Synthesis and Structural Characterization of [2-(2-1H-Imidazoly)-1H-imidazolium nitrate] and [2-(2-1H-Imidazoly)-2H-imidazolium phthalyl glycinate] Based on the 2,2′-bi-1H-Imidazole Molecule

Abstract

Two new compounds (H3biim)(NO3)(1) and (H4biim)(phthgly)2 (2) (H2biim=biimidazole; Hphthgly=N-phthaloylglycine) have been synthesized and characterized by luminescence and single crystal X-ray diffraction study. Compound 1 crystallizes in the monoclinic space group C2/c, where a = 14.8078(15), b = 5.9233(6), c = 20.028(2) A, β = 92.7910(10)°, V = 1754.6(3) A3 and Z = 8. Compound 2 crystallizes in the monoclinic space group P2(1)/n, where a = 15.3775(14), b = 5.3200(6), c = 6.4689(18)A, β = 115.418(2)° V = 1216.9(2)A3 and Z = 4. In 1, the N–H groups of H3biim+ and the oxygen atoms of NO3 − are linked by hydrogen bonds leading to H3biim+(N,N)–R 2 2 (10) and N–H···O interactions forming infinite 1D helical chains along the b-axis. Compound 2 consists of a planar diprotonated biimidazole moiety and two phthgly anions which connect to the dication by hydrogen bonds phthgly−(O,O)–R 2 2 (9). The unit crystal structure of (H3biim)(NO3) consists of one H3biim+ cation and one NO3 − anion. The (H3biim)(NO3) units form infinite 1D helical chains along the b axis through robust hydrogen bonds H3biim+(N,N)-R 2 2 (10) involving the N–H groups of H2biim ligands with the oxygen atoms of nitrate anions, and the two adjacent units of [(H3biim)(NO3)] connect each other by a direct side-by-side interaction.