@article{yarnell_chakraborty_myahkostupov_wright_castellano_2018, title={Long-lived triplet excited state in a platinum(ii) perylene monoimide complex}, volume={47}, ISSN={["1477-9234"]}, url={https://doi.org/10.1039/C8DT02496K}, DOI={10.1039/c8dt02496k}, abstractNote={We report the synthesis and solution based photophysical properties of a new Pt(ii)-terpyridine complex coupled to a perylene monoimide (PMI) chromophoric unit through an acetylene linkage. This structural arrangement resulted in quantitative quenching of the highly fluorescent PMI chromophore by introducing metal character into the lowest energy singlet state, thereby leading to the formation of a long-lived PMI-ligand localized triplet excited state (τ = 8.4 μs). Even though the phosphorescence from this triplet state was not observed, highly efficient quenching of this excited state by dissolved oxygen and the observation of singlet oxygen photoluminescence in the near-IR at 1270 nm initially pointed towards triplet excited state character. Additionally, the coincidence of the excited state absorbance difference spectra from the sensitized PMI ligand using a triplet donor and the Pt-PMI complex provided strong evidence for this triplet state assignment, which was further supported by TD-DFT calculations.}, number={42}, journal={DALTON TRANSACTIONS}, publisher={Royal Society of Chemistry (RSC)}, author={Yarnell, James E. and Chakraborty, Arnab and Myahkostupov, Mykhaylo and Wright, Katherine M. and Castellano, Felix N.}, year={2018}, month={Nov}, pages={15071–15081} }
 @article{koch_myahkostupov_oblinsky_wang_garakyaraghi_castellano_scholes_2017, title={Charge Localization after Ultrafast Photoexcitation of a Rigid Perylene Perylenediimide Dyad Visualized by Transient Stark Effect}, volume={139}, ISSN={0002-7863 1520-5126}, url={http://dx.doi.org/10.1021/jacs.7b01630}, DOI={10.1021/jacs.7b01630}, abstractNote={The intramolecular charge-transfer (CT) dynamics of a rigid and strongly conjugated perylenediimide-bridge-perylene dyad (PDIPe) has been investigated in dichloromethane using ultrafast transient electronic absorption spectroscopy and quantum chemical calculations. The strong electronic coupling between the dyad units gives rise to a CT band. Its photoexcitation forms a delocalized CT state with well-preserved ion bands despite the strong coupling. In the dyad, the electronic transition dipole moment of the electron donor perylene is aligned along the axis of the electric field vector with respect to the CT species. This alignment makes the donor sensitive to the Stark effect and thus charge density fluctuations in the CT state. Charge localization on the picosecond time scale manifests as a time-dependent Stark shift in the visible region. Quantum chemical calculations reveal a twist around the acetylene bridging unit to be the responsible mechanism generating a partial to an almost complete CT state. An estimate of the electric field strength in the CT state yields approximately 25 MV/cm, which increases to around 31 MV/cm during charge localization. Furthermore, the calculations illustrate the complexity of electronic structure in this strongly delocalized superchromophore and reflect the complications in the interpretation of transient absorption results when compared to steady-state approaches such as spectroelectrochemistry and model chromophore experiments such as photoinduced bimolecular charge transfer.}, number={15}, journal={Journal of the American Chemical Society}, publisher={American Chemical Society (ACS)}, author={Koch, Marius and Myahkostupov, Mykhaylo and Oblinsky, Daniel G. and Wang, Siwei and Garakyaraghi, Sofia and Castellano, Felix N. and Scholes, Gregory D.}, year={2017}, month={Apr}, pages={5530–5537} }
 @article{wang_deloach_jiang_papa_myahkostupov_castellano_liu_dougherty_2017, title={Tuning interfacial spin filters from metallic to resistive within a single organic semiconductor family}, volume={95}, ISSN={2469-9950 2469-9969}, url={http://dx.doi.org/10.1103/PhysRevB.95.241410}, DOI={10.1103/physrevb.95.241410}, abstractNote={Jingying Wang,1 Andrew Deloach,1 Wei Jiang,2 Christopher M. Papa,3 Mykhaylo Myahkostupov,3 Felix N. Castellano,3 Feng Liu,2 and Daniel B. Dougherty1,* 1Department of Physics, North Carolina State University, Raleigh, North Carolina 27695-8202, USA 2Department of Material Science and Engineering, University of Utah, Salt Lake City, Utah 84112, USA 3Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, USA (Received 6 January 2017; revised manuscript received 26 May 2017; published 30 June 2017)}, number={24}, journal={Physical Review B}, publisher={American Physical Society (APS)}, author={Wang, Jingying and Deloach, Andrew and Jiang, Wei and Papa, Christopher M. and Myahkostupov, Mykhaylo and Castellano, Felix N. and Liu, Feng and Dougherty, Daniel B.}, year={2017}, month={Jun} }
