Reversible and irreversible chemisorption in nonporous, crystalline hybrid structures

A method for irreversibly capturing gaseous iodine from a gas stream, comprising:

• contacting a gas stream comprising gaseous iodine with a sorbent in the form of a layered, non-porous perovskite, comprising parallel, alternating layers of:
• an organic layer, comprising an ordered array of organic moieties, wherein the organic moieties comprise alkyne groups;
• and
• an inorganic layer, comprising a metal-halide sheet, wherein each organic layer is sandwiched between inorganic layers,
• wherein the gaseous iodine in the gas stream reacts with the alkyne groups to form covalent C—I bonds.

A method for capturing one or more halogens from a gas stream, comprising:

• contacting a gas stream comprising one or more halogens with a sorbent in the form of a layered, non-porous perovskite, comprising parallel, alternating layers of:
• an organic layer, comprising an ordered array of organic moieties, wherein the organic moieties comprise alkene groups capable of reacting with one or more gaseous halogens;
• and
• an inorganic layer comprising, a metal-halide sheet, wherein each organic layer is sandwiched between inorganic layers,
• wherein one or more of the halogens in the gas stream react with the alkene groups to form dihaloalkanes.