Pressure dependence of the electronic spectra of quasi-one-dimensional Pt/sub 2/X semiconductors

Journal Article · Wed Jan 04 04:00:00 EST 1989 · J. Am. Chem. Soc.; (United States)

DOI:https://doi.org/10.1021/ja00183a012· OSTI ID:5913824

Stroud, M A; Drickamer, H G; Zietlow, M H; Gray, H B; Swanson, B I

The effects of high static pressure on the electronic absorption spectra of the mixed-valence semiconductors, K/sub 4/(Pt/sub 2/(P/sub 2/O/sub 5/H/sub 2/)/sub 4/X)/center dot/3H/sub 2/O (X = Cl, Br), have been investigated to 10.0 GPa. Their electronic spectra exhibit bands attributable to the reduced complex, (Bu/sub 4/N)/sub 4/(Pt/sub 2/(P/sub 2/O/sub 5/H/sub 2/)/sub 4/) (d/sub xz/,d/sub yz/ /yields/ p/sigma/, d/sigma/* /yields/ d/sub x/sup 2//-y/sub y/sup 2//, and d/sigma/* /yields/ p/sigma/), and the oxidized complex, K/sub 4/(Pt/sub 2/(P/sub 2/O/sub 5/H/sub 2/)/sub 4/X/sub 2/)/center dot/2H/sub 2/O (d/sub xz/, d/sub yz/ /yields/ d/sigma/* and /sigma/(X) /yields/ d/sigma/*), along with an intervalence charge-transfer (IVCT) band characteristic of a mixed-valence solid. The reduced (Pt/sub 2/) and oxidized (Pt/sub 2/X/sub 2/) complexes have also been studied so that direct comparisons with the monohalides (Pt/sub 2/X) could be made. The /sigma/X /yields/ d/sigma/* transition (observed at 34,500, 32,800, and 35,400 cm/sup /minus/1/ for Pt/sub 2/Cl/sub 2/, Pt/sub 2/Br, and Pt/sub 2/Cl, respectively) exhibits linear blue shifts of ca. 300 cm/sup /minus/1//GPa for each complex. The d/sigma/* /yields/ d/sub x/sup 2/-y/sup 2// transition in Pt/sub 2/ (35,300 cm/sup /minus/1/) shifts red initially and then begins to shift blue above 5.5 GPa, while the d/sigma/* /yields/ p/sigma/ band (ca. 27,000 cm/sup /minus/1/) exhibits little shift with pressure for Pt/sub 2/, Pt/sub 2/Cl, and Pt/sub 2/Br. The dominant pressure-induced effects that give rise to the above shifts are (i) destabilization of the d/sigma/* and p/sigma/ levels through increased orbital overlap and d/p mixing and (ii) destabilization of the d/sub x/sup 2/-y/sup 2// level at high pressure through increased ligand field interactions. 26 references, 14 figures, 1 table.

• Research Organization: Los Alamos National Lab., NM (USA)
• DOE Contract Number: AC02-76ER01198
• OSTI ID: 5913824
• Journal Information: J. Am. Chem. Soc.; (United States), Journal Name: J. Am. Chem. Soc.; (United States) Vol. 111:1; ISSN JACSA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603 -- Materials-- Properties
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
CHLORIDES
CHLORINE COMPOUNDS
DATA
ELECTRONIC STRUCTURE
EXPERIMENTAL DATA
HALIDES
HALOGEN COMPOUNDS
INFORMATION
MATERIALS
NUMERICAL DATA
PLATINUM CHLORIDES
PLATINUM COMPOUNDS
SEMICONDUCTOR MATERIALS
TRANSITION ELEMENT COMPOUNDS
VALENCE