Synthesis and single-crystal structure of lead oxide nanoclusters in zeolite Y, |Pb^sub 15.5^^sup 2+^(Pb^sub 4^O^sub 4^(Pb^sub 16/19^^sup 2+^Pb^sub 3/19^^sup 4+^)^sub 4^)^sub 4.75^|[Si^sub 117^Al^sub 75^O^sub 384^]-FAU

(ProQuest: ... denotes formulae and/or non-USASCII text omitted; see image) A single crystal of excessively Pb^sup 2+^-exchanged zeolite Y (|Pb^sub 15.5^^sup 2+^(Pb^sub 4^O^sub 4^(Pb^sub 16/19^^sup 2+^Pb^sub 3/19^^sup 4+^)^sub 4^)^sub 4.75^|[Si^sub 117^Al^sub 75^O^sub 384^]-FAU) was prepared by exchange of Na-Y (|Na^sub 75^|[Si^sub 117^Al^sub 75^O^sub 384^]-FAU, Si/Al = 1.56) with an aqueous stream 0.05 M Pb(C^sub 2^H^sub 3^O2)^sub 2^ at 294 K, followed by vacuum dehydration at 1 × 10^sup -6^ Torr and 693 K. Its structure was determined at 100 K, by X-ray diffraction techniques in the cubic space group Fd ... m and was refined to the final error indices R ^sub 1^/wR ^sub 2^ = 0.0639/0.1323. About 53.5 Pb^sup n+^ ions per unit cell occupy three different equipoints; 26 are at site I', 19 are at site II, and the remaining 8.5 are at another site II. Three Pb^sup 4+^ ions at some of the positions must have higher oxidation states due to elevated dehydration temperature; Pb(IIa) is supposed to coexist with Pb^sup 2+^ and Pb^sup 4+^ ions assuming the charge balance of the zeolite framework. A distorted Pb^sub 4^O^sub 4^ cube, alternating Pb^sup 2+^ at Pb(I') and O^sup 2-^ at O(5), coordinates with four Pb^sup 2+^ and/or Pb^sup 4+^ ions through its oxygen atoms to give a [Pb^sub 4^^sup 2+^O^sub 4^^sup 2-^(Pb^sub 16/19^^sup 2+^Pb^sub 3/19^^sup 4+^)^sub 4^]^sup 176/19+^ cluster in 4.75 of eight sodalite cavities per unit cell in zeolite Y.[PUBLICATION ABSTRACT]