1080-16-6

Basic information

• Product Name: (Z)-Azobenzene
• Synonyms: (Z)-Azobenzene;cis-Azobenzene;syn-Azobenzene
• CAS NO: 1080-16-6
• Molecular Formula: C₁₂H₁₀N₂
• Molecular Weight: 182.22
• Mol File: 1080-16-6.mol
• Article Data: 60

Chemical Properties

• Melting Point: 71°C
• Boiling Point: 305.62°C (rough estimate)
• Appearance: /
• Density: 1.1485 (rough estimate)
• Refractive Index: 1.6266 (estimate)
• CAS DataBase Reference: (Z)-Azobenzene(CAS DataBase Reference)
• NIST Chemistry Reference: (Z)-Azobenzene(1080-16-6)
• EPA Substance Registry System: (Z)-Azobenzene(1080-16-6)

Safety Data

• Hazardous Substances Data: 1080-16-6(Hazardous Substances Data)

Usage

General Description

(Z)-Azobenzene is a chemical compound that consists of a benzene ring with two nitrogen atoms connecting two phenyl groups. It exists as a yellow to orange solid at room temperature and is insoluble in water but soluble in organic solvents. (Z)-Azobenzene is mainly known for its use in the production of dyes and pigments due to its ability to undergo photoisomerization, or the process of converting from one isomer to another upon exposure to light. This property makes it valuable in the creation of photochromic materials and as a key component in the development of liquid crystals and molecular switches. Additionally, (Z)-Azobenzene is also studied for its potential application in the field of molecular electronics and as a building block in the synthesis of complex organic molecules.

Upstream product

• 64-19-7 acetic acid 
• 17082-12-1 trans-azobenzene 
• 50-00-0 formaldehyd 
• 122-66-7 diphenyl hydrazine 
• 74586-02-0 phenylnitrene anion radical 
• 622-37-7 Phenyl azide 
• 123703-80-0 C₈₄H₈₀N₈O₈ 
• 1227476-15-4 Azobenzene 
• 100-58-3 phenylmagnesium bromide 
• 62-53-3 aniline 
• 109-89-7 diethylamine 
• 71-43-2 benzene 
• 110-54-3 hexane 

Downstream Products

• 17082-12-1 trans-azobenzene 
• 1014-72-8 1-phenyl-3,3-diethylurea 
• 17685-52-8 triiron dodecarbonyl 
• 32490-61-2 (diiron)(carbonyl)6(μ-o-semidine) 
• 18716-94-4 (μ-ortho-semidinato)Fe2(CO)6 
• 122821-63-0 (CH₃)(OCH₃)C(C₆H₅)N(C₆H₅)NCr(CO)5 
• 10183-82-1 N-phenylfluorenimine 
• 134358-84-2 (CO)5W(C₆H₅NC(OCH₃)CH₃) 
• 118070-62-5 (CO)5WN(C₆H₅)N(C₆H₅)C(CH₃)(OCH₃) 
• 55504-04-6 methyl N-phenylacetimidate 
• 141556-58-3 N-Phenyl-4-trifluoromethyl-benzimidic acid methyl ester 

Relevant articles and documents

Cis ->/<- Trans Photoisomerization of Azobenzene-Cyclodextrin Inclusion Complexes

trans- and cis-azobenzene form with α-, β-, and γ-cyclodextrin inclusion complexes which can be evidenced by UV and induced circular dichroism spectra.The inclusion in the cyclodextrin cavity has different consequences on the photoreactivity of the two is

Concentration dependent photodimerization of azobenzenes in solution

Cis-trans photoisomerization of azobenzenes in higher concentrations proceeds through a bimolecular reaction process, probably involving the dimer biradical intermediates, in competition with a unimolecular isomerization process, which is the predominant reaction in lower concentrations.

