OCH3 Groups Research Articles

Photophysical Processes in Coumarin Sensitizers

The quantum-chemical and spectroscopic methods make it possible to record the features of photoactivated processes occurring within and between molecules, as well as the structural rearrangements of molecules. To solve the fundamental problem of establishing a relationship between the photophysical and spectral-luminescent properties of organic molecules and their structure, a comparative analysis of the nature of electronically excited states and photoprocesses in coumarin and its related compounds (furocoumarin and 8-methoxypsoralen) has been carried out. To understand the mechanism of forming the absorption and fluorescence spectra of compounds, the schemes of electronically excited states of the molecules under study and the charge localization on the molecular orbitals have been calculated and analyzed. The investigated compounds are effective sensitizers, and the presence of the OCH3 group in the molecular structure has the strongest effect on the spectral-luminescent characteristics. This paper presents the results of studying the induced absorption spectra of 8-methoxypsoralen by the pumb-probe method with a delay of 30 ns in the range of 350–700 nm. The experimentally recorded induced absorption of 8-methoxypsoralen belongs to long-living photoproducts of a radical nature.

Study of the Optical Spectra of 4-Hydroxy-3-Methoxibenzoic Acid

Using electronic spectroscopy and quantum chemistry methods, the electronic spectra of vanillic acid in various solvents are interpreted. In the ground electronic state, four protolytic forms of vanillic acid in water were detected: anionic, dianionic, cationic, and neutral. In water, vanillin and isovanillin in the ground state have the same spectral characteristics: the line position and intensity in their absorption spectra coincide. The absorption and fluorescence bands of vanillic acid shift toward shorter wavelengths compared to vanillin and isovanillin. The values of the minimum electrostatic potential indicate that vanillic acid has the deepest minimum in the region of the carbonyl oxygen atom. The study of the fluorescence spectra showed that the radiative properties of the ionic forms of vanillic acid are different. The data of quantum chemical calculations indicate that electronic transitions in the molecule are formed with the participation of charge transfer from the phenyl part of the molecule to the oxygen atoms of the methoxy and carbonyl groups. The presence of OH, OCH3, and carbonyl group in the structure of vanillic acid leads to the existence of a dianionic form, both in the ground and electronically excited states.

New 1-(Spiro[chroman-2,1′-cycloalkan]-4-yl)-1H-1,2,3-Triazoles: Synthesis, QTAIM/MEP analyses, and DNA/HSA-binding assays

This study synthesized and characterized the DNA/HSA properties of a new series of 12 examples of 4-(alkyl/aryl)-1-(spiro[chroman-2,1′-cycloalkan]-4-yl)-1H-1,2,3-triazoles (SCTz), in which alkyl = CH3(CH2)5 and aryl = C6H5, 4-NH2C6H4, 3-OCH3C6H4 (47–95% yield) by regioselective Copper-Catalyzed Azide–Alkyne Cycloaddition (CuAAC) reaction. Additioanally, single crystal X-ray diffraction (SC-XRD) analysis was carried out and the SC-XRD data enabled a broad molecular analysis using QTAIM and MEP analysis. Absorption UV–Vis properties of SCTz series were investigated and all derivatives absorb in the UV region and no are observed emission fluorescence in solution. The DNA-binding assays (UV–Vis analysis) showed that the all spiroderivatives demonstrated strong binding forces to CT-DNA. The Stern-Volmer quenching constants (KSV) of SCTz were calculated and derivatives containing the OCH3 group competed more strongly with DNA minor grooves, followed by the increasing general order of (KSV): EB-DNA < DAPI-DNA. Additionally, the high values observed for the bimolecular quenching constant rate (kq) indicated a static interaction between spiroderivatives and DNA in all cases. Finally, the HSA-binding experiments and molecular docking studies for the new spiroderivatives were determined and quenching (KSV) and quenching rate (kq) constants values obtained for the SCTz suggest good interaction between HSA and derivatives, probably by static mechanism, forming HSA:compound adduct in the ground state.

