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Search for "photoswitch" in Full Text gives 40 result(s) in Beilstein Journal of Organic Chemistry.
Effect of a photoswitchable rotaxane on membrane permeabilization across lipid compositions
Beilstein J. Org. Chem. 2025, 21, 2498–2512, doi:10.3762/bjoc.21.192
- bilayers through the shuttling of the macrocycle carrying the ions or through a relay mechanism [10][11]. In one example, the isomerization of an azobenzene photoswitch incorporated into the axle was used to modulate the shuttling rate of the macrocycle and, consequently, the efficiency of potassium ion
Rotaxanes with integrated photoswitches: design principles, functional behavior, and emerging applications
Beilstein J. Org. Chem. 2025, 21, 2345–2366, doi:10.3762/bjoc.21.179
- shuttling dynamics. In this review, we discuss key examples of photoswitchable rotaxanes, organized according to the position of the photoswitch, either embedded in the axle or incorporated into the macrocycle. We examine the major classes of photoswitches used, including their switching mechanisms and the
- based on the location of the photoswitch within the rotaxane structure – either integrated into the axle or situated in the macrocycle. Within these categories, we highlight widely used photoswitches, including acridane, anthracene, azobenzene, cycloheptatriene, dithienylethene, fumaramide, hydrazone
- the most extensively developed and studied class of photoswitchable rotaxanes, in contrast to those in which the photoswitch is integrated into the macrocycle. Incorporating a photoswitch into the axle is used to modulate the non-covalent interactions between the macrocycle and the axle, thereby
Photoswitches beyond azobenzene: a beginner’s guide
Beilstein J. Org. Chem. 2025, 21, 1808–1853, doi:10.3762/bjoc.21.143
- may be overwhelming: azobenzene is undoubtedly the most famous due to its easy synthesis and the extensively studied properties. However, there are several photoswitch classes beyond azobenzene with interesting properties that can be tailored to meet one’s needs. In this tutorial review, we aim to
- explain the important terminology and discuss the synthesis, switching mechanisms, and properties of seven interesting photoswitch classes, namely azoheteroarenes, diazocines, indigoid photoswitches, arylhydrazones, diarylethenes, fulgides, and spiropyrans. Keywords: photoswitches; photoswitch properties
- preparation. Before introducing the different photoswitch classes in this review, we familiarise ourselves with different photophysical properties. A photochromic molecule can switch reversibly between a stable and a metastable state, which are shown in an energetic profile as two local minima (Figure 1
Orthogonal photoswitching of heterobivalent azobenzene glycoclusters: the effect of glycoligand orientation in bacterial adhesion
Beilstein J. Org. Chem. 2025, 21, 736–748, doi:10.3762/bjoc.21.57
- . This could be due to incomplete electronic decoupling of the antennas as seen earlier in glycocluster 1 [24][40]. The results obtained here for compounds 2, 3, 4, and 5 are in accordance with those previously reported for the heterobivalent photoswitch 1 (cf. Figure 1) [24]. In any case, the half-lifes
- is dependent on the configuration of the azobenzene photoswitch (E or Z). In both cases, the E isomers exhibit significantly higher RIP(MeMan) values than the Z isomers, approx. two times higher for 4 and approx. three times higher for 5 (cf. Supporting Information File 1, Table S6). The bis
- to the O-azobenzene (AB) photoswitch. (Orthogonal) photoswitching alters the relative spatial orientation of the two sugar units. Glucose (Glc) moieties are colored in blue and mannose (Man) in green according to the symbol nomenclature for carbohydrates (SNFG) [29][30]. A: Wavelength-selective
Photocatalyzed elaboration of antibody-based bioconjugates
Beilstein J. Org. Chem. 2025, 21, 616–629, doi:10.3762/bjoc.21.49
- give satisfactory reproducibility. Histidine/Tyr More recently, the same research group demonstrated the divergent functionalization of tyrosine or histidine, thanks to the use of a DNA photoswitch Ru complex, either used as a standalone system or involved in an artificial metalloenzyme (ArM). The use
