Crystal and molecular structure, hydrogen bonding and electrostatic interactions of bis(trigonelline) hydrogen perchlorate monohydrateq

Bis(trigonelline) hydrogen perchlorate monohydrate, (TRG)2H·ClO4·H2O, crystallizes in space group P21: A pair of TRG molecules is bridged by an asymmetrical O·H·O hydrogen bond of length 2.484(3) A° to form a homoconjugated cation. Water molecules and ClO4 anions are linked alternatively by hydrogen bonds of lengths 2.961(3) and 3.254(3) A ° into planar, zigzag chains along the [z] direction. Both the ClO4 anion and H2O molecule display additionally electrostatic interactions with two positively charged nitrogen atoms of neighboring TRG molecules. The isolated entities of the complex were analyzed at the B3LYP/6-31G(d,p) level of theory in order to determine the influence of the ClO4 anion and H2O molecule on the hydrogen bond in (TRG·H·TRG). The FTIR spectrum shows a broad and intense absorption in the 1500–400 cm21 region, typical for short hydrogen bonds. Two bands at 3675 and 3580 cm21 confirmed a weak hydrogen bonds between water molecules and ClO4 anions. q 2004 Elsevier B.V. All rights reserved.