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1.
PLoS One ; 19(6): e0306225, 2024.
Article in English | MEDLINE | ID: mdl-38924015

ABSTRACT

INTRODUCTION: Older women living with HIV often go unnoticed due to societal biases and stigmas. Despite a rise in cases among older women, there is limited research on the psychosocial factors impacting their experiences. Aging complexities compounded by HIV and menopause affect these women's health, while factors like mental health impact, changing support networks, and ageism with HIV stigma influence their well-being. Existing studies mostly compare older HIV-positive individuals without considering gender and intersectional identities, limiting understanding of their unique experiences. The scarcity of research addressing age-related differences from diverse perspectives delays the development of tailored treatments and interventions. OBJECTIVES: The study aims to comprehensively explore the age-related experiences of older women with HIV through three sub-questions that address (1) Key experiences, medical and social challenges, and strengths; (2) Impact of intersectional identities on their experiences; and (3) Gaps and limitations in current research. METHODS: Utilizing a scoping review approach, the study seeks to map existing literature, employing a theoretical framework rooted in Sex- and Gender-Based Analysis Plus (SGBA+). Articles focusing on the age-related experiences of older women living with HIV aged 50 and above will be included. The study selection process will involve two independent reviewers screening articles based on pre-established inclusion criteria. Data extraction and synthesis will follow, analyzing the influence of sex, gender, and other identities on experiences. DISCUSSION: The study's comprehensive approach aims to bridge gaps in understanding older women's HIV experiences, emphasizing intersectionality. While limited to English-language peer-reviewed articles, this review seeks to offer valuable insights for healthcare, policy, and research, potentially fostering positive change in the lives of diverse older women living with HIV.


Subject(s)
HIV Infections , Humans , Female , HIV Infections/psychology , Aged , Middle Aged , Social Stigma , Aging/psychology , Age Factors , Women's Health
2.
J Phys Chem Lett ; 15(20): 5488-5494, 2024 May 23.
Article in English | MEDLINE | ID: mdl-38748557

ABSTRACT

Solid-state photochemically induced dynamic nuclear polarization (photo-CIDNP) is a nuclear magnetic resonance spectroscopy technique in which nuclear spin hyperpolarization is generated upon optical irradiation of an appropriate donor-acceptor system. Until now, solid-state photo-CIDNP at high magnetic fields has been observed only in photosynthetic reaction centers and flavoproteins. In the present work, we show that the effect is not limited to such biomolecular samples, and solid-state 13C photo-CIDNP can be observed at 9.4 T under magic angle spinning using a frozen solution of a synthetic molecular system dissolved in an organic solvent. Signal enhancements for the source molecule larger than a factor of 2300 are obtained. In addition, we show that bulk 13C hyperpolarization of the solvent can be generated via spontaneous 13C-13C spin diffusion at natural abundance.

3.
PLoS One ; 19(5): e0303580, 2024.
Article in English | MEDLINE | ID: mdl-38814951

ABSTRACT

There is a growing population of adults aged 50 years or older living with HIV, facing unique challenges in care due to age, minority status, and stigma. Co-design methodologies, aligning with patient-centered care, have potential for informing interventions addressing the complex needs of older adults with HIV. Despite challenges, co-design has shown promise in empowering older individuals to actively participate in shaping their care experiences. The scoping review outlined here aims to identify gaps in existing co-design work with this population, emphasizing the importance of inclusivity based on PROGRESS-Plus characteristics for future patient-oriented research. This scoping review protocol is informed by the Joanna Briggs Institute Manual to explore co-design methods in geriatric HIV care literature. The methodology encompasses six stages: 1) developing research questions, 2) creating a search strategy, 3) screening and selecting evidence, 4) data extraction, 5) data analysis using content analysis, and 6) consultation with key stakeholders, including community partners and individuals with lived experience. The review will involve a comprehensive literature search, including peer-reviewed databases and gray literature, to identify relevant studies conducted in the past 20 years. The inclusive criteria focus on empirical data related to co-design methods in HIV care for individuals aged 50 or older, aiming to inform future research and co-design studies in geriatric HIV care. The study will be limited by the exclusion of papers not published or translated to English. Additionally, the varied terminology used to describe co-design across different research may result in the exclusion of articles using alternative terms. The consultation with key stakeholders will be crucial for translating insights into meaningful co-design solutions for virtual HIV care, aiming to provide a comprehensive synthesis that informs evidence-based strategies and addresses disparities in geriatric HIV care.


