Where a sale of settled land is to be made to the tenant for life, or a purchase is to be made from him of land to be made subject to the limitations of the settlement, or an exchange is to be made with him of settled land for other land, or a partition is to be made with him of land an undivided share whereof is subject to the limitations of the settlement, the trustees of the settlement shall stand in the place of and represent the tenant for life, and shall, in addition to their powers as trustees, have all the powers of the tenant for life in reference to negotiating and completing the transaction.