Reaction Of Carbon Atoms Research Articles

Functionalized Amorphous Carbon Materials via Reactive Molecular Dynamics Simulations.

We derive a database of atomistic structural models of amorphous carbon materials endowed with exohedral functional groups. We start from phases previously derived using the DynReaxMas method for reactive molecular dynamics simulations, which exhibit atomistic and medium-length-scale features in excellent agreement with available experimental data. Given a generic input structure/phase, we develop postprocessing simulation algorithms mimicking experimental preparation protocols aimed at: (1) "curing" the phase to decrease the defect concentration; (2) automatically selecting the most reactive carbon atoms via interaction with a probe molecular species, and (3) stabilizing the phase by saturating the valence of carbon atoms with single-bond functional groups. Although we focus on oxygen-bearing functionalities, they can be replaced with other monovalent groups, such as -H, -COOH, -CHO, so that the protocol is quite general. We finally classify reactive sites in terms of their location within the structural framework and coordination environment (edges, tunnels, rings, aromatic carbons becoming aliphatic) and try to single out descriptors that correlate with tendency to functionalization.

M3C2 (Cr3C2 Type) carbides formed in steel

As an authigenic alloy phase, M3C2 (Cr3C2 type) carbide, Cr-rich M3C2 carbide with a simple orthorhombic crystal structure, was confirmed to be present in an 11%Cr ferritic/martensitic steel normalized at 1323 K (1050 °C) for 0.5 h and tempered at 873 K (600 °C) for 1.5 h by transmission electron microscopy. The identified Cr-rich M3C2 carbides were found to be the main phase as the Cr-rich M23C6 and M2C carbides according to the present TEM examination, and to have the following characteristics: irregular block, branch crystal-like and needle-like morphologies; larger sizes ranging from approximately 100 to 350 nm in diameter and approximately 200–470 nm for the length of the long axis of the needles; approximate chemical formula of (Cr0.55Fe0.4W0.05)3C2. The formation mechanism of the M3C2 carbides during the tempering is discussed. The M3C2 carbides may be transformed by the reaction of carbon atoms in the matrix with Cr-rich M7C3 carbides formed in situ from Cr-enriched M3C carbides, which were formed from Fe-rich M3C carbides already present in the normalized steel by the diffusion of Cr solute atoms.

Mechanistic Insight and Intersystem Crossing Dynamics of the C(3P) + H2CO/D2CO Reaction

The reaction of atomic carbon, C(3P), with H2CO has been investigated using the direct dynamics trajectory surface hopping (DDTSH) method with Tully's fewest switches algorithm. The lowest lying ground triplet and single states are considered for the dynamics study at a reagent collision energy of 8.0 kcal/mol. From the trajectory calculations, we observed that CH2 + CO and H + HCCO are the two major product channels for the title reaction. The insertion mechanism of the C(3P) + H2CO reaction is rather complex and is followed by three distinct intermediates with no entrance channel barrier to the reaction on the B3LYP/6-31G(d,p) potential energy surfaces. The triplet insertion complexes are formed by three different approaches; "Sideways", "End-on" and "Head-on" attack of the triplet carbon atom toward H2CO molecule. Our dynamics calculations predict a new product channel (H + HCCO(X 2A'')) with a contribution of ∼46% of the overall products formation via ketocarbene intermediate through "Head-on" approach. Despite the weak spin-orbit coupling (SOC) interactions, intersystem crossing (ISC) via a ketocarbene intermediate has a small but significant contribution, about 2.3%, for the CH2 + CO channel. To understand the kinetic isotope effects on the reaction dynamics, we have extended our study for the C(3P) + D2CO reaction. It is seen that isotopic substitution of both the H atoms has a small reduction in the extent of ISC dynamics for the carbene formation. Our results, certainly, reveal the importance of the ketocarbene intermediate and the H + HCCO products channel as one of the major product formation channels in the title reaction, which was not reported earlier.