Synthesis and characterization of chitosan - LiClO4 solid electrolyte membrán and its application in batteries

The Synthesis of chitosan - LiCLO4 solid electrolyte membrane has been carried out. The membrane is prepared by using a casting method. Chitosan 0.6 gram, LiClO4 (Sigma-Aldrich > 95%) with variations of 10% and 40% (w / w) and 10% PVA (w / w) put into the measuring cup. Furthermore, the mixture was dissolved in a 2% acetic acid solution of 30 mL (v / v) and stirred evenly at room temperature. The solution is then put into an acrylic casting plate measuring 30x5 cm and allowed to stand dry. The electrolyte membrane was then analyzed for functional groups using FTIR and conductivity using the HICRI 3532-50 Hi-Tester LCR. The FTIR results stated that the addition of lithium caused a shift in the wave number 2871 to 2920 cm-1 which showed the presence of the OCH3 group, while the highest conductivity value was 3.98 x 10-7 - 3.16 x 10-6 at a frequency of 42 Hz - 5MHz. These results provide information that the synthesized membrane can be applied as an electrolyte membrane on the batteries.

Substituent parameters from photoelectron spectra: Substituted benzenes

The substituent effects on π-orbital energies in three benzene derivatives have been examined on the basis of data provided by HeI ultraviolet photoelectron spectroscopy (UPS). We focus on cooperative action of substituents when acting on the π-electrons of benzene ring. We present UPS of substituted benzenes: 4-methoxybenzoic acid (MBA), 2,3,5,6-tetramethyl-nitroaniline (TMNA) and pentafluorobenzaldehyde (PFBA) which serve as examples of interplay of complex interactions between substituents where aromatic ring acts as electron density relay. We have shown that a simple method: linear combination of bond orbitals (LCBO) can be used to deduce the magnitude of resonance substituents effects on π energy levels in MBA. The splitting of two lowest π-energy levels was used to detect steric inhibition of resonance in TMNA. The resonance effects of CHO and COOH groups on π-orbitals are very small. On the other hand, the resonance effects of OCH3, NH2 and NO2 groups are significant.

Nonlinear optical properties and spectroscopic characterization of Y-shaped polymer using quantum chemical approach.

The present study reports nonlinear optical properties such as the first and second hyper polarizabilities (β and γ) of Y-shaped polymer (P1) and substituted polymers. The basic Y-shaped polymer (R = R1 = H) was named as P1. Upon substitution of one OCH3 group in ortho position of oxygen, it becomes polymer P2 (R1 = H, R = OCH3) and other OCH3 group on another ortho becomes P3 (R1 = R = OCH3). We have also reported structural parameters, vibrational and electronic absorption spectra of polymer, and its substituted polymers. The geometrical parameters such as dipole moment, bond length, and angles are reported at B3LYP/6-311++g** level of theory. In addition, the vibrational, electronic absorption spectra and nonlinear optical (NLO) properties are also reported at the same level of theory. There is a significant change in dipole moment and in energy observed whereas symmetry, bond length, and angles are resembling Y-shaped and substituted polymer. The vibrational spectra of Y-shaped polymer (P1) having the intense peak are C-H stretching mode observed at 1258cm-1. These theoretical vibrational modes are well matching with available experimental determinations. The method dependent hyperpolarizabilities calculated by applying the field along the X, Y, and Z direction. This study confirms the polymer P1 and P2 showing first and second hyperpolarizability response whereas P3 do not show. The electronic absorption spectra for polymer and substituted polymers are also reported at the same level of theory using (TDDFT) approach. The wavelength of electronic transition, oscillator strength, and HOMO-LUMO gap was also reported.

Efficient strategies for improving the performance of EDOT derivatives and TPA derivatives-based hole transport materials for perovskite solar cells

Developing cost-effective and high-performance hole transport materials (HTMs) is one of the hot topics in the researches of perovskite solar cells (PVSCs). By introducing a carboxyl group on the 3,4-ethylenedioxythiophene (EDOT) derivatives and replacing the –OCH3 (-OMe) groups on the Triphenylamine (TPA) derivatives to -N(CH3)2 groups, we present two efficient strategies for improving the performances of HTMs. The ground-state and excited-state properties, stabilities, solubilities and hole mobility of HTMs are comprehensively studied by DFT and TD-DFT. Both strategies have positive effects on the performance of HTMs. Two designed HTMs C1-R2 (μh = 1.05×10-2cm2 V−1 s−1) and C2-R2 (μh = 1.9×10-3cm2 V−1 s−1) show higher hole mobility than original HTMs C1-R1 (μh = 6.7×10-3cm2 V−1 s−1) and C2-R1 (μh = 1.3×10-3cm2 V−1 s−1) after the replacement on the TPA derivatives, which ensures the fact that these two designed HTMs have potentials in the application of PVSCs. It is hoped that our investigation can provide valuable strategies for conquering the predicament of the application and commercialization of PVSCs.

