Ring-shaped Molecules Research Articles

Development of a scalable recombinant system for cyclic beta-1,2-glucans production

BackgroundCyclic β-1,2-glucans (CβG) are bacterial cyclic homopolysaccharides with interesting biotechnological applications. These ring-shaped molecules have a hydrophilic surface that confers high solubility and a hydrophobic cavity able to include poorly soluble molecules. Several studies demonstrate that CβG and many derivatives can be applied in drug solubilization and stabilization, enantiomer separation, catalysis, synthesis of nanomaterials and even as immunomodulators, suggesting these molecules have great potential for their industrial and commercial exploitation. Nowadays, there is no method to produce CβG by chemical synthesis and bacteria that synthesize them are slow-growing or even pathogenic, which makes the scaling up of the process difficult and expensive. Therefore, scalable production and purification methods are needed to afford the demand and expand the repertoire of applications of CβG.ResultsWe present the production of CβG in specially designed E. coli strains by means of the deletion of intrinsic polysaccharide biosynthetic genes and the heterologous expression of enzymes involved in CβG synthesis, transport and succinilation. These strains produce different types of CβG: unsubstituted CβG, anionic CβG and CβG of high size. Unsubstituted CβG with a degree of polymerization of 17 to 24 glucoses were produced and secreted to the culture medium by one of the strains. Through high cell density culture (HCDC) of that strain we were able to produce 4,5 g of pure unsubstituted CβG /L in culture medium within 48 h culture.ConclusionsWe have developed a new recombinant bacterial system for the synthesis of cyclic β-1,2-glucans, expanding the use of bacteria as a platform for the production of new polysaccharides with biotechnological applications. This new approach allowed us to produce CβG in E. coli with high yields and the highest volumetric productivity reported to date. We expect this new highly scalable system facilitates CβG availability for further research and the widespread use of these promising molecules across many application fields.

Inverse Optically-Induced Ring Currents in Ring-Shaped Molecules.

Permanent electronic ring currents are supported within manifolds of ΓE degenerate excited electronic states as E± = Ex ± iEy excitations. In [ Phys. Rev. Res. 2021, 3, L042003] we showed the existence of inverse-current manifolds, where the direction of the electronic ring current in each degenerate state E± is opposite to the circular polarization of the generating light fields. This vibronic effect is caused by the exchange of orbital angular momentum between the electrons and the vibrational modes with the required symmetry. Here we consider the case of fixed nuclei and find that ring-shaped molecular systems possess inverse-current manifolds on a purely electronic-structure basis, i.e., without intervention of vibronic coupling. The effect is explained first on a tight-binding model with cyclic symmetry and then considering the ab initio electronic structure of benzene and sym-triazine. A framework for discriminating regular- and inverse-current ΓE manifolds in molecules using quantum chemistry calculations is provided.

Heterometallic Molecular Complexes Act as Messenger Building Units to Encode Desired Metal-Atom Combinations to Multivariate Metal-Organic Frameworks.

A novel synthetic approach is described for the targeted preparation of multivariate metal–organic frameworks (MTV-MOFs) with specific combinations of metal elements. This methodology is based on the use of molecular complexes that already comprise desired metal-atom combinations, as building units for the MTV-MOF synthesis. These units are transformed into the MOF structural constituents through a ligand/linker exchange process that involves structural modifications while preserving their originally encoded atomic combination. Thus, through the use of heterometallic ring-shaped molecules combining gallium and nickel or cobalt, we have obtained MOFs with identical combinations of the metal elements, now incorporated in the rod-shaped secondary building unit, as confirmed with a combination of X-ray and electron diffraction, electron microscopy, and X-ray absorption spectroscopy techniques.

Электронная зонная структура, распределение зарядовой плотности и химическая связь в молекулярных кристаллах халькогенов

The electronic band structure and the charge density distribution are theoretically studied in rhombohedral and monoclinic selenium, rhombohedral and orthorhombic sulphur with the aim to classify types of chemical bonding in molecular crystals of chalcogens. It is found that valence s- and lower in energy p-electrons contribute mainly in covalent bonds between nearest neighboring atoms in ring-shaped molecules, while all types of valence p-electrons provide bonding between rings of atoms in crystals. Parameters of critical points and the character of the charge density distribution in their vicinity point to coexistence of a number of types of chemical bonding in molecular crystals of Se and S: covalent, semimetallic and one more type, characterizing by the charge density fluctuations. Van der Waals forces, being important for finding equilibrium lattice parameters, have little impact on the charge density distribution and on the chemical bonding in crystals of chalcogens.

