1
|
Saltiel J, Krishnan SB, Gupta S, Chakraborty A, Hilinski EF, Lin X. Photochemistry and Photophysics of Cholesta-5,7,9(11)-trien-3β-ol in Ethanol. Molecules 2023; 28:molecules28104086. [PMID: 37241827 DOI: 10.3390/molecules28104086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 05/08/2023] [Accepted: 05/09/2023] [Indexed: 05/28/2023] Open
Abstract
Cholesta-5,7,9(11)-trien-3β-ol (9,11-dehydroprovitamin D3, CTL) is used as a fluorescent probe to track the presence and migration of cholesterol in vivo. We recently described the photochemistry and photophysics of CTL in degassed and air-saturated tetrahydrofuran (THF) solution, an aprotic solvent. The zwitterionic nature of the singlet excited state, 1CTL* is revealed in ethanol, a protic solvent. In ethanol, the products observed in THF are accompanied by ether photoadducts and by photoreduction of the triene moiety to four dienes, including provitamin D3. The major diene retains the conjugated s-trans-diene chromophore and the minor is unconjugated, involving 1,4-addition of H at the 7 and 11 positions. In the presence of air, peroxide formation is a major reaction channel as in THF. X-ray crystallography confirmed the identification of two of the new diene products as well as of a peroxide rearrangement product.
Collapse
Affiliation(s)
- Jack Saltiel
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306-4390, USA
| | - Sumesh B Krishnan
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306-4390, USA
| | - Shipra Gupta
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306-4390, USA
| | - Anjan Chakraborty
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306-4390, USA
| | - Edwin F Hilinski
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306-4390, USA
| | - Xinsong Lin
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306-4390, USA
| |
Collapse
|
2
|
Aldaz CR, Martinez TJ, Zimmerman PM. The Mechanics of the Bicycle Pedal Photoisomerization in Crystalline cis,cis-1,4-Diphenyl-1,3-butadiene. J Phys Chem A 2020; 124:8897-8906. [PMID: 33064471 DOI: 10.1021/acs.jpca.0c05803] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Direct irradiation of crystalline cis,cis-1,4-diphenyl-1,3-butadiene (cc-DPB) forms trans,trans-1,4-diphenyl-1,3,-butadiene via a concerted two-bond isomerization called the bicycle pedal (BP) mechanism. However, little is known about photoisomerization pathways in the solid state and there has been much debate surrounding the interpretation of volume-conserving isomerization mechanisms. The bicycle pedal photoisomerization is investigated using the quantum mechanics/molecular mechanics complete active space self-consistent field/Amber force-field method. Important details about how the steric environment influences isomerization mechanisms are revealed including how the one-bond flip and hula-twist mechanisms are suppressed by the crystal cavity, the nature of the seam space in steric environments, and the features of the bicycle pedal mechanism. Specifically, in the bicycle pedal, the phenyl rings of cc-DPB are locked in place and the intermolecular packing allows a passageway for rotation of the central diene in a volume-conserving manner. In contrast, the bicycle pedal rotation in the gas phase is not a stable pathway, so single-bond rotation mechanisms become operative instead. Furthermore, the crystal BP mechanism is an activated process that occurs completely on the excited state; the photoproduct can decay to the ground state through radiative and non-radiative pathways. The present models, however, do not capture the quantitative activation barriers, and more work is needed to better model reactions in crystals. Last, the reaction barriers of the different crystalline conformations within the unit cell of cc-DPB are compared to investigate the possibility for conformation-dependent isomerization. Although some difference in reaction barriers is observed, the difference is most likely not responsible for the experimentally observed periods of fast and slow conversion.
Collapse
Affiliation(s)
- Cody R Aldaz
- Department of Chemistry, University of Michigan, 930 N University Ave., Ann Arbor, Michigan 48109-1055, United States
| | - Todd J Martinez
- Department of Chemistry and the PULSE Institute, Stanford University, Stanford, California 94305, United States
| | - Paul M Zimmerman
- Department of Chemistry, University of Michigan, 930 N University Ave., Ann Arbor, Michigan 48109-1055, United States
| |
Collapse
|
3
|
Horbury MD, Turner MAP, Peters JS, Mention M, Flourat AL, Hine NDM, Allais F, Stavros VG. Exploring the Photochemistry of an Ethyl Sinapate Dimer: An Attempt Toward a Better Ultraviolet Filter. Front Chem 2020; 8:633. [PMID: 32850651 PMCID: PMC7399488 DOI: 10.3389/fchem.2020.00633] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 06/17/2020] [Indexed: 11/16/2022] Open
Abstract
The photochemistry and photostability of a potential ultraviolet (UV) radiation filter, dehydrodiethylsinapate, with a broad absorption in the UVA region, is explored utilizing a combination of femtosecond time-resolved spectroscopy and steady-state irradiation studies. The time-resolved measurements show that this UV filter candidate undergoes excited state relaxation after UV absorption on a timescale of ~10 picoseconds, suggesting efficient relaxation. However, steady-state irradiation measurements show degradation under prolonged UV exposure. From a photochemical standpoint, this highlights the importance of considering both the ultrafast and “ultraslow” timescales when designing new potential UV filters.
