molecular geometry
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Author(s):  
Okan Simsek ◽  
Muharrem Dincer ◽  
Necmi Dege ◽  
Eiad Saif ◽  
Ibrahim Yilmaz ◽  
...  

The title cyclobutyl compound, C18H18N2O3S, was synthesized by the interaction of 4-(3-methyl-3-phenylcyclobutyl)thiazol-2-amine and maleic anhydride, and crystallizes in the orthorhombic space group P212121 with Z′ = 1. The molecular geometry is partially stabilized by an intramolecular N—H...O hydrogen bond forming an S 1 1(7) ring motif. The molecule is non-planar with a dihedral angle of 88.29 (11)° between the thiazole and benzene rings. In the crystal, the molecules are linked by O—H...N hydrogen bonds, forming supramolecular ribbons with C 1 1(9) chain motifs. To further analyze the intermolecular interactions, a Hirshfeld surface analysis was performed. The results indicate that the most important contributions to the overall surface are from H...H (43%), C...H (18%), O...H (17%) and N...H (6%), interactions.


Molecules ◽  
2022 ◽  
Vol 27 (1) ◽  
pp. 315
Author(s):  
Jiaqi Mao ◽  
Ying Zhou ◽  
Guanglie Lv ◽  
Renxian Zhou

Raw Ca-based montmorillonite (MMT) was treated by H2SO4, calcination and organic compounds (hexadecyltrimethyl ammonium bromide (HTAB), cetylpyridinium chloride (CPC) and chitosan (CTS)), respectively. The modified montmorillonites were characterized by different methods and their adsorption performances for three mycotoxins (Aflatoxin B1 (AFB1), zearalenone (ZEA) and deoxynivalenol (DON)) were evaluated at pH = 2.8 and 8.0, respectively. The results indicate that surfactants (CPC and HTAB) intercalation is the most efficient modification, which obviously improves the adsorption performance of montmorillonite for mycotoxins, with adsorption efficiency of above 90% for AFB1 and ZEA whether under acid or alkaline conditions, due to the increase in basal spacing and the improvement of hydrophobicity. Moreover, the adsorption efficiencies of AFB1 and ZEA over CPC-modified montmorillonite (CPC-AMMT-3) coexisting with vitamin B6 or lysine are still at a high level (all above 94%). All modified montmorillonites, however, have low adsorption efficiency for DON, with somewhat spherical molecular geometry.


Author(s):  
Sehee Im ◽  
Chan Hee Ryu ◽  
Mingi Kim ◽  
Dong Kyun You ◽  
Sanghee Yi ◽  
...  

Herein, we compared the optical properties of four compounds with an o-carborane cage linked to 1H-phenanthro[9,10-d]imidazole at the ortho- (oPC), meta- (mPC), or para-position (pPC) of the 2-phenyl ring or...


2022 ◽  
Vol 34 (2) ◽  
pp. 297-304
Author(s):  
P.V. Sandhya ◽  
K.V. Satheesh Kumar ◽  
K.R. Haridas

Some biologically active pyrazole clubbed imino molecules have been designed and synthesized from 1-phenyl-3-nitro phenyl-1H- pyrazol-4-carboxaldehyde and substituted aromatic amines via acid catalyzed condensation reaction. All the synthesized molecules were characterized by IR, 1H NMR, 13C NMR and mass spectral techniques. The in vitro antibactericidal property of the synthesized compounds was screened and compared with the results of theoretical molecular docking. Optimization of molecular geometry, DNA binding interaction and FMO analysis were also investigated by computational studies using Gaussian 16 package at B3LYP/6-31G(d,p) level. All the synthesized compounds exhibited moderate to good biological activities both experimentally and theoretically.


2021 ◽  
Vol 37 (6) ◽  
pp. 1396-1408
Author(s):  
Sangeetha. R.K ◽  
Ayyappan. S S

In the current work, the vibrational frequencies, infrared intensities, molecular geometry and Raman scattering were determined and investigated using ab initio Hartree–Fock (HF) and density functional methods with a basis set of 6-311++ G (d, p) of the organic molecule under interpretation. The FT-IR and FT-Raman spectra of titled molecule have been recorded in the region 4000-400 cm-1 and 5000-70 cm-1, respectively. The optimized geometry structures (bond lengths and bond angles) achieved using HF shows the best result with the experimental values of the titled molecule. The frontier molecular orbitals help to distinguish chemical responsiveness and molecular kinetic steadiness, thus HOMO-LUMO analysis can be done using the quantum chemistry to improve thermodynamics. The electron density mapping to electrostatic potential surfaces were involved in finding the reactivity sites of the titled compound. With the help of Gauss view 5.0 and Chemcraft packages, the obtained outputs are analyzed. Hyperpolarizability and non-linear optical effect of isolated molecules of NLO materials are observed to be an extensive tool for molecular spectroscopy research. Therefore, for industrial application, Hyperpolarizability of the molecule is also studied.


