shall be allowed as a deduction to the estate in lieu of the limited charitable contributions deduction authorized by section 170(a).
shall be allowed, subject to the limitation provided in subparagraph (2) of this paragraph, as a deduction to the trust in lieu of the limited charitable contributions deduction authorized by section 170(a). The preceding sentence applied only to a trust which is required by the terms of its governing instrument to set amounts aside. See section 642(c)(6) and § 1.642(c)-4 for disallowance of a deduction under this section to a trust which is, or is treated under section 4947(a)(1) as though it were, a private foundation (as defined in section 509(a) and the regulations thereunder) that is not exempt from taxation under section 501(a).
For treatment of distributions by an estate to a charitable remainder trust, see paragraph (a)(5)(iii) of § 1.664-1 .
26 C.F.R. §1.642(c)-2