Subject(s)
HIV Infections , Research Design , Humans , HIV Infections/therapy , Aged , Middle Aged , Patient-Centered Care
4.
Nat Commun ; 15(1): 3072, 2024 Apr 09.
Article in English | MEDLINE | ID: mdl-38594293

ABSTRACT

Engineering asymmetric transmission between left-handed and right-handed circularly polarized light in planar Fabry-Pérot (FP) microcavities would enable a variety of chiral light-matter phenomena, with applications in spintronics, polaritonics, and chiral lasing. Such symmetry breaking, however, generally requires Faraday rotators or nanofabricated polarization-preserving mirrors. We present a simple solution requiring no nanofabrication to induce asymmetric transmission in FP microcavities, preserving low mode volumes by embedding organic thin films exhibiting apparent circular dichroism (ACD); an optical phenomenon based on 2D chirality. Importantly, ACD interactions are opposite for counter-propagating light. Consequently, we demonstrated asymmetric transmission of cavity modes over an order of magnitude larger than that of the isolated thin film. Through circular dichroism spectroscopy, Mueller matrix ellipsometry, and simulation using theoretical scattering matrix methods, we characterize the spatial, spectral, and angular chiroptical responses of this 2D chiral microcavity.

5.
Proc Natl Acad Sci U S A ; 120(48): e2313575120, 2023 Nov 28.
Article in English | MEDLINE | ID: mdl-37983509

ABSTRACT

Understanding how to utilize symmetry-breaking charge separation (SB-CS) offers a path toward increasingly efficient light-harvesting technologies. This process plays a central role in the first step of photosynthesis, in which the dimeric "special pair" of the photosynthetic reaction center enters a coherent SB-CS state after photoexcitation. Previous research on SB-CS in both biological and synthetic chromophore dimers has focused on increasing the efficiency of light-driven processes. In a chromophore dimer undergoing SB-CS, the energy of the radical ion pair product is nearly isoenergetic with that of the lowest excited singlet (S1) state of the dimer. This means that very little energy is lost from the absorbed photon. In principle, the relatively high energy electron and hole generated by SB-CS within the chromophore dimer can each be transferred to adjacent charge acceptors to extend the lifetime of the electron-hole pair, which can increase the efficiency of solar energy conversion. To investigate this possibility, we have designed a bis-perylenediimide cyclophane (mPDI2) covalently linked to a secondary electron donor, peri-xanthenoxanthene (PXX) and a secondary electron acceptor, partially fluorinated naphthalenediimide (FNDI). Upon selective photoexcitation of mPDI2, transient absorption spectroscopy shows that mPDI2 undergoes SB-CS, followed by two secondary charge transfer reactions to generate a PXX•+-mPDI2-FNDI•- radical ion pair having a nearly 3 µs lifetime. This strategy has the potential to increase the efficiency of molecular systems for artificial photosynthesis and photovoltaics.

6.
J Am Chem Soc ; 145(33): 18391-18401, 2023 Aug 23.
Article in English | MEDLINE | ID: mdl-37565777

ABSTRACT

Energy transfer and exciplex emission are not only crucial photophysical processes in many living organisms but also important for the development of smart photonic materials. We report, herein, the rationally designed synthesis and characterization of two highly charged bischromophoric homo[2]catenanes and one cyclophane incorporating a combination of polycyclic aromatic hydrocarbons, i.e., anthracene, pyrene, and perylene, which are intrinsically capable of supporting energy transfer and exciplex formation. The possible coconformations of the homo[2]catenanes, on account of their dynamic behavior, have been probed by Density Functional Theory calculations. The unique photophysical properties of these exotic molecules have been explored by steady-state and time-resolved absorption and fluorescence spectroscopies. The tetracationic pyrene-perylene cyclophane system exhibits emission emanating from a highly efficient Förster resonance energy transfer (FRET) mechanism which occurs in 48 ps, while the octacationic homo[2]catenane displays a weak exciplex photoluminescence following extremely fast (<0.3 ps) exciplex formation. The in-depth fundamental understanding of these photophysical processes involved in the fluorescence of bischromophoric cyclophanes and homo[2]catenanes paves the way for their use in future bioapplications and photonic devices.