Representative model compounds for understanding the pyrolytic behavior of pre-oxidized β-ether-type lignin

To achieve a better understanding of the pyrolysis behavior of pre-oxidized β-ether-type lignin, three Cα=O type dimers with different substituent groups on the aromatic ring were synthesized and analyzed by a simultaneous thermal analysis instrument (STA), in-situ Fourier transform infrared spectroscopy (in-situ FTIR), and pyrolysis-gas chromatography/ mass spectrometry (Py-GC/MS). The results showed that major primary pyrolysis reactions of Cα=O type models normally occurred at 200 to 400 °C, and connecting bridge structures of models were completely destroyed, causing the emission of abundant volatiles. Substituent groups of aromatic rings played direct roles in thermal stability of models, volatiles emission, product characteristics, and secondary reaction pathways of major primary products. Particularly, the aryl–OCH3 group clearly enhanced the reactivity of intramolecular linkages and was an important active functional group for secondary reactions. As major primary products and intermediates, guaiacol and 2-methoxy-benzaldehyde were formed via the cleavage of Cα–O and Cα–Cβ bonds and could also be converted into phenol, benzaldehyde, and 2-methylphenol via rearrangement of aryl–OCH3 into an aryl–CH3 group or –OCH3 group removal. Oxidization of benzylic alcohol to benzylic ketone not only simplified depolymerization pathways, but also resulted in better selectivity of phenolic monomers and a predictable product distribution.

Facile strategy for immobilizing horseradish peroxidase on a novel acetate functionalized ionic liquid/MWCNT matrix for electrochemical biosensing

Facile yet simple platforms for the immobilization of biomolecules have always been a substantial requirement for the fabrication of proficient biosensors. In this study, we report a naphthyl substituted acetate functionalized ionic liquid (NpAc-IL) for the covalent anchoring of horseradish peroxidase (HRP), using which the direct electrochemistry of HRP was successfully accomplished and a H2O2 biosensor was developed. The naphthyl substitution on the NpAc-IL was utilized for the π-π stacking with the MWCNT modified GCE and the terminal -OCH3 group of NpAc-IL was used for the covalent attachment with the free -NH2 group of HRP via amide bond formation. High conducting nature of the newly designed ionic liquid (NpAc-IL), facilitated an improved communication with the deeply buried redox centre of the HRP, while the covalent bonding provided enhanced stability to the fabricated biosensor by stably holding the water soluble HRP enzyme on the electrode surface. Furthermore, incorporation of MWCNT on the sensor setup synergistically enhanced the sensitivity of the developed biosensor. Under optimized conditions, the fabricated biosensor showed an enhanced electrocatalytic reduction of H2O2 in the range of 0.01 to 2.07 mM with a limit of detection and sensitivity of 2.7 μM and 55.98 μA mM−1 cm−2 respectively. Further, the proposed biosensor was utilized for the sensing of H2O2 spiked in real samples. Moreover, the newly fabricated biosensor demonstrated excellent stability with improved sensitivity and selectivity towards H2O2 reduction. The superior analytical characteristics are attributed to the facile fabrication strategy using this newly developed acetate functionalized ionic liquid platform.

Experimental and theoretical evaluation of new piperidine and oxaquinuclidine core containing derivatives as an efficient corrosion inhibitor for copper in nitric acid medium

