Ultrafast processes triggered by one- and two-photon excitation of a photochromic and luminescent hydrazone

Alessandro Iagatti,
Baihao Shao,
Alberto Credi,
Barbara Ventura,
Ivan Aprahamian and
Mariangela Di Donato

Full Research Paper
Published 15 Oct 2019

PDF
Album
1. Graphical Abstract
2. Figure 1: a) The photoinduced Z/E isomerization of hydrazone 1, and accompanied changes in b) UV–vis absorpti...
  
  Jump to Figure 1
3. Figure 2: Fluorescence decays (dots) in the 500–520 nm spectral region (emission range of the Z-isomer) for 1...
  
  Jump to Figure 2
4. Figure 3: Fluorescence decays (dots) in the 500–520 nm spectral region (red; induced Z-emission), and in the ...
  
  Jump to Figure 3
5. Figure 4: a) Transient absorption data recorded for hydrazone 1 in toluene upon excitation at 400 nm; b) EADS...
  
  Jump to Figure 4
6. Figure 5: EADS obtained by global fit of the transient data recorded in a) acetonitrile and b) methanol upon ...
  
  Jump to Figure 5
7. Figure 6: Kinetic traces recorded at the maximum of the excited state absorption band in toluene, acetonitril...
  
  Jump to Figure 6
8. Figure 7: a) Transient absorption spectra measured for hydrazone 1 in toluene upon excitation at 785 nm. b) C...
  
  Jump to Figure 7
Supp. Info

Beilstein J. Org. Chem. 2019, 15, 2438–2446, doi:10.3762/bjoc.15.236

Full Text

Photochromic diarylethene ligands featuring 2-(imidazol-2-yl)pyridine coordination site and their iron(II) complexes

Andrey G. Lvov,
Max Mörtel,
Anton V. Yadykov,
Frank W. Heinemann,
Valerii Z. Shirinian and
Marat M. Khusniyarov

Letter
Published 15 Oct 2019

PDF
Album
1. Graphical Abstract
2. Figure 1: Families of diarylethene-bases ligands with spatial proximity of coordination site (blue) and photo...
  
  Jump to Figure 1
3. Scheme 1: Synthesis of photochromic ligands.
  
  Jump to Scheme 1
4. Figure 2: Electronic spectra of diarylethene 6 upon UV irradiation (313 nm, toluene, c = 3.4 × 10⁻⁵ M). Inset...
  
  Jump to Figure 2
5. Scheme 2: Reversible photocyclization of ligand 6.
  
  Jump to Scheme 2
6. Figure 3: Molecular structure of complexes 8 (top) and 9 (bottom) at 100 K. The H atoms are omitted for clari...
  
  Jump to Figure 3
7. Figure 4: Variable temperature χT product (blue) and χ (green) of 8 (top) and 9 (bottom) measured at an exter...
  
  Jump to Figure 4
Supp. Info

Beilstein J. Org. Chem. 2019, 15, 2428–2437, doi:10.3762/bjoc.15.235

Full Text

Sugar-derived oxazolone pseudotetrapeptide as γ-turn inducer and anion-selective transporter

Sachin S. Burade,
Sushil V. Pawar,
Tanmoy Saha,
Navanath Kumbhar,
Amol S. Kotmale,
Manzoor Ahmad,
Pinaki Talukdar and
Dilip D. Dhavale

Full Research Paper
Published 14 Oct 2019

PDF
Album
1. Graphical Abstract
2. Figure 1: Oxazolone pseudodipeptide 1 and tetrapeptide 2a.
  
  Jump to Figure 1
3. Scheme 1: Synthesis of linear azido ester dipeptide 5 and tetrapeptide 7.
  
  Jump to Scheme 1
4. Scheme 2: Synthesis of oxazolone pseudopeptides 1, 2a and 2b.
  
  Jump to Scheme 2
5. Figure 2: Characteristic NOEs of 2a.
  
  Jump to Figure 2
6. Figure 3: DMSO titration study of 2a.
  
  Jump to Figure 3
7. Figure 4: ¹H NMR temperature study of 2a.
  
  Jump to Figure 4
8. Figure 5: Optimized helical conformations of (A) 2a, (B) 2b and (C) 9.
  
  Jump to Figure 5
9. Figure 6: Ion transport activity (A) for 1, (B) for 2a, across EYPC-LUVs HPTS.
  
  Jump to Figure 6
10. Figure 7: Cation (A) and anion (B) transport activity of 2a.
  
  Jump to Figure 7
11. Figure 8: Comparison of the ion transport activity of 2a and 2b at 20 µM across EYPC-LUVslucigenin (A). Conce...
  