7.
J Phys Chem A ; 127(13): 2946-2957, 2023 Apr 06.
Article in English | MEDLINE | ID: mdl-36961364

ABSTRACT

Understanding charge transfer (CT) dynamics in molecular donor-acceptor (D-A) dyads can provide insight into developing efficient D-A molecules for capturing solar energy. Here, we characterize the excited-state evolution of a julolidine-BODIPY (Jul-BD) D-A system with an emissive CT state using time-resolved fluorescence, femtosecond transient absorption, and two-dimensional electronic spectroscopies. Comparison of these results with those from phenyl-BODIPY (Ph-BD) allows us to identify the dynamics at play during CT state formation and its subsequent conversion to either a fully charge-separated or triplet state. Photoexcitation of Jul-BD in tetrahydrofuran results in the formation of an initial emissive CT state that relaxes before fully charge-separating. In contrast, Jul-BD in toluene exhibits similar CT state dynamics, albeit at slower timescales, before decaying to a terminal triplet species. Quantum beat analysis at early times in both solvents shows several vibronic modes, which are corroborated using density functional theory (DFT) calculations. For Ph-BD, a single 220 cm-1 compression mode about the single bond linking the phenyl to BODIPY modulates their orbital overlap. Three active vibronic modes, 147, 174, and 214 cm-1, are found in Jul-BD, regardless of the dielectric constant of the medium. These motions correspond to compression and torsional motions along the single bond joining Jul to BD and are responsible for the evolution of the spontaneous and stimulated emission features in the time-resolved spectroscopic data, which is further supported by time-dependent DFT calculations of the steady-state absorption spectrum of the Jul-BD as a function of increasing D-A dihedral core angle. These findings show how torsional and compression motions can play a pivotal role in intramolecular CT between a D and an A linked by a single bond.

8.
J Phys Chem Lett ; 14(10): 2573-2579, 2023 Mar 16.
Article in English | MEDLINE | ID: mdl-36880847

ABSTRACT

Singlet fission (SF) is a spin-allowed process in which a photogenerated singlet exciton down-converts into two triplet excitons. Perylene-3,4-dicarboximide (PMI) has singlet and triplet state energies of 2.4 and 1.1 eV, respectively; thus making SF slightly exoergic and providing triplet excitons that have sufficient energy to raise the efficiency of single-junction solar cells by reducing thermalization losses from hot excitons formed when absorbed photons have energies higher than the semiconductor bandgap. However, PMI SF in the solid state has not been studied previously. Here, we show that 2,5-diphenyl-N-(2-ethylhexyl)perylene-3,4-dicarboximide (dp-PMI) crystallizes into a slip-stacked intermolecular morphology favorable for SF. Transient absorption microscopy and spectroscopy show that dp-PMI SF occurs in ≤50 ps in both single crystals and polycrystalline thin films with a triplet yield of 150 ± 20%. Ultrafast SF in the solid state, the high triplet yield, and its photostability make dp-PMI an attractive candidate for SF-enhanced solar cells.

9.
Angew Chem Int Ed Engl ; 62(6): e202214668, 2023 Feb 01.
Article in English | MEDLINE | ID: mdl-36469535

ABSTRACT

Photoexcited organic chromophores appended to stable radicals can serve as qubit and/or qudit candidates for quantum information applications. 1,6,7,12-Tetra-(4-tert-butylphenoxy)-perylene-3,4 : 9,10-bis(dicarboximide) (tpPDI) linked to a partially deuterated α,γ-bisdiphenylene-ß-phenylallyl radical (BDPA-d16 ) was synthesized and characterized by time-resolved optical and electron paramagnetic resonance (EPR) spectroscopies. Photoexcitation of tpPDI-BDPA-d16 results in ultrafast radical-enhanced intersystem crossing to produce a quartet state (Q) followed by formation of a spin-polarized doublet ground state (D0 ). Pulse-EPR experiments confirmed the spin multiplicity of Q and yielded coherence times of Tm =2.1±0.1 µs and 2.8±0.2 µs for Q and D0 , respectively. BDPA-d16 eliminates the dominant 1 H hyperfine couplings, resulting in a single narrow line for both the Q and D0 states, which enhances the spectral resolution needed for good qubit addressability.