Electronic band structure, charge density distribution and chemical bonding in molecular crystals of chalcogens

The electronic band structure and the charge density distribution are theoretically studied in rhombohedral and monoclinic selenium, rhombohedral and orthorhombic sulphur with the aim to classify types of chemical bonding in molecular crystals of chalcogens. It is found that valence s- and lower in energy p-electrons contribute mainly in covalent bonds between nearest neighboring atoms in ring-shaped molecules, while all types of valence p-electrons provide bonding between rings of atoms in crystals. Parameters of critical points and the character of the charge density distribution in their vicinity point to coexistence of a number of types of chemical bonding in molecular crystals of Se and S: covalent, semimetallic and one more type, characterizing by the charge density fluctuations. Van der Waals forces, being important for finding equilibrium lattice parameters, have little impact on the charge density distribution and on the chemical bonding in crystals of chalcogens. Keywords: chalcogens, molecular crystals, electronic band structure, types of chemical bonding.

Scratch Properties of Clear Coat for Automotive Coating Comprising Molecular Necklace Crosslinkers with Silane Functional Groups for Various Environmental Factors

Automotive coatings, which comprise multiple layers, i.e., primer, base coating, and clear coat layers, are exposed to various environmental conditions that pose various types of damages to them. In particular, the outer layer of the automotive coating, i.e., the clear coat, is affected significantly by such damages. Therefore, a reliable and durable clear coat must be developed to improve the appearance of automobiles. In this study, a new clear coat based on an acrylic-based clear coat modified using polyrotaxane crosslinkers, which are necklace-shaped supramolecules composed of ring-shaped host molecules, is developed and characterized. The effects of polyrotaxane and silane on the scratch properties and mechanisms of the clear coating are analyzed. It is observed that the critical loads of the clear coat from scratch tests can be improved by adding optimal molecular necklace crosslinkers comprising silane functional groups. The improvement in the scratch properties of the modified acrylic-based clear coat may be attributed to the crosslinking characteristics and dynamic molecular movements of the polyrotaxane. In addition, the effects of environmental factors on the scratch characteristics of the modified acrylic-based clear coat are investigated by addressing the scratch durability of the clear coat.

Dynamical Jahn-Teller effects on the generation of electronic ring currents by circularly polarized light

The generation of electronic ring currents in ring-shaped molecules by photo-excitation with circularly polarized laser light is considered in the presence of vibronic coupling effects. $(E\times e)$ Jahn-Teller distortions, unavoidable by symmetry in the $(E)$ subset of electronic states supporting the ring current, mix the clockwise and anti-clockwise circulation directions of the electrons and can suppress the maximum achievable current by at least one order of magnitude, already for moderate vibronic coupling strengths, as compared to the Born-Oppenheimer limit of fixed atomic positions. The circulation direction of the electrons is found to depend on the spectral region of the $(E\times e)$ Hamiltonian. This fact results in the surprising effect that the same polarization direction of the laser pulse can trigger either clockwise or anti-clockwise electronic dynamics depending on the wavelength of the photons. These findings are illustrated in a model of the triazine molecule.