  Jump to Figure 8
Supp. Info

Beilstein J. Org. Chem. 2019, 15, 2419–2427, doi:10.3762/bjoc.15.234

Full Text

Effect of ring size on photoisomerization properties of stiff stilbene macrocycles

Sandra Olsson,
Óscar Benito Pérez,
Magnus Blom and
Adolf Gogoll

Full Research Paper
Published 11 Oct 2019

PDF
Album
1. Graphical Abstract
2. Scheme 1: The stiff stilbene photoisomerization from Z to E and vice versa by irradiation at 300 nm and 360 n...
  
  Jump to Scheme 1
3. Figure 1: The investigated SS-macrocycles (Z)-1a–d.
  
  Jump to Figure 1
4. Scheme 2: Synthetic route to SS-macrocycles. i. (1) Triflic acid (3 equiv), DCM (dry), Ar atmosphere, MW (110...
  
  Jump to Scheme 2
5. Scheme 3: The photoisomerization of the stiff stilbene macrocycles, showing the stretching of the linker (gre...
  
  Jump to Scheme 3
6. Scheme 4: Noncyclic stiff stilbene diester 7 used as reference in the photoisomerization study.
  
  Jump to Scheme 4
7. Figure 2: The photoisomerization of the SS-macrocycles shows a clear correlation between the Z/E ratio in the...
  
  Jump to Figure 2
8. Figure 3: Gibbs free energy differences (ΔG) between Z- and E-isomers of 1a–d and of the reference compound 7...
  
  Jump to Figure 3
9. Figure 4: Ring strain for E and Z-isomers of 1a–d expressed as the Gibbs free energy difference to an acyclic...
  
  Jump to Figure 4
10. Figure 5: The differences in ring strain between the E- and Z-isomers show an exponential correlation to the ...
  
  Jump to Figure 5
11. Figure 6: Conformer ensembles for the macrocyclic stiff stilbene diethers 1a–d. Dihedral angles between the t...
  
  Jump to Figure 6
12. Figure 7: Distances derived from NOE buildup experiments. Distances between pairs of protons or groups of pro...
  
  Jump to Figure 7
13. Figure 8: Numbering of carbons in compounds 6a–d, showing 6d as an example.
  
  Jump to Figure 8
14. Figure 9: Numbering of carbons in compounds (Z)-1a–d, showing (Z)-1d as an example.
  
  Jump to Figure 9
Supp. Info

Beilstein J. Org. Chem. 2019, 15, 2408–2418, doi:10.3762/bjoc.15.233

Full Text

Reversible switching of arylazopyrazole within a metal–organic cage

Anton I. Hanopolskyi,
Soumen De,
Michał J. Białek,
Yael Diskin-Posner,
Liat Avram,
Moran Feller and
Rafal Klajn

Full Research Paper
Published 10 Oct 2019

PDF
Album
1. Graphical Abstract
2. Scheme 1: Reversible photoisomerization of phenylazotrimethylpyrazole 1.
  
  Jump to Scheme 1
3. Figure 1: ¹H NMR spectrum of (E-1)₂2 (500 MHz, D₂O, 298 K).
  
  Jump to Figure 1
4. Figure 2: Partial ¹H-¹H NOESY NMR spectrum of (E-1)₂2 showing NOE correlations between host 2 and guest 1 (50...
  
  Jump to Figure 2
5. Figure 3: Front view (a) and side view (b) of the X-ray crystal structure of (E-1)₂2 (major conformations of 1...
  
  Jump to Figure 3
6. Figure 4: UV–vis absorption spectrum of an aqueous solution of (E-1)₂2 (blue) and following exposure of this ...
  
  Jump to Figure 4
7. Figure 5: Top view (a) and side view (b) of the energy-optimized structure of (Z-1)2. Color codes: C, gray; N...
  
  Jump to Figure 5
8. Figure 6: A series of ¹H NMR spectra of (E-1)₂2 (500 MHz, D₂O, 298 K) before (bottom) and after exposure to U...
  
  Jump to Figure 6
9. Figure 7: ¹H NMR and ¹H DOSY spectra of (E-1)₂2 (500 MHz, D₂O, 298 K) before (left) and after (center) UV irr...
  
  Jump to Figure 7
10. Figure 8: Palladium-accelerated back-isomerization of Z-1. a) Kinetics of the thermal back-isomerization of Z-...
  
