Tetracyanoquinodimethane (HCID 73697)

Overview

Tetracyanoquinodimethane is a quinodimethane that is p-quinodimethane in which the methylidene hydrogens are replaced by cyano groups. It is a nitrile, an alicyclic compound and a quinodimethane. It is functionally related to a p-quinodimethane.

Names & identifiers

Preferred name: Tetracyanoquinodimethane
IUPAC: 2-[4-(dicyanomethylidene)cyclohexa-2,5-dien-1-ylidene]propanedinitrile
English name: 7,7,8,8-Tetracyanoquinodimethane
Molecular formula: C12H4N4
Molecular weight: 204.19

Names & synonyms

1518-16-77,7,8,8-TetracyanoquinodimethaneTCNQTetracyanoquinodimethaneTetracyanoquinodimethanTetracyano-p-quinodimethanePropanedinitrile, 2,2'-(2,5-cyclohexadiene-1,4-diylidene)bis-Tetracyanoquinodimethan(e)7,7,8,8-Tetracyano-p-quinodimethane7,7,8,8-Tetracyano-1,4-quinodimethan7,7',8,8'-Tetracyanoquinodimethane2-[4-(dicyanomethylidene)cyclohexa-2,5-dien-1-ylidene]propanedinitrile

Show more names

Tetracyano p-Quinone Dimethane2,2'-(Cyclohexa-2,5-diene-1,4-diylidene)dimalononitrileTIMTEC-BB SBB0004357,7,8,8-Tetracyanoqutetracyano-quinodimethaetracyanoquinodimethane7,7,8,8-Tetracyanodimethan

2,5-Cyclohexadiene-1,4-diylidenedimalononitrileHC6FB4H2KW2,5-Cyclohexadiene-delta(sup1alpha:4alpha)dimalononitrileNSC-1052372,5-Cyclohexadiene-delta1,alpha:4,alpha'-dimalononitrileDTXSID5061748CHEBI:524452,5-Cyclohexadiene-1,4-diylidene-alpha,alpha'-dimalononitrile

Database identifiers

CAS: 1518-16-7
PubChem CID: 73697
DTXSID: DTXSID5061748
ChEBI: CHEBI:52445
UNII: HC6FB4H2KW
EC Number: 216-174-8
Nikkaji: J38.157H

Properties

Computed structural properties

XLogP: 1
Topological polar surface area: 95.2 Å²
Hydrogen bond donors: 0
Hydrogen bond acceptors: 4
Rotatable bonds: 0
Heavy atoms: 16
Formal charge: 0
Complexity: 535

Experimental & physicochemical properties

Chemical ClassesNitrogen Compounds -> Nitriles

SpringerMaterials PropertiesBand gap energy

Physical DescriptionGreen crystalline solid; [Alfa Aesar MSDS]

Physicochemical properties

Melting point: 287 · 287-289 °C (dec.) (lit.)
Boiling point: 332.67 °C · 332.67°C (rough estimate)
Density: 1.3596 · 1.3596 (rough estimate)
refractive index: 1.5 · 1.5000 (estimate)
storage temp.: Sealed in dry,Room Temperature
form: Crystalline Powder
color: Orange-brown to green
Water Solubility: insoluble
semiconductor properties: N-type (mobility=10-5cm2/V·s)
λmax: 395 nm · 395nm(CH3CN)(lit.)
BRN: 611604 · 611604
Stability: Stable. Incompatible with strong acids, strong bases, strong reducing agents, strong oxidizing agents.
InChI: InChI=1S/C12H4N4/c13-5-11(6-14)9-1-2-10(4-3-9)12(7-15)8-16/h1-4H
InChIKey: PCCVSPMFGIFTHU-UHFFFAOYSA-N
SMILES: C1(=C(C#N)C#N)C=CC(=C(C#N)C#N)C=C1 |c:8,t:0|
CAS DataBase Reference: 1518 · 1518-16-7(CAS DataBase Reference)
FDA UNII: 6 FB4H2KW · HC6FB4H2KW
NIST Chemistry Reference: 2 · Propanedinitrile, 2,2'-(2,5-cyclohexadiene-1,4-diylidene)bis-(1518-16-7)
EPA Substance Registry System: 2 · Propanedinitrile, 2,2'-(2,5-cyclohexadiene-1,4-diylidene)bis- (1518-16-7)
UNSPSC Code: 12352103 · 12352103
NACRES: 23 · NA.23
Symbol(GHS): 6 · GHS06
Signal word: Danger
Hazard statements: 301 · H301+H311+H331
Precautionary statements: 280 · P280-P301+P310+P330-P302+P352+P312-P304+P340+P311
PPE: 95 · dust mask type N95 (US), Eyeshields, Gloves
Hazard Codes: Xn,Xi,T
Risk Statements: 22 · 22-20/21/22-23/24/25
Safety Statements: 22 · 22-24/25-36/37-26-36-45
RIDADR: 3276 · 3276
WGK Germany: 3 · 3
RTECS: 4850000 · GU4850000
Hazard Note: Irritant
TSCA: TSCA listed
HazardClass: 6.1 · 6.1
PackingGroup: II
HS Code: 29269095 · 29269095
Storage Class: 6.1 A · 6.1A - Combustible acute toxic Cat. 1 and 2very toxic hazardous materials
Hazard Classifications: 3 DermalAcute · Acute Tox. 3 DermalAcute Tox. 3 InhalationAcute Tox. 3 Oral

