Crystal_structure_miningCarbonChemical BondingChemistryCyclopentadienyl AnionCiencias QuímicasInglés

The π-π stacking of aromatic rings: what is their closest parallel approach?

https://doi.org/10.59350/wznc0-9h884
Publicado in Henry Rzepa's Blog

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?

References

Inorganic Chemistry
Inglés

Synthesis, Structure, and Thermal Properties of Two New Inorganic‐organic Framework Compounds: Hexaaqua(μ2‐1,2,4,5‐benzenetetracarboxylato)‐bis(N,N′‐1,10‐phenathroline)dicobalt(II) Dihydrate and Hexaaqua(μ2‐1,2,4,5‐benzenetetracarboxylato)‐bis(N,N′‐2,2′‐dipyridylamine)dinickel(II) Tetrahydrate

https://doi.org/10.1002/zaac.200500292
Publicado in Zeitschrift für anorganische und allgemeine Chemie
Autores Jelena Rogan, Dejan Poleti, Ljiljana Karanović

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.

General Chemical EngineeringGeneral Chemistry
Inglés

Synthesis, crystal structure, DNA interaction and in vitro anticancer activity of a Cu(ii) complex of purpurin: dual poison for human DNA topoisomerase I and II

https://doi.org/10.1039/c4ra07127a
Publicado in RSC Adv.
Autores Piyal Das, Chetan Kumar Jain, Sanjoy K. Dey, Rajat Saha, Abhishek Dutta Chowdhury, Susanta Roychoudhury, Sanjay Kumar, Hemanta Kumar Majumder, Saurabh Das

Although generation of reactive oxygen species (ROS) by anthracycline anticancer drugs is essential for anti-tumor activity, they make these drugs cardiotoxic.