Kevin J. T. Noonan

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Name: Noonan, Kevin
Organization: Carnegie Mellon University , USA
Department: Department of Chemistry
Title: Assistant(PhD)

TOPICS

Co-reporter:C. Tyler Womble, Jamie Kang, Kristina M. Hugar, Geoffrey W. Coates, Stefan Bernhard, and Kevin J. T. Noonan
Organometallics October 23, 2017 Volume 36(Issue 20) pp:4038-4038
Publication Date(Web):October 9, 2017
DOI:10.1021/acs.organomet.7b00663
Hydroxide-stable organic cations are crucial components for ion-transport processes in electrochemical energy systems, and the tetrakis(dialkylamino)phosphonium cation is a promising candidate for this application. These phosphoniums are known to be highly resistant to alkaline media; however, very few investigations have systematically evaluated how these cations decompose in the presence of hydroxide or alkoxide anions. The excellent stability of several tetraaminophosphoniums in 2 M KOH/CH3OH at 80 °C led us to design experiments for the rapid assessment of phosphonium degradation in homogeneous solution and under phase-transfer conditions. The analysis illustrated how substituents around the cation core affect both degradation pathways and rates. β-H elimination and direct attack at the phosphorus atom are the most common degradation pathways observed in an alcoholic solvent, while α-H abstraction and direct attack are observed under phase-transfer conditions (PhCl and 50 wt % NaOH/H2O). The collected data provided a relative stability comparison for this family of cations to enable future design improvements and illustrated the utility of using multiple tests for degradation studies.
Co-reporter:Chia-Hua Tsai; Andria Fortney; Yunyan Qiu; Roberto R. Gil; David Yaron; Tomasz Kowalewski
Journal of the American Chemical Society 2016 Volume 138(Issue 21) pp:6798-6804
Publication Date(Web):April 22, 2016
DOI:10.1021/jacs.6b01916
Periodic π-conjugated polymers of the group 16 heterocycles (furan, thiophene, and selenophene) were synthesized with controlled chain lengths and relatively low dispersities using catalyst-transfer polycondensation. The optical gap and redox potentials of these copolymers were fine-tuned by altering the heterocycle sequence, and atomic force microscopy revealed nanofibrillar morphologies for all the materials. Grazing incidence wide-angle X-ray scattering of the thiophene-selenophene copolymers indicated that the π-stacking distance increased with incorporation of the larger heteroatom (from ∼3.7–4.0 Å), while the lamellar spacing decreased (from ∼15.8–15.2 Å). The study also revealed that periodic sequences allow electronic properties to be tuned while retaining nanofibrillar morphologies similar to those observed for poly(3-hexylthiophene).
Co-reporter:Yunyan Qiu, Andria Fortney, Chia-Hua Tsai, Matthew A. Baker, Roberto R. Gil, Tomasz Kowalewski, and Kevin J. T. Noonan
ACS Macro Letters 2016 Volume 5(Issue 3) pp:332
Publication Date(Web):February 16, 2016
DOI:10.1021/acsmacrolett.5b00666
There is intense interest in the rational design of semiconducting materials to improve organic electronics. Furan is a particularly attractive monomer for building biorenewable and biodegradable π-conjugated frameworks. In this report, regioregular head-to-tail and head-to-head poly(3-hexylfuran) were synthesized using chain-growth polycondensation. The resultant polyfurans have relatively low molecular weights but also low dispersities. The head-to-head polyfuran adopted a nearly identical coplanar backbone conformation as its head-to-tail analog in the solid state, as determined by UV–visible spectroscopy and atomic force microscopy. Extensive aggregation of the furan homopolymer during polymerization led to the investigation of an alternating furan-thiophene copolymer, confirming that furyl-based monomers can polymerize in a chain-growth manner. All of the synthesized polymers are sensitive when exposed to both oxygen and light.
