Acetylenedicarboxylate is a divalent

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 formula C₄O₄²⁻ or [O₂C–C≡C–CO₂]²⁻; or any salt or ester

Ester

Esters are chemical compounds derived by reacting an oxoacid with a hydroxyl compound such as an alcohol or phenol. Esters are usually derived from an inorganic acid or organic acid in which at least one -OH group is replaced by an -O-alkyl group, and most commonly from carboxylic acids and...

 thereof. 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....

 C₄H₂O₄ by the loss of two 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....

s. It is one of several oxocarbon anions which, like carbonate

Carbonate

In chemistry, a carbonate is a salt of carbonic acid, characterized by the presence of the carbonate ion, . The name may also mean an ester of carbonic acid, an organic compound containing the carbonate group C2....

 CO₃²⁻ and oxalate

Oxalate

Oxalate , is the dianion with formula C2O42− also written 22−. Either name is often used for derivatives, such as disodium oxalate, 2C2O42−, or an ester of oxalic acid Oxalate (IUPAC: ethanedioate), is the dianion with formula C2O42− also written (COO)22−. Either...

 C₂O₄²⁻, consist solely of carbon

Carbon

Carbon is the chemical element with symbol C and atomic number 6. As a member of group 14 on the periodic table, it is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds...

 and oxygen

Oxygen

Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...

.

Removal of a single proton from the acid gives the monovalent hydrogenacetylenedicarboxylate

Hydrogenacetylenedicarboxylate

Hydrogenacetylenedicarboxylate is a monovalent anion with the formula C4HO4− or HO2C-C≡C-CO2−...

 anion, HC₄O₄⁻.

Synthesis and reactions

The salt potassium acetylenedicarboxylate K₂C₄O₄ is an intermediate in the standard synthesis route of the acid. Both compounds were obtained 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.

The ADC anion can at as a ligand

Ligand

In coordination chemistry, a ligand is an ion or molecule that binds to a central metal atom to form a coordination complex. The bonding between metal and ligand generally involves formal donation of one or more of the ligand's electron pairs. The nature of metal-ligand bonding can range from...

 in organometallic complexes, e.g. the blue polymeric complex with copper

Copper

Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...

(II) and 2,2'-bipyridine

Bipyridine

Bipyridines are a family of chemical compounds with the formula 2, which are formed by the coupling of two pyridine rings. Six isomers of bipyridine exist, but two isomers are prominent: 2,2'-bipyridine is a popular ligand in coordination chemistry and 4,4'-bipyridine is a precursor to the...

, [Cu²⁺ · C₄O₄²⁻ · (C₅H₄N)₂]_n.

Thallium

Thallium

Thallium is a chemical element with the symbol Tl and atomic number 81. This soft gray poor metal resembles tin but discolors when exposed to air. The two chemists William Crookes and Claude-Auguste Lamy discovered thallium independently in 1861 by the newly developed method of flame spectroscopy...

acetylenedicarboxylate Tl₂C₄O₄ decomposes at 195°C leaving a residue of pyrophoric thallium powder.