## What is the point group of toluene?

Toluene is an aromatic hydrocarbon composed of a benzene ring linked to one methyl group.

### What are the five symmetry elements?

There are five types of symmetry operations including identity, reflection, inversion, proper rotation, and improper rotation.

#### What are the main symmetry elements?

The symmetry element consists of all the points that stay in the same place when the symmetry operation is performed….The symmetry elements that a molecule may possess are:

- E – the identity.
- Cn – an n-fold axis of rotation.
- σ – a plane of symmetry.
- i – a center of symmetry.

**What is the symmetry element of benzene?**

Any planar molecule, such as benzene, has its molecular plane as a plane of symmetry because reflection across the molecular plane leaves all nuclei unmoved. NH3 has three planes of symmetry each of which contains an N–H bond and is perpendicular to the plane containing the three hydrogen atoms.

**What are the hazards of toluene?**

Health Hazards of Toluene Symptoms of toluene exposure include: irritation of the eyes and nose; weakness, exhaustion, confusion, euphoria, dizziness, headache; dilated pupils, lacrimation (discharge of tears); anxiety, muscle fatigue, insomnia; numbness or tingling of the skin; dermatitis.

## What is proper symmetry?

The subgroup of orientation-preserving symmetries (translations, rotations, and compositions of these) is called its proper symmetry group. An object is chiral when it has no orientation-reversing symmetries, so that its proper symmetry group is equal to its full symmetry group.

### Is identity a symmetry element?

Identity. The identity symmetry element is found in all objects and is denoted E. It corresponds to an operation of doing nothing to the object.

#### What is the difference between symmetry elements and symmetry operations?

A symmetry element is a geometrical entity about which a symmetry operation is performed. A symmetry element can be a point, axis, or plane. A symmetry operation is the movement of a body (molecule) such that after the movement the molecule appears the same as before.

**How many main symmetry elements are there?**

Elements. The point group symmetry of a molecule can be described by 5 types of symmetry element. results in a molecule indistinguishable from the original.

**How many C2 axes are present in benzene?**

Benzene contains a main C6 axis which contains S6 and S3 axes. Perpendicular to the C6 axis are 6 C2 axes. There is a σh, 3 σv and 3 σd planes, as well as an inversion centre. Hence Benzene belongs to the D6h point group.

## How poisonous is toluene?

Toluene is irritating to the skin, eyes, and respiratory tract. It can cause systemic toxicity by ingestion or inhalation and is slowly absorbed through the skin. The most common route of exposure is via inhalation.

### Which is a point group of D 6h symmetry?

In the above reaction, the product benzene is of D 6h symmetry, but only C 2V symmetry elements are common for both Dewar benzene and benzene. We can perform therefore the symmetry analysis of the VB structures within the C2V point group framework. There are 6 essential valence electrons involved in the reaction, numbered from 1 to 6.

#### Is the product benzene of point group D6h?

In the above reaction, the product benzene is of D 6h symmetry, but only C 2V symmetry elements are common for both Dewar benzene and benzene. We can perform therefore the symmetry analysis of the VB structures within the C2V point group framework.

**What are the problems of point group D6h?**

Combining the MO method and VB calculations, we investigated atom exchange reactions: H + HLi → H 2 + Li and H + LiH → HLi + H, and discussed the effect of energy differences between the VB structures on the activation energy and properties of the transition state [70] Answers to all problems marked with * are given in Appendix 4.

**How are valence bond calculations done in D6h?**

The valence bond calculations were conducted at the VB/6-31G (d,p) level of theory, on B3LYP optimized structures, using TURTLE as implemented in the GAMESS-UK package.