An interesting azirine induced reaction of the cyclopentadienyliron dicarbonyl dimer

1979 ◽  
Vol 57 (12) ◽  
pp. 1541-1543 ◽  
Author(s):  
Howard Alper ◽  
Tsutomu Sakakibara
Keyword(s):  
Iron Atom ◽  
Anhydrous Benzene ◽  
Room Temperature ◽  
Induced Reaction

Reaction of cyclopentadienyliron dicarbonyl dimer with a series of 2-arylazirines in anhydrous benzene (room temperature or 40 °C, 41–96 h) affords cycloaddition products (pyrazines, isoxazoles) and the dimer of cyclopentadienone (1,8-diketo-4,7-methano-3a,4,7,7a-tetrahydroindene). The formation of the latter product is proposed to occur via a complex in which each cyclopentadienyl ring is π-complexed to one iron atom and σ-bound to another.

Photochemically Induced C-H Bond Activation and Ligand Transfer in the Reaction of [Cp2Rh2(CO)(CF3C2CF3)] With [(Cp′) Mn (CO)2( thf )]: Structural Characterization of the Rh4 Product

1994 ◽  
Vol 47 (8) ◽  
pp. 1613 ◽  
Author(s):  
RS Dickson ◽  
MJ Liddell ◽  
BW Skelton ◽  
AH White
Keyword(s):  
Room Temperature ◽  
Bond Activation ◽  
X Ray Diffraction ◽  
Full Matrix ◽  
X Ray ◽  
Corrected Data ◽  
Ligand Transfer ◽  
Hydrocarbon Solution ◽  
Induced Reaction

A room-temperature single-crystal X-ray diffraction study carried out on a product of a sunlight induced reaction between [Cp2Rh2(CO)(CF3C2CF3)] and [(Cp′) Mn (CO)2( thf )] in 2:1 ratio in hydrocarbon solution establishes it to be tetranuclear [(Cp4Rh4)(CF3C=CHCF3)2(CH3-C5H3)]; crystals of the latter are triclinic, Pī , a 15.803(9), b 13.445(8), c 8.966(6) Ǻ, α 75.92(5), β 80.68(5), γ 65.46(4)°, Z = 2. Full-matrix refinement for 3431 'observed' [I > 3σ(I)], absorption-corrected data converged at R 0.056. The structure comprises a pair of enantiomeric [(Cp2Rh2)(CF3C=CHCF3 binuclear units unsymmetrically linked by the central CH3C5H3 ring, by way of the η1,η2-C=CH and η1,η2-C= CMe functionalities.

Thio derivatives of β-diketones and their metal chelates. X. The anomalous paramagnetism of some iron(III) chelates of monothio-β-diketones

1968 ◽  
Vol 21 (8) ◽  
pp. 1987 ◽  
Author(s):  
RKY Ho ◽  
SE Livingstone
Keyword(s):  
Iron Atom ◽  
Thermal Equilibrium ◽  
Room Temperature ◽  
Magnetic Behaviour ◽  
The Other ◽  
Ligand Field ◽  
Pairing Energy ◽  
Temperature Dependent ◽  
Magnetic Susceptibilities ◽  
Derivatives Of

The magnetic susceptibilities of the iron(111) chelates Fe(R1CS=CHCOR2)3 (R1 = Ph, p-MeC6H4, p-MeOC6H4, p-BrC6H4, 2-thienyl, 2-furyl, R2 = CF3; R1 = Ph, R2 = Ph, OEt) have been investigated over a temperature range. The iron(111) complex of ethyl thiobenzoylacetate (R1 = Ph, R2 = OEt) is of the high-spin type and obeys the Curie-Weiss law with θ =-8�k. The moments of the other complexes vary between 2.31 and 6.61 B.M. at room temperature and are temperature-dependent, ranging from 1.86 to 4.07 B.M. at 80�k, depending on the nature of R1 and R2 This behaviour is postulated to be due to a thermal equilibrium between the nearly equi-energetic spin-paired (t5/2g) and spin-free (t3/2ge2/g) configurations of the iron atom, resulting from the approximately equal magnitudes of the ligand field (Δ) and the pairing energy (π) in these complexes. The ligand field and consequently the magnetic behaviour are sensitive to the nature of R1 and R2: electron-withdrawing groups appear to be the most effective in increasing the population of the spin-paired configuration.

Mechanically induced reaction between alkaline earth metal oxides and TiO2

1998 ◽  
Vol 13 (6) ◽  
pp. 1607-1613 ◽  
Author(s):  
N. J. Welham
Keyword(s):  
Metal Oxides ◽  
Alkaline Earth ◽  
Room Temperature ◽  
Lattice Strain ◽  
Earth Metal ◽  
Alkaline Earth Metal ◽  
X Ray Diffraction ◽  
X Ray ◽  
Alkaline Earth Metal Oxides ◽  
Induced Reaction

This paper outlines the formation of alkaline earth metal titanates, of the general formula MTiO3, directly from the metal oxides and rutile by mechanical activation in a laboratory ball mill at room temperature. X-ray diffraction analysis showed that the reaction was essentially complete within 100 h for all metals except magnesium. The titanates formed all had a Scherrer crystallite size of 11–12 nm and a lattice strain of 0.5–0.6%, neither of which were affected by extended milling. Annealing studies confirmed that the titanate was formed during milling and showed that grain growth could be achieved at temperatures below that generally used for their formation. Mixed cation titanates could also be formed by milling, but tended to be barium rich until annealed.