Discovery of the cyclic C5H radical in TMC-1

Cyclic C5H (c-C5H), the radical formed by substituting an ethynyl group CCH for the hydrogen atom in thec-C3H radical, has been detected for the first time in the space. Thec-C5H species is an isomer of the well-known linear radicall-C5H and is ∼6 kcal mol−1less stable. A total of 17 rotational transitions were detected for thec-C5H species in TMC-1 within the 31.0–50.3 GHz range using the Yebes 40m radio telescope. We derive a column density of (9.0 ± 0.9) × 1010cm−2forc-C5H. Additionally, we observed 12 lines forl-C5H and derive a column density for it of (1.3 ± 0.3) × 1012cm−2, which results in an abundance ratioc-C5H/l-C5H of 0.069. This is in sharp contrast with the value found for the analogue systemc-C3H/l-C3H, whose ratio is 5.5 in TMC-1. We discuss the formation ofc-C5H and conclude that this radical is probably formed in the reaction of atomic carbon with diacetylene.

Formation of the Elusive Silylenemethyl Radical (HCSiH2; X2B2) via the Unimolecular Decomposition of Triplet Silaethylene (H2CSiH2; a3A″).

We investigated the formation of small organosilicon molecules─potential precursors to silicon-carbide dust grains ejected by dying carbon-rich asymptotic giant branch stars─in the gas phase via the reaction of atomic carbon (C) in its 3P electronic ground state with silane (SiH4; X1A1) using the crossed molecular beams technique. The reactants collided under single collision conditions at a collision energy of 13.0 ± 0.2 kJ mol-1, leading to the formation of the silylenemethyl radical (HCSiH2; X2B2) via the unimolecular decomposition of triplet silaethylene (H2CSiH2; a3A″). The silaethylene radical was formed via hydrogen migration of the triplet silylmethylene (HCSiH3; X3A″) radical, which in turn was identified as the initial collision complex accessed via the barrierless insertion of atomic carbon into the silicon-hydrogen bond of silane. Our results mark the first observation of the silylenemethyl radical, where previously only its thermodynamically more stable methylsilylidyne (CH3Si; X2A″) and methylenesilyl (CH2SiH; X2A') isomers were observed in low-temperature matrices. Considering the abundance of silane and the availability of atomic carbon in carbon-rich circumstellar environments, our results suggest that future astrochemical models should be updated to include contributions from small saturated organosilicon molecules as potential precursors to pure gaseous silicon-carbides and ultimately to silicon-carbide dust.

Molecular engineering of an inverse hexacopper(II) coordination complex with a photoactive metallacyclophane centroligand as prototype of a magnetic photoswitch

A primary goal of molecular spintronics is detecting the response of the spins from a single magnetic molecule to an external stimulus and, eventually, being able to implement logic quantum memory capabilities for information data storage and processing applications in quantum computation. Having this in mind, a novel hexanuclear oxamatocopper(II) complex of formula {[Cu2(naba)2][Cu(pmdien)]4}(ClO4)4·8H2O (2) [naba = N,N'-1,5-naphthalenebis(oxamate) and pmdien = N,N,N’,N”,N”-pentamethyldiethylenetriamine] has been prepared by the reaction of stoichiometric amounts of (nBu4N)4[Cu2(naba)2] · 4H2O (1) (nBu4N+ = tetra-n-butylammonium cation) and [Cu(pmdien)](ClO4)2 (1:4 molar ratio) in water. 2 exhibits a ladder-like “dimer-of-trinuclears” structure featuring a photoactive dicopper(II) naphthalenophane core acting as inverse coordination centre (centroligand) towards four peripheral [Cu(pmdien)]2+ groups through the outer amidate/carboxylate oxygen atoms of the oxamato fragments. 2 undergoes a unique magnetic photoswitching ON/OFF behaviour upon UV light irradiation because of an intramolecular (“pseudo-bimolecular”) photocycloaddition of the two facing naphthalene spacers through the more reactive carbon atoms at the 1,4 and 1’,4’ positions of the benzene rings to afford the putative [4 + 4] cycloaddition product c-2. Hence, the two oxamato-bridged S = 1/2 CuII3 linear units antiferromagnetically coupled within the CuII6 precursor (2, ON state) become magnetically uncoupled in the corresponding [4 + 4] photocycloaddition product (c-2, OFF state) [jeff = –2.13 (2) and 0 cm−1 (c-2); H = – jeffSA.SB with SA = SB = 1/2]. This new example of inverse coordination complex constitutes thus a potential candidate to molecular magnetic photoswitch in the “bottom-up” approach to nanometer-scale spintronic and quantum computing devices.

A crossed molecular beams and computational study on the unusual reactivity of banana bonds of cyclopropane (c-C3H6; ) through insertion by ground state carbon atoms (C(3Pj)).

