Notwithstanding the foregoing provisions of this section, the comptroller may covenant with the purchasers of any state obligations that they shall have no further rights against the state for payment of such obligations or any interest thereon after an amount or amounts determined in accordance with the provisions of such covenant is deposited in a described fund or with a named or described agency or trustee. In such case, this section shall have no further application with respect to payment of such obligations or any interest thereon after the comptroller has complied with the prescribed conditions of such covenant.