American chemists have modeled the behavior of the negatively charged complex dimethylurea with water molecules in the liquid phase and found that the gold and the methyl group are capable of forming in the environment of hydrogen bonds. The results of a study published in the journal Journal of the American Chemical Society.
Hydrogen bonds, though considered to be relatively weak, but play a very important role in chemistry and biology. Increasingly, scientists are convinced that in addition to the usual hydrogen bond acceptors (O, N, F), transition metals can also contact sour (depleted electron density) protons. For example, scientists have shownthat platinum in anti-cancer tool cisplatine can form a relationship with the hydrogen atoms of water molecules.
Similar unusual interaction with hydrogen can be gold. Owing to the filled 5d orbitals of gold ion may exhibit similar unusual interaction with hydrogen. Of all metals this element has the greatest electron affinitythat is comparable to the Halogens, which allows to form auride in which the gold is in the oxidation state minus one, becoming a good acceptor of protons. Many researchers have carried out calculations of the formation of hydrogen bonds AuI…H-O in the gas phase. Will they be formed in a liquid medium, where there can be a more favorable energy competitive process, remains unresolved.
Mana Kumar (Manoj Kumar) and Joseph Francisco (Joseph S. Francisco) from the University of Pennsylvania calculated the molecular dynamic models of interactions dimethylurea with water. Simulation method molecular dynamics born-Oppenheimer allowed the scientists to trace the time dynamics of the system behavior from a finite number of molecules at a given temperature in different media.