  Jump to Figure 8
Supp. Info

Beilstein J. Org. Chem. 2019, 15, 2398–2407, doi:10.3762/bjoc.15.232

Full Text

In water multicomponent synthesis of low-molecular-mass 4,7-dihydrotetrazolo[1,5-a]pyrimidines

Irina G. Tkachenko,
Sergey A. Komykhov,
Vladimir I. Musatov,
Svitlana V. Shishkina,
Viktoriya V. Dyakonenko,
Vladimir N. Shvets,
Mikhail V. Diachkov,
Valentyn A. Chebanov and
Sergey M. Desenko

Full Research Paper
Published 08 Oct 2019

PDF
Album
1. Graphical Abstract
2. Scheme 1: Three synthetic approaches to dihydrotetrazolo[1,5-a]pyrimidines.
  
  Jump to Scheme 1
3. Scheme 2: Three-component reaction of 1, 7a,b and 8a–d in water.
  
  Jump to Scheme 2
4. Figure 1: Molecular structure of 9a according to X-ray data. Displacement ellipsoids are shown at the 50% pro...
  
  Jump to Figure 1
5. Scheme 3: Three-component reaction of 5-aminotetrazole (1) with formaldehyde (7a) and acetylacetone (10).
  
  Jump to Scheme 3
6. Scheme 4: a) Three-component reaction of 5-aminotetrazole (1) with acetaldehyde (7b) and ethyl 4,4,4-trifluor...
  
  Jump to Scheme 4
Supp. Info

Beilstein J. Org. Chem. 2019, 15, 2390–2397, doi:10.3762/bjoc.15.231

Full Text

Targeted photoswitchable imaging of intracellular glutathione by a photochromic glycosheet sensor

Xianzhi Chai,
Hai-Hao Han,
Yi Zang,
Jia Li,
Xiao-Peng He,
Junji Zhang and
He Tian

Full Research Paper
Published 07 Oct 2019

PDF
Album
1. Graphical Abstract
2. Scheme 1: The structure (A) of reporter Glyco-DTE and working principle (B) of photochromic glycosheet Glyco-...
  
  Jump to Scheme 1
3. Scheme 2: Synthetic route to dithienylethene fluorescence reporters Glyco-DTE and 8o. VcNa: sodium ascorbate.
  
  Jump to Scheme 2
4. Figure 1: Absorption spectral changes (A), absorption fatigue resistance (B), emission spectral changes (C) a...
  
  Jump to Figure 1
5. Figure 2: (A) The absorbance spectrum and (B) high resolution TEM image of 2D MnO₂ nanosheets (1 × 10⁻⁵ g/mL)...
  
  Jump to Figure 2
6. Figure 3: (A) Emission spectral changes of reporter Glyco-DTE (1 × 10⁻⁵ mol/L in PBS buffer, 0.25‰ Triton X-1...
  
  Jump to Figure 3
7. Figure 4: (A) Fluorescence imaging of HepG2 cells and HeLa cells after incubated with reporters Glyco-DTE (20...
  
  Jump to Figure 4
8. Figure 5: (A) Fluorescence imaging of HepG2 cells and HeLa cells after incubated with Glyco-DTE@MnO₂ photochr...
  
  Jump to Figure 5
Supp. Info

Beilstein J. Org. Chem. 2019, 15, 2380–2389, doi:10.3762/bjoc.15.230

Full Text

Excited state dynamics for visible-light sensitization of a photochromic benzil-subsituted phenoxyl-imidazolyl radical complex

Yoichi Kobayashi,
Yukie Mamiya,
Katsuya Mutoh,
Hikaru Sotome,
Masafumi Koga,
Hiroshi Miyasaka and
Jiro Abe

Full Research Paper
Published 04 Oct 2019

PDF
Album
1. Graphical Abstract
2. Scheme 1: Photochromic reaction schemes of (a) PIC and (b) Benzil-PIC.
  
  Jump to Scheme 1
3. Figure 1: Absorption spectra of PIC, benzil, and the two isomers of Benzil-PIC in benzene at 298 K. The inset...
  
  Jump to Figure 1
4. Figure 2: Nanosecond-to-microsecond transient absorption spectra of Benzil-PIC in benzene under (a) argon and...
  
  Jump to Figure 2
5. Figure 3: Femtosecond-to-nanosecond transient absorption spectra of (a) benzil and (b) Benzil-PIC (right) in ...
  
  Jump to Figure 3
6. Figure 4: Phosphorescence spectra of benzil at 77 K and 100 K and that of PIC at 77 K in EPA. A blue solid li...
  
  Jump to Figure 4
7. Figure 5: Energy diagram of the visible-light sensitized photochromic reaction of Benzil-PIC.
  
  Jump to Figure 5
8. Scheme 2: Synthetic procedure of Benzil-PIC (analogous to synthesis of PIC in [24]).
  
