ATTACHMENT OF 1,5,9-TRIAZACYCLODODECANE AND BETA-CYCLODEXTRIN TO POLY(ETHYLENIMINE) IN PROXIMITY BY SITE-DIRECTED FUNCTIONALIZATION

A novel methodology for the site-directed introduction of a functional group in the vicinity of beta-cyclodextrin (CD) on the backbone of br anched poly(ethylenimine) (PEI) is developed. Site-directed or random attachment of 1,5,9-triazacyclododecane (TC) to CD-containing PEI foll owed by acetylation of the primary and secondary amines of the polymer backbone produced [TC-CD](AcPEI)-Ac-SD or [TC-CD](Ran) AcPEI, respect ively. By the addition of Ni(II), Cu(II), or Zn(II) ion, [M(II)TC-CD]( SD) AcPEI or [M(II)TC-CD](AcPEI)-Ac-Ran was obtained. The formation co nstant for the complexation of a hydrophobic ester revealed that the T C portion was indeed positioned in the vicinity of the CD cavity in [M (II)TC-CD](SD) AcPEI. Compared with [M(II)TC-CD](Ran) AcPEI, [M(II)TC- CD]SDAcPEI appears to exert an extra stabilization effect (-Delta Delt a G degrees = 1.0-1.3 kcal/mol) on the complexed ester by hydrogen bon ding between the metal-bound water of the polymer and the carbonyl gro up of the ester. (C) 1998 Academic Press.