Fabrication and characterization of functionalized polyoxometalates
Polyoxometalates (POMs), a versatile group of metal oxide polyanions which exhibits variety of properties as it has a wide range of sizes and structures that can be tuned to suit the fabrication needs. Organic pyrene dye which has rather long fluorescence as well as long-lived excited state was chos...
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| Format: | Final Year Project (FYP) |
| Language: | English |
| Published: |
2012
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| Online Access: | http://hdl.handle.net/10356/48863 |
| _version_ | 1811684211640238080 |
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| author | Yu, Lingling. |
| author2 | School of Materials Science and Engineering |
| author_facet | School of Materials Science and Engineering Yu, Lingling. |
| author_sort | Yu, Lingling. |
| collection | NTU |
| description | Polyoxometalates (POMs), a versatile group of metal oxide polyanions which exhibits variety of properties as it has a wide range of sizes and structures that can be tuned to suit the fabrication needs. Organic pyrene dye which has rather long fluorescence as well as long-lived excited state was chosen to be grafted onto POM skeleton through its imido group to study and understand the charge-transfer mechanism in organic functionalized POMs. In this report, a detailed outline of synthesis and the characterization of organic-inorganic charge-transfer hybrid were recorded. The charge-transfer mechanism was analyzed with the time resolved transient absorption spectroscopy. The hybrid shown electronic absorption at 450nm, indicating that there was a strong electronic interaction between the organic pyreneimido group and inorganic hexamolybdate cluster. The overall studies revealed that the strong electronic absorption at the visible region mainly came from the optically allowed π-π* transition of the pyreneimido component (S0 to S2 transition). The charge-transfer process from the excited pyreneimido moiety to the inorganic POM cluster at the time scale of approximately 700fs was observed, which could be ascribed to the internal conversion of singlet excited state from S2 state to S1 state. This result shed light on new route for the design of new charge-transfer hybrid clusters of organic functionalized POMs and serves as crucial guidance for their applications in optical and electrical devices. |
| first_indexed | 2024-10-01T04:25:02Z |
| format | Final Year Project (FYP) |
| id | ntu-10356/48863 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T04:25:02Z |
| publishDate | 2012 |
| record_format | dspace |
| spelling | ntu-10356/488632023-03-04T15:40:17Z Fabrication and characterization of functionalized polyoxometalates Yu, Lingling. School of Materials Science and Engineering Facility for Analysis, Characterisation, Testing and Simulation Zhang Qichun DRNTU::Engineering::Materials::Organic/Polymer electronics Polyoxometalates (POMs), a versatile group of metal oxide polyanions which exhibits variety of properties as it has a wide range of sizes and structures that can be tuned to suit the fabrication needs. Organic pyrene dye which has rather long fluorescence as well as long-lived excited state was chosen to be grafted onto POM skeleton through its imido group to study and understand the charge-transfer mechanism in organic functionalized POMs. In this report, a detailed outline of synthesis and the characterization of organic-inorganic charge-transfer hybrid were recorded. The charge-transfer mechanism was analyzed with the time resolved transient absorption spectroscopy. The hybrid shown electronic absorption at 450nm, indicating that there was a strong electronic interaction between the organic pyreneimido group and inorganic hexamolybdate cluster. The overall studies revealed that the strong electronic absorption at the visible region mainly came from the optically allowed π-π* transition of the pyreneimido component (S0 to S2 transition). The charge-transfer process from the excited pyreneimido moiety to the inorganic POM cluster at the time scale of approximately 700fs was observed, which could be ascribed to the internal conversion of singlet excited state from S2 state to S1 state. This result shed light on new route for the design of new charge-transfer hybrid clusters of organic functionalized POMs and serves as crucial guidance for their applications in optical and electrical devices. Bachelor of Engineering (Materials Engineering) 2012-05-10T04:35:15Z 2012-05-10T04:35:15Z 2012 2012 Final Year Project (FYP) http://hdl.handle.net/10356/48863 en Nanyang Technological University 35 p. application/pdf |
| spellingShingle | DRNTU::Engineering::Materials::Organic/Polymer electronics Yu, Lingling. Fabrication and characterization of functionalized polyoxometalates |
| title | Fabrication and characterization of functionalized polyoxometalates |
| title_full | Fabrication and characterization of functionalized polyoxometalates |
| title_fullStr | Fabrication and characterization of functionalized polyoxometalates |
| title_full_unstemmed | Fabrication and characterization of functionalized polyoxometalates |
| title_short | Fabrication and characterization of functionalized polyoxometalates |
| title_sort | fabrication and characterization of functionalized polyoxometalates |
| topic | DRNTU::Engineering::Materials::Organic/Polymer electronics |
| url | http://hdl.handle.net/10356/48863 |
| work_keys_str_mv | AT yulingling fabricationandcharacterizationoffunctionalizedpolyoxometalates |