Atomic force microscope observation of athletes' hemoglobin imaging

Hemoglobin (Hb) is a protein and its functional form has a tetrameric structure. This structure is the result of a combination of four sub-units called globin and indicates the dynamic interaction between them. Each subunit has a ring-shaped organic molecule called a heme that contains an iron atom; Heme is a group that mediates the reversible binding of oxygen by hemoglobin. This research was performed to observe the image of Hb by an atomic force microscope (AFM) and measure the physical function of athletes. For this purpose, based on the principle of AFM imaging, the hemoglobin crosslinking method was used to measure the morphology and size of cross-linked Hb, glutaraldehyde and Hb diameter were detected to prepare cross-linked Hb samples with different molar ratio, the activity of peroxidase was detected by Trinder reaction. The AFM was used to detect the influence of physiological environment changes such as pH, temperature, oxygen partial pressure and osmotic pressure on the absorption spectrum of Hb imaging. Results showed that the size of the uncrosslinked Hb was 6.64 nm. With the increase of the molar ratio of glutaraldehyde to Hb, the number of Hb molecules involved in the crosslinking increased, and the molecular size increased. During the crosslinking process, the aggregation of the cross-linked molecules would make the particle size of some Hb molecules reach 80-100 nm. The peak height, peak position and peak shape of the characteristic absorption peaks of pH to hemoglobin at 550 and 589 nm occurred. When the temperature changes continuously in the range of 30-55℃, the peak height of Hb absorption spectrum of normal red blood cells at 550 nm and 589 nm decreases gradually with the increase of temperature, and the peak shape at 610 nm changes obviously at 42℃, which indicates that the molecular structure of Hb changes; the absorption spectrum curve of deoxygenation disappears at 500 nm, the oxygen-binding capacity of Hb is very low, and the oxygen affinity and oxygenated hemoglobin are low (The concentration of HbO2) decreased, the osmotic pressure increased, the RBC dehydrated, the volume decreased, and the concentration of Hb increased. Conclusion: It is more accurate and comprehensive to use AFM to observe athletes' hemoglobin.

A ring-shaped protein clusters gold nanoparticles acting as molecular scaffold for plasmonic surfaces

BackgroundProteins are efficient supramolecular scaffolds to drive self-assembly of nanomaterials into regular colloidal structures suitable for several purposes, including cell imaging and drug delivery. Proteins, in particular, can bind to gold nanoparticles (AuNPs) through van der Waals and electrostatic forces as well as coordination and hydrogen bonds leading their assembly into responsive nanostructures. MethodsBioconjugation of alkyne Raman tag-labeled 20 nm AuNPs with the ring-shaped protein Peroxiredoxin (Prx), characterized by a symmetric homo-oligomeric circular arrangement, has been investigated by absorption spectroscopy, transmission and scanning electron microscopy. The plasmonic behavior of the resulting hybrid assemblies has been assessed by Surface Enhanced Raman Scattering (SERS). ResultsThe ring-shaped Prx molecules are demonstrated to adsorb onto the gold surface acting as “sticky” bio-linkers between adjacent nanoparticles to drive self-assembly into small colloidal AuNPs arrays. The arrays show nanometric interparticle gaps tailored by the protein ring thickness. The arrays exhibit improved optical activity due to SERS allowing detection of the Raman signals from both the protein and alkyne molecules. ConclusionsThis method can be used to build up SERS-active nanostructures using Prx as both a bio-linker and platform for attaching dyes, two-dimensional materials, such as graphene, and other biomolecules including DNA and enzymes. General significanceThe development of colloidal SERS nanostructures is considered a significant step forward in spectroscopic bioanalysis. Though protein-tailored nanofabrication is in a childhood stage, these results demonstrate the versatility of supramolecular proteins as tools to build-up nanostructures which are still impractical to obtain through top-down techniques.

Diverse Transport Behaviors in Cyclo[18]carbon-Based Molecular Devices.

Scientists have been trying to synthesize ring-shaped pure carbon molecules for a half century. A breakthrough was made recently, and cyclo[18]carbon (C18) was produced successfully by bonding an 18-atom ring of carbon. Because of its potential application in molecular devices, it is natural and timely to study the transport behaviors of C18. Here we report the electron transport properties of the C18-ring connected to various electrodes, including 1D carbon chain, 2D graphene, and 3D silver electrodes, using density-functional theory combined with the nonequilibrium Green's function technique. Diverse transport behaviors are found for the C18 molecular devices, including an Ohmic characteristic, a quasi Schottky feature, and a current-limiting function. The origin and mechanism of unique nonlinear I-V characteristics are investigated by the transmission pathway, transmission spectra, density of states, and molecular frontier orbital theory. This study provides a theoretical guide for exploring the next-generation molecular devices based on this newcomer to the family of carbon allotropes.

