Bonding schemes for polar intermetallics through molecular orbital models : Ca-supported Pt-Pt Bonds in Ca10Pt7Si3
(2013) In Crystals 3(3). p.504-516- Abstract
Exploratory synthesis in the area of polar intermetallics has yielded a rich variety of structures that offer clues into the transition in bonding between Zintl and Hume-Rothery phases. In this article, we present a bonding analysis of one such compound, Ca10Pt7Si3, whose large Ca content offers the potential for negative formal oxidation states on the Pt. The structure can be divided into a sublattice of Ca cations and a Pt-Si polyanionic network built from Pt7Si3 trefoil units linked through Pt-Pt contacts of 3.14 Å. DFT-calibrated Hückel models reveal that the compound adheres well to a Zintl-like electron counting scheme, in which the Pt-Si and Pt-Pt contacts are equated with two-center two-electron bonds. The experimental electron... (More)
Exploratory synthesis in the area of polar intermetallics has yielded a rich variety of structures that offer clues into the transition in bonding between Zintl and Hume-Rothery phases. In this article, we present a bonding analysis of one such compound, Ca10Pt7Si3, whose large Ca content offers the potential for negative formal oxidation states on the Pt. The structure can be divided into a sublattice of Ca cations and a Pt-Si polyanionic network built from Pt7Si3 trefoil units linked through Pt-Pt contacts of 3.14 Å. DFT-calibrated Hückel models reveal that the compound adheres well to a Zintl-like electron counting scheme, in which the Pt-Si and Pt-Pt contacts are equated with two-center two-electron bonds. The experimental electron count is in excess of that predicted by 2%, a discrepancy which is attributed to the electron transfer from the Ca to the Pt-Si network being incomplete. For the Pt-Pt contacts, the occupancy of the bonding orbitals is dependent on the participation of the surrounding Ca atoms in bridging interactions. This use of multi-center interactions isolobal to classical two-center two-electron bonds may illustrate one path by which the bonds delocalize as one moves from the Zintl phases toward the Hume-Rothery domain.
(Less)
- author
- Fredrickson, Daniel C. ; Doverbratt, Isa LU ; Ponou, Siméon LU and Lidin, Sven LU
- organization
- publishing date
- 2013-09-03
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Electronic structure, Intermetallics, Platinides, Zintl phases
- in
- Crystals
- volume
- 3
- issue
- 3
- pages
- 13 pages
- publisher
- MDPI AG
- external identifiers
-
- scopus:84901379936
- ISSN
- 2073-4352
- DOI
- 10.3390/cryst3030504
- language
- English
- LU publication?
- yes
- id
- a1716461-8bb3-4e87-bec4-a05bc699472a
- date added to LUP
- 2019-04-08 14:54:46
- date last changed
- 2022-04-10 07:21:40
@article{a1716461-8bb3-4e87-bec4-a05bc699472a,
abstract = {{<p>Exploratory synthesis in the area of polar intermetallics has yielded a rich variety of structures that offer clues into the transition in bonding between Zintl and Hume-Rothery phases. In this article, we present a bonding analysis of one such compound, Ca10Pt7Si3, whose large Ca content offers the potential for negative formal oxidation states on the Pt. The structure can be divided into a sublattice of Ca cations and a Pt-Si polyanionic network built from Pt7Si3 trefoil units linked through Pt-Pt contacts of 3.14 Å. DFT-calibrated Hückel models reveal that the compound adheres well to a Zintl-like electron counting scheme, in which the Pt-Si and Pt-Pt contacts are equated with two-center two-electron bonds. The experimental electron count is in excess of that predicted by 2%, a discrepancy which is attributed to the electron transfer from the Ca to the Pt-Si network being incomplete. For the Pt-Pt contacts, the occupancy of the bonding orbitals is dependent on the participation of the surrounding Ca atoms in bridging interactions. This use of multi-center interactions isolobal to classical two-center two-electron bonds may illustrate one path by which the bonds delocalize as one moves from the Zintl phases toward the Hume-Rothery domain.</p>}},
author = {{Fredrickson, Daniel C. and Doverbratt, Isa and Ponou, Siméon and Lidin, Sven}},
issn = {{2073-4352}},
keywords = {{Electronic structure; Intermetallics; Platinides; Zintl phases}},
language = {{eng}},
month = {{09}},
number = {{3}},
pages = {{504--516}},
publisher = {{MDPI AG}},
series = {{Crystals}},
title = {{Bonding schemes for polar intermetallics through molecular orbital models : Ca-supported Pt-Pt Bonds in Ca<sub>10</sub>Pt<sub>7</sub>Si<sub>3</sub>}},
url = {{http://dx.doi.org/10.3390/cryst3030504}},
doi = {{10.3390/cryst3030504}},
volume = {{3}},
year = {{2013}},
}