Flexibility and Stability of Metal Coordination Macromolecules

Heyan Jiang; Diya Geng; Dapeng Liu; Nicholas Lanigan; Xiaosong Wang

doi:10.1002/chem.201701133

Flexibility and Stability of Metal Coordination Macromolecules

Chemistry. 2017 Jun 16;23(34):8280-8285. doi: 10.1002/chem.201701133. Epub 2017 May 23.

Authors

Heyan Jiang^{1

2}, Diya Geng¹, Dapeng Liu¹, Nicholas Lanigan¹, Xiaosong Wang¹

Affiliations

¹ Department of Chemistry, Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, ON, N2L 3G1, Canada.
² Chongqing Key Laboratory of Catalysis and Functional Organic Molecules, Chongqing Technology and Business University, Chongqing, 400067, P.R. China.

PMID: 28334462
DOI: 10.1002/chem.201701133

Abstract

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 FpC_X Fp (1) and PR₂ C_Y PR₂ (2) (Fp: CpFe(CO)₂ ; C_X and C_Y : 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(FpC_X P) synthesized from AB-type monomers (FpC_X P) has P-Fe bonds arranged in the same direction. P(1/2) is more rigid and stable than P(FpC_X P), 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.

Keywords: conformation analysis; coordination polymers; p ligands; polymerization; stability.