Synthesis of N-acetyl diazocine derivatives via cross-coupling reaction
Beilstein J. Org. Chem. 2025, 21, 490–499, doi:10.3762/bjoc.21.36
- switching efficiency in aqueous solutions. In order to investigate the chemistry of this promising photoswitch and to unlock further applications, we now investigate strategies for the synthesis of derivatives, which are based on cross-coupling reactions. Fourteen vinyl-, aryl-, cyano-, and amino
- -substituted diazocines were prepared via Stille, Suzuki, and Buchwald–Hartwig reactions. X-ray structures are presented for derivatives 1, 2 and 7. Keywords: cross-coupling; diazocine; N-acetyl diazocine; photoisomerization; photoswitch; thermal relaxation; Introduction Diazocines are frequently used
- tetracyclic steroid scaffolds such as 17β-estradiol [18], where the diazocine core mimics the framework of the bioactive compound (Figure 1a). The other option is to attach the diazocine photoswitch as a substituent (appendix) to the biologically active molecule (Figure 1b) [6][10][19][20][21]. The art of
Understanding X-ray-induced isomerisation in photoswitchable surfactant assemblies
Beilstein J. Org. Chem. 2024, 20, 2005–2015, doi:10.3762/bjoc.20.176
- light and X-ray irradiation on micelles formed from two different PS, containing either an Azo or AAP photoswitch using SAXS with in-situ light irradiation. The effect of X-ray irradiation on the Z isomer is shown to depend on the photoswitch, solvent, concentration and morphology. We use this to create
- guidelines for future X-ray experiments using photoswitchable molecules, which can aid more accurate understanding of these materials for application in solar energy storage, catalysis or controlled drug delivery. Keywords: arylazopyrazole; azobenzene; micelle; photoswitch; X-ray; Introduction The design
- molecules to create photosurfactants (PS), whose molecular shape and polarity can be modified using light [4][5][6]. Of the PS studied, most use an azobenzene (Azo) photoswitch that undergoes trans-to-cis (E-to-Z) isomerization on irradiation with UV light, typically forming a photostationary state (PSS
A fiber-optic spectroscopic setup for isomerization quantum yield determination
Beilstein J. Org. Chem. 2024, 20, 1684–1692, doi:10.3762/bjoc.20.150
- be obtained from the UV–vis absorption spectra. We show that our results for the prototypical photoswitch azobenzene are in excellent agreement with the literature. The analysis of the errors showed that the quantum yields determined using this method are in the same order of magnitude as when using
- ]. Among the different switches known in the literature, azobenzene is a textbook example of a photoswitch operating via a double bond isomerization mechanism, with the first reports of its trans-to-cis interconversion under direct sunlight dating back to the work of Hartley in 1937 [2]. Over the decades
- conclusion holds for any photoswitch where only one isomer can be isolated successfully. During the measurement and at the PSS, the relative concentrations of the two isomers are unknown. The total absorbance (Absobs) at a given total concentration (c) of the sample is a linear combination of the absorbance
Novel route to enhance the thermo-optical performance of bicyclic diene photoswitches for solar thermal batteries
Beilstein J. Org. Chem. 2024, 20, 1053–1068, doi:10.3762/bjoc.20.93
- we report our attempt to enhance both the thermochemical and photophysical properties in a single-bridged bicyclic diene (BBD)-based photoswitch by elongating the unsaturated bridge with different heteroatomic units. To elucidate the best elongation unit, the energy storage capacity and the TBR
- impose a serious limitation for their practical applications [8][9][10][11][12][13]. It is believed that the rational design of the molecular structure can assist to endow all the necessary properties in a single photoswitch [14]. Therefore, engineering of novel photochromic couples with an intention to
