Selective Duplex Formation in Mixed Sequence Libraries of Synthetic Polymers.

Area of Science:

• Polymer Chemistry
• Supramolecular Chemistry
• Organic Synthesis

Background:

• Recognition-encoded melamine oligomers (REMO) are synthetic polymers with a defined backbone and specific recognition units.
• Previous methods lacked automated, sequence-specific synthesis capabilities for complex polymer libraries.

Purpose of the Study:

• To develop an automated solid-phase synthesis (SPS) method for REMO with any specified sequence.
• To investigate the self-assembly and duplex formation of REMO, particularly in mixed-sequence libraries.

Main Methods:

• Automated solid-phase synthesis of REMO using dichlorotriazine monomer building blocks.
• Synthesis of complementary homo-oligomers and subsequent duplex formation confirmation via NMR denaturation.
• Covalent trapping of duplexes using copper-catalyzed alkyne-azide cycloaddition (CuAAC) after end-group functionalization.
• Adaptation of SPS for mixed-sequence library synthesis and screening of self-assembly properties.

Main Results:

• A robust automated SPS method for REMO synthesis was established.
• Complementary homo-oligomers formed stable duplexes in nonpolar solvents.
• Screening of mixed-sequence libraries demonstrated high-fidelity, sequence-selective duplex formation at micromolar concentrations.
• CuAAC reaction effectively trapped self-assembled duplexes, enabling functional property screening.

Conclusions:

• The automated synthesis approach provides efficient access to diverse REMO libraries.
• Sequence-complementary REMO oligomers exhibit precise self-assembly, even within statistical mixtures.
• This methodology facilitates the study of sequence-dependent properties in synthetic polymers.