PMID- 20886870
OWN - NLM
STAT- PubMed-not-MEDLINE
DCOM- 20110211
LR  - 20101026
IS  - 1520-510X (Electronic)
IS  - 0020-1669 (Linking)
VI  - 49
IP  - 21
DP  - 2010 Nov 1
TI  - Contrasts in structural and bonding representations among polar intermetallic 
      compounds. Strongly differentiated Hamilton populations for three related 
      condensed cluster halides of the rare-earth elements.
PG  - 9949-57
LID - 10.1021/ic101216z [doi]
AB  - The crystal and electronic structures of three related R(3)TnX(3) phases (R = 
      rare-earth metal, Tn = transition metal, X = Cl, I) containing extended 
      mixed-metal chains are compared and contrasted: (1) Pr(3)RuI(3) (P2(1)/m), (2) 
      Gd(3)MnI(3) (P2(1)/m), and (3) Pr(3)RuCl(3) (Pnma). The structures all feature 
      double chains built of pairs of condensed R(6)(Tn) octahedral chains encased by 
      halogen atoms. Pr(3)RuI(3) (1) lacks significant Ru-Ru bonding, evidently because 
      of packing restrictions imposed by the large closed-shell size of iodine. 
      However, the vertex Pr2 atoms on the chain exhibit a marked electronic 
      differentiation. These are strongly bound to the central Ru (and to four I), but 
      very little to four neighboring Pr in the cluster according to bond populations, 
      in contrast to Pr2-Pr "bond" distances that are very comparable to those 
      elsewhere. In Gd(3)MnI(3) (2), the smaller metal atoms allow substantial 
      distortions and Mn-Mn bonding. Pr(3)RuCl(3) (3), in contrast to the iodide (1), 
      can be described in terms of a more tightly bound superstructure of (2) in which 
      both substantial Ru-Ru bonding and an increased number of Pr-Cl contacts in very 
      similar mixed-metal chains are favored by the smaller closed-shell contacts of 
      chlorine. Local Spin Density Approximation (LSDA) Linearized Muffin-Tin Orbital 
      (LMTO)-ASA calculations and Crystal Orbital Hamilton Population (COHP) analyses 
      show that the customary structural descriptions in terms of condensed, 
      Tn-stuffed, R-R bonded polyhedral frameworks are poor representations of the 
      bonding in all. Hamilton bond populations (-ICOHP) for the polar mixed-metal R-Tn 
      and the somewhat smaller R-X interactions account for 75-90% of the total 
      populations in each of these phases, together with smaller contributions and 
      variations for R-R and Tn-Tn interactions. The strength of such R-Tn 
      contributions in polar intermetallics was first established or anticipated by 
      Brewer. The rare-earth-metal atoms are significantly oxidized in these compounds.
FAU - Gupta, Shalabh
AU  - Gupta S
AD  - Ames Laboratory, Iowa State University, Ames, Iowa 50011, USA.
FAU - Meyer, Gerd
AU  - Meyer G
FAU - Corbett, John D
AU  - Corbett JD
LA  - eng
PT  - Journal Article
PL  - United States
TA  - Inorg Chem
JT  - Inorganic chemistry
JID - 0366543
EDAT- 2010/10/05 06:00
MHDA- 2010/10/05 06:01
CRDT- 2010/10/05 06:00
PHST- 2010/10/05 06:00 [entrez]
PHST- 2010/10/05 06:00 [pubmed]
PHST- 2010/10/05 06:01 [medline]
AID - 10.1021/ic101216z [doi]
PST - ppublish
SO  - Inorg Chem. 2010 Nov 1;49(21):9949-57. doi: 10.1021/ic101216z.