- incorporate all desired features within a single photoswitch is a focus of current research [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30]. The bridged bicyclic diene (BBD)-based NBD/QC couple involves a reversible [2 + 2]-cycloaddition and the chemical transformation during its
Switchable molecular tweezers: design and applications
Beilstein J. Org. Chem. 2024, 20, 504–539, doi:10.3762/bjoc.20.45
- first part will be devoted to chemically responsive tweezers, including stimuli such as pH, metal coordination, and anion binding. Then, redox-active and photochemical tweezers will be presented. Keywords: coordination; molecular recognition; molecular switches; photoswitch; redox; supramolecular
Substituted nitrogen-bridged diazocines
Beilstein J. Org. Chem. 2021, 17, 1503–1508, doi:10.3762/bjoc.17.107
- makes them promising candidates for applications in photopharmacology. The halogen substituents allow further functionalization via cross-coupling reactions. Keywords: bridged azobenzene; diazocine; photopharmacology; photoswitch; triazocine; visible light switch; water-soluble switch; Introduction
Synthesis of 4-substituted azopyridine-functionalized Ni(II)-porphyrins as molecular spin switches
Beilstein J. Org. Chem. 2020, 16, 2589–2597, doi:10.3762/bjoc.16.210
- )-porphyrins; photoswitch; record player molecules; spin state; spin switch; Introduction Molecular spin switches operated with visible light in homogeneous solution [1] or on surfaces [2], hold promise for a number of hitherto unprecedented applications such as switchable contrast agents [3][4][5][6][7
Azo-dimethylaminopyridine-functionalized Ni(II)-porphyrin as a photoswitchable nucleophilic catalyst
Beilstein J. Org. Chem. 2020, 16, 2119–2126, doi:10.3762/bjoc.16.179
- activity. The rate constants in the two switching states differ by a factor of 2.2, and the catalytic switching is reversible. Keywords: catalysis; Ni(II)-porphyrins; nucleophilic catalyst; photoswitch; record player molecules; spin switch; Introduction Photoswitchable catalysis has been realized
Potent hemithioindigo-based antimitotics photocontrol the microtubule cytoskeleton in cellulo
Beilstein J. Org. Chem. 2020, 16, 125–134, doi:10.3762/bjoc.16.14
- molecular photoswitch that has only recently been applied as a photoswitchable pharmacophore for control over bioactivity in cellulo. Uniquely, in contrast to other photoswitches that have been applied to biology, the pseudosymmetric hemithioindigo scaffold has allowed the creation of both dark-active and
- addressable by photopharmacology. Keywords: antimitotics; cytoskeleton; hemithioindigo; photopharmacology; photoswitch; Introduction The cytoskeletal scaffolding protein tubulin, a heterodimer consisting of α and β subunits, each of various isotypes, reversibly assembles into giant non-covalent polymeric
- , all-visible-light photoswitching. Results and Discussion Design strategy for HTIs The HTI-based colchicinoid HOTubs (e.g., HOTub-31) that we previously explored had the HTI photoswitch embedded inside a methoxylation pattern, such that one isomer obeyed the structure–activity relationship (SAR) of
Light-controllable dithienylethene-modified cyclic peptides: photoswitching the in vivo toxicity in zebrafish embryos
Beilstein J. Org. Chem. 2020, 16, 39–49, doi:10.3762/bjoc.16.6
- , (iii) demonstrate photoswitching of the whole-body toxicity for the dithienylethene-modified peptides in vivo, (iv) re-analyze previous structure–toxicity relationship data, and (v) select promising candidates for potential clinical development. Keywords: diarylethene photoswitch; gramicidin S
- peptides [19][20][21]. The idea behind photopharmacology is based on the design and use of drugs containing a reversibly photoisomerizable fragment (“molecular photoswitch”) as part of their structure. Importantly, the photoisomerizable fragment should – in one of its photoforms – destroy or mask the
- photoswitch into the backbone of gramicidin S (1, GS), which is an intrinsically biostable cyclic peptide, as exemplified by one of our first prototypes compound 2 (Figure 1C). This natural antimicrobial agent has an amphipathic structure, whose functional mechanism is attributed to the permeabilization of
Starazo triple switches – synthesis of unsymmetrical 1,3,5-tris(arylazo)benzenes
