Flexibility and Stability of Metal Coordination Macromolecules.
The effect of chain structure on flexibility and stability of macromolecules containing weak P-Fe metal coordination bonds is studied. Migration insertion polymerization (MIP) of FpCXFp (1) and PR2CYPR2(2) (Fp: CpFe(CO)2; CXand CY: alkyl spacers; P: phosphine; R: phenyl or isopropyl) generates P(1/2), in which the P-Fe and Fe-P bonds with opposite bonding direction are alternatively arranged in the backbone. On the other hand, P(FpCXP) synthesized from AB-type monomers (FpCXP) has P-Fe bonds arranged in the same direction. P(1/2) is more rigid and stable than P(FpCXP), which is attributed to the chain conformation resulting from the P-Fe bonding direction. In addition, the longer spacers render P(1/2) relatively flexible; the phenyl substituents, as compared with the isopropyl groups, improves the rigidity, thermal, and solution stability of P(1/2). It is therefore possible to incorporate weak metal coordination bonds into macromolecules with improved stability and adjustable flexibility for material processing.
Department of Chemistry, Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, ON, N2L 3G1, Canada.|Chongqing Key Laboratory of Catalysis and Functional Organic Molecules, Chongqing Technology and Business University, Chongqing, 400067, P.R. China.
Heyan
H
Jiang
Department of Chemistry, Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, ON, N2L 3G1, Canada.
Diya
D
Geng
Department of Chemistry, Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, ON, N2L 3G1, Canada.
Dapeng
D
Liu
Department of Chemistry, Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, ON, N2L 3G1, Canada.
Nicholas
N
Lanigan
Department of Chemistry, Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, ON, N2L 3G1, Canada.
Xiaosong
http://orcid.org/0000-0002-6415-4768
X
Wang
conformation analysis; coordination polymers; p ligands; polymerization; stability