1
|
Moriyama N, Yagi S, Abe J. Stepwise Photochromism of Large Macrocycles Incorporating Two Negative Photochromic Units. J Phys Chem Lett 2024; 15:7548-7555. [PMID: 39024027 DOI: 10.1021/acs.jpclett.4c01752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/20/2024]
Abstract
Macrocyclic photochromic molecules incorporating multiple photochromic units are known to exhibit cooperative and nonlinear photochromic reactions among distinct photochromic components. While extensive research has concentrated on positive photochromic molecules, this study presents a pioneering attempt in synthesizing macrocyclic photochromic molecules that integrate negative photochromic units. Binaphthyl-bridged phenoxyl imidazolyl radical complex, BN-PIC, exhibits unique negative photochromism in which the thermally stable colored isomer converts to the metastable colorless isomer via a short-lived biradical upon visible-light irradiation. Macrocyclic biphotochromic molecules incorporating two BN-PIC units were synthesized and the effects of ring strain on the photochromic properties including the photoconversion efficiencies and the rates of the thermal reverse reaction were investigated. The photokinetic study of these macrocyclic biphotochromic molecules demonstrated that the structural distortion of the ring caused by the isomerization of one photochromic unit significantly influenced the photoisomerization efficiency and the rate of the thermal reverse reaction of the other photochromic unit.
Collapse
Affiliation(s)
- Natsuho Moriyama
- Department of Chemistry and Biological Science, College of Science and Engineering, Aoyama Gakuin University, Sagamihara, Kanagawa 252-5258, Japan
| | - Shiori Yagi
- Department of Chemistry and Biological Science, College of Science and Engineering, Aoyama Gakuin University, Sagamihara, Kanagawa 252-5258, Japan
| | - Jiro Abe
- Department of Chemistry and Biological Science, College of Science and Engineering, Aoyama Gakuin University, Sagamihara, Kanagawa 252-5258, Japan
| |
Collapse
|
2
|
Maafi M. On photokinetics under monochromatic light. Front Chem 2023; 11:1233151. [PMID: 37780986 PMCID: PMC10538970 DOI: 10.3389/fchem.2023.1233151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Accepted: 08/22/2023] [Indexed: 10/03/2023] Open
Abstract
The properties of photokinetics under monochromatic light have not yet been fully described in the literature. In addition, for the last 120 years or so, explicit, handy model equations that can map out the kinetic behaviour of photoreactions have been lacking. These gaps in the knowledge are addressed in the present paper. Several general features of such photokinetics were investigated, including the effects of initial reactant concentration, the presence of spectator molecules, and radiation intensity. A unique equation, standing for a pseudo-integrated rate law, capable of outlining the kinetic behaviour of any photoreaction is proposed. In addition, a method that solves for quantum yields and absorption coefficients of all species of a given photoreaction is detailed. A metric (the initial velocity) has been adopted, and its reliability for the quantification of several effects was proven by theoretical derivation, Runge-Kutta numerical integration calculations and through the model equation proposed. Overall, this study shows that, under monochromatic light, photoreaction kinetics is well described by Φ -order kinetics, which is embodied by a unifying model equation. This paper is aimed at contributing to rationalising photokinetics via reliable, easy-to-use mathematical tools.
Collapse
Affiliation(s)
- Mounir Maafi
- Leicester School of Pharmacy, De Montfort University, Leicester, United Kingdom
| |
Collapse
|
3
|
Maafi M, Al-Qarni MA. Photokinetics of Dacarbazine and Nifedipine under polychromatic light irradiation and their application as new reliable actinometers for the ultraviolet range. Sci Rep 2022; 12:7622. [PMID: 35538090 PMCID: PMC9090909 DOI: 10.1038/s41598-022-11570-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Accepted: 04/19/2022] [Indexed: 11/30/2022] Open
Abstract
The photokinetic behaviour of drugs driven by polychromatic light is an area of pharmaceutics that has not received a lot of attention. Most often, such photokinetic data is treated by thermal kinetic models (i.e., the classical 0th-, 1st- or 2nd-order equations). Such models were not analytically derived from the rate-laws of the photodegradation reactions. Polychromatic light kinetic modelling is hence of importance, as a means to providing adequate toolkits and metrics. This paper aims at proposing two reliable drug-actinometers useful for polychromatic UVA range. The general actinometric methodology offered here is also useful for any drugs/materials obeying a primary photoprocess where both reactant and photoproduct absorb the incident light, of the \documentclass[12pt]{minimal}
\usepackage{amsmath}
\usepackage{wasysym}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsbsy}
\usepackage{mathrsfs}
\usepackage{upgreek}
\setlength{\oddsidemargin}{-69pt}
\begin{document}$$AB{(1\Phi )}_{{\varepsilon }_{B}\ne 0}$$\end{document}AB(1Φ)εB≠0 type. The present method has been consolidated by the η-order kinetics. This framework further demonstrated the lamp-specificity of actinometers. Overall, Dacarbazine and Nifedipine photodegradations obeyed η-order kinetics, and stand as effective actinometers that can be recommended for the ICH Q1b photostability testing.
