Halogen bond the electron density on H or X appears to be reduced. Electron density transfers results in a penetration of the van der Waals volumes. Halogens participating in halogen bonding include: iodine (I), bromine (Br), chlorine (Cl), and sometimes fluorine (F). All four halogens are capable of acting as XB donors (as proven through theoretical and experimental data) and follow the general trend: F < Cl < Br < I, with iodine normally forming the strongest interactions. Dihalogens (I, Br, etc.) tend to form strong halogen bonds. The strength and effectiveness of chlorine and fluorine in XB formation depend on the
Fluorine perchlorate in a rare oxidation state of 0, due to the electronegativity of oxygen, which is higher than that of chlorine but lower than that of fluorine. FClO has a very dangerous and unpredictable series of reactions associated with it, as a covalent perchlorate (chlorine in the +7 oxidation state) and a compound featuring a very sensitive O-F single bond. Small amounts of reducing agent, such as organic compounds, can trigger explosive detonation. Products of these decomposition reactions could include oxygen halides, interhalogen compounds, and other hazardous substances. Accidental synthesis is possible if precursors are carelessly mixed. Like similar covalent fluorides