The mechanism and chemical dynamics of the reaction of ground electronic state atomic carbon C(3Pj) with cyclopropane c-C3H6 have been explored by combining crossed molecular beams experiments with electronic structure calculations of the pertinent triplet C4H6 potential energy surface and statistical computations of product branching ratios under single-collision conditions. The experimental findings suggest that the reaction proceeds via indirect scattering dynamics through triplet C4H6 reaction intermediate(s) leading to C4H5 product(s) plus atomic hydrogen via a tight exit transition state, with the overall reaction exoergicity evaluated as 231 ± 52 kJ mol-1. The calculations indicate that C(3Pj) can easily insert into one of the three equivalent C-C 'banana' bonds of cyclopropane overcoming a low barrier of only 2 kJ mol-1 following the formation of a van der Waals reactant complex stabilized by 15 kJ mol-1. The carbon atom insertion into one of the six C-H bonds is also feasible via a slightly higher barrier of 5 kJ mol-1. These results highlight an unusual reactivity of cyclopropane's banana C-C bonds, which behave more like unsaturated C-C bonds with a π-character than saturated σ C-C bonds, which are known to be generally unreactive toward the ground electronic state atomic carbon such as in ethane (C2H6). The statistical theory predicts the overall product branching ratios at the experimental collision energy as 50% for 1-butyn-4-yl, 33% for 1,3-butadien-2-yl, i-C4H5, and 11% for 1,3-butadien-1-yl, n-C4H5, with i-C4H5 (230 kJ mol-1 below the reactants) favored by the C-C insertion providing the best match with the experimentally observed reaction exoergicity. The C(3Pj) + c-C3H6 reaction is predicted to be a source of C4H5 radicals under the conditions where its low entrance barriers can be overcome, such as in planetary atmospheres or in circumstellar envelopes but not in cold molecular clouds. Both i- and n-C4H5 can further react with acetylene eventually producing the first aromatic ring and hence, the reaction of the atomic carbon with c-C3H6 can be considered as an initial step toward the formation of benzene.

Carbon Atom Reactivity with Amorphous Solid Water: H2O-Catalyzed Formation of H2CO.

We report new computational and experimental evidence of an efficient and astrochemically relevant formation route to formaldehyde (H2CO). This simplest carbonylic compound is central to the formation of complex organics in cold interstellar clouds and is generally regarded to be formed by the hydrogenation of solid-state carbon monoxide. We demonstrate H2CO formation via the reaction of carbon atoms with amorphous solid water. Crucial to our proposed mechanism is a concerted proton transfer catalyzed by the water hydrogen bonding network. Consequently, the reactions 3C + H2O → 3HCOH and 1HCOH → 1H2CO can take place with low or without barriers, contrary to the high-barrier traditional internal hydrogen migration. These low barriers (or the absence thereof) explain the very small kinetic isotope effect in our experiments when comparing the formation of H2CO to D2CO. Our results reconcile the disagreement found in the literature on the reaction route C + H2O → H2CO.

An efficient approach to diarylethene-amino acid photochromic fluorescent hybrids

• An effective approach to creating photo-controlled diarylethene-amino acid hybrids. • X-ray diffraction study, spectral luminescent and photochromic properties. • Thermally and photochemically reversible intramolecular photocyclization. • Dependence of the photoinduced form stability on the structure. • Modulation of emission under successive irradiation with light of different wavelengths. An effective approach to the synthesis of diarylethene-amino acid hybrids DE-Gly, DE-AABA and DE-DAA ( 5a-d - 7-a-d ) was developed via condensation of furan-2,5-dione-based diarylethenes (DE) and ethyl esters of glycine (Gly), α-aminobutyric acid (AABA) and D-aspartic acid (DAA) with moderate to good yields. According to X-ray diffraction data, DE-Gly hybrid 5a exists in an antiparallel conformation with a distance of 4.549 Å between the reactive carbon atoms C(1)-C(11), potentially capable of forming a single bond, which is suitable for the conrotatory photocyclization reaction allowed by the Woodward-Hoffman rules. The structures of the obtained compounds were proved by 1 H, COZY, HSQC, HMBC and 13 C NMR spectroscopy. The hybrids DE-Gly, DE-AABA and DE-DAA absorb at 443–456 nm, which corresponds to their existence in a ring-open form O, and display fluorescence at 531–612 nm. Irradiation with light of 436 nm results in their rearrangement into ring-closed colored nonfluorescent isomers C. Backwards re-opening occurs under the action of visible light (λ > 500 nm). Spectral kinetic investigation of 5a,c revealed that the efficiency of photocyclization, as well as the emission quantum yield, decreases with the growth of solvent polarity. The ring-closed isomer C of sterically hindered 5a (R 2 = R 3 = Me) is stable at room temperature, whereas for 5c (R 3 = H), ring opening readily occurs with the speed increasing with the polarity of the solvent. The internal emission of sterically hindered hybrids 5a, 6a and 7a (R 2 = R 3 = Me) is reversibly modulated in a binary response with good fatigue resistance under successive irradiation with light of 436 and 540 nm.

