Collect. Czech. Chem. Commun. 1988, 53, 294-300

The molecular and crystal structure of benzamidinium bromoacetate

Bohumil Kratochvíla, Jan Ondráčekb, Karel Malýc and László Csordásd

a Department of Mineralogy
b Computing Center, Prague Institute of Chemical Technology 166 28 Prague 6, Czechoslovakia
c Institute of Physics, Czechoslovak Academy of Sciences 180 40 Prague 8, Czechoslovakia
d Laboratory of Surface and Interface Physics Eötvös University, 1088 Budapest, Hungary


The molecular and crystal structure of benzamidinium bromoacetate was solved on the basis of Patterson and Fourier synthesis. The position of all the atoms were localized and the least squares method was employed to refine the coordinates of all the atoms together with their thermal vibration parameters. A final R factor value of 0.067 was obtained for 1 349 observed reflections (I 1.96 σ(I)). The substance crystallizes in the P21/n monoclinic space group with lattice parameters of a = 1 145.7(2), b = 1 571.3(3), c = 578.3(1) pm, γ = 90.65(1)°, Z = 4. Intramolecular hydrogen bonds form ion pairs in the structure between the nitrogen atoms of the amidinium group and the oxygen atoms of the bromoacetate. Intramolecular hydrogen bonds, also between nitrogen and oxygen atoms, connect the molecules in an infinite chain. The molecular chains are joined together by van der Waals forces. The N···O distance in the hydrogen bonds varies between 280.3(8) and 284.5(8) pm.