Problems in chemistry regarding the structure of organic compounds are collinear and coplanar

The C in the carbon-carbon double bond adopts the sp2 hybrid method, and the sp2 stereo conformation is a regular triangle with a bond angle of 120 degrees, so it can ensure that at least the atoms connected to it are coplanar (planar triangle). For example, the ethylene molecule is a planar molecule. But if the h around the ethylene is replaced by other groups, then you have to look at what the three-dimensional configuration of this group is, for example, a methyl group is connected, the methane is a tetrahedral, and the bond angle is 109 degrees, then except for the central atom c and the double bond are in the same plane, the other three hs of the methyl group are not in the same plane.

At this time, methyl C and ethylene C are connected by bonds, so they can rotate.

If the carbon-carbon double bond of ethylene is connected to a benzene ring, the benzene ring is a planar molecule, but it can form a p- conjugation with the carbon-carbon double bond, which is in a plane, but cannot rotate. Because the p-track is covered shoulder to shoulder, it will destroy this kind of overlap when rotated, so it cannot be rotated.

With the increase of the carbon-carbon double bond group, the possibility of coplanarity decreases due to the void resistance.

This problem should be analyzed using the geometrical configuration of the molecule, i.e., the valence shell electron mutual exclusion model (VSEPR).

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I can tell you responsibly that the statement of the third floor is wrong. A carbon-carbon double bond can have up to 14 atoms coplanar, typically tetramethylethylene, which is the product of all four hydrogens of ethylene being replaced by methyl groups. In fact, looking at the coplanar collinearity, you only need to remember that all the atoms of ethylene and benzene are coplanar, so all the atoms of styrene are also coplanar, and all the atoms of acetylene are collinear, and after determining the plane, the methyl group has a maximum of three atoms that are coplanar with the original plane, and at least one coplanar.

Complex judgments are just a superposition of these few. For example, the tetramethylethylene, the atoms attached to the carbon-carbon double bond must be coplanar, which is already six atoms. Considering the hydrogen atoms in the methyl group again, there are up to two hydrogen atoms in each methyl group that are coplanar with the original plane, which is again eight, for a total of fourteen.

This is actually very simple, it is recommended to find some organic matter to make a judgment, and after getting the result, find the teacher to check, and strive to fully understand. There's only so much more I can help you*

A carbon-carbon double bond guarantees that six atoms are coplanar. A carbon-carbon triple bond can ensure that four atoms are collinear, and a benzene ring has twelve atoms coplanar, and when they are combined, a single bond can be rotated, and at least how many atoms are coplanar, find a certain number of atoms in the coplanar. How many atoms are likely to be coplanar, find a maximum of several coplanarities under the condition that a single bond can be rotated.

Hope it helps.

You remember that carbon-carbon single bonds and carbon-hydrogen single bonds can be rotated, plus you remember the spatial structure of methyl groups, rotate the single bonds, so that you don't know at least or at most a few atoms are collinear or coplanar, a carbon-carbon double bond can ensure that at least six atoms are coplanar, such as ethylene, other olefins are equivalent to substitutions on the basis of ethylene, but the atoms connected to the double-bonded carbon must be coplanar with the double bond. If there's anything else you don't understand, you can ask again.

You only need to remember a few models: CH4 is a tetrahedral structure, C2H4 is a planar structure (all 6 atoms are coplanar), C2H2 is a linear structure (all 4 atoms are collinear), benzene ring is a planar structure (all 12 atoms are coplanar), if there is a carbon-oxygen double bond, it is considered as a carbon-carbon double bond (i.e., ethylene type), and the hydroxyl group is a single bond and can be rotated.

When you look at at least the most atomic collinear coplanar, you can rewrite the molecular formula into a structural formula, that is, write the above models, and it will be naturally organized.

6 atoms can be guaranteed to be coplanar. The way to judge is to note that C--C can rotate 360°, and like the autobiography of the Earth on its axis, double or triple bonds will not work.

The judgment of the collinear coplanarity problem of organic matter is introduced as follows:

Benzene ring 12 atoms coplanar. The carbon-carbon double bond hexadon is coplanar, and the carbon-carbon triple builds 4 atoms coplanar. Up to 3 atoms on a carbon coplanar.

The coplanar collinearity of atoms in organic molecules is a difficult point in the teaching of organic chemistry in middle schools. The thinking method for solving such problems is as follows: The basis of thinking on atomic coplanar collinear problems:

Tetrahedral structure of methane; Planar structure of ethylene, benzene, naphthalene, anthracene group; Linear structure of acetylene.