The inhibition efficiency of copper corrosion in 1 M HNO3 by five piperidine and oxaquinuclidine core containing compounds namely 2,4,6,11-tetraphenyl-9-oxa-1,5-diazatricyclo [5.3.1.03.8] undecane (OX1), 2,4,6,11-tetraaryl (4-methoxyphenyl)-9-oxa-1,5-diazatricyclo [5.3.1.03.8] undecane (OX2), 2,4,6,11-tetraaryl (4-chlorophenyl)-9-oxa-1,5-diazatricyclo [5.3.1.03.8] undecane (OX3), 2,4,6,11-tetraaryl-p-tolyl-9-oxa-1,5-diazatricyclo [5.3.1.03.8] undecane (OX4), and 2,4,6,11-tetraaryl (4-fluorophenyl)-9-oxa-1,5-diazatricyclo [5.3.1.03.8] undecane (OX5) has been investigated using gravimetric method, electrochemical studies, FT-IR, scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), DFT and Monte Carlo simulation techniques. Inhibitors are chosen based on electron donating and accepting ability to the metal surface. These compounds differentiated in phenyl ring containing electron withdrawing (Cl, F) and electron releasing (OCH3, CH3) substituents. Experimental and computational studies showed that methoxy (OCH3) substituent exhibit more efficiency compared to other compounds and it is due to more electron donating nature of the OCH3 group. The adsorption of the inhibitors on copper surface obeyed Langmuir adsorption isotherm. Polarization results show that OXs are acting as a mixed type of inhibitors. In the surface characterization studies, change in frequency (FT-IR), change in surface roughness (SEM) and appearance of additional element peaks (EDX) before and after film formation confirmed the protective layer formation. Quantum chemical parameters and Monte Carlo simulation studies further evidenced by the inhibitor adsorption of the copper surface.

Singlet oxygen production abilities of oxidated aromatic compounds in natural water

Singlet oxygen (1O2) is well known to be formed through energy transfer from excited state organic matters to O2, playing an important role in the transformations of contaminants. However, the contribution of small oxidated aromatic compounds (OACs) to the production of 1O2 in surface water is unclear. In this study, 28 OACs were selected to investigate the correlations between their photochemical production abilities of 1O2 and molecular structures. Our results showed that the steady-state concentrations and quantum yields of 1O2 (Φ1O2) generated by OACs were in the range of 7.0 × 10−14–1.4 × 10−12 M and 2.2 × 10−4–4.7 × 10−2, respectively, indicating that the photochemical production abilities of 1O2 by OACs varied greatly with types and positions of functional groups on the molecule. More importantly, the observed photochemical production of 1O2 was most notable in cases of molecules containing –OCH3 group and benzoquinone. A good quantitative structure-property relationship model was established between 1O2 producing ability, energy of the lowest unoccupied molecular orbitals (ELUMO) and the most positive net charge of hydrogen atoms (qH+) of OACs. In addition, the role of 1O2 produced by 2, 6-dimethoxy-1, 4-benzoquinone, the OAC with the highest Φ1O2, in the photodegradation of organic contaminants was validated by the enhanced degradation of atorvastatin under simulated sunlight, suggesting that OACs ubiquitously existed in surface water may greatly affect the fate and ecological risks of organic contaminants.

Serum Amiloid-A'nın Sıçanlarda Formaldehit Kaynaklı Kupffer Hücre Apoptozundaki Rolü ve Astaksantin'in Bu Süreçteki Olası Koruyucu Etkileri

The aim of this study is to investigate the alterations related to Serum amyloid-A in formaldehyde-induced apoptosis in Kupffer cells and to determine whether Astaxanthin has a protective effect against apoptosis. In this experiment, 32 rats were divided into 4 groups (n=8). The first group was named as control group, physiological saline was injected intraperitoneally to this group, and drinking water was given orally. In CH2O group, rats were injected with formaldehyde at a dose of 10 mg/kg daily intraperitoneally. The rats in CH2O+ATX16 and CH2O+ATX32 were injected with formaldehyde daily at a dose of 10 mg/kg intraperitoneally, and respectively 16 mg/kg and 32 mg/kg Astaxanthin were administered orally. Formaldehyde administration was caused by the highest and statistically significant Serum amyloid-A staining intensity (P<0.0125) and apoptotic index (P<0.05) in the CH2O group. Both doses of Astaxanthin administration reduced apoptosis in Kupffer cells but there were no significant differences in serum Serum amyloid-A levels between experimental groups (P>0.05). As a result, oral administration of Astaxanthin has been shown to reduce Serum Amyloid A, which increases due to exposure to formaldehyde, and possibly in this way, Kupffer cells successfully protect against formaldehyde-induced apoptosis. The subject should be examined more comprehensively

A water boost for methanol synthesis

Catalysis Model catalysts based on metals and metal oxides can dissociate methane (CH4) at room temperature, converting it directly to methanol (CH3OH). Liu et al. show that for one of these catalysts, an “inverted” CeO x -Cu2O oxide on Cu(111), water tunes the selectivity from forming CO and CO2 to forming surface CH3O groups, as revealed by ambient-pressure x-ray photoelectron spectroscopy. Theoretical modeling showed that adsorbed water blocks O2 dissociation and O2 instead oxidizes the reduced catalyst. Hydroxyl groups from water generate the CH3O species from dissociated CH4, and water then goes on to form and displace CH3OH to the gas phase. Science , this issue p. [513][1] [1]: /lookup/doi/10.1126/science.aba5005

Water-promoted interfacial pathways in methane oxidation to methanol on a CeO2-Cu2O catalyst.