Safety & regulation

GHS classification

GHS Classification · 4 items

Danger

H301+H311+H331 (87%): Toxic if swallowed, in contact with skin or if inhaled [Danger Acute toxicity, oral; acute toxicity, dermal; acute toxicity, inhalation]

P261, P262, P264, P270, P271, P280, P301+P316, P301+P317, P302+P352, P304+P340, P316, P317, P321, P330, P361+P364, P403+P233, P405, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 46 reports by companies from 4 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Hazard information

Regulatory Information7,7,8,8-Tetracyanoquinonedimethane: Does not have an individual approval but may be used under an appropriate group standard

Hazards SummaryIntravenous LD50 (mouse) = 56 mg/kg; [RTECS] May cause irritation; Harmful by ingestion and skin absorption; Toxic by inhalation; [Alfa Aesar MSDS] See NITRILES.

Hazard Classes and CategoriesAcute Tox. 3 (89.1%)

Safety & protection

Protective Action Criteria (PAC) · 3 items

0.18 [mg/m3]

2.0 [mg/m3]

12 [mg/m3]

Toxicology

Treatment · 1 item

Antidotes to cyanide poisoning include hydroxocobalamin and sodium nitrite, which release the cyanide from the cytochrome system, and rhodanase, which is an enzyme occurring naturally in mammals that combines serum cyanide with thiosulfate, producing comparatively harmless thiocyanate. Oxygen therapy can also be administered. (L97)

Health Effects · 1 item

Exposure to high levels of cyanide for a short time harms the brain and heart and can even cause coma, seizures, apnea, cardiac arrest and death. Chronic inhalation of cyanide causes breathing difficulties, chest pain, vomiting, blood changes, headaches, and enlargement of the thyroid gland. Skin contact with cyanide salts can irritate and produce sores. (L96, L97)

Exposure RoutesOral (L96) ; inhalation (L96) ; dermal (L96)

Toxicity Summary · 1 item

Organic nitriles decompose into cyanide ions both in vivo and in vitro. Consequently the primary mechanism of toxicity for organic nitriles is their production of toxic cyanide ions or hydrogen cyanide. Cyanide is an inhibitor of cytochrome c oxidase in the fourth complex of the electron transport chain (found in the membrane of the mitochondria of eukaryotic cells). It complexes with the ferric iron atom in this enzyme. The binding of cyanide to this cytochrome prevents transport of electrons from cytochrome c oxidase to oxygen. As a result, the electron transport chain is disrupted and the cell can no longer aerobically produce ATP for energy. Tissues that mainly depend on aerobic respiration, such as the central nervous system and the heart, are particularly affected. Cyanide is also known produce some of its toxic effects by binding to catalase, glutathione peroxidase, methemoglobin, hydroxocobalamin, phosphatase, tyrosinase, ascorbic acid oxidase, xanthine oxidase, succinic dehydrogenase, and Cu/Zn superoxide dismutase. Cyanide binds to the ferric ion of methemoglobin to form inactive cyanmethemoglobin. (L97)

Signs and SymptomsCyanide poisoning is identified by rapid, deep breathing and shortness of breath, general weakness, giddiness, headaches, vertigo, confusion, convulsions/seizures and eventually loss of consciousness. (L96, L97)

Carcinogen ClassificationNo indication of carcinogenicity to humans (not listed by IARC).

