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Sodium borohydride, also known as sodium tetrahydridoborate and sodium tetrahydroborate, [5] is an inorganic compound with the formula Na B H 4 (sometimes written as Na[BH 4]). It is a white crystalline solid, usually encountered as an aqueous basic solution .
Sodium borohydride can, under some circumstances, be used for ester reduction, especially with additives. [ 1 ] Forming aldehydes from carboxylic acid derivatives is challenging because weaker reducing agents (NaBH 4 ) are often very slow at reducing esters and carboxylic acids, whereas stronger reducing agents (LiAlH 4 ) immediately reduce the ...
At low pH values, it efficiently reduces aldehydes and ketones. [7] As the pH increases, the reduction rate slows and instead, the imine intermediate becomes preferential for reduction. [ 7 ] For this reason, NaBH 3 CN is an ideal reducing agent for one-pot direct reductive amination reactions that don't isolate the intermediate imine.
In chemistry, the mass concentration ρ i (or γ i) is defined as the mass of a constituent m i divided by the volume of the mixture V. [1]= For a pure chemical the mass concentration equals its density (mass divided by volume); thus the mass concentration of a component in a mixture can be called the density of a component in a mixture.
Lithium borohydride (LiBH 4) is a borohydride and known in organic synthesis as a reducing agent for esters.Although less common than the related sodium borohydride, the lithium salt offers some advantages, being a stronger reducing agent and highly soluble in ethers, whilst remaining safer to handle than lithium aluminium hydride.
In the reaction below, sodium tetraphenylborate allows N 2 to displace the chloride ligand, which is removed from solution as a precipitate of sodium chloride: FeHCl(diphosphine) 2 + NaB(C 6 H 5) 4 + N 2 → [FeH(N 2)(diphosphine) 2]B(C 6 H 5) 4 + NaCl. The use of tetraphenylborate is limited to non-acidic cations.
The result is that in dilute ideal solutions, the extent of boiling-point elevation is directly proportional to the molal concentration (amount of substance per mass) of the solution according to the equation: [2] ΔT b = K b · b c. where the boiling point elevation, is defined as T b (solution) − T b (pure solvent).
When a strong acid is neutralized by a strong base there are no excess hydrogen ions left in the solution. The solution is said to be neutral as it is neither acidic nor alkaline. The pH of such a solution is close to a value of 7; the exact pH value is dependent on the temperature of the solution. Neutralization is an exothermic reaction.