Charge Density Distribution and Bond Characterization of 2,2′‐Dipyridylamine (Hdpa): A Combined Study of Experiment and Theory

Li, Wu; Lee, Gene‐Hsiang; Chen, Chien‐Kai; Wang, Chih‐Chieh

doi:10.1002/jccs.201200651

Cited by 5 publications

(1 citation statement)

References 68 publications

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“…There are many ball seeds in the corn seed. While the inclined hole can better fill and cast seeds [19], it's suitable for non-spherical seeds such as corn, which are difficult to fill and easy to jam [20]. In this paper, the socket hole and the inclined hole are combined, and then a type of hole suitable for simultaneous sowing of corn is designed.…”

Section: Hole-type Structurementioning

confidence: 99%

Design and experiment of mechanical dustpan type-hole wheel corn seeder

Wang,

Pan,

Ren

et al. 2024

Preprint

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Using variable capacity seed filling technology, a dustpan type-hole wheel type corn seed discharging device with stopping plate was developed in order to enhance the mechanical hole wheel type corn seeder's seed discharging performance. By combining discrete element numerical simulation and methods that combine dynamics and kinematics theories. The structural parameters of the key components of the seeder were determined. Simultaneous corn hole sowing performance tests were done. The experimental findings indicated that the use of the dustpan type-hole resulted in qualified sowing rates of 97.2% for corn. The hole spacing rates for minimum qualification was 98.8%. Within the design parameters, changes in sowing operating parameters had a minor impact on the performance of the seeder. The bench performance test results demonstrate that the seeder's overall performance satisfies the criteria for agricultural planting.

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Section: Hole-type Structurementioning

confidence: 99%

Design and experiment of mechanical dustpan type-hole wheel corn seeder

Wang,

Pan,

Ren

et al. 2024

Preprint

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Experimental and Theoretical Charge Density Study on Di‐2‐pyrazylamine (Hdpza) Molecule in Crystal

Li¹,

Lee

2015

J Chinese Chemical Soc

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Electron density distribution of Di-2-pyrazylamine (Hdpza) is studied both by single-crystal X-ray diffraction method at 100K and theoretical calculation. Structural determination reveals that Hdpza molecules crystalize in a syn-anti conformation with an intramolecular C-H×××N hydrogen bond between two pyrazine rings and then gather together via two intermolecular N-H×××N and C-H×××N hydrogen interaction and p-p stacking interaction between pyrazine rings. Charge density analysis is made in terms of deformation density (Dr), Laplacian distribution and topological analysis of total electron density based on multipole model and theoretical calculation. The agreement between experiment and theory is good. The topological properties at bond critical points of C-C and C-N bonds reveal a covalent bond character, and those of intermolecular interactions, such as hydrogen bonds and p-p stacking interactions, reveal a closed-shell interaction. The potential energy curve of Hdpza molecule shows that the syn-anti conformation is the most stable one (global minima) than the other two of syn-syn and anti-anti conformations.

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Chemical Bonding in a Linear Chromium Metal String Complex

Thomsen

Madsen

et al. 2014

Inorg. Chem.

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A combined experimental and theoretical electron density study of the shortest trichromium metal wire, Cr3(dpa)4Cl2·(C2H5OC2H5)(x)(CH2Cl2)(1-x) (1, dpa = bis(2-pyridyl)amido), is reported. High resolution X-ray diffraction data has been collected both at 100 K using a conventional X-ray source (DS1) and at 15 K using a synchrotron X-ray source (DS2). The linear chromium string is terminated by Cl(-) ions at both ends, and each Cr atom is also coordinated by four N atoms from bridging dpa ligands. The two Cr-Cr bond distances are unequal at 100 K (with d(Cr1-Cr2) being 0.029 Å shorter than d(Cr2-Cr3)) but at 15 K they are almost equal (0.002 Å difference). Analysis of the slightly elongated thermal ellipsoids of the Cr2 atom suggests that it is not due to disorder, but the presence of a shallow potential energy surface. Laplacian maps clearly show local valence shell charge concentration (VSCC) in the electron density along the bisector of the equatorial Cr-N bonds. Integration over the atomic basins indicates that Cr2 has smaller atomic charge and volume than Cr1 and Cr3. The topological characterization of the Cr-Cr bonds indicates partly covalent characters with electron density at the bond critical point of ∼0.3 e Å(-3) and negative total energy density. The delocalization index of Cr-Cr is 0.8 for Cr1-Cr2 and 0.08 for Cr1-Cr3. Second-order perturbation analysis shows high stabilization energy of the Cr-Cr bonds (E(2) ∼ 190 kcal mol(-1)). Delocalization indices and source function and natural bond orbital analyses are all indicative of localized Cr-Cr bonding interactions.

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Charge Density Distribution and Bond Characterization of 2,2′‐Dipyridylamine (Hdpa): A Combined Study of Experiment and Theory

Cited by 5 publications

References 68 publications

Design and experiment of mechanical dustpan type-hole wheel corn seeder

Design and experiment of mechanical dustpan type-hole wheel corn seeder

Experimental and Theoretical Charge Density Study on Di‐2‐pyrazylamine (Hdpza) Molecule in Crystal

Chemical Bonding in a Linear Chromium Metal String Complex

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