Reactions of Hydrogen and Hydrocarbons with Iodine Excited by 1849 Å. Radiation¹

Surface Functionalization of Alkyl Monolayers by Free-Radical Activation: Gas-Phase Photochlorination with Cl2

“…For instance, chlorinated polyethylene has been prepared from inexpensive polyethylene and chlorine gas. 47 This paper joins a family of investigations on the gasphase and/or radical modification of alkyl monolayers on inorganic substrates. For example, Maoz, 56 working with Sagiv, reported the gas-phase chlorination of siloxane monolayers on silicon oxide in her thesis.…”

“…45 (Another potentially useful gas-phase free-radical method of monolayer functionalization may be I 2 activated with 1849 Å light. 47 Like the chlorine atom, this reagent effectively abstracts hydrogen from methyl groups. Although this iodination is rarely used in organic chemistry because the HI produced reduces the alkyl iodide, 45 the minute quantities of HI produced during monolayer functionalization should make this undesirable side reaction inconsequential.…”

“…These can lead to chlorination and/or other substitutions of hydrocarbons depending on conditions. Reactions of hydrocarbons with molecules of the form XCl have been shown to form C−X bonds in several cases, where X is Cl, Br, SO 2 Cl, COCl, CN, , SCl, , or SCN. , In addition, reactions of hydrocarbons with Cl 2 in the presence of a molecule, Y, often lead to C−Y, C−Y−Cl, or C(Cl)Y functionality: C−CO−Cl groups are formed from CO, C−SO 2 - Cl groups are formed from SO 2 , and C−NO and C(Cl)−NO groups are formed from NO . A significant advantage of these reagents is that the chlorine radical is a potent hydrogen abstractor with relatively low selectivity for secondary over primary hydrogens…”

“…The basic strategy that we are proposing to make modified monolayer surfaces with has previously been used to modify bulk polymers. For instance, chlorinated polyethylene has been prepared from inexpensive polyethylene and chlorine gas …”