Beilstein J. Org. Chem. 2020, 16, 22–31, doi:10.3762/bjoc.16.4
- of multiple AB units into one molecule allows to access multiple states upon isomerization, which dramatically increases the potential for information storage using this photoswitch. Ideally, one molecule can be treated with multiple different inputs, leading to defined, detectable outputs. An
Synthesis and characterization of bis(4-amino-2-bromo-6-methoxy)azobenzene derivatives
Beilstein J. Org. Chem. 2019, 15, 3000–3008, doi:10.3762/bjoc.15.296
- ; azonium; molecular switches; ortho substitution; photoisomerization; photoswitch; visible light; Introduction The application of photoswitches to control biological targets has been a driving force for the development of photoswitches that operate at wavelengths that are compatible with cells and tissues
- in an aqueous solution, it is useful as a photoswitch for the photocontrol of biomolecules [6]. It absorbs red light, undergoes trans-to-cis photoisomerization, and relaxes to the trans isomer in the dark on the timescale of seconds so that pulses of red light can be used to drive multiple
- isomerization cycles [10]. Efforts to apply 1 to photocontrol protein–protein interactions have recently been reported [13]. Despite the usefulness of 1 as a photoswitch, compounds undergoing photoisomerization at longer wavelengths (>700 nm) would be valuable since the penetration of light through tissue is
Design, synthesis and investigation of water-soluble hemi-indigo photoswitches for bioapplications
Beilstein J. Org. Chem. 2019, 15, 2822–2829, doi:10.3762/bjoc.15.275
- solubility of the photoswitch and increases the red shift of the absorption maximum of the E-isomer. As a further step, the synthetic approach towards the attachment of the RNA-affine alkylamino substituent was developed. Overall, the hemi-indigo derivatives were introduced as promising photoswitches for
Chemical tuning of photoswitchable azobenzenes: a photopharmacological case study using nicotinic transmission
Beilstein J. Org. Chem. 2019, 15, 2812–2821, doi:10.3762/bjoc.15.274
- glutathione. However, attempts to conjugate with a cysteine on a genetically modified nicotinic acetylcholine receptor did not afford the expected light-responsive channel. Our data indicate that the 4FAB photoswitch can be derivatized bifunctionally for genetically-targeted photopharmacology whilst
- regular AB-based photoswitch called "MAHoCh" [16]. The MAHoCh probe was originally designed [16] to activate nicotinic acetylcholine receptors in vivo. However, it was found that the trimethylammonium (TA) head group blocked acetylcholine binding when the photoprobe was cross-linked to the channel near
- % overall yield. Installation of the cationic head was performed in two steps: first bromination of 11 via Appel reaction, followed by treatment with trimethylamine to give 2 in 35% overall yield. Photoswitch 2 is the first example of a bifunctional, asymmetrically substituted 4FAB chromophore that actually
Photoreversible stretching of a BAPTA chelator marshalling Ca2+-binding in aqueous media
Beilstein J. Org. Chem. 2019, 15, 2801–2811, doi:10.3762/bjoc.15.273
- μM, respectively). Reversible photoliberation/uptake leading to a variation of free calcium concentration in solution was detected using a fluorescent Ca2+ chemosensor. Keywords: azobenzene; BAPTA; calcium binding; photorelease; photoswitch; Introduction In terms of synthetic calcium binding
- EDTA) such that photoswitching would enhance or lower Ca2+ binding based on the state of the adjacent photoswitch. Photogeneration of a positive charge proximal to the BAPTA site is undoubtedly the most robust approach to provoke calcium cation release, while diminishing electron density on the
A combinatorial approach to improving the performance of azoarene photoswitches
Beilstein J. Org. Chem. 2019, 15, 2753–2764, doi:10.3762/bjoc.15.266
- = 10 days), whereas 4pzMe-Cl2 (t1/2 ≈ 1 day) exhibits a reduction in half-life. Additionally, 4pzH-F2 boasts a vastly increased thermal half-life of 46 years over 4pzH (t1/2 = 1000 days) making it the longest-lived azoheteroarene photoswitch reported in the literature to date. This result demonstrates