Highly selective oxidation of methane to methanol has long been challenging in catalysis. Here, we reveal key steps for the pro-motion of this reaction by water when tuning the selectivity of a well-defined CeO2/Cu2O/Cu(111) catalyst from carbon monoxide and carbon dioxide to methanol under a reaction environment with methane, oxygen, and water. Ambient-pressure x-ray photoelectron spectroscopy showed that water added to methane and oxygen led to surface methoxy groups and accelerated methanol production. These results were consistent with density functional theory calculations and kinetic Monte Carlo simulations, which showed that water preferentially dissociates over the active cerium ions at the CeO2-Cu2O/Cu(111) interface. The adsorbed hydroxyl species blocked O-O bond cleavage that would dehydrogenate methoxy groups to carbon monoxide and carbon dioxide, and it directly converted this species to methanol, while oxygen reoxidized the reduced surface. Water adsorption also displaced the produced methanol into the gas phase.

Poly(ester imide)s Possessing Low Coefficients of Thermal Expansion and Low Water Absorption (V). Effects of Ester-linked Diamines with Different Lengths and Substituents.

A series of ester-linked diamines, with different lengths and substituents, was synthesized to obtain poly(ester imide)s (PEsIs) having improved properties. A substituent-free ester-linked diamine (AB-HQ) was poorly soluble in N-methyl-2-pyrrolidone at room temperature, which forced the need for polyaddition by adding tetracarboxylic dianhydride solid into a hot diamine solution. This procedure enabled the smooth progress of polymerization, however, accompanied by a significant decrease in the molecular weights of poly(amic acid)s (PAAs), particularly when using hydrolytically less stable pyromellitic dianhydride. On the other hand, the incorporation of various substituents (–CH3, –OCH3, and phenyl groups) to AB-HQ was highly effective in improving diamine solubility, which enabled the application of the simple polymerization process without the initial heating of the diamine solutions, and led to PAAs with sufficiently high molecular weights. The introduction of bulkier phenyl substituent tends to increase the coefficients of thermal expansion (CTE) of the PEsI films, in contrast to that of the small substituents (–CH3, –OCH3). The effects of ester-linked diamines, consisting of longitudinally further extended structures, were also investigated. However, this approach was unsuccessful due to the solubility problems of these diamines. Consequently, the CTE values of the PEsIs, obtained using longitudinally further extended diamines, were not as low as we had expected initially. The effects of substituent bulkiness on the target properties, and the dominant factors for water uptake (WA) and the coefficients of hygroscopic expansion (CHE), are also discussed in this study. The PEsI derived from methoxy-sustituted AB-HQ analog and 3,3′,4,4′-biphenyltetracarboxylic dianhydride achieved well-balanced properties, i.e., a very high Tg (424 °C), a very low CTE (5.6 ppm K−1), a low WA (0.41%), a very low CHE value (3.1 ppm/RH%), and sufficient ductility, although the 26 μm-thick film narrowly missed certification of the V-0 standard in the UL-94V test. This PEsI film also displayed a moderate εr (3.18) and a low tan δ (3.14 × 10−3) at 10 GHz under 50% RH and at 23 °C. Thus, this PEsI system is a promising candidate as a novel dielectric substrate material for use in the next generation of high-performance flexible printed circuit boards operating at higher frequencies (≥10 GHz).

Inclusion Complexation of Benzanilide and Fast Violet B with β-cyclodextrin-A Theoretical Approach

The theoretical investigation of inclusion complexation of amide-imidol tautomer of two guest molecules benzanilide (BA) and fast violet B (FVB) with β-cyclodextrin (β-CD) using DFT B3LYP 3-21G method in the gas phase. Benzanilide has no substitution in the basic skeleton and the other selected compound substituted with three groups such as –NH2, -CH3 and –OCH3 group in the same aromatic ring. The tautomer of two selected compounds was formed the stable inclusion complexes with the β-CD supramolecule. The theoretically calculated complexation energy was observed the negative value for all the inclusion complexes. This method was applicable to determine the structural assignment of the inclusion complexes between BA, FVB and β-CD.

