An orthorhombic polymorph of pyrazino[2,3-f][1,10]phenanthroline-2,3-dicarbonitrile

作者：Yang, Wei; Qiu, Qi-Ming; Zhou, Li-Li; Jin, Qiong-Hua^*; Zhang, Cun-Lin

来源：Acta Crystallographica Section E-Structure Reports Online, 2011, 67: O3250-U1952.

DOI：10.1107/S1600536811047039

• GALLIC ACID MONOHYDRATE
• PI-PI-STACKING
• 2-(PYRIMIDIN-2-YLSULFANYL)ACETIC ACID
• MONOCLINIC POLYMORPH
• COMPLEXES
• 6,7-DICYANODIPYRIDOQUINOXALINE

The title compound, C(16)H(6)N(6), is a polymorph of the previously reported structure [Kozlov & Goldberg (2008). Acta Cryst. C64, o498-o501]. Unlike the previously reported monoclinic polymorph (space group P2(1)/c, Z = 8), the title compound reveals orthorhombic symmetry (space group Pnma, Z = 4). The molecule shows crystallographic mirror symmetry, while the previously reported structure exhibits two independent molecules per asymmetric unit. In the title compound, adjacent molecules are essentially parallel along the c axis and tend to be vertical along the b axis with dihedral angles of 72.02 (6)degrees. However, in the reported polymorph, the entire crystal structure shows an antiparallel arrangement of adjacent columns related by inversion centers and the two independent molecules are nearly parallel with a dihedral angle of 2.48 (6)degrees.

• 出版日期2011-12
• 单位中国检验检疫科学研究院; 首都师范大学