Understanding the template preorganization step of an artificial arginine receptor.

A biomimetic complex which mimics the arginine-phosphonate diester interaction of the arginine fork is investigated with respect to structure and energetics of stable configurations. Within this work, we provide knowledge on local minima of the isolated system obtained from first-principles calculations. Non-negligible solvation effects are studied in a microsolvation approach. The interactions which govern the structural patterns of molecular recognition in this tweezer-guest complex can be significantly modulated by the action of hydrogen bond accepting and donating solvent molecules, such as dimethyl sulfoxide or water, which were present in experimental investigations on this system. Different tweezer-guest structures are evaluated with respect to their temperature-dependent thermodynamical properties as products of the first association reaction step of the bisphosphonate tweezer template and the guanidinium moiety.