Semistructural formulas

When wewant to summarise the structural formula of a compound withoutindicatingthe three-dimensional arrangement of atoms, we can use asemistructuralformula.

• In a semistructural formula, the carbon atomsand the attached hydrogen atoms, are listed in the order in which they appearin the structural formula.

• Single bonds are not indicated but any doubleor triple bonds are shown.

• Groups of atoms that form branches in amolecule are written inbracketsafter the carbon atom to which they are attached.

2,3dimethylbutane

CH3CH(CH3)CH(CH3)CH3

but-2-ene

CH3CH=CHCH3

Draw thestructural formulas theisomers of C4H10