Biphenylene
（重定向自Diphenylene）
![](/Images/godic/202501/09/Biphenylene-from-xtal-3D-vdW4500.png")
Biphenylene is an alternant, polycyclic hydrocarbon composed of two benzene rings joined together by a pair of mutual attachments (as opposed to a normal ring fusion), thus forming a 6-4-6 arene system. The resulting planar structure was one of the first pi-electronic hydrocarbon systems discovered to show evidence of antiaromaticity.