An Atomistic Study of the Stress Corrosion Cracking in Graphene.

Using molecular dynamics (MD) simulations, we study the mechanism of stress corrosion cracking in graphene. Two sets of modelings are conducted. In the first one, large graphene sheets with cracks in the armchair and zigzag directions are exposed to oxygen molecules. The crack growth as a result of chemical reactions between carbon radicals and oxygen molecules at different mechanical tensile stress levels is studied. In the second set of simulations, MD simulations are combined with the density functional-based tight bonding method to enhance the accuracy. This set of modelings focuses on a smaller zone in the vicinity of the crack tip. The impact of initial crack orientation on corrosion is studied by investigating corrosion of cracks in both armchair and zigzag directions. We investigate the subcritical crack propagation occurring as a result of the combined effects of both mechanical loading and chemical reactions. Our results show that cracks in graphene can grow due to chemical reactions with the environmental molecules. The MD modelings also predict that reaction of carbon atoms with oxygen molecules might lead to a stress relaxation at the crack tip, hence preventing further crack propagation. The results show that subcritical crack growth can happen by two mechanisms, which include the failure of C-C bonds or by removing the carbon atoms from graphene sheets in the form of CO or CO2 molecules.

An “electron lock” toward the photochromic activity of phenylacetylene appended bisthienylethene

Photochromic core structure of BTEs was configured in the design of BT (2,3-Bis(2,5-dimethylthiophen)−5-phenylethynylthiophene) and NT (2,3-Bis(2,5-dimethylthiophen)−5-(4-methoxyphenyl)−1,3-butadiene-1,1,4,4-tetracarbonitrile). BT exhibits regular photochromic behavior in hexane when excited with UV (254 nm) and visible light (>400 nm). The solution can be cycled between pink colors and colorless. Correspondingly, NT, with a more electron-withdrawing group attached, the photochromic reactivity was totally quenched. It is the lowered electron density on reactive carbon atoms in LUMO that influence the photochromism, which is one of the key elements to photochromism. Apart from the distance between reactive atoms, electron distribution on reactive atoms is another important key to the configuration of photochromic dyes.

High adhesion diamond films deposited on stainless steel by using nanocomposite films with mosaic interface as an interlayer

It suffers from poor adhesion to deposit diamond films on steel by using normal metal compound films as an interlayer. Here, high adhesion diamond films were successfully prepared on stainless steel by using Cr/CrSiN nanocomposite film as interlayer. The results show that with Si contents increasing to 10.6 at.%, spikes appear at the interface between diamond films and interlayer, exhibiting high adhesion with hardness increasing to 80 GPa. With Si contents further increasing to 15.5 at.%, the spikes disappear and diamond film peels off even though its hardness still keeps 62 GPa. This indicates that spikes, composed of Cr-C compounds, supply mosaic structure and mechanical lock effects to improve the adhesion. The spikes’ composition means that carbon atoms react with Cr/CrNx crystals in interlayer during HFCVD. Under lower Si contents, amorphous SiNx/Si phases are few, Cr/CrNx crystals can easily react with carbon atoms via different velocities, causing the co-existence of longer and shorter Cr-C phase to form the spikes. As Si content increases, more amorphous phases envelop the crystals, limiting the reaction of carbon atoms with Cr/CrNx crystals, so the spikes disappear. This supplies a way to control the adhesion of diamond films by adjusting Si contents to produce different interface structures.

Understand the Specific Regio- and Enantioselectivity of Fluostatin Conjugation in the Post-Biosynthesis.

