Tailoring polymer architectures through dynamic self assembly

Multiple hydrogen bonding has contributed significantly to recent advances in supramol. polymer chem. Much of the research has centered around ureido-pyrimidinone (UPy) due to its relatively straight-forward synthesis and very high assocn. const., Kassoc, on the order of 107 to 108 M-1. Self-assembly of new architectures and materials with directionality, however, is limited with the UPy functionality alone, and requires complementary hydrogen binding motifs. It is of great interest to move towards co-polymers with well-defined architectures. Accomplishing this goal requires the use of complementary quadruple hydrogen bonding arrays in order to eliminate the random self-assembly possible with self-complementary units. Fortunately, it has been recently demonstrated that bis-amido-naphthyridines (Napy) undergo selective hetero-complexation with UPy moieties with dimerization consts., Kdim, ranging from 105 to 106 M-1. Bi-functional UPy and Napy mols. enable the self-assembly of a variety of materials such as macrocycles and alternating co-polymers, as well as hyperbranched and star-shaped structures, all of which are highly dynamic. As a graduate student with Professor Robert H. Grubbs, I have gained expertise in olefin metathesis chem. This powerful C=C bond-forming reaction can be applied to highly functionalized quadruple hydrogen bond motifs to prep. a range of bi-functional mol. building blocks. As a postdoc in the group of E.W. Meijer, I have worked to develop a general method for prepg. high mol. wt. A-B alternating co-polymers and other well-defined material architectures through self-assembly. My research has lead to a modular approach for the prepn. of both A-A/B-B and A-B complementary quadruple hydrogen bond arrays. This poster will describe my chem. background as well as my general research interests in the field of precision control in polymer architectures. Moreover, it will highlight recent advances during my postdoctoral appointment in the synthesis and supramol. chem. of several multi-functional mols. contg. both UPy and Napy motifs.