Empirical Formula: C₄H₈
Molecular Weight: 56.1063 
EINECS: 206-014-5 
Index of Refraction: 1.432
Density: 0.79 g/cm³
Enthalpy of Vaporization: 24.19 kJ/mol
Boiling Point: 12.5 °C at 760 mmHg
Vapour Pressure: 1180 mmHg at 25 °C
Melting point: -91 °C
Appearance: Colourless gas
Structure of Cyclobutane (CAS NO.287-23-0):
             

Alkenes dimerize upon irradiation with UV-light. 1,4-Dihalobutanes convert to Cyclobutane (CAS NO.287-23-0) upon dehalogenation with reducing metals.
 

May be a simple asphyxiant. See also CYCLOHEXANE. Very dangerous fire hazard when exposed to heat or flame; can react with oxidizing materials. To fight fire, stop flow of gas; CO₂, dry chemicals, or water spray. When heated to decomposition it emits acrid smoke and fumes.

 Cyclobutane ,its cas register number is 287-23-0. It also can be called Tetramethylene . Itself is of no commercial or biological significance, but more complex derivatives are important in biology and biotechnology. As such, Cyclobutane (CAS NO.287-23-0) is unstable above about 500 °C. Its four carbon atoms in cyclobutane are not coplanar, instead the ring typically adopts a folded or "puckered" conformation. Despite inherent strain the cyclobutane motif is not an alien to molecules found in nature, and its photodimers ("CPD's") are formed by photochemical reactions that result in the coupling of the C=C double bonds of pyrimidines. It may be incompatible with strong oxidizing agents like nitric acid. In other settings, mostly unreactive. Not affected by aqueous solutions of acids, alkalis, most oxidizing agents, and most reducing agents.