Search results for "METHANE"
showing 10 items of 1763 documents
A Three-Component Palladium-Catalyzed Oxidative CC Coupling Reaction: A Domino Process in Two Dimensions
2013
Methane and carbon monoxide infrared emissions observed at the Canada-France-Hawaii Telescope during the collision of comet SL-9 with Jupiter
1995
Observations with the Fourier Transform Spectrometer were conducted in spectral ranges from 1.6 to 4.7 µm from July 17 to 21 (UT) on the hot plumes appearing on the limb as well as hours or days after the impacts. We present here an analysis of the methane emission observed at 3.3 µm some 10 min after the C impact, indicating the presence of a very small (less than 100 km wide) hot region with temperatures in the 750–1500 K range within the 0.1- to 0.01-mbar region. We also report the detection of CO emission at 4.7 µm 4.5 hrs after the L impact, indicative of a temperature of 274±10 K at the ∼1016 CO molec cm−2 level. The observations suggest that the stratospheric temperature decreases wi…
One‐pot synthesis of [2+2]‐helicate‐like macrocycle and 2+4‐μ 4 ‐oxo tetranuclear open frame complexes: Chiroptical properties and asymmetric oxidati…
2020
Constitution and conductivity of metalloporphyrin tapes
2020
Supported Single Atom Catalysts for C−H Activation: Selective C−H Oxidations, Dehydrogenations and Oxidative C−H/C−H Couplings
2021
Biindenyls, Biindenylides, and Diindeno‐Fused Heterocycles from Oxidative Coupling of 1‐ and 2‐Indanone
1988
1- and 2-indanone are transformed into the corresponding enolates and oxidatively coupled to yield 1,4-diketones providing easy access to a series of biindenyls, diindeno-fused heterocycles, and biindenylides. Biindenyle, Biindenylide und Diindeno-kondensierte Heterocyclen durch oxidative Kupplung von 1- und 2-Indanon 1- und 2-Indanon werden in die Enolate ubergefuhrt und oxidativ zu 1,4-Diketonen gekuppelt. Diese bieten einen einfachen Zugang zu einer Reiher von Biindenylen, Diindeno-kondensierten Heterocyclen und Biindenyliden.
Iron(II) Spin Transition Complexes with Dendritic Ligands, Part I
2008
The ligands G1- and G2-oligo (benzyl ether) (PBE) dendrons and their iron(II) complexes [Fe(Gn-PBE)3]A2·xH2O (with n = 1, 2 and A = triflate, tosylate) were prepared. The magnetic properties of the complexes were investigated by a SQUID magnetometer. All complexes exhibit gradual spin transition below room temperature. At very low temperatures the magnetic behaviour reflects zero-field splitting (ZFS) effects. 57Fe-Mossbauer spectroscopy was performed to distinguish between ZFS of high spin species and spin state conversion into the low spin state. Further characterisation was carried out by thermogravimetric analysis (TGA) and FT-IR spectroscopy. Structural features have been determined by…
Ferromagnetic coupling and spin canting behaviour in heterobimetallic ReIVMII/III(M = CoII/III, NiII) species
2012
Three novel heterobimetallic Re(IV) compounds of formulae [ReBr(4)(μ-ox)M(4,7-Cl(2)phen)(2)]·CH(3)CN·CH(3)NO(2) [M = Co(II) (1) and Ni(II) (2)] and [ReBr(4)(ox)](3)[Co(III)(5,6-dmphen)(3)](2)·CH(3)CN·2CH(3)NO(2)·4H(2)O (3) [ox = oxalate, 4,7-Cl(2)phen = 4,7-dichloro-1,10-phenanthroline and 5,6-dmphen = 5,6-dimethyl-1,10-phenanthroline] have been synthesised and the structures of 1 and 3 determined by single crystal X-ray diffraction. Compound 1 is an oxalato-bridged Re(IV)Co(II) heterodinuclear complex where the [ReBr(4)(ox)](2-) unit acts as a bidentate ligand towards the [Co(4,7-Cl(2)phen)(2)](2+) entity, the separation between Re(IV) and Co(II) across the oxalate being 5.482(1) Å. Compou…
Synthesen mit substituierten Malondialdehyden, XI. γ‐Formyl‐tetramethinmerocyanin‐, γ‐Formyl‐pentamethincyanin‐ und [2.2.2]Heptamethincyanin‐Farbstof…
1972
Durch Kondensation des Formylmalondialdehyds (Triformylmethan) 5 mit heterocyclischen Imoniumsalzen 4 werden je nach Reaktionsbedingungen neuartige γ-Formyl-tetramethinmerocyanin-(6), γ-Formyl-pentamethincyanin-(8) und trinucleare symmetrische [2.2.2]Heptamethincyanin-Farbstoffe (9) dargestellt. Die Isolierung der Mono- (6) und Dikondensationsprodukte (8) des Formylmalondialdehyds ermoglicht die Darstellung unsymmetrischer Farbstoffe 8 und 9 mit verschiedenen Endgruppen. — Die trinuclearen [2.2.2]Heptamethincyanine 9 lassen sich in Analogie zu den phenylogen Guanidiniumionen (Triphenylmethanfarbstoffe) als methinyloge Guanidiniumkationen 3 (n = 3) auffassen. — Die spektroskopischen Eigensch…
Cationic Iron Aminocarbene Complexes as Dienophiles in Diels‐Alder Reaction with Cyclopentadiene
1996
The cationic iron (alkynyl)aminocarbene complexes [Cp(CO)2Fe(C(NHR)CCSiMe3][PF6], (R C6H5, p-CH3C6H4) 1 derived from aromatic amines smoothly react with cyclopentadiene in dichloromethane to yield the cycloadducts 2. No reaction was observed for complexes derived from sterically demanding aliphatic amines, like L-alanine tert-butyl ester. For comparison, the alkynyl-substituted acyl iron compounds Cp(CO)2Fe(CO)CC (R SiMe3, C6H5) 3 were investigated, requiring TiCl4 catalysis to undergo the cycloaddition reaction. The structures of the cycloadducts 4 were determined by X-ray crystallography.