Fluostatins, benzofluorene-containing aromatic polyketides in the atypical angucycline family, conjugate into dimeric and even trimeric compounds in the post-biosynthesis. The formation of the C–C bond involves a non-enzymatic stereospecific coupling reaction. In this work, the unusual regio- and enantioselectivities were rationalized by density functional theory calculations with the M06-2X (SMD, water)/6–311 + G(d,p)//6–31G(d) method. These DFT calculations reproduce the lowest energy C1-(R)-C10′-(S) coupling pathway observed in a nonenzymatic reaction. Bonding of the reactive carbon atoms (C1 and C10′) of the two reactant molecules maximizes the HOMO–LUMO interactions and Fukui function involving the highest occupied molecular orbital (HOMO) of nucleophile p-QM and lowest unoccupied molecular orbital (LUMO) of electrophile FST2− anion. In particular, the significant π–π stacking interactions of the low-energy pre-reaction state are retained in the lowest energy pathway for C–C coupling. The distortion/interaction–activation strain analysis indicates that the transition state (TScp-I) of the lowest energy pathway involves the highest stabilizing interactions and small distortion among all possible C–C coupling reactions. One of the two chiral centers generated in this step is lost upon aromatization of the phenol ring in the final difluostatin products. Thus, the π–π stacking interactions between the fluostatin 6-5-6 aromatic ring system play a critical role in the stereoselectivity of the nonenzymatic fluostatin conjugation.

A cryogenic ice setup to simulate carbon atom reactions in interstellar ices.

The design, implementation, and performance of a customized carbon atom beam source for the purpose of investigating solid-state reaction routes in interstellar ices in molecular clouds are discussed. The source is integrated into an existing ultrahigh vacuum setup, SURFace REaction SImulation DEvice (SURFRESIDE2), which extends this double atom (H/D, O, and N) beamline apparatus with a third atom (C) beamline to a unique system that is fully suited to explore complex organic molecule solid-state formation under representative interstellar cloud conditions. The parameter space for this system is discussed, which includes the flux of the carbon atoms hitting the ice sample, their temperature, and the potential impact of temperature on ice reactions. Much effort has been put into constraining the beam size to within the limits of the sample size with the aim of reducing carbon pollution inside the setup. How the C-atom beam performs is quantitatively studied through the example experiment, C + 18O2, and supported by computationally derived activation barriers. The potential for this source to study the solid-state formation of interstellar complex organic molecules through C-atom reactions is discussed.

Formation of CN Radical from Nitrogen and Carbon Condensation and from Photodissociation in Femtosecond Laser-Induced Plasmas: Time-Resolved FT-UV-Vis Spectroscopic Study of the Violet Emission of CN Radical.

Exploring the formation of diatomic radicals in femtosecond plasmas is important to establish the most dominant kinetic pathways following ionization and dissociation of small molecules. In this work, cyano radical formation has been studied from bromoform, acetonitrile, and methanol in nitrogen and argon plasmas created with a focused femtosecond laser beam operating at 100 kHz repetition rate and 1030 nm wavelength with 43 fs pulse length and 250 μJ pulse energy. Time-resolved Fourier transform fluorescence spectroscopy was applied in the ultraviolet-visible (UV-vis) spectral range for the characterization of the rotational and vibrational temperatures of the CN(B) radicals via fitting the experimental data. The high repetition rate of the laser allows efficient coupling with the step-scan Fourier transform spectroscopy method. Coulomb explosion at the very high intensity (∼1016 W/cm2) resulted in the formation of nascent atoms, ions, and electrons. The condensation reactions of carbon and reactive nitrogen species resulted in the formation of CN(B2Σ+) radicals and C2(d3Πg) dicarbon molecules/radicals. The CN(B) radicals were formed at the highest concentration in the case of bromoform because the weak carbon-bromine bonds resulted in reactive carbon atoms and CH radicals, which are reactive precursors for the CN(B) radical formation. In the case of acetonitrile, immediate production of CN(B) is observed with nanosecond resolution, which suggests that the CN is formed either via photodetachment or via roaming reaction associated with the Coulomb explosion of the parent molecule. The nascent rotational temperature was very high (∼6000-8500 K) and rapidly decreased in all instances within 40 ns with bromoform and acetonitrile. The highest vibrational temperature (∼7800 K) was observed in an acetonitrile/Ar mixture that decreased in about 30 ns and then increased in the observed time window. The vibrational temperature increased in all samples between 30 and 200 ns. The time dependence of fluorescence is described with a monoexponential decay in the case of acetonitrile/Ar and with biexponential decays in all other instances in the 0-250 mbar total pressure range. The shorter time constant is close to the radiative lifetime of CN(B) emission (∼60-80 ns), which can be attributed to the CN(B) radicals produced in the first few collisions at lower pressures. The longer CN(B) emission is from CN(B) created by slower chemical reactions involving carbon atoms, C2 radicals, and reactive nitrogen-containing species.

