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Articles 1 - 10 of 10
Full-Text Articles in Other Chemistry
Receptor For Fluorescence Sensing Of Organic Acid And Method Of Preparation Thereof (유기산 형광 인지 수용체 및 이의 제조방법), Hong Seok Kim, Md Wasi Ahmad
Receptor For Fluorescence Sensing Of Organic Acid And Method Of Preparation Thereof (유기산 형광 인지 수용체 및 이의 제조방법), Hong Seok Kim, Md Wasi Ahmad
Dr. Mohammad Wasi Ahmad (Md Wasi Ahmad)
The invention relates to the receptor it is the novel cholestane -based fluorescence which selectively reacts to the organic acid the pyrene group is bound as the fluorescence having the selectivity in the organic acid the receptor and a manufacturing method thereof in the imidazole -based cholestane introducing the imidazole to more detailed cholestane skeleton and manufacturing method thereof. By showing the organic acid, especially, the oxalic acid and high binding affinity the receptor has the effect that it selectively senses and the receptor can use in the sensing of the oxalic acid whether it is the imidazole -based cholestane …
Benchmark Structures And Binding Energies Of Small Water Clusters With Anharmonicity Corrections, Berhane Temelso, Kaye A. Archer, George C. Shields
Benchmark Structures And Binding Energies Of Small Water Clusters With Anharmonicity Corrections, Berhane Temelso, Kaye A. Archer, George C. Shields
Berhane Temelso
For (H2O)n where n = 1–10, we used a scheme combining molecular dynamics sampling with high level ab initio calculations to locate the global and many low lying local minima for each cluster. For each isomer, we extrapolated the RI-MP2 energies to their complete basis set limit, included a CCSD(T) correction using a smaller basis set and added finite temperature corrections within the rigid-rotor-harmonic-oscillator (RRHO) model using scaled and unscaled harmonic vibrational frequencies. The vibrational scaling factors were determined specifically for water clusters by comparing harmonic frequencies with VPT2 fundamental frequencies. We find the CCSD(T) correction to the RI-MP2 binding …
The Role Of Anharmonicity In Hydrogen-Bonded Systems: The Case Of Water Clusters, Berhane Temelso, George Shields
The Role Of Anharmonicity In Hydrogen-Bonded Systems: The Case Of Water Clusters, Berhane Temelso, George Shields
Berhane Temelso
The nature of vibrational anharmonicity has been examined for the case of small water clusters using second-order vibrational perturbation theory (VPT2) applied on second-order Møller–Plesset perturbation theory (MP2) potential energy surfaces. Using a training set of 16 water clusters (H2O)n=2–6,8,9 with a total of 723 vibrational modes, we determined scaling factors that map the harmonic frequencies onto anharmonic ones. The intermolecular modes were found to be substantially more anharmonic than intramolecular bending and stretching modes. Due to the varying levels of anharmonicity of the intermolecular and intramolecular modes, different frequency scaling factors for each region were necessary to achieve the …
Broadband Fourier Transform Rotational Spectroscopy For Structure Determination: The Water Heptamer, Cristóbal Pérez, Simon Lobsiger, Nathan A. Seifert, Daniel P. Zaleski, Berhane Temelso, George C. Shields, Zbigniew Kisiel, Brooks H. Pate
Broadband Fourier Transform Rotational Spectroscopy For Structure Determination: The Water Heptamer, Cristóbal Pérez, Simon Lobsiger, Nathan A. Seifert, Daniel P. Zaleski, Berhane Temelso, George C. Shields, Zbigniew Kisiel, Brooks H. Pate
