Wikipedia - tridecane
Tridecane is any alkane hydrocarbon with the chemical formula C
28, or to a mixture of them. There are 802 constitutional isomers with that formula. In the IUPAC nomenclature, the name refers exclusively to one isomer, the straight-chain CH3(CH2)11CH3, also called normal or n-tridecane; the other isomers are named as derivatives of lighter hydrocarbons, as in 2,2,4,4-tetramethyl-3-t-butyl-pentane.