Hydrogenacetylenedicarboxylate
Encyclopedia
Hydrogenacetylenedicarboxylate (often abbreviated as Hadc or HADC) is a monovalent
anion with the formula C4HO4− or HO2C-C≡C-CO2−. The anion can be derived from acetylenedicarboxylic acid
by removal of a single proton
, or from the acetylenedicarboxylate
dianion by addition of a proton.
The name is also used for any salt of this anion; which may also be called acid, hydrogen, or monobasic acetylenedicarboxylate.
The parent acid was synthetized by E. Bandrowski
in 1877. Salts of this anion are of interest in crystallography
because they contain unusually short and strong hydrogen bonds.
one), the HADC units form linear chains connected by strong hydrogen bonds. Each carboxylate group is usually planar; but the two groups may lie in different planes due to rotation about the C-C bonds. They are coplanar in the hydrated salts Na
HC4O4·2H20 and CsHC4O4·2H20, nearly coplanar in the guanidinium salt [C(NH2)3]+ · C4HO4−, but off by 60 degrees or more in other salts such as anhydrous KHC4O4
.
Valence (chemistry)
In chemistry, valence, also known as valency or valence number, is a measure of the number of bonds formed by an atom of a given element. "Valence" can be defined as the number of valence bonds...
anion with the formula C4HO4− or HO2C-C≡C-CO2−. The anion can be derived from acetylenedicarboxylic acid
Acetylenedicarboxylic acid
Acetylenedicarboxylic acid or butynedioic acid is an organic compound with the formula C4H2O4 or HO2C-C≡C-CO2H. It is a crystalline solid that is soluble in diethyl ether....
by removal of a single proton
Proton
The proton is a subatomic particle with the symbol or and a positive electric charge of 1 elementary charge. One or more protons are present in the nucleus of each atom, along with neutrons. The number of protons in each atom is its atomic number....
, or from the acetylenedicarboxylate
Acetylenedicarboxylate
Acetylenedicarboxylate is a divalent anion with formula C4O42− or [O2C–C≡C–CO2]2−; or any salt or ester thereof. The anion can be derived from acetylenedicarboxylic acid C4H2O4 by the loss of two protons...
dianion by addition of a proton.
The name is also used for any salt of this anion; which may also be called acid, hydrogen, or monobasic acetylenedicarboxylate.
The parent acid was synthetized by E. Bandrowski
Ernest Tytus Bandrowski
Ernest Tytus Bandrowski was a Polish chemist.Bandrowski was professor at the Jagiellonian University starting in 1896. He studied crystalloluminescence and described a number of chemical compounds, such as acetylenedicarboxylic acid....
in 1877. Salts of this anion are of interest in crystallography
Crystallography
Crystallography is the experimental science of the arrangement of atoms in solids. The word "crystallography" derives from the Greek words crystallon = cold drop / frozen drop, with its meaning extending to all solids with some degree of transparency, and grapho = write.Before the development of...
because they contain unusually short and strong hydrogen bonds.
Structure
In many crystalline salts (with the exception of the lithiumLithium
Lithium is a soft, silver-white metal that belongs to the alkali metal group of chemical elements. It is represented by the symbol Li, and it has the atomic number 3. Under standard conditions it is the lightest metal and the least dense solid element. Like all alkali metals, lithium is highly...
one), the HADC units form linear chains connected by strong hydrogen bonds. Each carboxylate group is usually planar; but the two groups may lie in different planes due to rotation about the C-C bonds. They are coplanar in the hydrated salts Na
Sodium
Sodium is a chemical element with the symbol Na and atomic number 11. It is a soft, silvery-white, highly reactive metal and is a member of the alkali metals; its only stable isotope is 23Na. It is an abundant element that exists in numerous minerals, most commonly as sodium chloride...
HC4O4·2H20 and CsHC4O4·2H20, nearly coplanar in the guanidinium salt [C(NH2)3]+ · C4HO4−, but off by 60 degrees or more in other salts such as anhydrous KHC4O4
Potassium hydrogenacetylenedicarboxylate
Potassium hydrogenacetylenedicarboxylate is a potassium salt with chemical formula KC4HO4 or K+·HC4O4−, often abbreviated as KHadc. It is often called potassium hydrogen acetylenedicarboxylate or monopotassium acetylenedicarboxylate....
.