Tetrahedral structure of methane;

In the methane molecule, one carbon atom and any two hydrogen atoms determine a plane, and the remaining two hydrogen atoms are located on either side of the plane, i.e., there are and only three atoms in the methane molecule that are coplanar (called the triangle rule). When a hydrogen atom in a methane molecule is replaced by another atom or cluster of atoms, the coplanarity of the substituted atom can be regarded as the original hydrogen atom position.

Flat structure of ethylene.

All the atoms in the ethylene molecule are in the same plane with a bond angle of 120°When a hydrogen atom in an ethylene molecule is replaced by other atoms or clusters, the atom that replaces the hydrogen atom must be in the plane of ethylene. Three hydrogen atoms ( and three carbon atoms ( Six atoms must be coplanar.

According to the slag triangle rule [ c, c, h form a triangle].

h may also be in this plane. At least 6 atoms (6 carbon atoms) and up to 10 atoms [6 carbon atoms and 4 hydrogen atoms (each methyl group can provide one hydrogen atom)] are coplanar.

Planar structure of benzene.

All atoms of the benzene molecule are in the same plane with a bond angle of 120°When one hydrogen atom in a benzene molecule is replaced by another atom or cluster of atoms, the atom that replaces the hydrogen atom must be in the plane where the benzene molecule is located.

The 7 carbon atoms in toluene (6 carbon atoms on the benzene ring and one carbon atom on the methyl group), 5 hydrogen atoms (5 hydrogen atoms on the benzene ring) these 12 atoms must be coplanar. In addition, one hydrogen atom (h, c, c forming a triangle) on the methyl group can also be transferred to this plane, and the remaining two hydrogen atoms are distributed on both sides of the plane. Therefore, it is possible that a maximum of 13 atoms are coplanar in the toluene molecule.

The O of hydroxyl-OH is sp3 hybridized, regular tetrahedral structure, but it has two lone pairs of electrons, so it is V-shaped, and three atoms form a plane, which can be said to be coplanar.

C of carbonyl group C=O is sp2 hybrid, planar triangle, three-atom coplanar aldehyde group as above.

The carboxyl group is not, -Cooh, CSP2 hybridized, planar triangle, with double-bonded oxygen, and the group on the left, i.e., hydroxyl oxygen, is coplanar. But it is not in the same plane as H in the hydroxyl group because the o of the hydroxyl-OH is a sp3 hybrid, regular tetrahedral structure.

The position of the two C-junctions of the carbon-carbon double bond is both coplanar. The position of the 6 C connections of the benzene ring is also coplanar.

The two positions of the two Cs of the carbon-carbon double bond are colinear.

That's all you learn in middle school. It's basic.

The most coplanar c atoms are 9.

All c's are coplanar.

Because the ethylene molecule is linear.

The benzene ring is above 6 C coplanar.

Plus the c atom above the methyl group.

There are 9 in total. At least 6 c atoms are coplanar (above the benzene ring).

The maximum number of coplanar atoms is 17.

In the same way, all atoms on ethylene are coplanar.

Plus 11 above the benzene ring.

2 above the methyl group (Methane is a tetrahedral structure.

Only 2 coplanar) plus 4 of the ethylene molecule (2 h was replaced) for a total of 17.

At least 11 (also above the benzene ring).

You remember that carbon-carbon single bonds and carbon-hydrogen single bonds can be rotated, plus you remember the spatial structure of methyl groups, rotate the single bonds, this cherry blossom does not know at least or at most a few atoms collinear or coplanar, a carbon-carbon double bond can ensure that at least six atoms are coplanar, such as ethylene, other olefins are equivalent to replacing round oranges on the basis of ethylene, but the atoms connected to the double-bonded carbon must be coplanar with the double bond. If you still have an orange preparation group, you can ask again if you don't understand it.

1. Colinear coplanarity in organic matter. You just see whether C and C are double bonds, triple bonds or keys, and a single key can be turned. Double and triple bonds cannot be turned.

2. Remember a few examples: ch4 tetrahedron ch2 = ch2 (ethylene) planar structure c2h2 (b missing) linear all atoms coplanar ben (planar structure) (all atoms coplanar).

According to the above two scenarios, all problems can be solved.

6 carbons and 5 hydrogens on the benzene ring plus one carbon and one hydrogen on the methyl group, for a total of 13 6 carbons on one benzene ring and two carbons on another benzene ring, because the sigma bond connecting the two benzene rings can rotate.

Add a hydrogen atom to each of the benzene rings on the biphenyl" What does this mean? I don't understand the collinear problem, mainly grasp the rotation of the sigma key and the key can not rotate, add a little space imagination, and draw it if you can't think of it, it's actually very simple.