Structure-Correlation NMR Spectroscopy for Macromolecules Using Repeated Bidirectional Photoisomerization of Azobenzene

Control over macromolecular structure offers bright potentials for manipulation of macromolecular functions. We here present structure-correlation NMR spectroscopy to analyze the correlation between polymorphic macromolecular structures driven by photoisomerization of azobenzene. The structural conversion of azobenzene was induced within the mixing time of a NOESY experiment using a colored light source, and the reverse structural conversion was induced during the relaxation delay using a light source of another color. The correlation spectrum between trans- and cis-azobenzene was then obtained. To maximize the efficiency of the bidirectional photoisomerization of azobenzene-containing macromolecules, we developed a novel light-irradiation NMR sample tube and method for irradiating target molecules in an NMR radio frequency (rf) coil. When this sample tube was used for photoisomerization of an azobenzene derivative at a concentration of 0.2 mM, data collection with reasonable sensitivity applicable to macromolecules was achieved. We performed isomerization of an azobenzene-cross-linked peptide within the mixing time of a NOESY experiment that produced cross-peaks between helix and random-coil forms of the peptide. Thus, these results indicate that macromolecular structure manipulation can be incorporated into an NMR pulse sequence using an azobenzene derivative and irradiation with light of two types of wavelengths, providing a new method for structural analysis of metastable states of macromolecules.

Toward photoswitchable dendritic hosts. Interaction between azobenzene- functionalized dendrimers and eosin

Two poly(propyleneimine) dendrimers bearing up to 32 photoisomerizable azobenzene groups in the periphery have been used as potential hosts for eosin Y (2',4',5',7'-tetrabromofluorescein dianion). The all-E azobenzene dendrimers can be reversibly switched

Azobenzene-bridged calix[8]arenes

An azobenzene bridge was introduced into the lower (or smaller) rim of p-tert-butylcalix[8]arene (1) and 1,5-calix[8]crown-3 (2) to form 1,4-singly bridged (3) and 1,5:3,7-doubly bridged (4) calix[8]arene derivatives, respectively. Trans and cis isomers o

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Photoinduced Trans-to-cis Phase Transition of Polycrystalline Azobenzene at Low Irradiance Occurs in the Solid State

The ability to produce large-scale, reversible structural changes in a variety of materials by photoexcitation of a wide variety of azobenzene derivatives has been recognized for almost two decades. Because photoexcitation of trans-azobenzene produces the cis-isomer in solution, it has generally been inferred that the macroscopic structural changes occurring in materials are also initiated by a similar large-amplitude trans-to-cis isomerization. This work provides the first demonstration that a trans-to-cis photoisomerization occurs in polycrystalline azobenzene, and is consistent with the previously hypothesized nature of the trigger in the photoactuated mechanisms of the materials in question. It is also demonstrated that under low irradiance, trans-to-cis isomerization occurs in the solid (not via a pre-melted phase); and the presence of the cis-isomer thus lowers the melting point of the sample, providing a liquid phase. A variety of experimental techniques were employed, including X-ray diffraction measurements of polycrystalline azobenzene during exposure to laser irradiation and fluorescence measurements of the solid sample. A practical consequence of this work is that it establishes trans-azobenzene as an easily obtainable and well-defined control for monitoring photoinduced structural changes in X-ray diffraction experiments, using easily accessible laser wavelengths.

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Photoisomerization of azobenzenes isolated in cryogenic matrices

2,2′-Dihydroxyazobenzene (DAB), 2,2′-azotoluene (AT) and azobenzene (AB) were isolated in argon and xenon matrices and their molecular structures and photochemical transformations were characterized by infrared spectroscopy and theoretical calculations. A

Reversible photoisomerisability and particle size changes of mill-dispersed azobenzene crystals in water

Azobenzene crystals exhibited E/Z photoisomerisability at a level of ca. 30%, accompanied by particle size changes, when they were milled in water to fabricate submicron-sized particles.

