When you say deleted, do you mean you have deleted them using a DELETE statement, or have you updated them so their comm_deleted = 1?

If you have just updated them, you can use this:

UPDATE Comm_Link

SET cmli_deleted = 1

FROM Comm_Link

INNER JOIN Communication on cmli_comm_communicationId = comm_communicationId

WHERE cmli_deleted IS NULL AND comm_status = 'Pending'

If you have run a DELETE statement, then you could find all comm_link records that do not have an existing communication record:

SELECT Comm_Link.*

FROM Comm_Link

LEFT JOIN Communication on comm_communicationId = cmli_comm_communicationId

WHERE comm_communicationId IS NULL AND cmli_comm_communicationId IS NOT NULL

The records returned here do not have a communication attached to them.