Molecular Dynamics Investigation of the Physical Binding of the NNK Diazonium Ion to TP53 exon 5

The diazonium ion metabolite of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is a strong carcinogen found in tobacco smoke. NNK diazonium ion has been shown to damage DNA through the formation of pyridyloxobutyl (POB) adducts. The current study focuses on the physical interaction of a tumor suppressor gene (TP 53, exon 5) with NNK diazonium ion. TP53 is mutated in nearly 50% of all human tumors and 40% of lung cancer cases. Our work explores the physical interactions that precede bond formation. Density functional theory was used to generate improved force field parameters for the diazonium ion. Molecular dynamics simulations were performed on two systems: NNK diazonium ion and TP53/NNK diazonium ion. Results of the MD simulations that will be presented include an analysis of the various conformations NNK diazonium ion explores and distances of its reactive carbon atoms to reactive atoms of TP53 bases. This will provide insight into the possible reaction mechanism of POB adduct formation.

Photochromic reactivity induced by electron distribution: active or inactive

Photochromic core structure, triangle terthiophene, is configured to the design of 2,3-Bis(2,5-dimethylthiophen)-5-methoxyphenylethynylthiophene (PT) and 2,3-Bis(2,5-dimethylthiophen)-5-(4-methoxyphenyl)-1,3-butadiene-1,1,4,4-tetracarbonitrile(MPT) and characterized by NMR and HRMS technology. The photochromic behavior is investigated in typical solvents. With PT in hexane, reversibly photochromic process is induced by alternative irradiation of UV and Visible light. The solution color of PT can be toggled between colorless and pink, forming a switch cycle. In chloroform, the photochromic wavelength moves to shorter wavelength side. For MPT, UV light induced photochromism is not observed. Due to the addition of tetracarbonitrile, its strong electron-withdrawing character significantly lowers the electron density on reactive carbon atoms in LUMO, which is one of the key elements to support the photoactive of photochromism. Therefore, the molecular configuration of electron distribution is important to the design of photochromic dyes.

Theoretical Calculation of Products Distribution in the Reaction of Atomic Carbon with Pyridine

The elementary reaction of atomic carbon C(3P) with pyridine C5H5N is studied using quantum-mechanical calculations of the electronic structure and statistical calculations on the potential energy surface of the C6H5N triplet state. At least two most probable reaction ways associated with hydrogen atom abstraction reaction are revealed. The important role of the molecular fragmentation channel, including acetylene C2H2 molecule abstraction, is also shown.

Spectral properties and structure of unsymmetrical diarylethenes based on thiazole ring with hydrogen at the reactive carbon

Six new photoactive unsymmetrical diarylethenes bearing thiazole ring with hydrogen at the reactive carbon atom have been synthesized. Their structures have been studied by DFT calculations and X-ray crystallography. All compounds undergo irreversible photochemical transformations under irradiation with ultraviolet light, proceeding through the photocyclization stage. It has been found that only some normal (thiophene, imidazole and pyrazole derivatives) and inverse type (oxazole derivative) diarylethenes form colored photoinduced isomers under UV. In polar acetonitrile these intermediates show relatively fast irreversible thermal reaction, while in nonpolar toluene slow cycloreversion to initial diarylethenes is the predominant process of these species.

Photochromic behavior of triangle trithiophene with π-extension at the bridge unit

ABSTRACTA photochromic triangle terthiophene with phenylethynyl attached was synthesized under Sonogashira coupling condition and fully characterized. The photochromic behavior was investigated in typical solvents. In hexane, the reversibly photochromic process was induced by UV and Visible light. The solution color could be toggled between colorless and pink color. The photo- and thermo-stability were also investigated at 273 and 323 K. It is stable in the dark at the room temperature, while the degradation accelerated with the temperature rising. Correspondingly, the optimized geometry structure and frontier molecular orbitals were calculated. Both the distance between reactive carbon atoms and the HOMO distribution of ring-open form support the photo-cyclization reaction.