Pyridazine

Pyridazine
Names
	Preferred IUPAC name Pyridazine
	Systematic IUPAC name 1,2-Diazabenzene
	Other names 1,2-Diazine; Orthodiazine; Oizine
Identifiers
CAS Number	289-80-5 ;
3D model (JSmol)	Interactive image;
Beilstein Reference	103906
ChEBI	CHEBI:30954 ;
ChEMBL	ChEMBL15719 ;
ChemSpider	8902 ;
ECHA InfoCard	100.005.478
EC Number	206-025-5;
Gmelin Reference	49310
PubChem CID	9259;
UNII	449GLA0653 ;
CompTox Dashboard (EPA)	DTXSID7059777 ;
	InChI InChI=1S/C4H4N2/c1-2-4-6-5-3-1/h1-4H Key: PBMFSQRYOILNGV-UHFFFAOYSA-N ; InChI=1/C4H4N2/c1-2-4-6-5-3-1/h1-4H Key: PBMFSQRYOILNGV-UHFFFAOYAA;
	SMILES n1ncccc1;
Properties
Chemical formula	C4H4N2
Molar mass	80.090 g·mol−1
Appearance	Colorless liquid
Density	1.107 g/cm3
Melting point	−8 °C (18 °F; 265 K)
Boiling point	208 °C (406 °F; 481 K)
Solubility in water	miscible
Solubility	miscible in dioxane, ethanol ; soluble in benzene, diethyl ether ; negligible in cyclohexane, ligroin
Refractive index (nD)	1.52311 (23.5 °C)
Thermochemistry
Std enthalpy of; formation (ΔfH⦵298)	224.9 kJ/mol
Hazards
	GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H302, H315, H319, H335
Precautionary statements	P261, P264, P264+P265, P270, P271, P280, P301+P317, P302+P352, P304+P340, P305+P351+P338, P319, P321, P330, P332+P317, P337+P317, P362+P364, P403+P233, P405, P501
Flash point	85 °C (185 °F; 358 K)
Related compounds
Related compounds	pyridine; pyrimidine; pyrazine;
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Pyridazine is an aromatic, heterocyclic, organic compound with the molecular formula C₄H₄N₂. It contains a six-membered ring with two adjacent nitrogen atoms. It is a colorless liquid with a boiling point of 208 °C. It is isomeric with two other diazine (C₄H₄N₂) rings, pyrimidine and pyrazine.