A Roth IRA is an after-tax instrument; that is, you cannot deduct contributions to a Roth IRA.
This is so that when you take the money out of the Roth IRA (at the proper time) that neither the original contributions nor their earnings are taxable to you.
You may be able to contribute to the Roth (I don't have enough information on your situation to know), but you wouldn't be able to deduct it in any case.