Portraying an image of a type of chemical bond involving carbon (6)
I believe the answer is:
iconic
'portraying an image' is the definition.
(an icon is an image)
'bond involving carbon' is the wordplay.
'bond' becomes 'ionic' (ionic bond is a kind of bond).
'involving' means one lot of letters goes inside another.
'carbon' becomes 'c' (chemical symbol).
'ionic' going around 'c' is 'ICONIC'.
'of a type of chemical' acts as a link.
This may not be right. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for iconic that I've seen before include "Having the characteristics of revered person" , "Representative or relating to a sacred image" , "Symbolic, emblematic" , "that's like an emoji?" , "Worthy of veneration" .)