Solid-State Pharmaceutical Cluster, Materials and Surface Science Institute, University of Limerick, Limerick, Ireland.
Chemistry. 2013 Aug 5;19(32):10663-71. doi: 10.1002/chem.201203578. Epub 2013 Jun 21.
Four new ternary crystalline molecular complexes have been synthesised from a common 3,5-dinitrobenzoic acid (3,5-dnda) and 4,4'-bipyridine (bipy) pairing with a series of amino-substituted aromatic compounds (4-aminobenzoic acid (4-aba), 4-(N,N-dimethylamino)benzoic acid (4-dmaba), 4-aminosalicylic acid (4-asa) and sulfanilamide (saa)). The ternary crystals were created through the application of complementary charge transfer and hydrogen-bonding interactions. For these systems a dimer was created through a charge-transfer interaction between two of the components, while hydrogen bonding between the third molecule and this dimer completed the construction of the ternary co-crystal. All resulting structures display the same acid⋅⋅⋅pyridine interaction between 3,5-dnba and bipy. However, changing the third component causes the proton of this bond to shift from neutral OH⋅⋅⋅N to a salt form, O(-) ⋅⋅⋅HN(+) , as the nature of the group hydrogen bonding to the carboxylic acid was changed. This highlights the role of the crystal environment on the level of proton transfer and the utility of ternary systems for the study of this process.
已经合成了四个新的三元结晶分子配合物，它们是由一种常见的 3,5-二硝基苯甲酸（3,5-dnda）和 4,4'-联吡啶（bipy）与一系列氨基取代的芳香化合物（4-氨基苯甲酸（4-aba）、4-(N,N-二甲基氨基)苯甲酸（4-dmaba）、4-氨基水杨酸（4-asa）和磺胺）配对而成的。这些三元晶体是通过互补的电荷转移和氢键相互作用形成的。对于这些体系，通过两个组分之间的电荷转移相互作用形成二聚体，而第三个分子与这个二聚体之间的氢键完成了三元共晶的构建。所有得到的结构都显示了 3,5-dnba 和 bipy 之间相同的酸···吡啶相互作用。然而，改变第三个组分会导致这个键的质子从中性 OH···N 转移到盐形式，O(-) ⋅⋅⋅HN(+)，因为与羧酸氢键的基团性质发生了变化。这突出了晶体环境对质子转移水平的作用以及三元体系在研究这一过程中的应用。
