Heterometallic condensed cluster compounds: Pr sub 4 I sub 5 Z (Z = Co, Ru, Os) and La sub 4 I sub 5 Ru. Synthesis, structure, and bonding

Journal Article · Wed Apr 03 00:00:00 EST 1991 · Inorganic Chemistry; (United States)

DOI:https://doi.org/10.1021/ic00007a008· OSTI ID:5517170

Payne, M W; Dorhout, P K; Corbett, J D ^[1]

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1. Iowa State Univ., Ames (USA)

The title R{sub 4}I{sub 5}Z compounds are synthesized in high yield by reaction of R and RI{sub 3} with Ru, Os, or CoI{sub 2} at 875-975 C in welded Nb containers. The yields of these Ru and Os compounds vs other phases appear to be significant functions of temperature. The structure of Pr{sub 4}I{sub 5}Ru was refined from single-crystal data as isotypic with Y{sub 4}I{sub 5}C, and the crystal parameters are reported. The phase consists of Ru-centered, Pr{sub 6}I{sub 12}-type cluster that share trans metal edges and iodine to generate quasi-infinite chains. The nominal Pr{sub 6} octahedra therein are more uniformly proportioned than previously observed in chain structures, but the apical Pr-Ru bond is shorter than the waist Pr-Ru bond by 0.327 (1){angstrom}. The magnetic susceptibility of Pr{sub 4}I{sub 5}Ru is Curie-Weiss in character with 7.1 {mu}{sub B}/formula unit while La{sub 4}I{sub 5}Ru behaves like a Pauli paramagnet, {chi} = {approximately}5.0 {times} 10{sup {minus}4} emu/(mol Oe) after correction for core diamagnetism. The bonding in Pr{sub 4}I{sub 5}Ru has been considered in terms of the results of charge-consistent, extended-Hueckel band calculations. Pr-I and Ru-Pr bonding is dominant, the Ru-Pr bonding states lying at the bottom of a Pr-Pr- and Pr-Ru-based conduction band crossed by E{sub F}. Charges calculated for the two metals are similar and slightly positive, indicating the importance of covalence. The marked compression of the apical Pr-Ru bonds relative to distances in chain analogues centered by the main-group elements C or Si results from unequal {pi} bonding within the distorted octahedra by the d orbitals of Ru. 22 refs., 6 figs., 5 tabs.

• OSTI ID: 5517170
• Journal Information: Inorganic Chemistry; (United States), Vol. 30:7; ISSN 0020-1669
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
COBALT COMPOUNDS
CHEMICAL PREPARATION
IODINE COMPOUNDS
LANTHANUM COMPOUNDS
OSMIUM COMPOUNDS
PRASEODYMIUM COMPOUNDS
RUTHENIUM COMPOUNDS
CHEMICAL BONDS
EXPERIMENTAL DATA
MOLECULAR STRUCTURE
DATA
HALOGEN COMPOUNDS
INFORMATION
NUMERICAL DATA
RARE EARTH COMPOUNDS
REFRACTORY METAL COMPOUNDS
SYNTHESIS
TRANSITION ELEMENT COMPOUNDS
400201* - Chemical & Physicochemical Properties