CONSTANTS OF SPIN-SPIN INTERACTION BETWEEN CARBON NUCLEI IN STERICALLY STRESSED SYSTEMS ON THE EXAMPLE OF BICYCLOPENTANES AND BICYCLOHEXANES

Within the framework of the self-consistent theory of finite perturbations SCPT INDO, the calculation of the spin-spin interaction constants 13C-13C with preliminary optimization of geometric parameters in 16 bicyclo derivatives is carried out[2.1.0] pentane and 11 bicyclo derivatives[2.2.0]hexane. According to the results of the calculations, the bridge connection in the studied series of compounds is characterized by an unusually low s-character of hybrid orbitals, amounting to 4.8-8.8 % in bicyclo derivatives[2.1.0] pentane and 11.3-12.9 % in bicyclo derivatives[2.2.0]hexane, which corresponds to the orbital hybridization from sp10. 30 to sp19. 92 in bicyclo[2.1.0]pentanes and from sp6. 76 to sp7. 89 in bicyclo[2.2.0]hexanes. The spin-spin interaction constants between bridged and non-bridged, or between two non-bridged carbon atoms in the studied series of compounds correlate with the corresponding spin-spin interaction constants 13C-13C in isostructured cyclopropanes and cyclobutanes, which indicates close hybridization

MECHANISMS OF TRANSMISSION OF THE SPIN-SPIN INTERACTION OF CARBON-CARBON IN A SERIES OF BICYCLOBUTANE DERIVATIVES

Within the framework of the self-consistent theory of finite perturbations SCPT INDO, the calculation of the spin-spin interaction constants 13C-13C with preliminary optimization of geometric parameters in 17 bicyclo derivatives is carried out[1.1.0.] of Bhutan. There is a good correspondence of the calculated constants with the experimental values known in the literature and measured in this work. Based on the results of the calculations performed, the study of hybridization effects in the considered series of compounds was carried out. All bicyclobutane derivatives are characterized by an abnormally low s-character of endocyclic hybrid orbitals forming a bond between bridging carbon atoms. Substitution effects have a weak effect on the s-order of the bridge connection. The presence of an unsaturated alcohol structure in the 2-position of the bicyclo-butane fragment leads to a sharp decrease in the s-character of the endocyclic hybrid orbitals of the bridged carbon atoms.

Systematics of Atomic Orbital Hybridization of Coordination Polyhedra: Role of f Orbitals

The combination of atomic orbitals to form hybrid orbitals of special symmetries can be related to the individual orbital polynomials. Using this approach, 8-orbital cubic hybridization can be shown to be sp3d3f requiring an f orbital, and 12-orbital hexagonal prismatic hybridization can be shown to be sp3d5f2g requiring a g orbital. The twists to convert a cube to a square antiprism and a hexagonal prism to a hexagonal antiprism eliminate the need for the highest nodality orbitals in the resulting hybrids. A trigonal twist of an Oh octahedron into a D3h trigonal prism can involve a gradual change of the pair of d orbitals in the corresponding sp3d2 hybrids. A similar trigonal twist of an Oh cuboctahedron into a D3h anticuboctahedron can likewise involve a gradual change in the three f orbitals in the corresponding sp3d5f3 hybrids.

From Abstract to Manipulatable – The Hybridization Explorer, A Digital Interactive for Studying Orbitals

<p>The abstract nature of atomic and hybrid orbitals makes it a challenging concept for students to understand. Presented is the Hybridization Explorer, a web-based interactive learning tool, for manipulating and experimenting with hybridization concepts. Through the explorer students can explore both the combination of atomic orbitals, and the visual representation of both atomic and hybrid orbitals and corresponding bond formation. Case studies from an undergraduate and graduate-level demonstration of the explorer are described. Finally, self-reported student confidence levels on solving hybridization questions both before and after use of the explorer are analyzed and discussed.</p>

From Abstract to Manipulatable – The Hybridization Explorer, A Digital Interactive for Studying Orbitals

<p>The abstract nature of atomic and hybrid orbitals makes it a challenging concept for students to understand. Presented is the Hybridization Explorer, a web-based interactive learning tool, for manipulating and experimenting with hybridization concepts. Through the explorer students can explore both the combination of atomic orbitals, and the visual representation of both atomic and hybrid orbitals and corresponding bond formation. Case studies from an undergraduate and graduate-level demonstration of the explorer are described. Finally, self-reported student confidence levels on solving hybridization questions both before and after use of the explorer are analyzed and discussed.</p>

Effects of halogen substituted on the Mn-O electron transfer of NiMn2O4

To observe the effect of halogen-substitution on the Mn-O electron transfer of NiMn2O4, we calculated Mn-mixed-valence configuration (charge-disproportionation) and oxygen vacancy by the density functional theory (DFT). The results indicate that the halogen-p5 state induces the O-2p orbital splitting to create an oxygen vacancy in the VB (valence band: about −5 eV). The oxygen vacancy can capture an electron from Mn[Formula: see text]-3d5 orbital that makes the Mn[Formula: see text]-3d5 change to Mn[Formula: see text]-3d4 states (Mn-charge disproportionate), and providing many effective-hole (40.14 [Formula: see text] 96.72 × 10[Formula: see text] kg). The halogen-p5-O-2p4 hybrid orbitals enhance the O-2p4-Mn-3d5 p-d hybrid orbital (about 19.18 electron). That increases the surface potential in Mn-O octahedron (for Cl-substituted: about 60 meV), the corresponding electron–electron interactions change from complex t[Formula: see text] (O-2p4-Mn[Formula: see text]-3d[Formula: see text] to complete [Formula: see text] (O-2p4-Mn[Formula: see text]-3d[Formula: see text]-e[Formula: see text](O-2p4-halogen-p5) orbital. This study effectively analyzes the microscopic changes of the electron transfer caused by the small amount of doping, provides a theoretical basis for the design of NMO-based semiconductor material.