Co-reporter:C. Tyler Womble, Geoffrey W. Coates, Krzysztof Matyjaszewski, and Kevin J. T. Noonan
ACS Macro Letters 2016 Volume 5(Issue 2) pp:253
Publication Date(Web):February 1, 2016
DOI:10.1021/acsmacrolett.5b00910
A tetrakis(dialkylamino)phosphonium cation ([P(NR2)4]+) was appended to a styrenic monomer and explored in reversible addition–fragmentation chain transfer polymerization (RAFT) to conduct random copolymerizations of the cationic monomer with styrene. Well-defined polyelectrolytes with molecular weights up to ∼30 100 and dispersities between ∼1.2 and 1.4 were obtained. Up to 18.9 mol % of the ionic monomer could be incorporated into the polymer with hexafluorophosphate or bis(trifluoromethane)sulfonimide acting as the counterion during polymerization. Differential scanning calorimetry of the hexafluorophosphate polymers revealed glass transition temperatures higher than polystyrene likely due to interactions between the anion and the polymer. Thermogravimetric analysis indicated these materials have high thermal stability with decomposition temperatures approaching 400 °C.
Co-reporter:Yunyan Qiu, Joshua C. Worch, Andria Fortney, Chakicherla Gayathri, Roberto R. Gil, and Kevin J. T. Noonan
Macromolecules 2016 Volume 49(Issue 13) pp:4757-4762
Publication Date(Web):June 23, 2016
DOI:10.1021/acs.macromol.6b01006
Controlled synthesis of conjugated polymers with functional side chains is of great importance, affording well-defined optoelectronic materials possessing enhanced stability and tunability as compared to their alkyl-substituted counterparts. Herein, a chain-growth Suzuki polycondensation of an ester-functionalized thiophene is described using commercially available nickel precatalysts. Model compound studies were used to identify suitable catalysts, and these experiments provided guidance for the polymerization of the ester-substituted monomer. This is the first report of nickel-catalyzed Suzuki cross-coupling for catalyst-transfer polycondensation, and to further illustrate the versatility of this method, block and alternating copolymers with 3-hexylthiophene were synthesized. The presented protocol should serve as an entry point into the synthesis of other electron-deficient polymers and donor–acceptor copolymers with controlled molecular weights and low dispersity.
Co-reporter:Yunyan Qiu;Jacob Mohin;Chia-Hua Tsai;Stephanie Tristram-Nagle;Roberto R. Gil;Tomasz Kowalewski
Macromolecular Rapid Communications 2015 Volume 36( Issue 9) pp:840-844
Publication Date(Web):
DOI:10.1002/marc.201500030
Co-reporter:Joshua C. Worch, Erich Hellemann, Gabrielle Pros, Chakicherla Gayathri, Tomislav Pintauer, Roberto R. Gil, and Kevin J. T. Noonan
Organometallics 2015 Volume 34(Issue 22) pp:5366-5373
Publication Date(Web):September 8, 2015
DOI:10.1021/acs.organomet.5b00583
The synthesis and functionalization of the parent 1,3-benzothiaphosphole is reported. The phosphole could not be isolated, but the compound could be manipulated in solution to produce several new phosphorus compounds. Metalation of the 2-position using lithium diisopropylamide proceeded smoothly according to 31P NMR spectroscopy, and quenching with trimethylsilyl chloride resulted in the desired 2-(trimethylsilyl)-1,3-benzothiaphosphole. The P═C bond of the thiaphosphole was also explored as a dienophile in Diels–Alder reactions with isoprene, 2,3-dimethylbutadiene, 2,3-dibenzylbutadiene, and cyclopentadiene. The fused-ring structures were fully characterized, and a solid-state molecular structure of the 2,3-dimethylbutadiene cycloadduct was obtained. Residual dipolar coupling (RDC) NMR experiments were used to assign major and minor products for the isoprene and cyclopentadiene adducts.
Co-reporter:Chia-Hua Tsai ;Danielle N. Chirdon ;Husain N. Kagalwala;Andrew B. Maurer;Aman Kaur; Tomislav Pintauer; Stefan Bernhard; Kevin J. T. Noonan
Chemistry - A European Journal 2015 Volume 21( Issue 32) pp:11517-11524
Publication Date(Web):
DOI:10.1002/chem.201500543