Protective effects of beta-cyclodextrins vs. zearalenone-induced toxicity in HeLa cells and Tg(vtg1:mCherry) zebrafish embryos

Zearalenone is a xenoestrogenic mycotoxin produced by Fusarium species. High exposure with zearalenone induces reproductive disorders worldwide. Cyclodextrins are ring-shaped host molecules built up from glucose units. The apolar cavity of cyclodextrins can entrap so-called guest molecules. The formation of highly stable host-guest type complexes with cyclodextrins can decrease the biological effect of the guest molecule. Therefore, cyclodextrins may be suitable to decrease the toxicity of some xenobiotics even after the exposure. In this study, the protective effect of beta-cyclodextrins against zearalenone-induced toxicity was investigated in HeLa cells and zebrafish embryos. Fluorescence spectroscopic studies demonstrated the formation of stable complexes of zearalenone with sulfobutyl-, methyl-, and succinyl-methyl-substituted beta-cyclodextrins at pH 7.4 (K = 1.4–4.7 × 104 L/mol). These chemically modified cyclodextrins considerably decreased or even abolished the zearalenone-induced loss of cell viability in HeLa cells and mortality in zebrafish embryos. Furthermore, the sublethal effects of zearalenone were also significantly alleviated by the co-treatment with beta-cyclodextrins. To test the estrogenic effect of the mycotoxin, a transgenic bioindicator zebrafish model (Tg(vtg1:mCherry)) was also applied. Our results suggest that the zearalenone-induced vitellogenin production is partly suppressed by the hepatotoxicity of zearalenone in zebrafish. This study demonstrates that the formation of stable zearalenone-cyclodextrin complexes can strongly decrease or even abolish the zearalenone-induced toxicity, both in vitro and in vivo. Therefore, cyclodextrins appear as promising new mycotoxin binders.

Interactions of Mycotoxin Alternariol with Cyclodextrins and Its Removal from Aqueous Solution by Beta-Cyclodextrin Bead Polymer

Alternariol is an Alternaria mycotoxin that appears in fruits, tomatoes, oilseeds, and corresponding products. Chronic exposure to it can induce carcinogenic and xenoestrogenic effects. Cyclodextrins (CDs) are ring-shaped molecules built up by glucose units, which form host–guest type complexes with some mycotoxins. Furthermore, insoluble CD polymers seem suitable for the extraction/removal of mycotoxins from aqueous solutions. In this study, the interactions of alternariol with β- and γ-CDs were tested by employing fluorescence spectroscopic and modeling studies. Moreover, the removal of alternariol from aqueous solutions by insoluble β-CD bead polymer (BBP) was examined. Our major observations/conclusions are the following: (1) CDs strongly increased the fluorescence of alternariol, the strongest enhancement was induced by the native γ-CD at pH 7.4. (2) Alternariol formed the most stable complexes with the native γ-CD (logK = 3.2) and the quaternary ammonium derivatives (logK = 3.4–3.6) at acidic/physiological pH and at pH 10.0, respectively. (3) BBP effectively removed alternariol from aqueous solution. (4) The alternariol-binding ability of β-CD polymers was significantly higher than was expected based on their β-CD content. (5) CD technology seems a promising tool to improve the fluorescence detection of alternariol and/or to develop new mycotoxin binders to decrease alternariol exposure.

Interaction of Dihydrocitrinone with Native and Chemically Modified Cyclodextrins.

Citrinin (CIT) is a nephrotoxic mycotoxin produced by Aspergillus, Penicillium, and Monascus genera. It appears as a contaminant in grains, fruits, and spices. After oral exposure to CIT, its major urinary metabolite, dihydrocitrinone (DHC) is formed, which can be detected in human urine and blood samples. Cyclodextrins (CDs) are ring-shaped molecules built up from glucose units. CDs can form host-guest type complexes with several compounds, including mycotoxins. In this study, the complex formation of DHC with native and chemically modified beta- and gamma-cyclodextrins was tested at a wide pH range, employing steady-state fluorescence spectroscopic and modeling studies. The weakly acidic environment favors the formation of DHC-CD complexes. Among the CDs tested, the quaternary-ammonium-γ-cyclodextrin (QAGCD) formed the most stable complexes with DHC. However, the quaternary-ammonium-β-cyclodextrin (QABCD) induced the strongest enhancement in the fluorescence signal of DHC. Our results show that some of the chemically modified CDs are able to form stable complexes with DHC (logK = 3.2–3.4) and the complex formation can produce even a 20-fold increase in the fluorescence signal of DHC. Considering the above-listed observations, CD technology may be a promising tool to increase the sensitivity of the fluorescence detection of DHC.