Role of Solvent and Effect of Substituent on Azobenzene Isomerization by Using Room-Temperature Ionic Liquids as Reaction Media

The effects of a para substituent, as the electron-donating -OCH3 and -OtBu groups and the electron-withdrawing -Br and -F atoms, on azobenzene isomerization have been investigated in a series of imidazolium ionic liquids (BMIM PF6,

Photoisomerization quantum yield of azobenzene-modified DNA depends on local sequence

Photoswitch-modified DNA is being studied for applications including light-harvesting molecular motors, photocontrolled drug delivery, gene regulation, and optically mediated assembly of plasmonic metal nanoparticles in DNA-hybridization assays. We study

Azobenzene: a Visible-Light Chemical Actinometer for the Characterization of Fluidic Photosystems

(E)-Azobenzene is introduced as a suitable chemical actinometer in the visible spectral range (440–540 nm) for photon flux determination of fluidic microphotoreactors or for assessing efficiency of visible light photo-induced reactions, its evaluation is straightforward without tedious analytics. Photoisomerization quantum yields (ΦE→Z) of (E)-azobenzene were accurately determined upon irradiation at several wavelengths and in different solvents based on well-known diarylethene.

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Guest-to-host transmission of structural changes for stimuli-responsive adsorption property

We show that structural changes of a guest molecule can trigger structural transformations of a crystalline host framework. Azobenzene was introduced into a flexible porous coordination polymer (PCP), and cis/trans isomerizations of the guest azobenzene b

Dynamic internal cavities of dendrimers as constrained media. A study of photochemical isomerizations of stilbene and azobenzene using poly(alkyl aryl ether) dendrimers

Dendritic microenvironments defined by dynamic internal cavities of a dendrimer were probed through geometric isomerization of stilbene and azobenzene. A third-generation poly(alkyl aryl ether) dendrimer with hydrophilic exterior and hydrophobic interior was used as a reaction cavity in aqueous medium. The dynamic inner cavity sizes were varied by utilizing alkyl linkers that connect the branch junctures from ethyl to n-pentyl moiety (C 2G3-C5G3). Dendrimers constituted with n-pentyl linker were found to afford higher solubilitiesof stilbene and azobenzene. Direct irradiation of trans-stilbene showed that C5G3 and C4G3 dendrimers afforded considerable phenanthrene formation, in addition to cis-stilbene, whereas C3G3 and C2G3 gave only cis-stilbene. An electron-transfer sensitized trans-cis isomerization, using cresyl violet perchlorate as the sensitizer, also led to similar results. Thermal isomerization of cis-azobenzene to trans-azobenzene within dendritic microenvironments revealed that the activation energy of the cis- to trans-isomer was increasing in the series C5G3 4G3 3G3 2G3. With the change in the alkyl linker from C5 to C2, significant changes in the activation parameters were observed.

In Situ Observation of Photoswitching by NMR Spectroscopy: A Photochemical Analogue to the Exchange Spectroscopy Experiment

We present 1D and 2D NMR experiments that provide in situ insights into photoinduced isomerizations. Irradiation during the mixing period of an exchange spectroscopy (EXSY) experiment leads to characteristic cross peaks in 2D spectra. The phototriggered e

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Computational Design and Synthesis of a Deeply Red-Shifted and Bistable Azobenzene

We computationally dissected the electronic and geometrical influences of ortho-chlorinated azobenzenes on their photophysical properties. X-ray analysis provided the insight that trans-tetra-ortho-chloro azobenzene is conformationally flexible and thus subject to molecular motions. This allows the photoswitch to adopt a range of red-shifted geometries, which account for the extended n → π? band tails. On the basis of our results, we designed the di-ortho-fluoro di-ortho-chloro (dfdc) azobenzene and provided computational evidence for the superiority of this substitution pattern to tetra-ortho-chloro azobenzene. Thereafter, we synthesized dfdc azobenzene by ortho-chlorination via 2-fold C-H activation and experimentally confirmed its structural and photophysical properties through UV-vis, NMR, and X-ray analyses. The advantages include near-bistable isomers and an increased separation of the n → π? bands between the trans- and cis-conformations, which allows for the generation of unusually high levels of the cis-isomer by irradiation with green/yellow light as well as red light within the biooptical window.