Layer stacking in structures such as graphite is well-studied. The separation between the π-π planes is ~3.35Å, which is close to twice the estimated van der Waals (vdW) radius of carbon (1.7Å). But how much closer could such layers get, given that many other types of relatively weak interaction such as hydrogen bonding can contract the vdW distance sum by up to ~0.8Å or even more?
AbstractTwo binuclear complexes [Co2(C10H2O8)(C12H8N2)2 (H2O)6]·2H2O (1) and [Ni2(C10H2O8)(C10H9N3)2(H2O)6]·4H2O (2) were synthesized and their structures were determined by X‐ray structure analysis. In both structures metal centres are in deformed octahedral environments and they are linked by bis‐monodentately coordinated 1,2,4,5‐benzenetetracarboxylate ligands as bridging units. In the packing arrangements of both compounds, binuclear units are connected by hydrogen bonds forming 2D pseudo‐layers, strengthened by face‐to‐face π‐π stacking interactions. The pseudo‐layers further construct 3D inorganic‐organic frameworks via system of hydrogen bonds. The complexes were also characterized by IR spectroscopy, TG and DSC analysis. Dehydration processes and thermal stability of the complexes are discussed. The dehydration enthalpies are calculated and the possible decomposition mechanisms are assumed.
Although generation of reactive oxygen species (ROS) by anthracycline anticancer drugs is essential for anti-tumor activity, they make these drugs cardiotoxic.