Two advances in the synthesis of hairpin pyrrole-imidazole polyamides (PAs) are described. First, the application of a convergent synthetic strategy is shown, involving the Boc-based solid phase synthesis of a C-terminal fragment and the solution phase synthesis of the N-terminal fragment. Second a new hybrid resin is developed that allows for the preparation of hairpin PAs lacking a C-terminal β-alanine tail. Both methods are compatible with a range of coupling reagents and provide a facile, modular route to prepare PA libraries in high yield and crude purity.

The thermodynamic background to three calorimetric techniques is discussed; (i) titration microcalorimetry, (ii) adiabatic calorimetry, and (iii) heat conduction calorimetry. Relevant equations for each technique are derived from a common equation for the enthalpy H of a closed system. General patterns which emerge in the measured parameters are presented for adiabatic and heat conduction calorimeters linked to applications of these techniques.

General equations are developed relating the dependence of temperature on time for a closed system undergoing chemical reaction. Equations are reported for thermally insulated systems and for systems where Newton's law of cooling describes the exchange of thermal energy between system and surroundings. These equations provide the basis for analysing and modelling thermal methods for screening combinatorial libraries. Key equations describe the impact of chemical reactions having different orders and molecularities. The potential of resulting differential equations is illustrated using numerical integration to yield temperature–time plots which highlight the roles of rate constants and enthalpies of reactions.