@article{tichnell_miller_liu_mukherjee_jakubikova_mccusker_2020, title={Influence of Electrolyte Composition on Ultrafast Interfacial Electron Transfer in Fe-Sensitized TiO2-Based Solar Cells}, volume={124}, ISSN={["1932-7455"]}, DOI={10.1021/acs.jpcc.9b09404}, abstractNote={TiO2-based dye-sensitized solar cells employing Fe(2,2′-bipyridine-4,4′-dicarboxylic acid)2(CN)2 (F2CA) have been studied by spectroscopic, electrochemical, photoelectrochemical, time-resolved spec...}, number={3}, journal={JOURNAL OF PHYSICAL CHEMISTRY C}, author={Tichnell, Christopher R. and Miller, Jennifer N. and Liu, Chang and Mukherjee, Sriparna and Jakubikova, Elena and McCusker, James K.}, year={2020}, month={Jan}, pages={1794–1811} }
 @article{yang_kersi_richers_giles_dangi_stein_feng_tichnell_shultz_kirk_2018, title={Ground State Nuclear Magnetic Resonance Chemical Shifts Predict Charge-Separated Excited State Lifetimes}, volume={57}, ISSN={["1520-510X"]}, url={https://doi.org/10.1021/acs.inorgchem.8b02087}, DOI={10.1021/acs.inorgchem.8b02087}, abstractNote={Dichalcogenolene platinum(II) diimine complexes, (LE,E')Pt(bpy), are characterized by charge-separated dichalcogenolene donor (LE,E') → diimine acceptor (bpy) ligand-to-ligand charge transfer (LL'CT) excited states that lead to their interesting photophysics and potential use in solar energy conversion applications. Despite the intense interest in these complexes, the chalcogen dependence on the lifetime of the triplet LL'CT excited state remains unexplained. Three new (LE,E')Pt(bpy) complexes with mixed chalcogen donors exhibit decay rates that are dominated by a spin-orbit mediated nonradiative pathway, the magnitude of which is proportional to the anisotropic covalency provided by the mixed-chalcogen donor ligand environment. This anisotropic covalency is dramatically revealed in the 13C NMR chemical shifts of the donor carbons that bear the chalcogens and is further probed by S K-edge XAS. Remarkably, the NMR chemical shift differences also correlate with the spin-orbit matrix element that connects the triplet excited state with the ground state. Consequently, triplet LL'CT excited state lifetimes are proportional to both functions, demonstrating that specific ground state NMR chemical shifts can be used to evaluate spin-orbit coupling contributions to excited state lifetimes.}, number={21}, journal={INORGANIC CHEMISTRY}, publisher={American Chemical Society (ACS)}, author={Yang, Jing and Kersi, Dominic K. and Richers, Casseday P. and Giles, Logan J. and Dangi, Ranjana and Stein, Benjamin W. and Feng, Changjian and Tichnell, Christopher R. and Shultz, David A. and Kirk, Martin L.}, year={2018}, month={Nov}, pages={13470–13476} }
 @article{tichnell_shultz_popescu_sokirniy_boyle_2015, title={Synthesis, Characterization, and Photophysical Studies of an Iron(III) Catecholate-Nitronylnitroxide Spin-Crossover Complex}, volume={54}, ISSN={["1520-510X"]}, DOI={10.1021/acs.inorgchem.5b00298}, abstractNote={The synthesis and characterization of an Fe(III) catecholate-nitronylnitroxide (CAT-NN) complex (1-NN) that undergoes Fe(III) spin-crossover is described. Our aim is to determine whether the intraligand exchange coupling of the semiquinone-nitronylnitroxide Fe(II)(SQ-NN) excited state resulting from irradiation of the CAT → Fe(III) LMCT band would affect either the intrinsic photophysics or the iron spin-crossover event when compared to the complex lacking the nitronylnitroxide radical (1). X-ray crystallographic analysis provides bond lengths consistent with a ferric catecholate charge distribution. Mössbauer spectroscopy clearly demonstrates Fe(III) spin-crossover, hyperfine couplings, and a weak ferromagnetic Fe(III)-CAT-NN exchange, and spin-crossover is corroborated by variable-temperature magnetic susceptibility and electronic absorption studies. To explore the effect of the NN radical on photophysical processes, we conducted room-temperature transient absorption experiments. Upon excitation of the ligand-to-metal charge transfer band, an Fe(II)SQ state is populated and most likely undergoes fast intersystem crossing to the ligand field manifold, where it rapidly decays into a metastable low-spin Fe(III)CAT state, followed by repopulation of the high-spin Fe(III)CAT ground state. The decay components of 1-NN are slightly faster than those obtained for 1, perhaps due to the higher number of microstates present within the LMCT and LF manifolds for 1-NN. Although the effects of the NN radical are manifest in neither the spin-crossover nor the photophysics, our results lay the groundwork for future studies.}, number={9}, journal={INORGANIC CHEMISTRY}, author={Tichnell, Christopher R. and Shultz, David A. and Popescu, Codrina V. and Sokirniy, Ivan and Boyle, Paul D.}, year={2015}, month={May}, pages={4466–4474} }
 @article{yang_kersi_giles_stein_feng_tichnell_shultz_kirk_2014, title={Ligand Control of Donor–Acceptor Excited-State Lifetimes}, volume={53}, ISSN={0020-1669 1520-510X}, url={http://dx.doi.org/10.1021/IC500217Y}, DOI={10.1021/ic500217y}, abstractNote={Transient absorption and emission spectroscopic studies on a series of diimineplatinum(II) dichalcogenolenes, LPtL', reveal charge-separated dichalcogenolene → diimine charge-transfer (LL'CT) excited-state lifetimes that display a remarkable and nonperiodic dependence on the heteroatoms of the dichalcogenolene ligand. Namely, there is no linear relationship between the observed lifetimes and the principle quantum number of the E donors. The results are explained in terms of heteroatom-dependent singlet-triplet (S-T) energy gaps and anisotropic covalency contributions to the M-E (E = O, S, Se) bonding scheme that control rates of intersystem crossing. For the dioxolene complex, 1-O,O', E(T2) > E(S1) and rapid nonradiative decay occurs from S1 to S0. However, E(T2) ≤ E(S1) for the heavy-atom congeners, and this provides a mechanism for rapid intersystem crossing. Subsequent internal conversion to T1 in 3-S,S produces a long-lived, emissive triplet. The two LPtL' complexes with mixed chalcogen donors and 5-Se,Se show lifetimes intermediate between those of 1-O,O' and 3-S,S.}, number={10}, journal={Inorganic Chemistry}, publisher={American Chemical Society (ACS)}, author={Yang, Jing and Kersi, Dominic K. and Giles, Logan J. and Stein, Benjamin W. and Feng, Changjian and Tichnell, Christopher R. and Shultz, David A. and Kirk, Martin L.}, year={2014}, month={Apr}, pages={4791–4793} }