Safety data

PPE: dust mask type N95 (US), Eyeshields, Gloves
wgk: 3
tsca: TSCA listed
rtecs: GU4850000
ridadr: 3276
hs_code: 29269095
risk_code: 22-20/21/22-23/24/25
Signal word: Danger
Symbol(GHS): GHS06
hazard_code: Xn,Xi,T
hazard_note: Irritant
safety_code: 22-24/25-36/37-26-36-45
hazard_class: 6.1
Storage Class: 6.1A - Combustible acute toxic Cat. 1 and 2very toxic hazardous materials
packing_group: II
Hazard statements: H301+H311+H331
Hazard Classifications: Acute Tox. 3 DermalAcute Tox. 3 InhalationAcute Tox. 3 Oral
Precautionary statements: P280-P301+P310+P330-P302+P352+P312-P304+P340+P311

Chemistry & industry

Pharmacology

Metabolism/Metabolites · 1 item

Organic nitriles are converted into cyanide ions through the action of cytochrome P450 enzymes in the liver. Cyanide is rapidly absorbed and distributed throughout the body. Cyanide is mainly metabolized into thiocyanate by either rhodanese or 3-mercaptopyruvate sulfur transferase. Cyanide metabolites are excreted in the urine. (L96)

Uses & manufacturing

Uses · 2 items

Synthetic Polymer MALDI Matrix Compounds

Tetracyanoquinodimethane is an electron-acceptor that is used to prepare charge transfer salts, which are of interest in the area of molecular electronics. (L614)

General Manufacturing InformationPropanedinitrile, 2,2'-(2,5-cyclohexadiene-1,4-diylidene)bis-: ACTIVE

Applications · 4 items

Description7,7,8,8-tetracyanoquinodimethane (TCNQ), with a LUMO at 4.5 eV, is known for the charge-transfer salts formed by its radical anion TCNQ inphotovoltaic, light-emitting diodes, and organic field-effect transistordevices. TCNQ and its derivativeshave been used as dopants, leading to an increase in hole mobility or to the lowering of injectionbarriers. One classic example of such is the treatment of tetrathiafulvene (TTF), an electron donor with TCNQ. TFF and TCNQ form an ion pair, the TTF-TCNQ complex. This process of doping leads to the crystallisation of the ion pair into a one-dimensionally stacked polymer. This polymer consists of segregated stacks of cations and anions of the donors and the acceptors, respectively. The complex crystal is an organic semiconductor that exhibits metallic electric conductivity [1, 2].

HistoryThe first report on the electrical conductivity in an organic solid appeared in 1954, namely, a perylene—bromine complex with a room-temperature conductivity of 0.1 S cm1. In 1960, the organic acceptor Tetracyanoquinodimethane (TCNQ; 7,7,8,8-Tetracyanoquinodimethane) was synthesized, as well as a great number of its conducting charge-transfer complexes and radical ion salts. In the 1970s, the organic donor TTF led to the first organic metal TTF-TCNQ. Its room-temperature conductivity (500 S cm1) increases with a decrease in the temperature to the value of 6000 S cm1 at 60 K, where a metal-insulator transition occurs[1].

Uses7,7,8,8-Tetracyanoquinodimethane is an electron-acceptor molecule used to form charge-transfer superconductors. It is an effective catalyst used for the -chlorination of carboxylic acids using chlorosulfonic acid; the presence of TCNQ suppresses competing free-radical chlorination.

General Description7,7,8,8-Tetracyanoquinodimethane (TNCQ) is a strong electron acceptor as it has four cyano groups and π-conjugation bonds that form charge transferring chains and ion radical salts which are mainly used as p-dopants for the fabrication of a variety of semiconductor applications.