Abstract / Description of output
The alpha-diimine iron complexes, (R',R '')[N,N]FeCl2 ((R',R '')[N,N] = R'-N=CR"-CR ''=N-R', where R' = tert-butyl (tBu), cyclohexyl (Cy) and R '' = phenyl (Ph), para-fluorophenyl (F-Ph), para-bromophenyl (Br-Ph), para-methylphenyl (Me-Ph), or para-methoxyphenyl (MeO-Ph)), are found to polymerize styrene through a catalytic chain transfer (CCT) mechanism. Magnetic moment measurements indicate that Fe(III) complexes containing these ligands possess intermediate (S = 3/2) spin-state iron centers. In contrast, Fe(III) complexes bearing proton (R '' = H) and paradimethylaminophenyl (R '' = NMe2-Ph) substituents are high-spin and are efficient atom transfer radical polymerization (ATRP) catalysts. Hammett plots show a linear correlation of the substituent constant, sigma, with polymerization rate and polymer molecular weight, respectively.
Original language | English |
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Pages (from-to) | 8963-8970 |
Number of pages | 8 |
Journal | Inorganic Chemistry |
Volume | 46 |
Issue number | 21 |
DOIs | |
Publication status | Published - 15 Oct 2007 |