Collapse
Affiliation(s)
- Mounir Maafi
- Leicester School of Pharmacy, De Montfort University, The Gateway, Leicester, LE1 9BH, UK.
| | - Mohammed Ahmed Al-Qarni
- Department of Pharmaceutical Chemistry, College of Pharmacy, Taif University, P.O. Box 11099, Taif, 21944, Saudi Arabia
| |
Collapse
|
4
|
Boursalian GB, Nijboer ER, Dorel R, Pfeifer L, Markovitch O, Blokhuis A, Feringa BL. All-Photochemical Rotation of Molecular Motors with a Phosphorus Stereoelement. J Am Chem Soc 2020; 142:16868-16876. [PMID: 32905701 PMCID: PMC7530895 DOI: 10.1021/jacs.0c08249] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
![]()
Unidirectional molecular
rotation based on alternating photochemical
and thermal isomerizations of overcrowded alkenes is well established,
but rotary cycles based purely on photochemical isomerizations are
rare. Herein we report three new second-generation molecular motors
featuring a phosphorus center in the lower half, which engenders a
unique element of axial chirality. These motors exhibit unusual behavior,
in that all four diastereomeric states can interconvert solely photochemically.
Kinetic analysis and modeling reveal that the behavior of the new
motors is consistent with all-photochemical unidirectional rotation.
Furthermore, X-ray crystal structures of all four diastereomeric states
of two of these new motors were obtained, which constitute the first
achievements of crystallographic characterization of the full 360°
rotational cycle of overcrowded-alkene-based molecular motors. Finally,
the axial phosphorus stereoelement in the phosphine motor can
be thermally inverted, and this epimerization enables a “shortcut”
of the traditional rotational cycle of these compounds.
Collapse
Affiliation(s)
- Gregory B Boursalian
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Eise R Nijboer
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Ruth Dorel
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Lukas Pfeifer
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Omer Markovitch
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.,Groningen Institute for Evolutionary Life Sciences, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands.,Origins Center, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Alex Blokhuis
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.,Groningen Institute for Evolutionary Life Sciences, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Ben L Feringa
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| |
Collapse
|
5
|
Some physical parameters influencing the comprehensive evaluation of kinetic data in photochemical reactions and its application in the periodate-chemistry. J Photochem Photobiol A Chem 2020. [DOI: 10.1016/j.jphotochem.2019.112021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
6
|
Implementation of a mathematical model for the photochemical kinetics of a solid form active pharmaceutical ingredient. Int J Pharm 2019; 566:500-512. [PMID: 31129341 DOI: 10.1016/j.ijpharm.2019.05.054] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 05/17/2019] [Accepted: 05/20/2019] [Indexed: 11/22/2022]
Abstract
We present here the development of a photochemical model used to quantify the risk to photodegradation of a solid drug substance. A key feature of the proposed model development is streamlined estimation of the dependence of the absorption spectra and the quantum yield to the wavelength. A mathematical description of the relationship between the quantum yield and the wavelength enables estimation of photodegradation kinetics under any light anticipated to be encountered in the manufacturing environment. The system studied here consisted of a first order irreversible transformation (A → B(1Φ)) and the formalism strongly suggested the quantum yield was constant over the relevant wavelength range. The predictive power of the model enabled the design of a control strategy to limit the formation of the photo-degradant to very low levels. Also presented are insights obtained from quantum mechanical modeling of the electronic transitions associated with the UV absorption spectra.
Collapse
|
7
|
Ahmad I, Anwar Z, Ahmed S, Sheraz MA, Khattak SUR. Metal ion mediated photolysis reactions of riboflavin: A kinetic study. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2017; 173:231-239. [PMID: 28599240 DOI: 10.1016/j.jphotobiol.2017.05.033] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Revised: 04/20/2017] [Accepted: 05/22/2017] [Indexed: 11/18/2022]
Abstract
The effect of metal ion complexation on the photolysis of riboflavin (RF) using various metal ions (Ag+, Ni2+, Co2+, Fe2+, Ca2+, Cd2+, Cu2+, Mn2+, Pb2+, Mg2+, Zn2+, Fe3+) has been studied. Ultraviolet and visible spectral and fluorimetric evidence has been obtained to confirm the formation of metal-RF complexes. The kinetics of photolysis of RF in metal-RF complexes at pH7.0 has been evaluated. The apparent first-order rate constant (kobs) for the photolysis of RF and the formation of lumichrome (LC) and lumiflavin (LF) (0.001M phosphate buffer) and LC, LF and cyclodehydroriboflavin (CDRF) (0.2-0.4M phosphate buffer) have been determined. The values of kobs indicate that the rate of photolysis of RF is promoted by divalent and trivalent metal ions. The second-order rate constants (k' ) for the interaction of metal ions with RF are in the order: Zn2+>Mg2+>Pb2+>Mn2+>Cu2+>Cd2+>Fe2+>Ca2+>Fe3+>Co2+>Ni2+>Ag+. In phosphate buffer (0.2-0.4M), an increase in the metal ion concentration leads to a decrease in the formation of LC compared to that of CDRF by different pathways. The photoproducts of RF have been identified and RF and the photoproducts have simultaneously been assayed by a multicomponent spectrometric method. The mode of photolysis of RF in metal-RF complexes has been discussed.
Collapse
Affiliation(s)
- Iqbal Ahmad
- Baqai Institute of Pharmaceutical Sciences, Baqai Medical University, Super Highway, Gadap Road, Karachi 74600, Pakistan
| | - Zubair Anwar
- Baqai Institute of Pharmaceutical Sciences, Baqai Medical University, Super Highway, Gadap Road, Karachi 74600, Pakistan.
| | - Sofia Ahmed
- Baqai Institute of Pharmaceutical Sciences, Baqai Medical University, Super Highway, Gadap Road, Karachi 74600, Pakistan
| | - Muhammad Ali Sheraz
- Baqai Institute of Pharmaceutical Sciences, Baqai Medical University, Super Highway, Gadap Road, Karachi 74600, Pakistan
| | - Saif-Ur-Rehman Khattak
- Central Drug Laboratories, Ministry of Health, DRAP, Block-B, S.M.C.H., Karachi 74400, Pakistan
| |
Collapse
|