Collapse
Affiliation(s)
- Michael D Horbury
- School of Electronic and Electrical Engineering, University of Leeds, Leeds, United Kingdom
| | - Matthew A P Turner
- Department of Chemistry, University of Warwick, Coventry, United Kingdom
| | - Jack S Peters
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford, United Kingdom
| | | | | | - Nicholas D M Hine
- Department of Chemistry, University of Warwick, Coventry, United Kingdom
| | | | - Vasilios G Stavros
- Department of Chemistry, University of Warwick, Coventry, United Kingdom
| |
Collapse
|
4
|
Saltiel J, Redwood CE, V. K. RK. The photoisomerization of cis, trans-1,2-dideuterio-1,4-diphenyl-1,3-butadiene in solution. No bicycle-pedal. Photochem Photobiol Sci 2019; 18:2174-2179. [DOI: 10.1039/c9pp00113a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
cis,trans-1,2-Dideuterio-1,4-diphenyl-1,3-butadiene (ct-DPBd2) was synthesized and its cis–trans photoisomerization in cyclohexane-d12 (C6D12) at room temperature was monitored by 1H NMR spectroscopy.
Collapse
Affiliation(s)
- Jack Saltiel
- Department of Chemistry and Biochemistry
- Florida State University
- Tallahassee
- USA
| | | | | |
Collapse
|
5
|
Saltiel J, Redwood CE, Laohhasurayotin K, Samudrala R. Photochemistry of the 1,6-Dideuterio-1,3,5-hexatrienes in Solution: Efficient Terminal Bond Photoisomerization in One-Bond-Twist and Bicycle Pedal Ways. J Phys Chem A 2018; 122:8477-8489. [PMID: 30277763 DOI: 10.1021/acs.jpca.8b08288] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The report that the central bond photoisomerization of the 1,3,5-hexatrienes (Hts) is highly inefficient has encouraged theoreticians to seek conical intersections (CIs) at geometries that can explain rapid nonradiative return to the initially excited isomer. Because they are photochemically silent, torsional relaxations about the terminal double bonds of the Hts have not been evaluated as significant radiationless decay pathways. Study of the photoisomerization of trans,trans,trans- and trans,cis,trans-1,6-dideuterio-1,3,5-hexatrienes ( ttt- and tct-Htd2) addresses this issue. Degassed cyclohexane- d12 (C6D12) and CD3CN solutions were irradiated at 254 nm in quartz NMR tubes, and the progress of the reactions was followed by 1H NMR. Photoisomerization rates based on the integration of terminal hydrogen NMR peaks are in reasonable agreement with rates obtained by fitting pure isomer NMR spectra to the phase shift and baseline corrected experimental NMR spectra. The results show that terminal bond isomerization is highly efficient, especially when one considers that central bond isomerization is much more efficient than previously reported and is mainly observed together with terminal bond isomerization. A mechanism involving terminal one-bond-twist (OBT) in competition with a bicycle pedal (BP) process accounts for all terminal and most central bond photoisomerization. OBT central bond isomerization is a minor reaction that is observed primarily in the tct to ttt direction. Most surprising is the prominent role of the BP process in central bond photoisomerization. Proposed initially to account for photoisomerization in free volume constraining media, it is observed here in the absence of medium constraints.
Collapse
Affiliation(s)
- Jack Saltiel
- Department of Chemistry and Biochemistry , Florida State University , Tallahassee , Florida 32306-4390 , United States
| | - Christopher E Redwood
- Department of Chemistry and Biochemistry , Florida State University , Tallahassee , Florida 32306-4390 , United States
| | - Kritapas Laohhasurayotin
- Department of Chemistry and Biochemistry , Florida State University , Tallahassee , Florida 32306-4390 , United States
| | - Ramakrishna Samudrala
- Department of Chemistry and Biochemistry , Florida State University , Tallahassee , Florida 32306-4390 , United States
| |
Collapse
|
6
|
Saltiel J, Gupta S. Photochemistry of the Stilbenes in Methanol. Trapping the Common Phantom Singlet State. J Phys Chem A 2018; 122:6089-6099. [DOI: 10.1021/acs.jpca.8b04011] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Jack Saltiel
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306-4390, United States
| | - Shipra Gupta
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306-4390, United States
| |
Collapse
|
7
|
Milanese JM, Provorse MR, Alameda E, Isborn CM. Convergence of Computed Aqueous Absorption Spectra with Explicit Quantum Mechanical Solvent. J Chem Theory Comput 2017; 13:2159-2171. [DOI: 10.1021/acs.jctc.7b00159] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Joel M. Milanese
- Chemistry and Chemical Biology, University of California at Merced, Merced, California 95343, United States
| | - Makenzie R. Provorse
- Chemistry and Chemical Biology, University of California at Merced, Merced, California 95343, United States
| | - Enrique Alameda
- Chemistry and Chemical Biology, University of California at Merced, Merced, California 95343, United States
| | - Christine M. Isborn
- Chemistry and Chemical Biology, University of California at Merced, Merced, California 95343, United States
| |
Collapse
|