Abstract

The synthesis and characterization of electron-poor thiophene 1,1-dioxides bearing cyanated phenyl groups are reported. The electron-accepting nature of these compounds was evaluated by cyclic voltammetry, and highly reversible and facile reductions were observed for several derivatives. Moreover, some of the reduced thiophene dioxides form colorful anions, which were investigated spectroelectrochemically. Photoluminescence spectra of the electron-deficient sulfones were measured in CH2Cl2, and they emit in the blue-green region with significant variation in the quantum yield depending on the aryl substituents. By expanding the degree of substitution on the phenyl rings, quantum yields up to 34 % were obtained. X-ray diffraction data are reported for two of the thiophene 1,1-dioxides, and the electronic structure was probed for all synthesized derivatives through DFT calculations. The dioxides were also examined as electron relays in a photocatalytic water reduction reaction, and they showed potential to boost the efficiency.

Co-reporter:Yunyan Qiu;Joshua C. Worch;Danielle N. Chirdon;Aman Kaur;Andrew B. Maurer;Samuel Amsterdam;Christopher R. Collins; Tomislav Pintauer; David Yaron; Stefan Bernhard; Kevin J. T. Noonan
Chemistry - A European Journal 2014 Volume 20( Issue 25) pp:7746-7751
Publication Date(Web):
DOI:10.1002/chem.201402561

Abstract

1,4-Dimercapto-2,5-diphosphinobenzene and 3,6-bis(hexyloxy)-1,4-dimercapto-2,5-diphosphinobenzene were synthesized and combined with various acid chlorides to obtain a series of benzobisthiaphospholes. Electrochemical and photophysical properties of the substituted benzobisthiaphospholes have been evaluated, and the observed reductions are more facile than the related benzothiaphospholes and 2,6-diphenylbenzobisthiazole. A benzobisthiaphosphole with C6H4-p-CN substituents was reduced at E1/2=−1.08 V (vs. saturated calomel electrode (SCE)). X-ray diffraction data for several of these phosphorus heterocycles has been obtained, and DFT calculations at the B3LYP level have been performed.

Co-reporter:Chia-Hua Tsai, Danielle N. Chirdon, Andrew B. Maurer, Stefan Bernhard, and Kevin J. T. Noonan
Organic Letters 2013 Volume 15(Issue 20) pp:5230-5233
Publication Date(Web):October 3, 2013
DOI:10.1021/ol4024024
A 2,5-bis(tributylstannyl)thiophene 1,1-dioxide was prepared from 2,5-bis(trimethylsilyl)thiophene 1,1-dioxide, bis(tributyltin) oxide, and tetrabutylammonium fluoride (TBAF). The 2,5-bis(tributylstannyl)thiophene 1,1-dioxide and a 2,5-diiodothiophene 1,1-dioxide were utilized in a series of Stille cross-coupling reactions to afford thiophene 1,1-dioxides with either electron-donating or electron-withdrawing substituents. Electron-withdrawing groups greatly facilitate the reduction of these sulfone heterocycles, and –C6H4-p-NO2 substituents produce a 510 mV shift as compared to a thiophene 1,1-dioxide with two phenyl groups.
Co-reporter:Joshua C. Worch, Danielle N. Chirdon, Andrew B. Maurer, Yunyan Qiu, Steven J. Geib, Stefan Bernhard, and Kevin J. T. Noonan
The Journal of Organic Chemistry 2013 Volume 78(Issue 15) pp:7462-7469
Publication Date(Web):June 19, 2013
DOI:10.1021/jo400947u
A series of 2-aryl-1,3-benzothiaphospholes have been synthesized from 1-mercapto-2-phosphinobenzene and a variety of acid chlorides. The structure of 2-phenyl-1,3-benzothiaphosphole was established using X-ray diffraction. The electrochemical and photophysical properties of each benzothiaphosphole are reported and some of these molecules exhibit reversible 1-electron reductions.
1,3,2-Dioxaborolane, 2-(5-bromo-4-hexyl-2-thienyl)-4,4,5,5-tetramethyl-
Stannane, (3,4'-dihexyl[2,2'-bithiophen]-5-yl)trimethyl-
Carbonotrithioic acid, 1-cyano-1-methylethyl dodecyl ester
2,2':5',2'':5'',2'''-Quaterthiophene, 5-bromo-3',3'',3''',4-tetrahexyl-
Stannane, (4-hexyl-2-thienyl)trimethyl-
2,2'-Bithiophene, 5'-bromo-3,4'-dihexyl
3,4'-Dihexyl-2,2'-bithiophene
3-HEXYL-2-IODOTHIOPHENE
Methyl 2,5-dibromothiophene-3-carboxylate
Furan, 3-hexyl-