A record-breaking polycatenane

Through the use of some time-tested chemistry and clever monomer design, chemists led by the University of Chicago’s Stuart J. Rowan have managed to make a record-breaking polycatenane that mechanically links 26 ring-shaped molecules in a single chain. Their branched polycatenanes are even larger, boasting as many as 130 rings in a single mechanically interlocked molecule. The structures could have unusual properties and would allow chemists to see if the flexible behavior seen in strands of metal chain-links also occurs on the molecular scale. Chemists have been dreaming about making these types of polycatenanes ever since the University of Strasbourg’s Jean-Pierre Sauvage hooked two ring-shaped molecules together to make a basic catenane in 1983—a feat for which he shared the 2016 Nobel Prize in Chemistry. Although chemists have managed to make polycatenanes with up to nine rings in a row, making longer chains has proven difficult. “One of the key

World’s first nanocar race crowns champion

It’s hard to understand why Eric Masson’s excited about a picture of his car with a missing wheel. The fact that the car in the sepia micrograph on his computer screen looks more like a toasted marshmallow than a Maserati doesn’t help, either. But Masson, a supramolecular chemist at Ohio University, patiently explains that the lumpy, cream-colored rectangle he’s pointing to in the scanning tunneling microscope (STM) image is an assembly of atoms that scientists can drive across a surface. It is a nanocar. There are several similar rectangles in this STM image. All of them, except for one, feature four discernible lumps, one at each corner. These lumps are nanocar wheels made of large, ring-shaped cucurbituril molecules. But the car Masson’s pointing at has only three lumps. Resting nearby is a bright circle—a cucurbituril wheel lying on its side. The car missing its wheel refuses to move, Masson has

The angular electronic band structure and free particle model of aromatic molecules: High-frequency photon-induced ring current

This work introduces an analysis of the relationship of first-principles calculations based on DFT method with the results of free particle model for ring-shaped aromatic molecules. However, the main aim of the study is to reveal the angular electronic band structure of the ring-shaped molecules. As in the case of spherical molecules such as fullerene, it is possible to observe a parabolic dispersion of electronic states with the variation of angular quantum number in the planar ring-shaped molecules. This work also discusses the transition probabilities between the occupied and virtual states by analyzing the angular electronic band structure and the possibility of ring currents in the case of spin angular momentum (SAM) or orbital angular momentum (OAM) carrying light. Current study focuses on the benzene molecule to obtain its angular electronic band structure. The obtained electronic band structure can be considered as a useful tool to see the transition probabilities between the electronic states and possible contribution of the states to the ring currents. The photoinduced current due to the transfer of SAM into the benzene molecule has been investigated by using analytical calculations within the frame of time-dependent perturbation theory.

Spin and orbital angular momentum transfer into GanAsn nanocage: The change in induced magnetic field by tuning the light parameters and size of the molecule

In this study, we demonstrate that the direction of a photoinduced magnetic field in semiconductor nano-scale quantum dots (nanocages) can be changed by tuning the frequency and the light parameters. In the case of the spin angular momentum (SAM) transfer to ring-shaped GanAsn molecule, some electrons of occupied states are excited into the unoccupied states for a special laser frequency. As a result of the transition due to the circular polarized light, the excited electron which has a nonzero magnetic quantum number start to circulate around the molecular GaAs ring. The transfer of orbital angular momentum (OAM) due to the twisted light can induce similar effect on the molecular ring. In the case of twisted light, the electron can be excited different unoccupied states with higher magnetic quantum numbers. In the study, the optimization and electronic structure calculation have been performed by using density functional theory (DFT). The induced current and corresponding induced magnetic field can be controlled by the change in the frequency. Also, the type of the angular momentum of the light (SAM or OAM) can be used as a tool to manipulate the magnitude and direction of the magnetic moment.

Ring and Tails: Exploring the Intimacy of Cyclodextrin - Membrane Interactions

Cyclodextrins (CDs) are cyclic, ring-shaped molecules made of sugar moieties, consisting of a hydrophobic cavity and a hydrophilic outer part. Such a structure allows CDs to form inclusion complexes with hydrophobic molecules, where the guest molecule is physically entrapped in the host's (CD) cavity. This feature finds a wide range of applications in drug delivery, pharmaceutical and food industries, as inclusion complexes with CDs show enhanced bioavailability and longer circulation times.Recently, αCDs have been reported to directly interact with aliphatic tails of phospholipids from biological and model bilayer membranes. As the tails are not directly accessible for molecules from the aqueous solution, this observation suggests complex interplays and possible membrane remodeling occurring at the CD/membrane/water interface. Interestingly, despite the wide applications of CDs, the essentials of this process and its possible consequences in vivo remain poorly understood.Herein, we use a combination of complementary biophysical techniques to uncover the inner workings of interactions between CDs and model lipid membranes, focusing on CDs’ membrane-perturbing properties. Specifically, we employ Quartz Crystal Microbalance (QCMB-D) to reveal variations in viscoelastic properties of a lipid membrane induced by the presence of αCD. Furthermore, the application of confocal microscopy and CryoTEM allows us to explore the role of membrane curvature-mediated interactions between αCDs and the lipid membrane.

