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
Bromine production in the United States rail access, and difficult highway access, and was shut down in 1945. Dow found a better permanent location at Freeport, Texas, where a seawater extraction plant started in 1940, and a second in 1943. The Freeport plants recovered magnesium, sodium compounds, and chlorine, in addition to the bromine. The Freeport chemical operations are still active, but they stopped extracting bromine in 1969. Brine mining Bromine production in the United States Bromine production in the United States of 225,000 tonnes in 2013 made that country the second-largest producer of bromine, after Israel. The US supplied 29 percent of world production. Since