Several photochromic dihydropyrenes were designed to test whether the DHP molecule retains its response to light when it is bound to the first row transition metals. DAP 26, NDAP 22 and BDAP 21 were composed of the parent DHP 11, naphthoyl-DHP 38 and the BDHP 12 fragments respectively that were bound via a Sonogashira coupling to the phenanthroline unit through an acetylene linker. A condensation reaction between DHP-imid 29 and BDHP-imid 50 with phenanthroline diketone 28 in the presence of an excess of NH4+OAc- yielded the imidazole functionalized dihydropyrenes DHP-imid 23 and BDHP-imid 24 respectively. PDD 25 which is a [e]pyrazino annelated DHP 11 was obtained from condensation of the DHP-diamine, generated in situ from its dinitro precursor 45, with phenanthroline diketone 28. Compounds 21, 24 and 25 responded reversibly to UV and visible irradiation while also undergoing thermal return. NDAP 22 decomposed upon exposure to UV while being converted from its open to the closed state.
Acac and hfac complexes of BDAP 52-55 and of PDD 60-61 were synthesized by reacting Co(acac)2(H2O)2 51 and M(hfac)2 59 (where M = Co2+, Mn2+, Ni2+) with one equivalent of either BDAP 21 or PDD 25 photochrome respectively. Co(acac)2(BDAP) 52 and Co(acac)2(PDD) 60 complexes showed reversible opening and closing under alternative UV and visible irradiation for at least 10 cycles. Mn(hfac)2(BDAP) 53, Ni(hfac)2(BDAP) 54 and Co(hfac)2(BDAP) 55 complexes opened upon exposure to visible light and then closed with heating in the dark. Thermodynamic parameters ΔEact, ΔH‡ and ΔS‡ were determined after fitting the closing rate constant data for each species at 54, 64 and 74 °C (unless stated otherwise) to Arrhenius and Eyring equations.
| Identifer | oai:union.ndltd.org:uvic.ca/oai:dspace.library.uvic.ca:1828/3037 |
| Date | 07 September 2010 |
| Creators | Sarytcheva, Olga Valerii |
| Contributors | Mitchell, Reginald H., Berg, David Jay |
| Source Sets | University of Victoria |
| Language | English, English |
| Detected Language | English |
| Type | Thesis |
| Rights | Available to the World Wide Web |
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