نتایج جستجو برای: homo lumo energy gap

تعداد نتایج: 802006  

Journal: :The journal of physical chemistry. B 2008
Qiang Peng Kuyson Park Tong Lin Michael Durstock Liming Dai

A class of new conjugated copolymers containing a donor (thiophene)-acceptor (2-pyran-4-ylidene-malononitrile) was synthesized via Stille coupling polymerization. The resulting copolymers were characterized by 1H NMR, elemental analysis, GPC, TGA, and DSC. UV-vis spectra indicated that the increase in the content of the thiophene units increased the interaction between the polymer main chains t...

Journal: :Nucleation and Atmospheric Aerosols 2021

The conducting polymers (CPs) are the important materials due to their large surface area, high thermal stability, good conductivity, easy shape, process and properties can be tuned by modifying structures or processing. Few have emerged as potential candidate for determination of a few anti-cancer drugs. In present study, sensing ability Poly-pyrrole (poly-py) has been investigated with withou...

Journal: :journal of physical & theoretical chemistry 2013
roya ahmadi reza soleymani

using the computational methods, the interaction effect of tyrosine amino acid on graphene wasinvestigated. for this purpose, the density functional theory (dft) in the ground state of 6-31gwas used, and the interaction effects of tyrosine on graphene was investigated through attachmentto three different base positions. different parameters such as energy levels, the amount ofchemical shift in ...

Journal: :organic chemistry research 2016
mehdi nabati mehrdad mahkam

one main group of organic chemistry is related to the aromatic compounds. in the present work, we replaced the ch group of benzene by silicon and nitrogen analogues. then, density functional theory (dft) calculations were carried out for six-membered heterocyclic si-n aromatic rings. full geometry optimizations were performed in gas-phase, and at b3lyp level using 6-311++g(d,p) and cbsb7 basis ...

Journal: :international journal of nano dimension 0
kh. tavakoli chemistry department, islamic azad university-, shahrekord branch, shahrekord, iran. m. keshavarz islamic azad university, shahreza branch, isfahan, iran chemistry department, shahreza university, p o box 311-86145, isfahan, iran. a. kazemi chemistry department, islamic azad university-, shahrekord branch, shahrekord, iran.

in this study the hardness swct was calculated with b3lyp,hf method and 3-21g,6-31g,6-311g basis set .then it was investigated with the best method(b3lyp) and basis set(6-31g) to study the adsorption effects co2 on the hardness of swcnt with gap homo-lumo in two shape: horizontal, vertical and top-center-bridge and we also provide the effects of co2 adsorption on the electronic properties(dos) ...

ژورنال: :شیمی کاربردی 0
لیلی رحیمی اهر leile rahimi ahar department of chemistry, ahar branch, islamic azad university, ahar, iranگروه شیمی، دانشگاه آزاد اسلامی واحد اهر، اهر، ایران زهره رحیمی اهر zohreh rahimi ahar department of chemical engineering, ahar branch, islamic azad university, ahar, iranگروه مهندسی شیمی، دانشگاه آزاد اسلامی واحد اهر، اهر، ایران لیدا اسدی lida asadi department of chemistry, omidiyeh branch, islamic azad university, khuzestan, iranگروه شیمی، دانشگاه آزاد اسلامی واحد امیدیه، امیدیه، ایران

در این تحقیق، طیف سنجی ir، مطالعات nbo، آنالیز homo-lumo، تعیین قطبیت، طول پیوند ها، زاویه پیوند ها، بار الکتریکی اتم ها، سختی کل، نرمی، الکتروندوستی و پتانسیل شیمیایی از h2o به h2te محاسبه شده است. محاسبات با استفاده از dft (نظریه تابعی دانسیته) با روشهای (pbepbe و hcth ) و با مجموعه پایه dgdzvp انجام شده است. مطابق محاسبات قطبش پذیری از h2oبه h2te افزایش یافته و اختلاف انرژی homo-lumo یا به ع...

2003
Zhiyong Zhou Louis Brus Richard Friesner

The difference between oxide and hydrogen passivation of small Si nanocrystals is explored by all-electron, hybrid functional DFT calculations with unrestricted geometry optimization. Oxide passivation lowers the band gap by about 2.4 eV for Si35 cores and by about 1.5 eV for Si66 cores. The oxide-passivated nanocrystals have optically forbidden, indirect-gap-type transitions whereas the hydrog...

2015
Gleb Sorohhov Chenyi Yi Michael Grätzel Silvio Decurtins Shi-Xia Liu

Two new photosensitizers featured with a cyanoacrylic acid electron acceptor (A) and a hybrid electron donor (D) of cyclopentadithiophene and dithiafulvenyl, either directly linked or separated by a phenyl ring, were synthesized and characterized. Both of them undergo two reversible oxidations and strongly absorb in the visible spectral region due to a photo-induced intramolecular charge-transf...

2006
Aurora Costales Ravindra Pandey

We report the results of a theoretical study of sequential oxidation of gallium oxide clusters from Ga3O4 to Ga3O8. These results, based on density functional theory calculations, find the ground state of the neutral clusters to be in the lowest spin state with nearly the same binding energy of 3.5 eV per atom. Electron affinity, ionization potential and HOMO–LUMO gap values of these oxygen-ric...

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