Devdatt S. Nagvekar

SELF-ORGANIZATION OF A HETERODITOPIC MOLECULE TO LINEAR POLYMOLECULAR ARRAYS IN SOLUTION

Like the proverbial monkey chain one heteroditopic self-complementary molecule, comprising a crown ether unit and a paraquat unit, catches a second such molecule in solution and thus by self-organization forms novel linear oligo- and polymolecular arrays (shown schematically; the crown ether unit is denoted by the ellipse, and the paraquat unit by the rectangle).

POLYROTAXANES BY IN SITU SELF THREADING DURING POLYMERIZATION OF FUNCTIONAL MACROCYCLES. PART 2 : POLY(ESTER CROWN ETHER)S

Abstract Poly(ester crown ether)s were synthesized by direct condensation of bis(5-carboxy-m-phenylene)-(3x + 2)-crown-x, x = 6,8 and 10 ( 1a, 1b and 1c ) with bisphenols via the Higashi method. The formation of higher molecular weight poly(ester crown ether) 5 from the 32-membered crown ether 1c and bisphenol-A ( 2a ) as compared to polyester 3 from 20-membered crown ether 1a and bisphenol-A, polyester 4 made from the 26-membered crown ether 1b and bisphenol-A ( 2a ) and polyester 6 derived from 32-membered 1c and bis(p-t-butylphenyl)-bis(p-hydroxyphenyl)methane ( 2b ) under identical conditions is believed to be the result of threading (rotaxane formation) in 5 but no or less threading in 3 , 4 or 6 ; indeed polyester 3 provides a control because its macrocyclic component ( 1a ) too small to be threaded, even by a polymethylene chain. Threading in 5 was undetectable through NOESY experiments. However, melt polymerization of bis(5-hydroxymethyl-m-phenylene)-32-crown-10 ( 7 ) with sebacoyl chloride ( 8 ) gave an insoluble, but swellable elastomeric material 9 , a polyrotaxane network, as a result of more extensive in situ threading brought about by hydrogen bonding of the crown ether with the alcohol moieties in the more concentrated medium.

Selbstorganisation eines heteroditopen Moleküls zu linearen Aggregaten in Lösung

Wie Schlangen, die sich gegenseitig in den Schwanz beisen: Eine heteroditope, selbstkomplementare Verbindung, bestehend aus einer Kronenethereinheit und einer Paraquateinheit, angelt sich in Losung ihresgleichen und bildet so unter Selbstorganisation neuartige, oligo- und polymolekulare Aggregate (siehe Schema; die Kronenethereinheit ist durch die Ellipse und die Paraquateinheit durch das Rechteck symbolisiert).