scholarly journals REFRACTIVE INDICES OF THE SYSTEMS URANIUM HEXAFLUORORIDE-BROMINE TRIFLUORIDE AND URANIUM HEXAFLUORIDE-BROMINE PENTAFLUORIDE

1953 ◽  
Author(s):  
L Stein ◽  
R C Vogel
Keyword(s):  
Uranium Hexafluoride ◽  
Refractive Indices ◽  
Bromine Trifluoride

Recent Advances in the Synthesis of Acyl Fluorides

Synthesis ◽  
2020 ◽  
Author(s):  
Marie Gonay ◽  
Chloé Batisse ◽  
Jean-François Paquin
Keyword(s):  
Transition Metal ◽  
Organic Synthesis ◽  
Peptide Synthesis ◽  
Uranium Hexafluoride ◽  
Metal Catalysts ◽  
Recent Advances ◽  
Transition Metal Catalyzed ◽  
Metal Catalyzed ◽  
Nucleophilic Fluorination ◽  
Bromine Trifluoride

AbstractAcyl fluorides are valuable intermediates in organic synthesis. They are increasingly employed in peptide synthesis, in challenging esterification and amidation reactions or in transition-metal-catalyzed transformations. This review summarizes recent advances in their preparation.1 Introduction2 Nucleophilic Fluorination2.1 α-Fluoroamine Reagents2.2 Sulfur-Based Reagents2.3 Metal Catalysts2.4 Phosphorus-Based Reagents2.5 N,N′-Dicyclohexylcarbodiimide/HF·Pyridine2.6 Uranium Hexafluoride2.7 Bromine Trifluoride3 Radical Fluorination4 Conclusion

The spindle stage: A powerful optical tool

1988 ◽  
Vol 46 ◽  
pp. 52-53
Author(s):  
Mickey E. Gunter ◽  
F. Donald Bloss
Keyword(s):  
Significant Error ◽  
Optical Data ◽  
Refractive Indices ◽  
Axis Of Rotation ◽  
Polarizing Microscope ◽  
Microscope Stage

A single, reasonably homogeneous, nonopaque 30-to-300 μm crystal, mounted on a spindle stage and studied by immersion methods under a polarizing microscope, yields optical data frequently sufficient to identify and characterize a substance unequivocally. The data obtainable include (1) the orientation of the crystal's principal vibration axes and (2) its principal refractive indices, to within 0.0002 if desired, for light vibrating along these principal vibration axes. Spindle stages tend to be simple and relatively inexpensive, some costing less than $50. They permit rotation of the crystal about a single axis which is parallel to the microscope stage. This spindle or S-axis is thus perpendicular to the M-axis, namely the microscope stage's axis of rotation.A spindle stage excels when studying anisotropic crystals. It orients uniaxial crystals within minutes and biaxial crystals almost as quickly so that their principal refractive indices - ɛ and ω (uniaxial); α, β and γ (biaxial) - can be determined without significant error from crystal misorientation.

Light microscopy of ceramics

1993 ◽  
Vol 51 ◽  
pp. 908-909
Author(s):  
Walter C. McCrone
Keyword(s):  
Refractive Index ◽  
Light Microscopy ◽  
Light Microscope ◽  
Polarized Light ◽  
Refractive Indices ◽  
Complete Coverage ◽  
The Subject ◽  
Lower Refractive Index

An excellent chapter on this subject by V.D. Fréchette appeared in a book edited by L.L. Hench and R.W. Gould in 1971 (1). That chapter with the references cited there provides a very complete coverage of the subject. I will add a more complete coverage of an important polarized light microscope (PLM) technique developed more recently (2). Dispersion staining is based on refractive index and its variation with wavelength (dispersion of index). A particle of, say almandite, a garnet, has refractive indices of nF = 1.789 nm, nD = 1.780 nm and nC = 1.775 nm. A Cargille refractive index liquid having nD = 1.780 nm will have nF = 1.810 and nC = 1.768 nm. Almandite grains will disappear in that liquid when observed with a beam of 589 nm light (D-line), but it will have a lower refractive index than that liquid with 486 nm light (F-line), and a higher index than that liquid with 656 nm light (C-line).

On electronic polarizabilities and refractive indices in SbSI crystal

1983 ◽  
Vol 44 (12) ◽  
pp. 349-359
Author(s):  
Wataru Kinase ◽  
Tadataka Morishita ◽  
Yutaka Hiyama ◽  
Tomoo Maeda
Keyword(s):  
Refractive Indices
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