فهرس المقالات Molecular orbital

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  1 - Theoretical Studies of Solvent Effects on the Electronic Properties of 1, 3-Bis [(Furan-2-yl) Methylene] Urea and Thiourea
  M. D. Adeoye I. O. Abdulsalami G. O. Oyeleke K. A Alabi
  The synthesis and characterization of 1, 3-bis [(furan-2-yl) methylene] urea (BFMU) and 1, 3-bis [furan-2-yl) methylene] thiourea (BFMT) have been reported by our research team. The effects of solvents polarity on their electronic transition energies (HOMO-LUMO) and ass أکثر

  The synthesis and characterization of 1, 3-bis [(furan-2-yl) methylene] urea (BFMU) and 1, 3-bis [furan-2-yl) methylene] thiourea (BFMT) have been reported by our research team. The effects of solvents polarity on their electronic transition energies (HOMO-LUMO) and associated qualitative structure activity relationship parameters (i.e. log P, ionization energies and global hardness) were investigated in this study. The lower HOMO-LUMO energy gap values of BFMT (3.42 - 3.76 eV) in the solvents of choice (water, ethanol, toluene and dimethylsulphoxide) is an indication of higher distribution of charges and probability of higher activities of BFMT relative to BFMU with energy gap in the range: 4.27 - 4.54 eV. From the frontier molecular orbital study of BFMU, the HOMO centers over the entire molecule. However, the π- electrons of the LUMO are also over the entire molecule except one of the furan rings. Similar trends was observed for the HOMO of BFMT with electron delocalization excluding one of the furan ring, while the LUMO π- electrons system are more localized on the C=N, C=O and C-S bonds than the furan rings. These attest to the charge transfer (CT) characteristic properties of the compounds in the studied solvents. The logPoctanol/water values for the studied compounds which are less than 3, pointed to their usefulness in industrial development especially for agrochemical products. تفاصيل المقالة
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  2 - بررسی نظری پیوند هیدروژنی درون مولکولی در مشتقات هالو، متوکسی و سیانو- مالون آلدهید
  هادی زارع یوسفخانی محمد وکیلی وحیدرضا داروگر
  پیوند هیدروژنی درون مولکولی (IHB) مالون آلدهید به عنوان ساده ترین سیستم پیوند هیدروژنی تقویت شده با رزونانس در گروه متقارن O-H…O را انتخاب کرده و مشتقات هالوی آن (F ، Cl وBr )، متوکسی و سیانو در سطح تئوری DFT B3LYP / 6-311 ++ G ** مورد بررسی قرار گرفته است. محاسب أکثر

  پیوند هیدروژنی درون مولکولی (IHB) مالون آلدهید به عنوان ساده ترین سیستم پیوند هیدروژنی تقویت شده با رزونانس در گروه متقارن O-H…O را انتخاب کرده و مشتقات هالوی آن (F ، Cl وBr )، متوکسی و سیانو در سطح تئوری DFT B3LYP / 6-311 ++ G ** مورد بررسی قرار گرفته است. محاسبات پارامترهای توپولوژیکی، ساختاری، NBO و طیف سنجی را نیز در همان سطح برای آنها انجام دادیم. همبستگی خطی خوب بین انرژی پیوند هیدروژنی از طریق معادله اسپینوزا و پارامترهای محاسباتی از قبیل طول پیوند هیدروژنی، طول پیوند کووالانسی، فاصله دو اتم اکسیژن، زاویه سیستم پیوند هیدروژنی، پارامترهای توپولوژیکی از قبیل چگالی و لاپلاسین در نقاط بحرانی پیوند هیدروژنی و حلقه کی لیتی، پارامترهای NBO از جمله مرتبه پیوند پیوند هیدروژنی و انرژی برهمکنش فوق مزدوج شدن lp (O) → σ * (O-H) و همچنین پارامترهای طیف سنجی از جمله فرکانس ارتعاش کششی و خمشی O-H و جابجایی شیمایی محاسباتی هیدروژن پل در فاز گازی و محلول به دست آمد. تفاصيل المقالة
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  3 - Computational studies on the interaction of vitamin C (ascorbic acid) with nitrogen modified TiO2 anatase nanoparticles
  Amirali Abbasi Jaber Jahanbin Sardroodi
  10.22034/jna.2018.541848
  Density functional theory calculations were performed to investigate vitamin C interaction withN-doped TiO2 anatase nanoparticles. The adsorption of vitamin C on the energy favorable fivefoldcoordinated titanium sites was investigated. Various adsorption geometries of v أکثر

  Density functional theory calculations were performed to investigate vitamin C interaction withN-doped TiO2 anatase nanoparticles. The adsorption of vitamin C on the energy favorable fivefoldcoordinated titanium sites was investigated. Various adsorption geometries of vitamin C towardsthe nanoparticle were examined. Since the adsorption energies of N-doped nanoparticles are higherthan those of undoped ones, the N-doped TiO2 nanoparticles can interact with vitamin C moleculemore strongly. Besides, adsorption on the pristine nanoparticle is less favorable, whereas on theN-doped one, the adsorption process is more energy favorable. The electronic structure analysis wasperformed in view of the density of states and molecular orbitals of the considered nanoparticles withthe adsorbed vitamin C molecule. The significant overlaps between the PDOS spectra of the oxygenatom of vitamin C molecule and titanium atom of TiO2 confirm the chemisorption of vitamin C onthe TiO2 nanoparticle. After the adsorption, the electronic densities in the HOMOs of the adsorptionsystems were mainly distributed over the vitamin C molecule, while the LUMOs were dominant atthe TiO2 nanoparticle. Our calculations shed light on understanding the interaction between vitamin Cand TiO2 nanoparticles, which provides an efficient outline for future experimental studies. تفاصيل المقالة
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  4 - Adsorption Behaviors of Curcumin on N-doped TiO2 Anatase Nanoparticles: Density Functional Theory Calculations
  Amirali Abbasi Jaber Jahanbin Sardroodi
  10.22034/jna.2017.01.010
  The density functional theory (DFT) calculations were used to get information concerning the interaction of curcumin with pristine and N-doped TiO2 anatase nanoparticles. Three adsorption geometries of curcumin over the TiO2 anatase nanoparticles were studied in order t أکثر

  The density functional theory (DFT) calculations were used to get information concerning the interaction of curcumin with pristine and N-doped TiO2 anatase nanoparticles. Three adsorption geometries of curcumin over the TiO2 anatase nanoparticles were studied in order to fully exploit the sensing properties of TiO2 nanoparticles. Curcumin molecule adsorbs on the fivefold coordinated titanium sites of the TiO2 nanoparticle because of the higher affinity of these sites with respect to the curcumin molecule. A preferred perpendicular adsorption of curcumin on the OC-substituted nanoparticle was found to be the most favorable conformation with the estimated adsorption energy of about -5.33 eV. The results suggest that the curcumin molecule favorably interacts with the N-doped TiO2 nanoparticle, that is, the interaction of curcumin with the pristine nanoparticle is less favorable in energy than the interaction with the N-doped one. The structural parameters such as bond lengths/angles and adsorption energies were examined for the discussion of results. The electronic structures of the system were analyzed in view of the density of states and molecular orbitals. The analysis of projected density of states and molecular orbitals showed forming new chemical bonds between the nanoparticle and curcumin molecule. By including vdW interactions, the adsorption energies of the most stable curcumin+TiO2 couples were increased, implying the dominant effect of dispersion energy. تفاصيل المقالة