Role of reaction media in "green" radiation-induced polymerization of white phosphorus

2009 ◽  
Vol 81 (11) ◽  
pp. 2115-2122 ◽  
Author(s):  
Natalia P. Tarasova ◽  
Yury V. Smetannikov ◽  
Alexander S. Vilesov ◽  
Alexey A. Zanin
Keyword(s):  
Ionic Liquids ◽  
Dimethyl Sulfoxide ◽  
Room Temperature ◽  
White Phosphorus ◽  
Phosphorus Containing ◽  
Radiation Induced ◽  
Reaction Media ◽  
Induced Reaction ◽  
Green Radiation

Phosphorus-containing polymers were synthesized using a "green" radiation-induced reaction at room temperature in the presence of ionic liquids (ILs). The nature of ILs allowed us to adjust the properties of reaction media (dimethyl sulfoxide, DMSO–benzene solvents). The effects of various factors on the efficiency of the synthesis of phosphorus-containing polymers are discussed.

Dependence of Intergranular Fracture on Boundary Topography and Cohesion

1973 ◽  
Vol 31 ◽  
pp. 150-151
Author(s):  
J. E. Doherty ◽  
A. F. Giamei ◽  
B. H. Kear ◽  
C. W. Steinke
Keyword(s):  
Grain Boundary ◽  
Room Temperature ◽  
Nickel Base Superalloy ◽  
Boundary Shear ◽  
Room Temperature Ductility ◽  
Solid Solution Matrix ◽  
Nickel Base ◽  
Solution Matrix ◽  
Different Levels ◽  
Base Superalloy

Recently we have been investigating a class of nickel-base superalloys which possess substantial room temperature ductility. This improvement in ductility is directly related to improvements in grain boundary strength due to increased boundary cohesion through control of detrimental impurities and improved boundary shear strength by controlled grain boundary micros true tures.For these investigations an experimental nickel-base superalloy was doped with different levels of sulphur impurity. The micros tructure after a heat treatment of 1360°C for 2 hr, 1200°C for 16 hr consists of coherent precipitates of γ’ Ni3(Al,X) in a nickel solid solution matrix.

Hepatocyte Alterations in Guinea Pigs FED Polychlorinated Biphenyls (PCBs), Dibenzodioxins (PCDD), AND DIBENZOFURANS (PCDF)

1982 ◽  
Vol 40 ◽  
pp. 56-57
Author(s):  
J. N. Turner ◽  
D. N. Collins
Keyword(s):  
Guinea Pigs ◽  
Room Temperature ◽  
Dose Group ◽  
Methyl Cellulose ◽  
Uranyl Acetate ◽  
Target Organ ◽  
Office Building ◽  
Lead Citrate ◽  
Control Groups ◽  
Cooling Fluid

A fire involving an electric service transformer and its cooling fluid, a mixture of PCBs and chlorinated benzenes, contaminated an office building with a fine soot. Chemical analysis showed PCDDs and PCDFs including the highly toxic tetra isomers. Guinea pigs were chosen as an experimental animal to test the soot's toxicity because of their sensitivity to these compounds, and the liver was examined because it is a target organ. The soot was suspended in 0.75% methyl cellulose and administered in a single dose by gavage at levels of 1,10,100, and 500mgm soot/kgm body weight. Each dose group was composed of 6 males and 6 females. Control groups included 12 (6 male, 6 female) animals fed activated carbon in methyl cellulose, 6 males fed methyl cellulose, and 16 males and 10 females untreated. The guinea pigs were sacrificed at 42 days by suffocation in CO2. Liver samples were immediately immersed and minced in 2% gluteraldehyde in cacadylate buffer at pH 7.4 and 4°C. After overnight fixation, samples were postfixed in 1% OsO4 in cacodylate for 1 hr at room temperature, embedded in epon, sectioned and stained with uranyl acetate and lead citrate.

Domain Formation in Synthetic Quartz

1971 ◽  
Vol 29 ◽  
pp. 156-157
Author(s):  
Joseph J. Comer
Keyword(s):  
Electron Beam ◽  
Room Temperature ◽  
Domain Formation ◽  
Synthetic Quartz ◽  
Transmission Electron ◽  
Black Spots ◽  
Diffraction Mode ◽  
Domain Boundaries ◽  
Kikuchi Lines ◽  
Straight Lines

Domains visible by transmission electron microscopy, believed to be Dauphiné inversion twins, were found in some specimens of synthetic quartz heated to 680°C and cooled to room temperature. With the electron beam close to parallel to the [0001] direction the domain boundaries appeared as straight lines normal to <100> and <410> or <510> directions. In the selected area diffraction mode, a shift of the Kikuchi lines was observed when the electron beam was made to traverse the specimen across a boundary. This shift indicates a change in orientation which accounts for the visibility of the domain by diffraction contrast when the specimen is tilted. Upon exposure to a 100 KV electron beam with a flux of 5x 1018 electrons/cm2sec the boundaries are rapidly decorated by radiation damage centers appearing as black spots. Similar crystallographio boundaries were sometimes found in unannealed (0001) quartz damaged by electrons.

A Liquid Nitrogen Cooled Stage for STEM

1974 ◽  
Vol 32 ◽  
pp. 444-445
Author(s):  
Louis T. Germinario
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Liquid Nitrogen ◽  
Room Temperature ◽  
Objective Lens ◽  
Thermal Drift ◽  
Specimen Holder ◽  
Resolution Capability ◽  
Focal Position

A liquid nitrogen stage has been developed for the JEOL JEM-100B electron microscope equipped with a scanning attachment. The design is a modification of the standard JEM-100B SEM specimen holder with specimen cooling to any temperatures In the range ~ 55°K to room temperature. Since the specimen plane is maintained at the ‘high resolution’ focal position of the objective lens and ‘bumping’ and thermal drift la minimized by supercooling the liquid nitrogen, the high resolution capability of the microscope is maintained (Fig.4).

Sign in / Sign up

Export Citation Format

Share Document