Electron Redistribution in Pt₂(dta)₄I: From Building Blocks to the Infinite Chain. A Theoretical Investigation of Possible Peierls Distortions

Abstract

We here present a quantum chemical analysis of the possible Peierls distortions accompanying charge redistribution in the Pt 2 (dta) 4 I infinite chain. Starting with the building block calculations, we point out the participation of the CH 3 CS 2 -(dta) ligand in the mechanism of electron transfer. As the chain grows, the position and the geometry of the equatorial dta ligands are significantly altered. These changes indirectly control the Pt-I distances and lead to noticeable reduction of electron-phonon coupling through bridging halogen. These results agree with experimental data suggesting the involvement of internal degrees of freedom in the electron trapping phenomenon.

Intramolecular charge ordering in the multi molecular orbital system (TTM-TTP)I3

“…In ͑TMTSF͒ 2 PF 6 , the first superconductivity behavior in molecular solids has been reported. [5][6][7][8] Theoretical approaches that focus on a single highest-occupied-molecular orbital ͑HOMO͒ or lowest-unoccupied-molecular orbital ͑LUMO͒ have been successful in describing fascinating electronic ordered phase. 2 Since the pioneer work of Su et al 3 in polyacetylene, the charge trapping phenomenon has been much studied in Peierls transition issues.…”

“…4 In that sense, quasi-one-dimensional chains have received much attention from experimental and theoretical points of view. [5][6][7][8] Theoretical approaches that focus on a single highest-occupied-molecular orbital (HOMO) or lowestunoccupied-molecular orbital (LUMO) have been successful in describing fascinating electronic ordered phase. Such a treatment can be justified since in these conventional systems, the HOMO or LUMO levels are well-separated from the rest of the MOs spectrum.…”

A vibronic approach to the band-filling and temperature-dependent metal-insulator transition

“…Therefore, these systems may be regarded as 3/4-filled single-band materials, or as recently suggested as 5/6-filled a͒ Electronic mail: vrobert@ens-lyon.fr two-band ones. 18 The low-temperature (TϽ80 K) charge ordering mode Pt 2ϩ ϪPt 3ϩ ϪPt 3ϩ ϪPt 2ϩ has been supported by experimental 18 ( 129 I Mössbauer͒ and theoretical 13,22 studies. 18 The low-temperature (TϽ80 K) charge ordering mode Pt 2ϩ ϪPt 3ϩ ϪPt 3ϩ ϪPt 2ϩ has been supported by experimental 18 ( 129 I Mössbauer͒ and theoretical 13,22 studies.…”

Rationalization of the behavior of M2(CH3CS2)4I (M = Ni, Pt) chains at room temperature from periodic density functional theory and ab initio cluster calculations

“…Most of the existing theoretical work on MMX chains deals with the description of the metal‐semiconductor transition, excitation mechanisms, and structural distortions. [53–61] Both the Pt and Ni MMX chains undergo phase transitions with associated changes of conductivity. These changes are strongly dependent on the nature of the bridging ligands that form the M 2 units.…”

“…The electronic state of the chain was assigned basically an AV state. [41–63] However, the electronic structure of the homologous Ni chain seems to be less established. X‐ray photoelectron spectra for the Ni complexes suggest valence delocalization on a regular chain structure.…”