Dr. Kuo Li [HPSTAR Associate Staff Scientist]

Title: Pressure induced Polymerization of Unsaturated Compounds and Enhanced Conductivity

Time: 14:00 - 15:30, August 29

Place: Auditorium Room 410, Building 6, HPSTAR (Shanghai)

Abstract:

This is a talk about High Pressure Chemistry. Dr. Kuo Li and Dr. Haiyan Zheng hope to share with you some interesting chemical reaction under high pressure and their research plan in Beijing and Shanghai, looking for collaborations. The talk includes the researches on the polymerization process and the corresponding transport properties of acetonitrile, K3Fe(CN)6 and CaC2 using in-situ Raman, IR , X-ray, neutron powder diffraction, impedance spectra combining with the pair distribution function analysis and solid state NMR of the recovered high pressure polymerized phase. In the research of acetonitrile under high pressure, a novel reaction mechanism which includes the hydrogen transfer process from methyl group to nitrogen atom was proposed and the obtained polymerized phase was confirmed to be a nano-graphene like materials with onion structure. The enhanced conductivity were observed in CaC2 and K3Fe(CN)6. For CaC2, it shows more than 107 times enhancement when compressed to ~ 20 GPa. An insulator-metal transition and bonding between acetylide anions was confirmed. For K3Fe(CN)6, bonding between CN anions and enhanced conductivity were observed and the bonding properties is closely related with the charge transfer from CN to Fe(III).