What is the chemical structure of iso-sec-tert-butyl and how does it differ from other isomers of butyl compounds?

Iso-sec-tert-butyl has a chemical structure of (CH3)3C-CH(CH3)2. It differs from other isomers of butyl compounds in its branching pattern, which results in a more compact and symmetrical structure compared to straight-chain or branched isomers. This can affect its physical and chemical properties, such as boiling point and reactivity.