Fun Hoong-Kun, Loh Wan-Sin, Johnson Atim, Yousuf Sammer, Eno Ededet
X-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia ; Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, PO Box 2457, Riyadh 11451, Saudi Arabia.
Acta Crystallogr Sect E Struct Rep Online. 2013 Mar 1;69(Pt 3):o353-4. doi: 10.1107/S160053681300322X. Epub 2013 Feb 6.
The asymmetric unit of the title compound, 2C2H6N5(+)·C4O4(2-), contains two 3,5-diamino-4H-1,2,4-triazolium cations and one squarate dianion. The squaric acid mol-ecule donated one H atom to each of the two 3,5-diamino-1,2,4-triazole mol-ecules at their N atoms. The squaric acid dianion has four C-O bonds which are shorter than a normal single C-O bond (1.426 Å) and are slightly longer than a normal C=O bond (1.23 Å), which indicates the degree of electron delocalization in the dianion. In the crystal, the cations and dianions are linked by N-H⋯N and N-H⋯O hydrogen bonds into a three-dimensional network.
标题化合物2C₂H₆N₅⁺·C₄O₄²⁻的不对称单元包含两个3,5-二氨基-4H-1,2,4-三唑阳离子和一个方酸二价阴离子。方酸分子在两个3,5-二氨基-1,2,4-三唑分子的N原子处分别向它们各提供一个H原子。方酸二价阴离子有四个C - O键,其键长比正常的C - O单键(1.426 Å)短,且比正常的C = O双键(1.23 Å)略长,这表明了该二价阴离子中的电子离域程度。在晶体中,阳离子和阴离子通过N - H⋯N和N - H⋯O氢键连接成三维网络。