Berhane Temelso
Over the recent years chirped-pulse, Fourier-transform microwave (CP-FTMW) spectrometers have chan- ged the scope of rotational spectroscopy. The broad frequency and large dynamic range make possible structural determinations in molecular systems of increasingly larger size from measurements of heavy atom (13C, 15N, 18O) isotopes recorded in natural abundance in the same spectrum as that of the parent isotopic species. The design of a broadband spectrometer operating in the 2–8 GHz frequency range with further improvements in sensitivity is presented. The current CP-FTMW spectrometer performance is benchmarked in the analyses of the rotational spectrum of the water …
Collaborative Chemical Information Literacy: Is It "Scholarly?", Barbara C. Harvey
Collaborative Chemical Information Literacy: Is It "Scholarly?", Barbara C. Harvey
Barbara C. Harvey
This symposium illustrates a collaborative classroom activity that incorporates information literacy into an introductory chemistry course. The primary learning outcomes of the activity are to understand the peer-review process, knowing how to locate original research articles based on “clues” in a general news article, and how to differentiate between popular and scholarly periodicals. Students work in small groups in a highly-collaborative classroom setting. Each group is given a recent chemistry-related news item, and must determine how and where to find the original research article the news item is based on. Emphasis is placed on identifying original, peer-reviewed research publications. Each …
Pyrene Appended Imidazole Compound And Selective Fluorescence Sensing Of Aromatic Carboxylic Acids Using The Same (파이렌-이미다졸기가 연결된 화합물 및 이를 이용한 방향족 카르복실산의 선택적 형광인지), Hong Seok Kim, Md Wasi Ahmad
Pyrene Appended Imidazole Compound And Selective Fluorescence Sensing Of Aromatic Carboxylic Acids Using The Same (파이렌-이미다졸기가 연결된 화합물 및 이를 이용한 방향족 카르복실산의 선택적 형광인지), Hong Seok Kim, Md Wasi Ahmad
Dr. Mohammad Wasi Ahmad (Md Wasi Ahmad)
The invention relates to the novel compound and the manufacturing method thereof, and the benzoic acid derivative and the salicylic acid derivative composition for detecting using the same. The novel compound of the present invention is comprised of the pyrene and imidazole. And it hydrogen-bonds with the compound which the imidazole part detects. It interacts with the benzene ring and strong π - π of the compound which the pyrene part detects and the fluorescence intensity is changed the aromatic carboxylic acid can be recognized.
Isoquinoline-Derivatized Tris(2-Pyridylmethyl)Amines As Fluorescent Zinc Sensors With Strict Zn2+/Cd2+ Selectivity, Shawn Burdette, Yuji Mikata, Keiko Kawata, Saaya Takeuchi, Kaori Nakanishi, Hideo Konno, Saori Itami, Keiko Yasuda, Satoshi Tamotsu
Isoquinoline-Derivatized Tris(2-Pyridylmethyl)Amines As Fluorescent Zinc Sensors With Strict Zn2+/Cd2+ Selectivity, Shawn Burdette, Yuji Mikata, Keiko Kawata, Saaya Takeuchi, Kaori Nakanishi, Hideo Konno, Saori Itami, Keiko Yasuda, Satoshi Tamotsu
Shawn C. Burdette