Rotational Spectroscopic and Ab Initio Investigation of the Rotamer Geometries of 2-Fluoroanisole and 3-Fluoroanisole.

The rotational spectra of 2-fluoroanisole and 3-fluoroanisole were investigated using Fourier transform microwave spectroscopy in the 4-26 GHz range. Assigned transitions correspond to the lowest energy rotamer for 2-fluoroanisole which has the O-CH3 group directed away (anti) from the fluorine substituent whereas for 3-fluoroanisole, the spectrum is consistent with the presence of two rotamers arising from syn and anti orientations of the methoxy moiety relative to fluorine. Ab initio calculations at the MP2/cc-pVTZ level were used to estimate the equilibrium (re) geometries of the three observed rotamers. Their assignments were confirmed through the observation of the rotational transitions of eight minor isotopologues (13C and 18O) in natural abundance for each species. The mass dependence (rm(1)) structures derived using the experimentally determined rotational constants compare favorably with the ab initio estimates. The resulting sets of geometric parameters suggest that the aromatic ring backbone is distorted by the introduction of the angular methoxy substituent, with a tendency to induce bond length alternation around the ring, and by the electron withdrawing effects of fluorine.

Resonance enhanced two-photon ionization and mass analyzed threshold ionization spectroscopy of 4-ethylanisole

We report the resonance enhanced two-photon ionization (REMPI) and mass analyzed threshold ionization (MATI) spectra of 4-ethylanisole. The band origin of S1 ← S0 transition and accurate adiabatic ionization energy of 4-ethylanisole are determined to be 35575 ± 2 cm−1 and 63718 ± 5 cm−1, respectively. The Franck-Condon simulation of the vibrationally resolved electronic spectrum for D0 ← S1 transition is calculated and employed to assist us in assigning the observed vibronic bands in MATI experiment. Many vibrations in the S1 and D0 states, not only the aromatic ring bending, OCH3 and ethyl group bending but also their combination, are observed. The substitution effects of ethyl on transition energy and ionization energy are discussed.

Microwave assisted synthesis of imidazolyl fluorescent dyes as antimicrobial agents

In this article, we report, the synthesis and characterization of series of novel fluorescent imidazolyl dyes (5a-d)via highly efficient and cost-effective microwave assisted protocol as a potential candidate to overcome the problem of microbial resistance. By utilizing the green microwave protocol the reactions are completed in a short span of time without using the harsh conditions. The incorporation of imidazole nucleus is an important strategy in drug discovery. While designing desired fluorescent imidazole dyes 5a-d, with a suitable auxiliary donor such as aromatic rings and −OCH3 group on one end of the imidazolyl moiety and electron acceptors such as -NO2 and −COOH on other end of the compounds was achieved to get a promising fluorescent dyes for antimicrobial. The optoelectronic properties and antimicrobial studies of the synthesized materials indicated their exploration as a promising candidate as antimicrobial agents.

N-Phenyl substituent controlled diastereoselective synthesis of β-lactam-isatin conjugates

Unprecedented diastereoselective synthesis of novel β-lactam-isatin conjugates via a Staudinger [2+2] cycloaddition is described. The electronic nature of substituents on the imine N-phenyl moiety induced high levels of stereocontrol and plausibly controlled the competition between direct ring closure (conrotatory) and isomerization of the azabutadiene intermediate. The presence of electron-donating groups (OCH3 and CH3) at the para-position of the imine N-phenyl moiety increases the electron density of the imine nitrogen atom. This in turn increases direct conrotatory ring closure favoring the cis-isomer. On the other hand, electron-withdrawing groups (NO2 and CF3) at the para-position gave the thermodynamically more stable trans-isomer as the major products by promoting isomerization of the azadiene zwitterionic intermediate presumably due to a decrease in the electron density on the imine nitrogen atom. A varied diastereoselective behavior was observed for meta-position substituents, where OCH3, CH3 and NO2 groups favored the cis-isomer, hence indicating the additional role of steric hindrance in the observed diastereoselectivity. Additionally, the transition states of these reactions computed at the density functional theory (DFT) level were in accordance with the experimental results.