Intercalation Compounds by Dr. Julekha A. Shaikh

This presentation is purely academic for undergraduate and postgraduate students

1. Dr. Julekha . A. Shaikh Maharashtra College of Arts, Science and Commerce Intercalation Compounds

2. Intercalation Compounds Intercalation is the reversible inclusion or insertion of a   molecule   (or ion) into compounds with layered structures. Dr. Julekha Shaikh

3. Dr. Julekha Shaikh

4. Dr. Julekha Shaikh

5. Dr. Julekha Shaikh

6. Dr. Julekha Shaikh

7. Dr. Julekha Shaikh

8. Dr. Julekha Shaikh

9. Dr. Julekha Shaikh

10. Dr. Julekha Shaikh

11. Dr. Julekha Shaikh

12. Dr. Julekha Shaikh

13. Dr. Julekha Shaikh

14. Dr. Julekha Shaikh

15. Dr. Julekha Shaikh

16. MC 8 (M = K, Rb , Cs) prep through no of stages Dr. Julekha Shaikh

17. Intercalation Compounds of oxo acids Intercalation compounds of oxo acids are formed by treating graphite with strong acids in the presence of oxidizing agents. Graphite bisulfate, [C 24 ] + [HSO 4 ] − lamellar graphite salts 48 C + 0.25 O 2  + 3 H 2 SO 4  → [C 24 ] + [HSO 4 ] − ·2H 2 SO 4  + 0.5 H 2 O Intercalation Compounds of metal halides A number of metal halides intercalate into graphite. The chloride derivatives have been most extensively studied. Examples include MCl 2  (M = Zn, Ni, Cu, Mn ), MCl 3  (M = Al, Fe, Ga ), MCl 4  (M = Zr , Pt), etc.  e.g. [C 27 ] + [AlCl 4 ] − ·2AlCl 3 , [C 10 ] + [FeCl 4 ] − ·5FeCl 3    Intercalation Compounds of halogens, oxides and sulphides Chlorine and bromine reversibly intercalate into graphite. Iodine does not. Fluorine reacts irreversibly. In the case of bromine, the following stoichiometries are known: C n Br for n = 8, 12, 14, 16, 20, and 28. Because it forms irreversibly,  carbon monofluoride  is often not classified as an intercalation compound. It has the formula (CF) x . It is prepared by reaction of gaseous  fluorine  with graphitic carbon at 215–230°C. The color is greyish , white, or yellow. The bond between the carbon and fluorine atoms is covalent. Carbon monofluoride is not electrically conductive. It has been studied as a  cathode  material in one type of primary (non-rechargeable)  lithium batteries . A number of oxides and sulphides also intercalate into graphite. SO 3 , N 2 O 5 , CrO 3 , MoO 3 , V 2 S 3 , Cr 2 S 3 , PdS , WS 2 , Sb 2 S 3 etc. Dr. Julekha Shaikh

18. Intercalation Compounds of Metal dichalcogenides Another well-known family of intercalation hosts are the layered  metal dichalcogenides  such as  titanium disulfide . These materials are prepared by treating graphite with a strong oxidant or a strong reducing agent: C + m X → CX m The reaction is reversible.The host (graphite) and the guest X interact by  charge transfer . A analogous process is the basis of commercial  lithium-ion batteries . LiS batteries . Intercalation of Li into a  titanium disulfide  cathode. The process involves swelling of one crystal axis and charge transfer from Li to Ti. Dr. Julekha Shaikh

19. DNA intercalation Intercalation induces structural distortions. Left: unchanged DNA strand. Right: DNA strand intercalated at three locations (black areas). In  biochemistry , intercalation is the insertion of molecules between the planar bases of DNA. Intercalation occurs when ligands of an appropriate size and chemical nature fit themselves in between base pairs of DNA. These ligands are mostly positively charged, planar,  polycyclic ,  aromatic compounds  that unwind the  DNA double helix  and insert themselves between DNA  base pairs . Dr. Julekha Shaikh

20. Therapeutic applications metallo-intercalators can combat cancerous tumor cells within the body by targeting specific mismatched DNA base pairs; the ability to modify the ligands bound to the metal center allows for a high degree of specificity in the binding interactions between the metallo-intercalator and the DNA sequence. DNA intercalators are used in  chemotherapeutic  treatment to inhibit DNA replication in rapidly growing cancer cells. Examples include doxorubicin ( adriamycin ) and daunorubicin (both of which are used in treatment of Hodgkin's lymphoma), and dactinomycin (used in Wilm's tumour , Ewing's Sarcoma). Dr. Julekha Shaikh

21. Properties and applications GICs exhibit diverse electronic and electrical properties. improves in-plane transport properties can change magnetic properties can produce superconductors (CaC 6  exhibits the highest critical temperature T c  = 11.5 K) Increases reactivity can dope other properties depending on electronic mobility intercalation is a powerful means of controlling physical properties i . e obtain tailor made properties. Dr. Julekha Shaikh