Question

sigma bonded organometallic compounds

Answer 1

Organometallic compounds have at least one carbon to metal bond, according to most definitions. This bond can be either a direct carbon to metal bond metal complex bond 

Answer 2

The organo-metallic compounds which have single bond between carbon and metal/other element is also known as sigma bond or we can say sharing of one - one electron bond .

Examples -
$CH_{4}$

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