Key Difference – VBT vs CFT
VBT一词代表价键理论。这是一种用于描述原子之间不同化学键的形成的理论。该理论解释了原子轨道形成化学键的重叠或混合。CFT一词代表晶体场理论。这是一种旨在解释电子轨道（通常是能量的电子壳）（通常是d或f轨道）的破裂（电子壳）的模型，这是由于周围环境产生的静态电场anionor anions (orligands). The key difference between VBT and CFT is thatVBT explains the mixing of orbitals whereas CFT explains the splitting of orbitals.
What is VBT
VBT一词代表价键理论。它解释了共价化合物的化学键合。因此，VBT解释了如何covalent bondis formed. A covalent bond is formed via sharing of electrons between atoms. Atoms share electrons to fill their electron configuration (otherwise they are unstable). The electrons are shared by mixing or overlapping ofatomic orbitals。But before overlapping occurs, several requirements should be fulfilled.
There are three major hybrid orbitals that can be formed:
- sp Hybrid Orbital – Formed via hybridization of one s and one p orbital.
- sp2 Hybrid Orbital – Formed via hybridization of one s and two p orbitals.
- sp3 Hybrid Orbital – Formed via hybridization of one s and three p orbitals.
CFT一词代表晶体场理论。Crystals field theory is a model designed to explain the breaking of degeneracies (electron shells of equal energy) of electron orbitals (usually d or f orbitals) due to the static electric field produced by a surrounding anion or anions (or ligands). Crystal field theory is often used to demonstrate the behavior oftransition metalions complexes. This theory can also explain about magnetic properties, colors of coordination complexes, hydration enthalpies, etc.
The interaction between the metal ion and ligands is due to the attraction between the metal ion with a positive charge and the unpaired electrons (negative charge) of the ligand. This theory is mainly based on the changes that occur in five degenerate d electron orbitals (a metal atom has five d orbitals). When a ligand comes close to the metal ion, the unpaired electrons are closer to some d orbitals when compared with other d orbitals of the metal ion. This causes a loss of degeneracy. The electrons in the d orbitals repel the electrons of the ligand (both are negative charged). Hence the d orbitals that are closer to the ligand have a high energy than other d orbitals. This result in the splitting of d orbitals into high energy d orbitals and low energy d orbitals, based on the energy.
Since there are five d orbitals, the splitting occurs in a ratio of 2:3. In octahedral complexes, two orbitals are in the high energy level (collectively known as eg) and three orbitals are in the lower energy level (collectively known as t2g). In tetrahedral complexes, the opposite occurs; three orbitals are in the higher energy level and two in the lower energy level.
|VBT是一种解释通过原子轨道杂交共价键形成的理论。||CFT is a model that is designed to explain the breaking of degeneracies of electron orbitals due to static electric field produced by a surrounding anion or anions|
|VBT explains the mixing of orbitals.||CFT explains the splitting of orbitals.|
摘要 - VBT与CFT