Shishkina Svitlana V, Isaiev Ivan A, Urzhuntseva Viktoriya V, Palchykov Vitalii A
SSI `Institute for Single Crystals', NAS of Ukraine, 60 Nauky Avenue, Kharkiv, 61001, Ukraine.
Department of Inorganic Chemistry, V. N. Karazin Kharkiv National University, 4 Svobody Square, Kharkiv, 61077, Ukraine.
Acta Crystallogr B Struct Sci Cryst Eng Mater. 2019 Apr 1;75(Pt 2):192-200. doi: 10.1107/S205252061900115X. Epub 2019 Mar 20.
The possible interaction of 6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline (heliamine) with bicyclo[2.2.1]hept-5-ene-endo-2,3-dicarboxylic acid anhydride has been studied. Instead of the reaction with heliamine, the acid anhydride was hydrolyzed into the appropriate dicarboxylic acid. An equimolar mixture of unreacted heliamine and in-situ-generated dicarboxylic acid crystallized in space group P2/c. The comprehensive study of the obtained crystals shows that the peculiarities of the crystallization process lead to the formation of the salt-cocrystal structure where the dianion interacts simultaneously with two cations forming a chain as the primary structural motif. The neutral molecules of dicarboxylic acid link the dianions of the neighbouring chains, forming a layer as the secondary structural motif. As a result, the stronger hydrogen bonds formed by the neutral molecules play a secondary role in the crystal structure formation.