10.
J Am Chem Soc ; 144(51): 23551-23559, 2022 12 28.
Article in English | MEDLINE | ID: mdl-36512436

ABSTRACT

Motion-induced change in emission (MICE) is a phenomenon that can be employed to develop various types of probes, including temperature and viscosity sensors. Although MICE, arising from the conformational motion in particular compounds, has been studied extensively, this phenomenon has not been investigated in depth in mechanically interlocked molecules (MIMs) undergoing coconformational changes. Herein, we report the investigation of a thermoresponsive dynamic homo[2]catenane incorporating pyrene units and displaying relative circumrotational motions of its cyclophanes as evidenced by variable-temperature 1H NMR spectroscopy and supported by its visualization through molecular dynamics simulations and quantum mechanics calculations. The relative coconformational motions induce a significant change in the fluorescence emission of the homo[2]catenane upon changes in temperature compared with its component cyclophanes. This variation in the exciplex emission of the homo[2]catenane is reversible as demonstrated by four complete cooling and heating cycles. This research opens up possibilities of using the coconformational changes in MIMs-based chromophores for probing fluctuations in temperature which could lead to applications in biomedicine or materials science.


Subject(s)
Anthracenes , Catenanes , Molecular Conformation , Temperature , Anthracenes/chemistry , Catenanes/chemistry
11.
J Am Chem Soc ; 144(37): 16841-16854, 2022 09 21.
Article in English | MEDLINE | ID: mdl-36083184

ABSTRACT

Polar and polarizable π-conjugated organic molecules containing push-pull chromophores have been investigated extensively in the past. Identifying unique backbones and building blocks for fluorescent dyes is a timely exercise. Here, we report the synthesis and characterization of a series of fluorescent dyes containing quadrupolar A-D-A constitutions (where A = acceptor and D = donor), which exhibit fluorescence emission at a variety of different wavelengths. We have investigated the effects of different electron-withdrawing groups, located at both termini of a para-terphenylene backbone, by steady-state UV/vis and fluorescence spectroscopy. Pyridine and substituted pyridinium units are also introduced during the construction of the quadrupolar backbones. Depending on the quadrupolarity, fluorescence emission wavelengths cover from 380 to 557 nm. Time-resolved absorption and emission spectroscopy reveal that the photophysical properties of those quadrupolar dyes result from intramolecular charge transfer. One of the dyes we have investigated is a symmetrical box-like tetracationic cyclophane. Its water-soluble tetrachloride, which is non-cytotoxic to cells up to a loading concentration of 1 µM, has been employed in live-cell imaging. When taken up by cells, the tetrachloride emits a green fluorescence emission without any hint of photobleaching or disruption of normal cell behavior. We envision that our design strategy of modifying molecules through the functionalization of the quadrupolar building blocks as chromophores will lead to future generations of fluorescent dyes in which these A-D-A constitutional fragments are incorporated into more complex molecules and polymers for broader photophysical and biological applications.


Subject(s)
Fluorescent Dyes , Pyridines , Alcohols , Fluorescent Dyes/chemistry , Polymers , Water
12.
Cureus ; 14(7): e26842, 2022 Jul.
Article in English | MEDLINE | ID: mdl-35974868

ABSTRACT

Vanishing bile duct syndrome (VBDS) is an acquired condition characterized by the destruction and loss of intrahepatic bile ducts resulting in cholestasis. VBDS has been described in various conditions including neoplastic and immunologic disorders, infections, hepatic ischemia, and drug toxicity. The diagnosis is confirmed by liver biopsy revealing the loss of interlobular bile ducts in greater than 50% of portal tracts. Prognosis is variable and often unpredictable but appears to be influenced by the etiology of bile duct destruction and overall patient health. VBDS has been described as a rare paraneoplastic process in patients with Hodgkin lymphoma. This case describes a 26-year-old female who presented with a neck mass, jaundice, and pruritus. Initial workup revealed direct hyperbilirubinemia, transaminitis, elevated alkaline phosphatase, and elevated international normalized ratio. She went on to receive a diagnosis of stage II classical Hodgkin lymphoma, nodular sclerosing subtype, and biopsy-proven VBDS. Over the course of chemotherapy, complete metabolic resolution of Hodgkin lymphoma and complete normalization of bilirubin were achieved. She was given gemcitabine and cyclophosphamide as a liver sparing regimen initially with some improvement in liver function tests and a reduction in lymph node volumes. She received six cycles of adriamycin/bleomycin/vinblastine/dacarbazine (ABVD) with complete remission attained after four cycles by positron emission tomography/computed tomography criteria. This report illustrates asafe chemotherapy regimen in the presence of marked liver dysfunction. Workup for VBDS including liver biopsy should be pursued in Hodgkin lymphoma patients with evidence of cholestasis in the absence of extrahepatic bile duct damage or other known etiology of liver injury.

