The Basic Physical Propetries Of Typical Linear And Cyclic Organic Compounds Under High Pressure Conditions

The in-situ high-pressure infrared absorption, Raman scattering and synchrotronX-ray diffraction measurements are performed on n-heptane, cyclopentane,cyclopentanone, cyclopentanol, cycloheptane, cycloheptanone and cycloheptanol byusing diamond anvil cells. The original and innovational research results as below:1. In-situ high-pressure Raman scattering and synchrotron X-ray diffractionmeasurements are performed on n-heptane by using diamond anvil cells at roomtemperature. Liquid n-heptane transforms into rotator phase III (RIII) at1.2GPa andthen into rotator phase IV (RIV) at3.0GPa, with pressure increasing to7.5GPa,n-heptane begins to turn into truly crystalline phase and completes at14.5GPa, themolecular orientation changes from disorder to order. The pressure-induced phasetransition of n-heptane, liquid-RIII-RIV-truly crystalline, is just same as that observed insolid n-alkanes under increasing temperature.2. In-situ high-pressure infrared absorption, Raman scattering and synchrotron X-raydiffraction measurements are performed on cyclopentane by using diamond anvil cells.The phase diagram of cyclopentane is determined in the pressure and temperaturerange of0-4.0GPa and105-350K, the melting curve of cyclopentane is observed forthe first time. Within the pressure range of84.3GPa, two crystalline phase transitionsare observed around16.0and40.0GPa, cyclopentane ultimately is not turn intoamorphization. The pressure-induced phase transition of cyclopentane is fullyreversible.3. In-situ high-pressure infrared absorption, Raman scattering and synchrotron X-raydiffraction measurements are performed on cyclopentanone by using diamond anvilcells up to30.4GPa. Liquid cyclopentanone transforms into truly crystalline phase atabout1.5GPa. The pressure-induced phase transition of cyclopentanone is fullyreversible at room temperature condition.4. In-situ high-pressure infrared absorption, Raman scattering and synchrotron X-ray diffraction measurements are performed on cyclopentanol by using diamond anvil cellsat room temperature. The results show that liquid cyclopentanlo transforms into trulycrystalline phase at1.6-1.8GPa, and then turns into another phase of truly crystalline,with pressure increasing to26.0GPa, cyclopentanol gradually goes into amorphousstate. The pressure effect of50.3GPa made no hysteresis on the phase transition ofcyclopentanol.5. In-situ high-pressure infrared absorption, Raman scattering and synchrotron X-raydiffraction measurements are performed on cycloheptane by using diamond anvil cellsat room temperature. Liquid cycloheptane turns into plastic phase at0.18GPa, and twoplastic phase transitions are observed at0.50and1.1GPa, respectively. With pressureincreasing higher than3.0GPa, cycloheptane gradually transforms into glass state. Thepressure-induced phase transition of cycloheptane is fully reversible with the pressurerange of30.3GPa.6. In-situ high-pressure infrared absorption, Raman scattering and synchrotron X-raydiffraction measurements are performed on cycloheptanone by using diamond anvilcells at room temperature. Liquid cycloheptanone transforms into plastic phase atabout0.6GPa, and then into truly crystalline phase at1.0-1.2GPa. With pressurehigher than24.0GPa, cycloheptanol gradually turns into amorphous state. In theplastic to truly crystalline phase transition, the molecular orientation changes fromdisorder to order. The pressure-induced phase transition of cycloheptanone is fullyreversible within the pressure range of31.3GPa.7. In-situ high-pressure infrared absorption, Raman scattering and synchrotron X-raydiffraction measurements are performed on cycloheptanol by using diamond anvil cellsat room temperature. Liquid cycloheptanol goes into plastic phase at about0.77GPaand turns into another plastic phase at1.1GPa, with pressure higher than3.0GPa,cycloheptanol gradually turns into amorphous state. The pressure-induced phasetransition of cycloheptanol is fully reversible within the pressure range of29.7GPa. 8. The pressure-induced amorphization of cycloalkanes and their derivatives isanalyzed from the point of conformation and bond length. If the number of carbon inthe derivatives of cyclalkanes is the same, and the bond length of substituent group ismuch longer, the amorphous transition pressure will be much lower; if the carbon ringof same type materials is much bigger, the amorphous transition pressure will also bemuch lower.