Chemists Attain Accurate Manipulation of Synthetic Polymer Stereochemistry Employing DNA-Like Methods
In a remarkable breakthrough, chemists have created a technique to carefully regulate the stereochemical arrangement of synthetic polymers, resembling the creation of synthetic DNA. This method, which entails assembling polymers one monomer at a time, is expected to result in unparalleled polymer sequences with distinct characteristics.
Synthetic polymers commonly display inconsistency, characterized by variations in both length and structure. Traditional synthesis methods, such as radical or anionic polymerization, provide limited accuracy in managing stereocentres along the polymer chain. Jean-François Lutz, from the University of Strasbourg, voiced his discontent with current polymer synthesis techniques, prompting this forward-thinking investigation.
Lutz, in collaboration with Ranajit Barman, formulated a technique that grants full control over the order of monomer sequences, enabling precise regulation of stereocentre arrangement. Their approach included synthesizing two chiral phosphodiester amide monomers with contrasting configurations. These were applied in a solid-phase phosphoramidite chemistry process to systematically build polymers, mirroring the procedures used for the synthesis of DNA and RNA.
The team successfully produced twenty distinct polymers, each comprising up to 50 monomers. Some of these sequences had previously been challenging to manufacture, although their current attributes were not considered particularly novel, functioning primarily as a demonstration of the method’s potential effectiveness.
Presently, three main categories of stereochemical polymers exist: isotactic, syndiotactic, and heterotactic, determined by the configuration of their substituents. Lutz emphasized that the novel method paves the way for entirely innovative sequences, with over a million distinct configurations possible for polymers as short as 20 monomers featuring stereocentres.
Nevertheless, the current applicability of the method is constrained by cost, limiting its scale, as noted by polymer chemist Róża Szweda from Adam Mickiewicz University. This constraint may present challenges for material applications, but offers promise in fields like digital information storage or artificial enzyme development, where only minimal quantities of polymers are necessary.
Szweda proposed that advanced 2D-NMR techniques could provide further confirmation of the stereochemistry of these polymers. She foresees that this progress could stimulate the creation of new characterization methodologies capable of accurately analyzing chiral sequences.
Lutz aspires to broaden this approach to construct polymers using different monomers, particularly aiming at polymers with stereocentres situated in closer proximity. This modification could greatly impact polymer characteristics, potentially unlocking new material possibilities.