Search results
Results from the WOW.Com Content Network
Boron tribromide is commercially available and is a strong Lewis acid.. It is an excellent demethylating or dealkylating agent for the cleavage of ethers, also with subsequent cyclization, often in the production of pharmaceuticals.
Boron trifluoride is a versatile Lewis acid that forms adducts with such Lewis bases as fluoride and ethers: CsF + BF 3 → Cs[BF 4] O(CH 2 CH 3) 2 + BF 3 → BF 3 ·O(CH 2 CH 3) 2. Tetrafluoroborate salts are commonly employed as non-coordinating anions.
The trihalides adopt a planar trigonal structure. These compounds are Lewis acids in that they readily form adducts with electron-pair donors, which are called Lewis bases. For example, fluoride (F −) and boron trifluoride (BF 3) combined to give the tetrafluoroborate anion, BF 4 −. Boron trifluoride is used in the petrochemical industry as ...
Lewis structure of a water molecule. Lewis structures – also called Lewis dot formulas, Lewis dot structures, electron dot structures, or Lewis electron dot structures (LEDs) – are diagrams that show the bonding between atoms of a molecule, as well as the lone pairs of electrons that may exist in the molecule.
The most common Lewis bases are anions. The strength of Lewis basicity correlates with the pK a of the parent acid: acids with high pK a 's give good Lewis bases. As usual, a weaker acid has a stronger conjugate base. Examples of Lewis bases based on the general definition of electron pair donor include: simple anions, such as H − and F −
In its pure state, boron triiodide forms colorless, otherwise reddish, shiny, air and hydrolysis-sensitive [3] crystals, which have a hexagonal crystal structure (a = 699.09 ± 0.02 pm, c = 736.42 ± 0.03 pm, space group P6 3 /m (space group no. 176)). [4] Boron triiodide is a strong Lewis acid and soluble in carbon disulfide. [2]
A new report from the United States Department of Agriculture (USDA) suggests that beans and legumes are healthier proteins than lean meat: here's why.
Given a list of NBOs for an idealized natural Lewis structure, the NRT functional creates a list of Lewis resonance structures and calculates the resonance weights of each contributing resonance structure. [1] Structural and chemical properties, such as bond order, valency, and bond polarity, may be calculated from resonance weights. [2]