13.
Angew Chem Int Ed Engl ; 61(40): e202208679, 2022 10 04.
Article in English | MEDLINE | ID: mdl-35904930

ABSTRACT

Here, we report an approach to the synthesis of highly charged enantiopure cyclophanes by the insertion of axially chiral enantiomeric binaphthyl fluorophores into the constitutions of pyridinium-based macrocycles. Remarkably, these fluorescent tetracationic cyclophanes exhibit a significant AIE compared to their neutral optically active binaphthyl precursors. A combination of theoretical calculations and time-resolved spectroscopy reveal that the AIE originates from limited torsional vibrations associated with the axes of chirality present in the chiral enantiomeric binaphthyl units and the fine-tuning of their electronic landscape when incorporated within the cyclophane structure. Furthermore, these highly charged enantiopure cyclophanes display CPL responses both in solution and in the aggregated state. This unique duality of AIE and CPL in these tetracationic cyclophanes is destined to be of major importance in future development of photonic devices and bio-applications.


Subject(s)
Luminescence , Luminescent Measurements , Fluorescent Dyes/chemistry , Luminescent Measurements/methods , Stereoisomerism
14.
Vaccines (Basel) ; 10(7)2022 Jun 28.
Article in English | MEDLINE | ID: mdl-35891203

ABSTRACT

BACKGROUND: Blacks are dying from the novel coronavirus of 2019 (COVID-19) at disproportionate rates and tend to have more COVID-19 vaccine hesitancy than Whites. These disparities may be attributable to health knowledge and government/medical mistrust stemming from negative experiences with the medical system historically and presently (e.g., the Tuskegee Experiment, provider maltreatment). METHOD: The present study assessed COVID-19 vaccine hesitancy and the effectiveness of a 1.5 h, dialogue-based, web intervention hosted by an academic-community partnership team. The webinar included approximately 220 male and female, English speaking, Black churchgoers in the western U.S. The webinar focused on the psychology of fear and facts about the vaccine development. RESULTS: The sample was mostly females who had higher vaccine hesitancy than men. A third of participants feared hospitalization if they contracted COVID-19. Many participants reported that learning facts about COVID-19 was most impactful. Statistical analyses indicated an increased willingness to get vaccinated after the webinar in comparison to before (t(25) = -3.08, p = 0.005). CONCLUSION: The findings suggest that virtual webinars may be effective at reducing COVID-19 vaccine hesitancy among Black churchgoers and may be applicable in addressing other health behaviors.

15.
Plant Reprod ; 35(3): 179-188, 2022 09.
Article in English | MEDLINE | ID: mdl-35235027

ABSTRACT

Although the seed remains small in size during the initial stage of seed development (the lag phase), several studies indicate that environment and assimilate supply level manipulations during the lag phase affect the final seed size. However, the manipulations were not only at the lag phase, making it difficult to understand the specific role of the lag phase in final seed size determination. It also remained unclear whether environmental cues are sensed by plants and regulate seed development or if it is simply the assimilate supply level, changed by the environment, that affects the subsequent seed development. We investigated soybean (Glycine max L. Merr.) seed phenotypes grown in a greenhouse using different source-sink manipulations (shading and removal of flowers and pods) during the lag phase. We show that assimilate supply is the key factor controlling flower and pod abortion and that the assimilate supply during the lag phase affects the subsequent potential seed growth rate during the seed filling phase. In response to low assimilate supply, plants adjust flower/pod abortion and lag phase duration to supply the minimum assimilate per pod/seed. Our results provide insight into the mechanisms whereby the lag phase is crucial for seed development and final seed size potential, essential parameters that determine yield.


