Seven-membered rings

Cycloheptatriene (CHT) is an organic compound with the formula C7H8. It is a closed ring of seven carbon atoms joined by three double bonds (as the name implies) and four single bonds. This colourless liquid has been of recurring theoretical interest in organic chemistry. It is a ligand in organometallic chemistry and a building block in organic synthesis. Cycloheptatriene is not aromatic, as reflected by the nonplanarity of the methylene bridge () with respect to the other atoms; however the related tropylium cation is, rendering the compound relatively suspectible to oxidation.

Cycloheptene is a 7-membered cycloalkene with a flash point of −6.7 °C. It is a raw material in organic chemistry and a monomer in polymer synthesis. Cycloheptene can exist as either the cis- or the trans-isomer. 400px

Thiepane (also hexathiophane) is the organosulfur compound with the formula (CH2)6S. Thiepanes are seven-membered ring heterocycles that contains sulfide. The parent thiepane has seldom been studied.

Cycloheptanone, (CH2)6CO, is a cyclic ketone also referred to as suberone. It is a colourless volatile liquid. Cycloheptanone is used as a precursor for the synthesis of pharmaceuticals.

thumb|rightBorepins are a class of boron-containing heterocycles used in main group chemistry. They consist of a seven-membered unsaturated ring with a tricoordinate boron in it. Simple borepins are analogues of cycloheptatriene, which is a seven-membered ring containing three carbon-carbon double bonds, each of which contributes 2π electrons for a total of 6π electrons. Unlike other seven-membered systems such as silepins and phosphepins, boron has a vacant p-orbital that can interact with the π and π* orbitals of the cycloheptatriene. This leads to an isoelectronic state akin to that of the

Cycloheptadiene may refer to: 1,2-Cycloheptadiene, CAS 6577-10-2 1,3-Cycloheptadiene 1,4-Cycloheptadiene

1,3-Cycloheptadiene is a highly flammable cycloalkene that occurs as a colorless clear liquid.

1,4-Cycloheptadiene is a highly flammable cycloalkene that occurs as a colorless clear liquid. It can form a yellow complex with palladium.