 @article{hirai_myahkostupov_castellano_gabbai_2016, title={1-Pyrenyl- and 3-Perylenyl-antimony(V) Derivatives for the Fluorescence Turn-On Sensing of Fluoride Ions in Water at Sub-ppm Concentrations}, volume={35}, ISSN={["1520-6041"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84974696668&partnerID=MN8TOARS}, DOI={10.1021/acs.organomet.6b00233}, abstractNote={In the context of our work on main group-based anion sensors, we have synthesized the bromide salts of a series of tetraarylstibonium cations of general formula [ArSbPh3]+ with Ar = 9-phenanthryl ([1]+), 1-pyrenyl- ([2]+), and 3-perylenyl ([3]+). While [1]+ is not stable in water, we found that [2]+ and [3]+ can be used as sensors for the sub-ppm detection of fluoride anions in aqueous solutions consisting of 9/1 (v/v) H2O/DMSO (pH 4.8). Fluoride sensing, which rests on the formation of the fluorostiboranes 2–F and 3–F, is accompanied by a distinct turn-on fluorescence response. This response is especially marked upon conversion of [3]+ into 3–F, with a fluorescence intensity enhancement by ∼8 fold and a quantum yield of 59.2% for 3–F. The relevance of this study is established by demonstrating that [3]+ can be used as a selective fluoride sensor for bottle or tap water.}, number={11}, journal={ORGANOMETALLICS}, author={Hirai, Masato and Myahkostupov, Mykhaylo and Castellano, Felix N. and Gabbai, Francois P.}, year={2016}, month={Jun}, pages={1854–1860} }
 @article{myahkostupov_castellano_2015, title={Tetrahedral rigid core antenna chromophores bearing bay-substituted perylenediimides}, volume={71}, ISSN={["0040-4020"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84947996715&partnerID=MN8TOARS}, DOI={10.1016/j.tet.2015.10.083}, abstractNote={Two new representative methane- and adamantane-centered ‘antenna’ tetramers bearing bay-substituted π-conjugated phenylethynyl-perylenediimides (PDICCPh) as chromophoric subunits, tetrakis-[1-(4-ethynylphenyl)-N,N′-bis(1-hexylheptyl)-perylene-3,4:9,10-tetracarboxylic diimide]-methane (1) and tetrakis-1,3,5,7-[1-(4-ethynylphenyl)-N,N′-bis(1-hexylheptyl)-perylene-3,4:9,10-tetracarboxylic diimide]-adamantane (2), have been synthesized and their structural aspects have been thoroughly investigated by NMR spectroscopy. These PDI tetramers (1 and 2) represent the first successful example of incorporating the bay-substituted phenylethynyl-perylenediimides into the large rigid core tetrahedral frameworks. In these PDI tetramers, dynamic NMR experiments revealed the existence of perylene-centered conformational dynamic equilibrium (ΔG≠=15−17 kcal/mol), the primary cause of the observed spectral broadening in conventional 1H NMR spectra (295 K). In addition, PDI tetramers 1 and 2 were found to possess exceptional (photo)chemical stability, and their corresponding photophysical properties (ɛmax∼180,000; τFL=6.9 ns; ΦFL∼60%) make them viable candidates for various photonic applications and are in good agreement with other related multichromophoric PDI-based systems.}, number={51}, journal={TETRAHEDRON}, author={Myahkostupov, Mykhaylo and Castellano, Felix N.}, year={2015}, month={Dec}, pages={9519–9527} }
 @article{jumper_anna_stradomska_schins_myahkostupov_prusakova_oblinsky_castellano_knoester_scholes_2014, title={Intramolecular radiationless transitions dominate exciton relaxation dynamics}, volume={599}, ISSN={["1873-4448"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84897401500&partnerID=MN8TOARS}, DOI={10.1016/j.cplett.2014.03.007}, abstractNote={Reports of long-lived exciton coherences have lead researchers to expect that model dimer systems inevitably generate exciton superposition states observable by two-dimensional electronic spectroscopy. Here we report a careful photophysical characterization of a model dimer system, a diacetylene-linked perylenediimide dimer to examine that issue. The absorption spectrum of the dimer shows molecular exciton splitting, indicating that excitation is delocalized. The assignment of exciton states was supported by other photophysical measurements as well as theoretical calculations. Ultrafast two-dimensional electronic spectroscopy was employed to identify and characterize excitonic and vibrational features, as they evolve over time. Population transfer between the two exciton states is found to happen in <50 fs, thus preventing the sustainment of exciton coherences. We show that such fast radiationless relaxation cannot be explained by coupling to a solvent spectral density and is therefore missed by standard approaches such as Redfield theory and the hierarchical equations of motion.}, journal={CHEMICAL PHYSICS LETTERS}, author={Jumper, Chanelle C. and Anna, Jessica M. and Stradomska, Anna and Schins, Juleon and Myahkostupov, Mykhaylo and Prusakova, Valentina and Oblinsky, Daniel G. and Castellano, Felix N. and Knoester, Jasper and Scholes, Gregory D.}, year={2014}, month={Apr}, pages={23–33} }