from dimethyl malonate and sym.-dimethylhydrazine. Condensation with aliphatic and aromatic aldehydes leads to electrically neutral organic Lewis acids. Their UV-spectra are similar to those of the corresponding cyclic isopropylidene acylals of substituted malonic acids.Herrn Prof. Dr.Leopold Schmid zum 70. Geburtstag gewidmet.     

1,2-Bis(dimethylamino)-3,4,5-triphenyl-3,4,5-triphospha-1,2-diborolan und 1,2-Bis(dimethylamino)-3,4,5,6-tetra-tbutyl-3,4,5,6-tetraphospha-1,2-diborin: Synthese und Struktur sowie Berechnungen zur Molekülstruktur

1,2-Bis(dimethylamino)-3,4,5-triphenyl-3,4,5-triphospha-1,2-diborolane and 1,2-Bis(dimethylamino)-3,4,5,6-tetra-tbutyl-3,4,5,6-tetraphospha-1,2-diborine: Synthesis and Structure as well as Calculations on the Molecular Structure The diphosphides K₂[(C₆H₅)P? (C₆H₅)P? P(C₆H₅)], 4 or K₂[(tBuP)? (tBuP)₂? P(tBu)], 5 , react with (ClBNMe₂)₂ to form the binary 5-membered ring system 1,2-bis(dimethylamino)-3,4,5-triphenyl-3,4,5-triphospha-1,2-diborolane (C₆H₅P)₃(BNMe₂)₂, 2a , and the 6-membered ring system 1,2-bis(dimethylamino)-3,4,5,6-tetra-tbutyl-3,4,5,6-tetraphospha-1,2-diborine, (tBuP)₄(BNMe₂)₂, 3a , respectively. 2a and 3a could be obtained in a pure form and characterized NMR spectroscopically and by X-ray structure analyses. The two ring systems are folded; 2a exists in the ?envelope”?- 3a in the ?boat”?-conformation. Ab initio computations for 3,4,5-triphospha-1,2-diborolane M5 show that the global minimum is characterized by one B? P double bond. The parent compound geometry M6 is characterized by transannular bonding in the PH? BH? BH? PH moiety which differs in character from those in the four- and five-membered rings (BH)₂(PH)₂ and (BH)₂(PH)₃ M5 d , respectively. Explicit calculation of the influence of amino substituents on boron improved agreement of the bond length between computed and X-ray data.     

Zwischenmolekulare Wechselwirkungen von Jod mit 1,2-Bis-pyridyl-ethylenen und -acetylenen

Spectra of trans-1,2-bis-(2-pyridyl)-ethylene (I), cis-1,2-bis-(2-pyridyl)-ethylene (II), trans-1,2-bis-(4-pyridyl)-ethylene (III), cis-1,2-bis-(4-pyridyl)-ethylene (IV), 1,2-bis-(2-pyridyl)-acetylene (V) and 1,2-bis-(4-pyridyl)-acetylene (VI) with low molar amounts of iodine, in dilute solutions in dichloromethane, are studied in the visible spectral region. Wavelengths and molar extinction coefficients for the shifted iodine band in the visible region, equilibrium constants and the wavelength of the isosbestic point for each system are reported. The experimental results are attributed to the formation of complexes between I–VI and iodine in which one pyridyl ring in I–VI is coordinated with one molecule of iodine.