The Correlation between Calculated Electrostatic Potential and Crystal Structures; Theoretical Study and the Crystal Structure of 3-Bromopyridinium Aquatrichlorocuprate(II)

The supramolecular structure of (3bp)[cu(h2o)cl3] (3bp = 3-bromopyridinium cation) is developed based on n-h···cl, n-h···o , c-br···cl, o-h···cl and cu···cl interactions. cu···cl semi- coordinate bond and o-h···cl hydrogen bonding interactions connect [cu(h2o)cl3]- anions to form chains. the two legs of the bifurcated hydrogen bonding interactions of the pyridinium cation nitrogen (n-h···cl and n-h···o) link these chains to form layer structures. the three- dimensional structure is developed by interdigitating these layers based on c-br···cl halogen bonding interactions. the energy of the interactions n-h···cl and c-br···cl was calculated, the n- h···cl hydrogen bonding interactions are found stronger than the analogous c-br···cl halogen bonding interactions. the calculated electrostatic potential of 3bp+ cation and [cu(h2o)cl3]- anion was used to describe cation-anion, inter-anions and inter-cations interactions and the relative strength of the n-h···cl and c-br···cl interactions. moreover, the electrostatic potential model was found to be efficient in describing the arrangement of [cu(h2o)cl3]- anions inside crystalline lattices in all crystal structures published in cambridge structural data base (csd).