Phosphorus has a structure with five coordination

this compound is easy to form enantiomers and can hardly be separated.In this paper

four propargylphosphonamide monomers ［ HCCCH2 NH( P=O )-R1R2.Monomer 1 :R1=OPh

R2=NC4H7COOCH3;monomer 2 :R1=OPh

R2=NC4H7COOCH2CH3;monomer 3 :R1=OPh

R2=NC4H7COOC(CH3)3 and monomer 4 :R1=Ph

R2=NC4H7COOC(CH3)3］ were designed and synthesized.1H-NMR and 31 P-NMR show that monomer 1 can only form enantiomer and cannot be separated.But monomer 2

monomer 3 and monomer 4 can be separated by resolving agent to form P-chiral diastereomeric monomers.Polymerization was carried out with (nbd)Rh+［6-C6H5B--(C6H5)3］ as catalyst in CHCl3 giving four polymers with moderate molecular weights (Mn) (0.4104~0.7104) and Mw/Mn (1.26~1.98) by GPC

two factors (the pendent group and temperature) were observed to affect the helix structure of polymers.The optical activity and secondary structure of the polymers were characterized by specific rotations (［］D)

circular dichroism (CD) spectra and UV-Vis.It shows that the polymers have good optical activity and can form a single direction of the helical conformation.It was found that the secondary structure stability of the copolymer is better than homopolymers in different mixed solvents

when the methanol quantity was up to 50%

CD spectra of poly 3 and poly4 change largely

which shows methanol broke the hydrogen bond between phosphorus-oxygen bond and nitrogen-hydrogen bond.