Photochemically reactive polymers: synthesis and photochemistry of polyamides containing Cp2Mo2(CO)6 molecules along the polymer backbone

Nieckarz, Gregory F.; Tyler, David R.

doi:10.1016/0020-1693(95)04880-4

Cited by 20 publications

(15 citation statements)

References 22 publications

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“…Synthesis. Molecules 1 − 1 to 4 − 4 were synthesized by the route shown in Scheme . The molecules were obtained rigorously pure by repeated filtrations and recrystallizations from hexanes.…”

Section: Resultsmentioning

confidence: 99%

“…Photochemically reactive polymers − are of considerable interest because they are useful as degradable plastics, photoresists, − biomedical materials, and precursors to ceramic materials. − ,− To expand the repertoire of photodegradable polymers, we have been developing a new class of polymers that contain metal−metal bonded organometallic dimers interspersed along the polymer backbone. − These polymers are photodegradable because the metal−metal bonds can be cleaved with visible light and the resulting metal radicals captured with oxygen or other traps (Scheme ) 1 Photochemical Degradation of a Polymer with Metal−Metal Bonds along Its Backbone …”

Section: Introductionmentioning

confidence: 99%

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Radical Cage Effects in the Photochemical Degradation of Polymers: In-Cage Trapping of Photochemically Generated Radical Cage Pairs in Polymer Model Compounds

et al. 1999

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This study explored the origins of the observation that the overall quantum yields for polymer photodegradation depend on the polymer chain length. The (CH3(CH2) n C(O)NHCH2CH2Cp)2Mo2(CO)6 (n = 3, 8, 13, 18) complexes (1 − 1 − 4 − 4) were synthesized and used as model complexes for the study. As is common for metal−metal bonded complexes of this type, irradiation of these molecules cleaved the metal−metal bonds and formed free radicals via the intermediate formation of a radical cage pair. Studies on previous model complexes showed that the quantum yields for degradation decreased as the chain length of the complex increased. The decrease in quantum efficiency was partially attributed to an increase in the radical cage effect as the chain length increased. Surprisingly, however, the overall quantum yields and cage effects for complexes 1 − 1 − 4 − 4 did not vary significantly with chain length. The similarity in the quantum yields and in the cage effects for these molecules is attributed to an internal trapping reaction of the metal radicals in the solvent cage by the H atom of the amide group. The resulting Mo···(H)−N agostic interaction forms a six-membered ring. The trapping reaction takes place by segmental rotation of the metal-containing end of the radical chain; the rate of this motion is independent of the chain length, and thus differences in the cage effects and the overall quantum yields will be diminished for the four molecules. The X-ray crystal structure of the (CH3(CH2)3C(O)NHCH2CH2Cp)2Mo2(CO)6 molecule is also reported.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Radical Cage Effects in the Photochemical Degradation of Polymers: In-Cage Trapping of Photochemically Generated Radical Cage Pairs in Polymer Model Compounds

et al. 1999

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“…Figure shows an example for the synthesis of polyurethanes with Mo‐Mo bonds via the reaction between metal‐metal bonded diol complex 1 and hexamethylene diisocyanate (HMDI). Based on the same strategy, other types of polyurethane, polyureas and polyamides with Mo‐Mo bonds in the polymer's backbone have been prepared . The molecular weight of the synthesized polymers usually falls into the range of 5000–20 000 g mol −1 (DP = 7–25).…”

Section: Mcmcoms Containing Metal‐metal Bondsmentioning

confidence: 99%

“…Based on the same strategy, other types of polyurethane, [ 37 ] polyureas and polyamides with Mo-Mo bonds in the polymer's backbone have been prepared. [ 38 ] The molecular weight of the synthesized polymers usually falls into the range of 5000-20 000 g mol −1 (DP = 7-25). As stated in a previous review, [ 35 ] no effort had been made to increase molecular weight, since the photo-degradable properties of the macromolecules rather than the polymerization process itself was the focus of the research.…”

Section: Step-growth Polymerizationmentioning

confidence: 99%

Synthesis of Main‐Chain Metal Carbonyl Organometallic Macromolecules (MCMCOMs)

Cao

Murshid

Wang

2015

Macromol. Rapid Commun.

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Synthesis of main-chain metal carbonyl organometallic macromolecules (MCMCOMs) is difficult, mainly due to the instability of metal carbonyl complexes. Despite its challenge a number of MCMCOMs has been prepared by strategically using organometallic, organic, and polymer synthetic chemistry. Main contributions to this research field were reported by the groups of Tyler, Pannell, and Wang and are briefly summarized in this article.

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“…Interestingly, the polyamide 60 shown contains a metal-metal bond that can be cleaved photochemically. This property is potentially useful in photolithography [118,119]. Tyler has recently reviewed polymers containing metal-metal bonds [120].…”

Section: Ncmentioning

confidence: 99%

Optical and Luminescence Properties and Applications of Metal Complex‐Based Polymers

Crayston

Ritchie

2010

Photochemistry and Photophysics of Polymer Materials

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Photochemically reactive polymers: synthesis and photochemistry of polyamides containing Cp2Mo2(CO)6 molecules along the polymer backbone

Cited by 20 publications

References 22 publications

Radical Cage Effects in the Photochemical Degradation of Polymers: In-Cage Trapping of Photochemically Generated Radical Cage Pairs in Polymer Model Compounds

Radical Cage Effects in the Photochemical Degradation of Polymers: In-Cage Trapping of Photochemically Generated Radical Cage Pairs in Polymer Model Compounds

Synthesis of Main‐Chain Metal Carbonyl Organometallic Macromolecules (MCMCOMs)

Optical and Luminescence Properties and Applications of Metal Complex‐Based Polymers

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