In the past G. Märkl has collaborated on articles with G. Graser and M. Duchoslav. One of their most recent publications is Zur chemie des cyclooctatetraenyldilithiums: 9.(N,N-dialkylamino)-9-phosphabicyclo[4.2.1]nona-2,4,7-triene, 9-halogen-9-phosphabicyclo[14.2.1]Nona-2,4,7-triene und deren nucleophile substitution, 9-H-9-phosphabicyclo]4.2.1]nona-2,4,7-trien. Which was published in journal Journal of Organometallic Chemistry. More information about G. Märkl research including statistics on their citations can be found on their Copernicus Academic profile page.
AbstractN, N(Dialkylamino)-dichlorophosphanes react with cyclooctatetraenyldilithium to give the syn/anti-9-(N,N-dialkylamino)-9-phosphabicyclo[4.2.1]nona-2,4,7-trienes 5 (syn/anti ratio 100/0 to 54/46); syn-9-(N,N-Diethylamino)-9- phosphabicyclo[4.2.1]nona-2,4,7-triene (5a) is halogenated with PCl3 and PBr3 respectively to form the syn/anti-9-chloro(9-bromo)-9-phosphabicyclo[4.2.1.]nona-2,4,7- trienes 6a,6b (ratio of the isomers 30/70). The 9-fluoro derivative 6c can be obtained from 6a by Cl → F exchange with KF/-crown-6 as a syn/anti mixture (60/40). The 1H and 31P NMR spectra of all the syn/anti isomers are discussed.The stereochemistry of the nucleophilic substitution of syn/anti-9-chloro-phosphane 6a with lithium alkyls, with phenolates, thiophenolates and alcoholates is studied.By reduction of 6a with LiAlH4 the 9-H-9-phosphabicyclo[4.2.1]nona-2,4,7-triene 12 is obtained as a mixture of the syn/anti isomers (38/62).The phosphide anion 13, obtained by reaction of 12 with n-BuLi, does not rearrange into the 10π-system of the trans,cis,cis,cis-phosphoninyl anion 2.
AbstractAminoacidesters and hydroxymethylphosphines form the title compounds, which react as bidentate ligands with Mo (CO)6 to give the cyclic Mo (CO)4 -complexes.
Abstract1,1-Dialkyl-4R-1-silacyclohexa-2,4-dienes as well as 1,1-diaryl-4R-1-silacyclohexa-2,4-dienes (R = cyclo-C6H11, C(CH3)3, C6H5) react with Fe(CO)5 at 150–170°C to give Fe(CO)3 complexes. By the same method also the corresponding complexes of 1-silacyclohexa-2,4-dienes with functional groups at the silicon atom can be prepared. The 1-methyl-1-methoxy-(-isopropoyx-, -chloro-)4-cyclohexyl-1-silacyclohexa-2,4-dienes react with Fe(CO)5 at 180°C and form mixtures of diastereotopic endo/exo-Fe(CO)3 complexes. 1-Methyl-1,6-dichloro-4-cyclohexyl-1-silacyclohexa-2,4-diene reacts with Fe(CO)5 by reductive dimerisation at the 6-position to give the 6,6′-linked1-methyl-1-chloro-1-silacyclohexa-2,4-diene dimer, which forms a monoFe(CO)3 complex. The 90 MHz 1H NMR, 13C NMR, IR and mass spectra are discussed.
AbstractThe persodic, 1.16 Ga old Ilímaussaq intrusion consists of alkali granites, syenites, and agpaitic nepheline syenites. These rocks are cut by late-magmatic veins and lenses consisting of albite, aegirine, ussingite (Na2AlSi3O8(OH)), fluorite, and occasionally quartz. Oxygen-isotope compositions of quartz indicates both orthomagmatic (δ18Oqtz = 8.5‰) and country rock-influenced (δ18Oqtz ~ 10‰) origin. While albite and aegirine do not contain fluid inclusions suitable for investigations, ussingite contains secondary hydrocarbon fluid inclusions, fluorite contains brine inclusions of primary and secondary origin with up to 26.3 wt.% NaClequiv., and quartz contains predominantly secondary brine inclusions with up to 29.7 wt.% NaClequiv. or CH4–H2O–NaCl mixtures. These fluids are interpreted to reflect fluids in equilibrium with late-stage melts at Ilímaussaq at ≤ 450 °C.The carbon- and hydrogen-isotope composition of CH4 in ussingite (δ13C = − 6 to − 3‰, δD = ~− 121‰) is indicative of a magmatic abiogenic origin. However, the isotopic composition of CH4 in fluid inclusions in quartz veins resembles the signature of thermogenic CH4 (δ13C = − 43 to − 23‰, δD = − 176 to − 121‰), but the higher hydrocarbons are mostly 13C-depleted in relation to CH4 (up to 7.3‰), which is typical of abiogenically-derived hydrocarbons.Ion-chromatography of fluid inclusion leachates from the late-stage veins reveals Cl/Br ratios of ~ 100. As such values seem to be typical of peralkaline magmatic rocks, at least in the Gardar Province of South Greenland, it is suggested that this ratio is typical of Gardar magmatic fluids and may be characteristic of the Cl/Br ratio of the lithospheric mantle from which these alkaline melts are derived.
ZusammenfassungBy reaction of λ5-phosphabutatrienes (4, n = 2) and λ5-phosphaallenes (4, n = 1) with (2,4,6-tri-tert-butyl)phenylmonochlorophosphane 2 the title compounds are formed.
AbstractOptically active N.N′-bis[(1-phenyl)-1-ethyl]-ethylendiamine reacts with aryl- and alkyl-bis-hydroxymethylphosphines and diaryl-hydroxymethyl-phosphines to give the title compounds. The molybdenum-complexes of the diphosphines are described.
AbstractDepending on the reaction conditions the carbene, formed by N2-elimination out of the title compound rearranges by silyl-migration to give the silabenzene and by carben-migration to give the silafulvene as reactive intermediates.In der Literatur sind Beispiele für die 1,2-Verschiebung von Silylresten auf benachbarte - aus Diazoalkanen 1 erseugte - Carben-C-Atome in 2 unter Bildung der Silaalkene 3 bekannt .
ZusammenfassungThe title compounds react with nitrilimines, nitriloxides and 1.3-dienes to give the corresponding regular 1.3-dipolar respectively Diels-Alder-cycloadducts with the PC-bond.
AbstractThe title compounds are obtained by reaction of 5-methyl-1,3,4-oxathiazol-2-one with phosphaalkenes. Arguments for the intermediate formation of the P-analog of nitrilsulfides (via the thiaphosphirenes) as 1,3-dipoles are presented.
Highlights•Late-magmatic and hydrothermal tourmaline is distinguished by texture and composition.•Tourmaline records element partitioning during fluid exsolution.•Zoned tourmaline unravels the hydrothermal history of ore precipitating fluids.•As potential exploration tool tourmaline records Sn concentration and redox state.