Biomedical subjects
Publications and source records attributed to Lance J Twyman.
The single step synthesis of an Fe(II) porphyrin cored hyperbranched polymer, possessing similar size and topology to the natural heme containing proteins, is reported: UV spectroscopy successfully demonstrated the ability of this polymer to reversibly bind oxygen.
Functionalization at the focal point of hyperbranched polyester was achieved using a series of amines and a postsynthetic reaction utilizing an activated p-nitrophenyl ester unit. An element of dense packing was also detected, as evident from differences in levels of incorporation between linear and bulky reagents.
This communication describes a self assembled porphyrin sphere. The globular macromolecular assembly contains 12 terminal porphyrins and has a molecular mass in excess of 15,000 g mol-1.
New supramolecular A2B2 co-polymers formed in solution from a rigid diporphyrin monomer (the A2 unit) and a short flexible dipyridine monomer (the B2 unit) are reported; NMR experiments show that complete binding occurs at mM concentrations; UV titrations reveal that the dipyridine unit and a monomeric control ligand have identical binding constants, confirming that linear polymers were generated (in preference to small cyclic oligomers); at 2 x 10(-2) M polymers with an average molecular weight of 17,100 g mol-1 and containing approximately 14 porphyrin units have formed.
Catalytic sites can be placed at the core, at interior positions or at the periphery of a dendrimer. There are many examples of the use of peripherally functionalized dendrimers in catalysis and this subject has been thoroughly reviewed in the recent literature. This review is concerned only with dendrimer based catalysis involving catalytic sites at the core of a dendrimer and within the interior voids. In covering the significant achievements in this area, we have concentrated on examples that highlight key features with respect to positive and/or negative catalytic activity.