Ca[sub 31]Sn[sub 2] and related compounds: Novel Zintl phases containing dimers and pentamers of tin of lead

Journal Article · Wed Sep 29 00:00:00 EDT 1993 · Inorganic Chemistry; (United States)

DOI:https://doi.org/10.1021/ic00072a031· OSTI ID:5054675

Ganguli, A K; Guloy, A M; Leon-Escamilla, E A; Corbett, J D ^[1]

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1. Iowa State Univ., Ames, IA (United States)

The phases Ca[sub 31]Sn[sub 20], Sr[sub 31]Pb[sub 20], and Yb[sub 31]Pb[sub 20] are obtained by allowing the pure elements to react in sealed Ta containers at 1100-1180 [degrees]C followed by slow cooling. All are isostructural with Pu[sub 31]Pt[sub 20]. The structure of Ca[sub 31]sN[sub 20] was redetermined (I4/mcm, Z = 4, a = 12.5267(5) [angstrom], c = 39.912(7) [angstrom], R/R[sub w] = 3.2%/3.7%). A new description of the structure is given in terms of isolated tin atoms plus well-bonded tin dimers and linear pentamers (d(Sn-Sn) = 3.06-3.16 [angstrom]) in proportions of 5:5:1 within a rather distorted W[sub 5]Si[sub 3]-like framework. Assignment of classical two-center bonds to the Sn-Sn interactions shows that the compound is electron-precise, consistent with Zintl-Klemm concepts for a valence compound. The diamagnetic susceptibilities of Ca[sub 31]Sn[sub 20] and Sr[sub 31]Pb[sub 20] and the semiconducting behavior of Ca[sub 31]Sn[sub 20] are in accord with this description.

• OSTI ID: 5054675
• Journal Information: Inorganic Chemistry; (United States), Vol. 32:20; ISSN 0020-1669
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CALCIUM ALLOYS
STRUCTURAL CHEMICAL ANALYSIS
LEAD ALLOYS
STRONTIUM ALLOYS
TIN ALLOYS
YTTERBIUM ALLOYS
CHEMICAL PREPARATION
ELECTRIC CONDUCTIVITY
LATTICE PARAMETERS
MAGNETIC SUSCEPTIBILITY
ALLOYS
ELECTRICAL PROPERTIES
MAGNETIC PROPERTIES
PHYSICAL PROPERTIES
RARE EARTH ALLOYS
SYNTHESIS
360102* - Metals & Alloys- Structure & Phase Studies
360104 - Metals & Alloys- Physical Properties