Nothing contained in sections 12-345b to 12-345e, inclusive, shall be deemed to relieve from taxation, under this chapter, in the estate of the donor of a general power of appointment, the transfer of the property subject to such power. For purposes of computing the rate of taxation under this chapter in the estate of the donor, the property transferred subject to such power shall be deemed to pass to the donee of the power, and the donee of the power shall be deemed to take such property. The provisions of § 12-340 shall apply with respect to any tax imposed by this section.