The 2016 Nobel Prize for Chemistry, awarded for: "The Design and Synthesis of Molecular Machines".

Keywords: Jean-Pierre Sauvage, Sir J. Eraser Stoddart, Bernard L. Feringa, 2016, Nobel Prize, molecular machines Jean-Pierre Sauvage, Sir J. Fraser Stoddart and Bernard L. Feringa share the 2016 Nobel Prize Chemistry (1), awarded jointly to them for the design and synthesis of molecular machines. A molecular machine, or nanomachine, is any discrete number of molecular components that produce quasi-mechanical movements (output) response to specific stimuli (input). (2) This was demonstrated (3) 1983, when Jean-Paul Sauvage managed to synthesise a catenane (Figure 1), which is formed by linking together two ring-shaped molecules by a mechanical bond, a recently coined term to describe the connection between the macrocycles of a catenane. In order that the molecular machine can perform a specific task, its components must be able to move relation to one another, as is the case the two interlocked rings the catenane. It was Fraser Stoddart, who 1991 synthesised a rotaxane (4), which has a molecular axle threaded through a molecular ring (Figure 2a,b), and demonstrated that the ring could move up and down the axle, leading to such devices as a molecular elevator, a molecular muscle and a molecule-based computer chip. In 1999, Bernard Feringa managed to demonstrate a molecular motor (5), which the rotor blade spins continually the same direction. Using a molecular motor, he managed to rotate a glass cylinder that was 10,000 times bigger than the motor itself. concept of a has emerged, a version of which was developed at Rice University by the research group of James Tour (6), and consisted of a molecule with an H-shaped 'chassis' with fullerene groups attached at the four comers to act as wheels (Figure 3). However, the original device did not have a molecular motor, and so might not be regarded as an actual Feringa and his co-workers have synthesised a molecule with four motorized wheels, which they deposited onto a copper surface and used electrons from a scanning tunnelling microscope (STM) to provide sufficient energy that they could drive some of the molecules a specific direction, similar fashion to steering a car. As a result of inelastic electron tunnelling, conformational changes are induced the rotors which propels the molecule over the surface. Since it is possible to change, individually, the direction of the rotary motion the motor units, either random or preferentially linear trajectories can be attained the self-propelling molecular 'four-wheel' device. It is believed that it might be possible to produce more sophisticated molecular cars, which a more complete control of the direction of motion can be achieved. (7) Jean-Francois Morin et al. (8) are working on a nanocar of the future, fitted with carborane wheels and a light powered helicene molecular motor. However, although a unidirectional rotation was observed the motor solution, it has not yet proved possible to drive it on a surface by means of light-energy. A nanocar race event, initially scheduled October 2016 and described as The First Ever Race of Molecule-Cars, has been postponed (9) in order to give enough time the teams to prepare and the microscope to be optimized. This postponement is essential to make the event a true > challenge. As yet, the real future molecular machines is unknown and probably unknowable, but we may note the following, taken from the 2016 Nobel Prize Chemistry website (10). …

The effect of twisted light on the ring-shaped molecules: The manipulation of the photoinduced current and the magnetic moment by transferring spin and orbital angular momentum of high frequency light

In this study, we aim to investigate the possibility of the manipulation of an aromatic ring current and magnetic moment induced by spin angular momentum (SAM) and orbital angular momentum (OAM) carrying light by changing the frequency of the light beam. In the study, the possibility of transitions and the contribution of the excited states into the induced current have been investigated by analyzing the angular band structure. The induced current density has been obtained by using time-dependent perturbation theory and calculations have been performed in Cartesian coordinate. The induced magnetic field is calculated by using the well-known Biot-Savart law. The result confirms the possibility of controlling the spin direction of a magnetic atom which can be located at the center of the ring-shaped molecule.