  Jump to Scheme 2
Supp. Info

Beilstein J. Org. Chem. 2019, 15, 2369–2379, doi:10.3762/bjoc.15.229

Full Text

Current understanding and biotechnological application of the bacterial diterpene synthase CotB2

Ronja Driller,
Daniel Garbe,
Norbert Mehlmer,
Monika Fuchs,
Keren Raz,
Dan Thomas Major,
Thomas Brück and
Bernhard Loll

Review
Published 02 Oct 2019

PDF
Album
1. Graphical Abstract
2. Figure 1: CotB1 synthesizes geranylgeranyl diphosphate (GGDP) 3 from the substrates dimethylallyl diphosphate...
  
  Jump to Figure 1
3. Figure 2: The bacterial diterpene synthase CotB2^wt·Mg²⁺₃·F-Dola in the closed, active conformation (PDB-ID 6G...
  
  Jump to Figure 2
4. Figure 3: Conformational changes of CotB2 upon ligand binding. Superposition of CotB2’s open (teal), pre-cata...
  
  Jump to Figure 3
5. Figure 4: View into the active site of CotB2^wt·Mg²⁺₃·F-Dola [37] superimposed with CotB2^wt·Mg²⁺_B·GGSDP [36]. (A) The ...
  
  Jump to Figure 4
6. Figure 5: View into the active site of CotB2^wt·Mg²⁺₃·F-Dola [37]. Identical view as in Figure 4. (A) The bound F-Dola rea...
  
  Jump to Figure 5
7. Figure 6: The WXXXXXRY motif in protein sequences of diterpene TPS from different bacteria. Highlighted is th...
  
  Jump to Figure 6
8. Scheme 1: Overview of the altered product portfolio as a result of introduced point mutations in the active s...
  
  Jump to Scheme 1
9. Scheme 2: Catalytic mechanism of CotB2, derived from isotope labeling experiments [34,35], density functional theory...
  
  Jump to Scheme 2
10. Figure 7: (A) The inner surface of the active site is shown in gray. The bound F-Dola reaction intermediate i...
  
  Jump to Figure 7
11. Scheme 3: Variants of CotB2 open the route to a novel product portfolio with altered cyclic carbon skeletons,...
  
  Jump to Scheme 3

Beilstein J. Org. Chem. 2019, 15, 2355–2368, doi:10.3762/bjoc.15.228

Full Text

Mono- and bithiophene-substituted diarylethene photoswitches with emissive open or closed forms

A. Lennart Schleper,
Mariano L. Bossi,
Vladimir N. Belov and
Stefan W. Hell

Full Research Paper
Published 01 Oct 2019

PDF
Album
1. Graphical Abstract
2. Figure 1: Structures of “thiophenylated” DAEs prepared and studied in this work.
  
  Jump to Figure 1
3. Scheme 1: Synthesis routes towards mono- and diiodinated core structures 4, 5, 7, and 8.
  
  Jump to Scheme 1
4. Scheme 2: Synthesis of thiophene- and bithiopheneboronic esters 9 and 12 (bpy – 4,4’-di-tert-butyl-2,2’-dipyr...
  
  Jump to Scheme 2
5. Scheme 3: Photoswitchable diarylethenes AsTh₁, SyTh₁, AsTh₂, SyTh₂, AsOTh₁, SyOTh₁, AsOTh₂, and SyOTh₂ synthe...
  
  Jump to Scheme 3
6. Scheme 4: Saponification of methyl ester groups in tetraester SyTh₂ leading to tetracarboxylic acid SyTh₂-H.
  
  Jump to Scheme 4
7. Figure 2: Absorption (A) and emission (B) spectra of SyTh₂ in acetonitrile in the course of the cyclization r...
  
  Jump to Figure 2
8. Figure 3: Absorption spectra of the OFs (A) and CFs (B) of AsTh₁ (a), SyTh₁ (b), AsTh₂ (c), SyTh₂ (d), AsOTh₁...
  
  Jump to Figure 3
9. Figure 4: Solutions of compounds AsTh₁ (a), SyTh₁ (b), AsTh₂ (c), SyTh₂ (d), AsOTh₁ (e), SyOTh₁ (f), AsOTh₂ (...
  
  Jump to Figure 4
10. Figure 5: Fatigue resistances of compounds SyOTh₁ (A and B) and SyTh₁ (C). Parts A and C show the absorbance ...
  
  Jump to Figure 5
11. Figure 6: (A) Absorption spectra of compound SyOTh₁ in MeCN at the photostationary states under irradiation w...
  
  Jump to Figure 6
Supp. Info

Beilstein J. Org. Chem. 2019, 15, 2344–2354, doi:10.3762/bjoc.15.227

Full Text

Keep Informed