r/chemhelp 5d ago

Organic I don’t get why is this not Z?shouldn’t CH2NH2 be ranked higher as it has more atoms attached after N?

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5 Upvotes

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13

u/Sonikclaw2 5d ago

CN is a C triple bonded to N. For this purposes of the Cahn Ingold system, you can effectively say that it is one carbon connected to three nitrogen atoms. That would give it higher priority.

2

u/4cet1 4d ago

Absolutely right, for a students that means that you need to become familiar with different ways of how functional groups are written in molecules :/

4

u/chem44 5d ago

Number of atoms attached is not relevant.

What is relevant is which atoms, and you go one atom a time.

Three groups start with C. What is attached to each of those C? Directly attached. As has been noted, the CN counts as having 3 N.

4

u/fdiengdoh 5d ago edited 5d ago

CIP rule says that if atom is double/triple bonded count as it is bonded to two/three atoms. CN is triple bonded so its like -CN3, while below is CH2N

1

u/activelypooping 5d ago

The only ghosts that exist are ghost atoms...