2-Aminopyrimidine-Silver(I) Based Hybrid Organic Polymers: Self-Assembly and Phase Transitions of a Novel Class of Electronic Material

Solution processing methods of conjugated polymers are an important strategy for the preparation of organic semiconductors. We introduce a novel family of semiconductors prepared by the solution based small molecule self-assembly of 2-amino-5-pentafluorophenylpyrimidine and various silver(I) salts (AgX; X = CO 2 CF 3, SO 3 CF 3, NO 3 ). The compounds are analyzed by single crystal analysis revealing that the solid state assembly consists of alternating polymer strands of 2-aminopyrimidine and silver(I). The solid state assembly can be controlled by the silver counterion and the solvent yielding polymer strands with different interatomic parameters and optoelectrical properties. The compounds are optically characterized and reveal remarkably different solid state absorption when compared to the parent compound 2-aminopyrimidine in solution. Also, an exclusive solid state emissive state is observed. Herein, the excitation occurs not at the maximum but at the onset of absorbance. The silver(I)triflate-2-aminopyrimidine yields two different porous frameworks depending on the solvent used for crystallization. These porous frameworks are made of 1-dimensional polymer strands, and the pores are filled with solvent molecules. By heating and addition of solvent the frameworks can be reversibly converted into each other in the solid state, changing the optoelectrical properties. The compounds are thermodynamically analyzed by differential scanning calorimetry. Also, the electrical conductance was proven in a preliminary experiment on a thin crystalline film of 4 .