- °) to 4pzMe-Cl1 (127°) and to 4pzMe-Cl2 (113°; Figure 4). The effect of ortho-substitution on photoconversion efficiency To a first approximation, in order to achieve high Z–E photoconversion efficiency, the two isomers of an azo photoswitch must offer well-separated absorption bands. Most frequently, E
- . Thus, a tilting of the pyrazole moiety away from orthogonality with respect to the plane generated by the aryl ring leads the n–π* excitation to be symmetry-allowed, with the corresponding increase in intensity. For example, the heteroring in fluorine-substituted 4pzH-F2 photoswitch is tilted with a θ
A toolbox of molecular photoswitches to modulate the CXCR3 chemokine receptor with light
Beilstein J. Org. Chem. 2019, 15, 2509–2523, doi:10.3762/bjoc.15.244
- VUF16216, a compound we have previously communicated as a small-molecule efficacy photoswitch for the peptidergic chemokine GPCR CXCR3. A series of photoswitchable azobenzene ligands was prepared through various synthetic strategies and multistep syntheses. Photochemical and pharmacological properties were
- pharmacological alternative, especially with respect to spatial and temporal precision [1][2]. Photochromic ligands usually contain a molecular photoswitch (photoswitchable moiety) that under certain wavelengths of illumination undergoes an isomerization event, thereby changing the properties of the molecule and
- by large peptides CXCL9, CXCL10 and CXCL10 and involved in inflammatory responses. In fact, the six compounds reported in that study represent the first photochromic small-molecule class that harbors a dynamic efficacy photoswitch (from antagonism to agonism) on a peptidergic GPCR (Figure 1B). Here
In search of visible-light photoresponsive peptide nucleic acids (PNAs) for reversible control of DNA hybridization
Beilstein J. Org. Chem. 2019, 15, 2500–2508, doi:10.3762/bjoc.15.243
- first compounds here reported, may find applications in different fields such as chemical biology, nanotechnology and materials science. Keywords: azobenzene; hemithioindigo; peptide nucleic acid (PNA); photoswitch; visible-light irradiation; Introduction Light-driven control of oligonucleotide
- translation [24][25]. Except a handful of current examples [22][24][26], most of these photoresponsive oligonucleotides are canonical ones where the classical azobenzene is the prominently used photoswitch; although spiropyrans [27], stilbenes [28], diarylethanes [29] and overcrowded alkenes [30] have also
- used, we gained versatility using the divergent linear approach introduced by Seitz (Scheme 1) [42]. This strategy enabled the straightforward access to functionalized PNA via on-resin coupling of the corresponding photoswitch in good yields. Of note, this post-synthetic modification is compatible with
Ultrafast processes triggered by one- and two-photon excitation of a photochromic and luminescent hydrazone
Beilstein J. Org. Chem. 2019, 15, 2438–2446, doi:10.3762/bjoc.15.236
- – Istituto Nazionale di Ottica, Largo Enrico Fermi 6, 50125 Firenze, Italy 10.3762/bjoc.15.236 Abstract In this work we apply a combination of steady state and time resolved luminescence and absorption spectroscopies to investigate the excited-state dynamics of a recently developed molecular photoswitch
- drawbacks still remain, calling for the development of new systems with improved behavior. Although the properties of a successful photoswitch have to be tailored on the application for which it is designed, there are several aspects whose improvement can be of benefit on a general basis. Major concerns on
Excited state dynamics for visible-light sensitization of a photochromic benzil-subsituted phenoxyl-imidazolyl radical complex
Beilstein J. Org. Chem. 2019, 15, 2369–2379, doi:10.3762/bjoc.15.229
- photoswitch molecules, the phenoxyl-imidazolyl radical complex (PIC) is a recently developed thermally reversible photochromic molecule whose thermal back reaction can be tuned from tens of nanoseconds to tens of seconds by rational design of the molecular structure. While the wide range of tunability of the
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