Subject(s)
Glycine max , Seeds , Endosperm , Flowers , Phenotype , Reproduction , Seeds/genetics , Seeds/growth & development , Glycine max/genetics , Glycine max/growth & development
16.
J Phys Chem A ; 125(35): 7633-7643, 2021 Sep 09.
Article in English | MEDLINE | ID: mdl-34431674

ABSTRACT

Perylenediimides (PDIs) are important molecular building blocks that are being investigated for their applicability in optoelectronic technologies. Covalently linking multiple PDI acceptors at the 2,5,8,11 (headland) positions adjacent to the PDI carbonyl groups is reported to yield higher power conversion efficiencies in photovoltaic cells relative to PDI acceptors linked at the 1,6,7,12 (bay) positions. While the photophysical properties of PDIs linked via the bay positions have been investigated extensively, those linked at the headland positions have received far less attention. We showed previously that symmetry-breaking charge separation (SB-CS) in PDIs hold promise as a strategy for increasing photovoltaic efficiency. Here we use transient absorption and emission spectroscopies to investigate the competition between SB-CS, fluorescence, and internal conversion in three related PDI dimers linked at the headland positions with o-, m-, and p-phenylene moieties: o-PDI2, m-PDI2, and p-PDI2, respectively. It is found that o-PDI2 supports SB-CS yielding PDI•+-PDI•-, which is in equilibrium with the o-PDI2 first excited state in a polar solvent (CH2Cl2) while m-PDI2 and p-PDI2 exhibit accelerated internal conversion due to the motion of the linker along with subnanosecond intersystem crossing (ISC). Electronic coupling and structural dynamics are shown to play a significant role, with o-PDI2 being the only member of the series that exhibits significant through-bond interchromophore coupling. The pronounced o-PDI2 steric congestion prevents the free internal rotation that leads to rapid deactivation of the excited state in the other dimers.

17.
Phys Chem Chem Phys ; 21(44): 24383-24392, 2019 Nov 28.
Article in English | MEDLINE | ID: mdl-31663559

ABSTRACT

This paper highlights the challenge of predicting the excited state proton transfer (ESPT) reactions of small organic compounds with multiple proton transfer sites. Aminonaphthols, naphthalene compounds with both hydroxyl and amino substituents, can be viewed as a combination of two monoprotic photoacids, naphthol and naphthylammonium. Here, the ESPT reactions of 3-ammonium-2-naphthol (3N2OH) and 1-ammonium-2-naphthol (1N2OH) were studied in water and methanol using a combination of steady-state and time-correlated single-photon counting emission spectroscopy. For 3N2OH, ESPT was observed at the OH site in water but at neither of the sites in methanol; for 1N2OH, ESPT was observed at both the OH and NH3+ sites in water but only at the NH3+ site in methanol. Evidence of ESPT at the NH3+ site is limited for aminonaphthols. The divergent dynamics of 3N2OH and 1N2OH in water and methanol are discussed; dependent on the substitution and solvent, the ESPT reactions were analysed within the frameworks of reference photoacids 2-naphthol and 1-naphthylammonium. The application of crown ether and salt to control the release of select protons in non-aqueous media is also discussed.

18.
J Phys Chem B ; 123(19): 4301-4310, 2019 May 16.
Article in English | MEDLINE | ID: mdl-31021637

ABSTRACT

The rational design of photoacids requires accessible predictive models of the electronic effect of functional groups on chemical templates of interest. Here, the effect of substituents on the photoacidity and excited-state proton transfer (PT) pathways of prototype 2-naphthol (2OH) at the symmetric C7 position was investigated through photochemical and computational studies of 7-amino-2-naphthol (7N2OH) and 7-methoxy-2-naphthol (7OMe2OH). Time-resolved emission experiments of 7N2OH revealed that the presence of an electron-withdrawing versus electron-donating group (EWG vs EDG, NH3+ vs NH2) led to a drastic decline in photoacidity: p Ka* = 1.1 ± 0.2 vs 9.6 ± 0.2. Time-dependent density functional theory calculations with explicit water molecules confirmed that the excited neutral state (x = NH2) is greatly stabilized by water, with equation-of-motion coupled cluster singles and doubles calculations supporting potential mixing between the La and Lb states. Similar suppression of photoacidity, however, was not observed for 7OMe2OH with EDG OCH3, p Ka* = 2.7 ± 0.1. Hammett plots of the ground- and excited-state PT reactions of substituted 7-x-2OH compounds (x = CN, NH3+, H, CH3, OCH3, OH, and NH2) vs Hammett parameters σp showed breaks in the linearity between the EDG and EWG regions: ρ ∼ 0 vs 1.14 and ρ* ∼ 0 vs 3.86. The divergent acidic behavior most likely arises from different mixing mechanisms of the lowest Lb state with the La and possible Bb states upon substitution of naphthalene in water.

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