Related Experiment Video
Updated: Jun 11, 2026

Construction and Systematical Symmetric Studies of a Series of Supramolecular Clusters with Binary or Ternary Ammonium Triphenylacetates
Published on: February 15, 2016
Stability rules of main-group element compounds with planar tetracoordinate carbons
Congjie Zhang1, Wenhong Jia, Zexing Cao
1Key Laboratory of Macromolecular Science of Shaanxi Province, School of Chemistry & Materials Science, Shaanxi Normal University, Xi'an 710062, China. zcjwh@snnu.edu.cn
Abstract:
We have investigated the structures, stabilities, aromaticities, and Wiberg bond indices of four types of compounds (8-like, trapezia, umbrella-like, and quadrangle) containing planar tetracoordinate carbon (ptC), and the stability rules for the compound with ptC were concluded on the basis of extensive calculations. Generally, the stability or viability of compound with ptC strongly depends on the number of three-membered ring and conjugated three-membered ring, as well as pi electrons. These rules can be successfully used to identify the stability of other compounds reported in previous studies. On the basis of these rules, eight stable compounds with planar tetracoordinate nitrogen (ptN) are successfully constructed.
Related Concept Videos
Structures of Carboxylic Acid Derivatives
Carboxylic acid derivatives contain an acyl group attached to a heteroatom such as chlorine, oxygen, or nitrogen. The carbonyl carbon and oxygen are both sp2-hybridized with an unhybridized p orbital.
The three sp2 orbitals of the carbonyl carbon form three σ bonds, one each with the carbonyl oxygen, the α carbon, and the heteroatom, whereas the other two sp2 orbitals of the carbonyl oxygen are occupied by the lone pairs. Further, the unhybridized p...
Stability of Substituted Cyclohexanes
The two chair conformations of cyclohexanes undergo rapid interconversion at room temperature. Both forms have identical energies and stabilities, each comprising equal amounts of the equilibrium mixture. Replacing a hydrogen atom with a functional group makes the two conformations energetically non-equivalent.
For example, in...
Crystal Field Theory - Tetrahedral and Square Planar Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
Coordination Compounds and Nomenclature
Chair Conformation of Cyclohexane
The hydrogen atoms linked to carbons are arranged in two different axial and equatorial orientations to achieve this staggered...
Radicals: Electronic Structure and Geometry
Accordingly, the structure of a trivalent radical lies between the geometries of carbocations and carbanions. An sp2-hybridized carbocation is trigonal planar, while an sp3-hybridized carbanion is trigonal pyramidal. Here, the difference in geometry is...

