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Beryllium fluoride has distinctive optical properties. In the form of fluoroberyllate glass, it has the lowest refractive index for a solid at room temperature of 1.275. Its dispersive power is the lowest for a solid at 0.0093, and the nonlinear coefficient is also the lowest at 2 × 10 −14.
The Be–F bond length is between 145 and 153 pm.The beryllium is sp 3 hybridized, leading to a longer bond than in BeF 2, where beryllium is sp hybridized. [11] In trifluoroberyllates, there are actually BeF 4 tetrahedra arranged in a triangle, so that three fluorine atoms are shared on two tetrahedra each, resulting in a formula of Be 3 F 9.
The water molecules function as Lewis bases, donating a pair of electrons to the metal ion and forming a dative covalent bond with it. Typical examples are listed in the following table. Typical examples are listed in the following table.
The fluorine–fluorine bond of the difluorine molecule is relatively weak when compared to the bonds of heavier dihalogen molecules. The bond energy is significantly weaker than those of Cl 2 or Br 2 molecules and similar to the easily cleaved oxygen–oxygen bonds of peroxides or nitrogen–nitrogen bonds of hydrazines. [8]
In organic chemistry, a Schiff base (named after Hugo Schiff) is a compound with the general structure R 1 R 2 C=NR 3 (R 3 = alkyl or aryl, but not hydrogen). [ 1 ] [ 2 ] They can be considered a sub-class of imines , being either secondary ketimines or secondary aldimines depending on their structure.
The bond angle for water is 104.5°. Valence shell electron pair repulsion ( VSEPR ) theory ( / ˈ v ɛ s p ər , v ə ˈ s ɛ p ər / VESP -ər , [ 1 ] : 410 və- SEP -ər [ 2 ] ) is a model used in chemistry to predict the geometry of individual molecules from the number of electron pairs surrounding their central atoms. [ 3 ]
The reaction with lithium hydride (in which the hydride ion is the Lewis base), forms sequentially LiBeH 3 and Li 2 BeH 4. [3] The latter contains the tetrahydridoberyllate(2-) anion BeH 2− 4. Beryllium hydride reacts with trimethylamine, N(CH 3) 3 to form a dimeric adduct with bridging hydrides. [11]
A metal ion in aqueous solution or aqua ion is a cation, dissolved in water, of chemical formula [M(H 2 O) n] z+.The solvation number, n, determined by a variety of experimental methods is 4 for Li + and Be 2+ and 6 for most elements in periods 3 and 4 of the periodic table.