Tri-block amphiphilic copolymers with hybrid architectures were synthesized by coupling linear poly(ethylene glycol) (PEG) and dendritic second-generation Fréchet-type poly (benzyl ether) (PBE) via the Williamson reaction (Gisotv

et al．Angew Chem

Int Ed Engl

1992

31:1200～1202). Our experimental study shows that the powerful two-dimensional 1H- 13C heteronuclear multiple-quantum correlation (HMQC) and two-dimensional 1H- 13C heteronuclear multiple-bond correlation (HMBC) NMR techniques rather than the classical one-dimensional 1H and 13C-NMR methods can provide clear evidence to verify the formation of the tri-block copolymers．In our measurements HMQC and HMBC NMR techniques directly detected the signal of ether bonds bridged in-between PBE dendrons and PEG blocks

therefore

the formation of the block copolymers are evidently confirmed in molecular level．This work also provides a general method to exactly confirm the formation of block copolymers．