the molecular geometry of complex of adenine with 8 water molecules was calculated with hartree-fock (hf). the standard 6-31g(d) basis set has been employed. the existence of c-h…o hydrogen bonds between the water molecules and the hydrophobic part of nucleobase is stablished. we optimized structures and computed interaction energies of all complexes of adenine with water molecules step by step...

a quantum chemical investigation was carried out to study the properties of intermolecular f•••f, br•••br and br•••o interactions in crystalline 1-bromo-2,3,5,6-tetrafluoro-nitrobenzene (bfnb). this system was selected to mimic the halogen-halogen as well as halogen bonding interactions found within crystal structures as well as within biological systems. we found that fluorine atoms have weak ...

In the title compound, C(10)H(16)N(2)S(2+)·2Br(-), the pyrrolidine ring displays an envelope conformation, with the flap C atom lying 0.484 (5) Å out of the plane of the rest of the pyrrolidine ring. The thio-ether group connects the pyridine ring and the 2-methyl-pyrrolidine group. Both pyrrolidine NH bonds form hydrogen bonds to the bromide anions. These hydrogen bonds link the cations and an...

Carboxylic acids are hydrocarbon derivatives containing a carboxyl (COOH) moiety. Recall that carbon has four valence electrons and therefore requires four electrons or bonds to complete its octet. Based on this valence and bonding order, carbon forms four bonds in its neutral state, and these may be four single bonds or combinations of single and multiple bonds. Oxygen has six valence electron...

In nature, atoms form bonds with other atoms to form molecules, but these bonds can be of different types, for example single or double bonds. We can easily perceive these bonds, but assigning types to each bond is harder. This requires assigning bonds such that: • All carbon atoms have only one double bond • Pyrrol NH group have no double bonds • Pyridine N groups have only one double bond • H...