Tris(2-pyridylmethyl)amine-based fluorescent ligands, N,N-bis(1-isoquinolylmethyl)-2-pyridylmethylamine (1-isoBQPA) and N,N-bis(7-methoxy-1-isoquinolylmethyl)-2-pyridylmethylamine (7-MeO-1-isoBQPA), have been prepared and the Zn2+-induced fluorescence enhancement has been investigated. Upon excitation at 324 nm, 1-isoBQPA exhibits a very weak emission (ϕ = [similar]0.010) in DMF–H2O (1 : 1). Upon Zn2+ addition, the 1-isoBQPA fluorescence increases (ϕZn = 0.055) at 357 nm and 464 nm. The fluorescence enhancement at longer wavelengths is Zn2+-specific, whereas Cd2+ induces a small emission increase at 464 nm (ICd/I0 = 1.1, ICd/IZn = 14%). The Zn2+/Cd2+ selectivity of the fluorescent response correlates with the Cd–Nisoquinoline and Zn–Nisoquinoline bond distances measured in the crystal structures. Introduction of …
Bis(2-Quinolylmethyl)Ethylenediaminediacetic Acids (Bqendas), Tqen–Edta Hybrid Molecules As Fluorescent Zinc Sensors, Shawn Burdette, Yju Mikata, Saaya Takeuchi, Hideo Konno, Satoshi Iwatsuki, Sakiko Akaji, Ikuko Hamagami, Masato Aoyama, Keiko Yasuda, Satoshi Tamotsu
Bis(2-Quinolylmethyl)Ethylenediaminediacetic Acids (Bqendas), Tqen–Edta Hybrid Molecules As Fluorescent Zinc Sensors, Shawn Burdette, Yju Mikata, Saaya Takeuchi, Hideo Konno, Satoshi Iwatsuki, Sakiko Akaji, Ikuko Hamagami, Masato Aoyama, Keiko Yasuda, Satoshi Tamotsu
Shawn C. Burdette
Molecular hybrids of TQEN (N,N,N′,N′-tetrakis(2-quinolylmethyl)ethylenediamine) and EDTA (ethylenediamine-N,N,N′,N′-tetraacetic acid) were examined as fluorescent Zn2+ sensors. Upon the addition of Zn2+, N,N-BQENDA (N,N-bis(2-quinolylmethyl)ethylenediamine-N′,N′-diacetic acid, 1a) exhibits a 30-fold emission enhancement at 456 nm (λex = 315 nm, ϕZn = 0.018) in buffer (HEPES, pH = 7.5, 100 mM KCl). The fluorescence enhancement is Zn2+-specific as Cd2+ induces much smaller increases (ICd/I0 = 5 and ICd/IZn = 16%). These spectroscopic properties, as well as the excellent water-solubility, represent a significant improvement compared to the parent TQEN sensor (ϕZn = 0.007, ICd/IZn = 64%). The isoquinoline analog N,N-1-isoBQENDA (N,N-bis(1-isoquinolylmethyl)ethylenediamine-N′,N′-diacetic acid, 1b) possesses a …
Stereoselective Synthesis Of 3,7-Diarylaminocholestanes By Titanium-Mediated Reductive Amination, Md Wasi Ahmad, Hong Seok Kim
Stereoselective Synthesis Of 3,7-Diarylaminocholestanes By Titanium-Mediated Reductive Amination, Md Wasi Ahmad, Hong Seok Kim
Dr. Mohammad Wasi Ahmad (Md Wasi Ahmad)
An efficient method for the synthesis of aryl aminocholestanes, using a chlorotriisopropoxytitanium (IV)-mediated reductive amination reaction of 5a-cholestane-3,7-dione, is reported. A series of 3, 7-diarylaminocholestane derivatives were prepared according to this methodology in up to 98% yield. These compounds were primarily characterized by 1H NMR, 13C NMR, and mass spectrometry.
Selective Fluorescence Sensing Of Salicylic Acid Using A Simple Pyrene Appended Imidazole Receptor, Md Wasi Ahmad, Bo Yeon Kim, Hong Seok Kim
Selective Fluorescence Sensing Of Salicylic Acid Using A Simple Pyrene Appended Imidazole Receptor, Md Wasi Ahmad, Bo Yeon Kim, Hong Seok Kim
Dr. Mohammad Wasi Ahmad (Md Wasi Ahmad)
A simple salicylic acid selective fluorescence receptor 1 was designed by combining 1-pyrenecarboxaldehyde and 1-(3-aminopropyl)imidazole. The selective sensing of salicylic acid resulted in a significant increase in monomer emissions due to the p–p interactions between the benzene and pyrene rings. The nature of the interactions between receptor 1 and salicylic acid was investigated further by 1H NMR spectroscopy, and the energy minimised structure of the complex between receptor 1 and salicylic acid was optimised. Receptor 1 showed the highest binding constant with 5-nitrosalicylic acid among all the aromatic carboxylic acids tested. 5-Nitrosalicylic acid formed a complex with receptor 1 at …