2021 ◽  
Vol 9 (2) ◽  
pp. 220
Author(s):  
Ainun Nisa ◽  
Kusumawati Dwiningsih

Chemistry is a branch of science that encourages various advances in various fields. However, the characteristics of chemistry which have complex concepts make it difficult for class X high school students to understand chemistry. Thus, the problem that is the focus of discussion in this study is how to overcome the low visuospatial skills of high school students in class X, so that students can understand complex concepts in chemistry. This study uses the research design and development of the 4D Thiaganrajan modified 3D Ibrahim method. This study aims to determine the effectiveness of Mobile Virtual Reality (MVR)-based molecular geometry learning media in improving visuospatial skills. The effectiveness of the MVR-based molecular geometry learning media is stated based on the interpretation of the N-Gain score. The results showed an increase in the percentage of correct answers on the posttest by 32.15% with a significance level ranging from 0.57-1 in the medium to high category. In this regard, the use of MVR-based molecular geometry learning media is said to be effective because it can improve students' visuospatial skills. That is, MVR-based molecular geometry learning media can help students to comprehensively represent molecular geometry sub-materials.AbstrakKimia merupakan salah satu cabang ilmu pengetahuan yang mendorong berbagai kemajuan di berbagai bidang. Namun, karakteristik ilmu kimia yang memiliki konsep kompleks membuat peserta didik SMA kelas X sulit memahami ilmu kimia. Dengan demikian, masalah yang menjadi fokus pembahasan di dalam penelitian ini adalah Bagaimana cara mengatasi visuospasial skills peserta didik SMA kelas X yang tergolong rendah, agar peserta didik mampu memahami konsep kompleks dalam ilmu kimia.   Penelitian ini menggunakan desain penelitian dan pengembangan metode 4D Thiaganrajan modifikasi 3D Ibrahim. Penelitian ini bertujuan untuk mengetahui efektivias media pembelajaran geometri molekul berbasis Mobile Virtual Reality (MVR) dalam meningkatkan visuospasial skills. Efektivitas media pembelajaran geometri molekul berbasis MVR dinyatakan berdasarkan interpretasi skor N-Gain. Hasil penelitian menunjukkan peningkatan persentase jawaban benar pada postest sebesar 32,15% dengan tingkat signifikansi berkisar antara 0,57-1 pada kategori sedang sampai dengan tinggi. Dalam kaitan ini, pemanfaatan media pembelajaran geometri molekul berbasis MVR dikatakan efektif karena dapat meningkatkan visuospasial skills peserta didik. Artinya, media pembelajaran geometri molekul berbasis MVR dapat membantu peserta didik untuk merepresentasikan submateri geometri molekul secara komprehensif.


Langmuir ◽  
2021 ◽  
Author(s):  
Jing Shi ◽  
Weiqing Liu ◽  
Shuqing Yang ◽  
Zongjian Wu ◽  
Baoshuo Han ◽  
...  

2021 ◽  
Vol 923 (2) ◽  
pp. 202
Author(s):  
A. Ricca ◽  
C. Boersma ◽  
E. Peeters

Abstract This study revisits the role that nitrogen inclusion in polycyclic aromatic hydrocarbons (PAHs; those with nitrogen inclusion, PANHs) plays in their infrared (IR) spectral properties. We present spectra of pure PAHs, PANHs, and protonated PANHs, computed using density functional theory and basis sets that treat polarization. We investigate trends in peak position and relative intensities as a function of nitrogen position, charge, and geometry. We use Spitzer-IRS spectral map data of the northwest photodissociation region of NGC 7023 and a database-fitting approach, using exclusively the PA(N)H spectra computed in this paper, to assess their IR contribution to the cosmic PAH emission. We find that, by including the treatment of polarization, pure PAH cations can account for the class A 6.2 μm PAH emission, with the 6.2 μm band position being dependent on the molecular geometry. PANH cations are required to reproduce the most blueshifted 6.2 μm bands observed in class A sources, albeit PANH cations come with strong 11.0 μm emission. Blind database fits demonstrate that the restriction imposed by the 11.0 μm emission in the astronomical spectra limits the contribution of PANH cations and the fits have to use neutral PANHs to avoid inflating the 11.0 μm feature even further. By assuming that all of the 11.0 μm emission is due to PANHs, we derive an upper limit for the contribution of PANH cations to the astronomical 6.2 μm PAH band of ∼12%. The fits further show hydrogenated PANHs significantly contributing in NGC 7023's more benign region, supporting the view that shielded environments could sustain protonated PA(N)Hs.


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