Fluorine Segregation Controls the Solid-State Organization and Electronic Properties of Ni and Au Dithiolene Complexes: Stabilization of a Conducting Single-Component Gold Dithiolene Complex

Abstract

Electrooxidation of the nickel dithiolene complex [Ni(F2pdt)2]–· (F2pdt2‐: 6,6‐difluoro‐6,7‐dihydro‐5H‐[1,4]dithiepine‐2,3‐dithiolato) affords the corresponding neutral complex [Ni(F2pdt)2]0 whose layered structure is highly reminiscent, albeit not isostructural, of that of the isosteric fluorinated bis(propylenedithio)tetrathiafulvalene and characterized by a segregation of the fluorinated moieties into fluorous bilayers. The gold neutral complex [Au(F2pdt)2]·, which is isostructural with the fluorinated bis(propylenedithio)tetrathiafulvalene, was prepared by electrocrystallization of the [n‐Bu4N][Au(F2pdt)2] salt. [Au(F2‐pdt)2]· is a semiconductor with high room temperature conductivity. The origin of this semiconducting behavior as well as possible guidelines in order to realize metallic conductivity in gold dithiolene neutral molecular solids are discussed.

Sulfur-rich CpCo(dithiolene) complexes: Isostructural or non-isostructural couples of CpCo(III) with CpNi(III) dithiolene complexes

“…4(c)). Several fluorine segregations have been reported in the CF 2 -bound [M (dithiolene) 2 ] complexes (M ¼ Ni, Au) [31], CF 2 -bound TTF derivatives [32] and CF 3 -substituted TTF compounds [33]. No Cp/Cp interaction has been found in the [CpNi(F 2 pddt)] because of the non-isostructure with the Co complex [24].…”

Neutral d8 metal bis-dithiolene complexes: Synthesis, electronic properties and applications

“…In the neutral gold derivative 12, such segregation organization is observed [56], but is not efficient enough to raise the conductivity as much as in extended TTF-dithiolene complexes: the room temperature conductivity of 12 is 0.05 S cm −1 [50], that of [Ni(tmdt) 2 ] 14 is 400 S cm −1 . [10] As a matter of fact, the best way for reaching metallic phases is to extend the -conjugated system on ligands.…”

Chiral, radical, gold bis(dithiolene) complexes

“…41 The off-diagonal matrix elements of the Hamiltonian were calculated according to the modified Wolfsberg-Helmholz formula. 15,43 The exponents, contraction coefficients, and atomic parameters for Au, C, S, O and H were taken from previous work.…”

“…3 In these salts, the degree of charge transfer can be fractional (r = 1 2 , 1 3 . Originally developed by Kobayashi 20 Considering the limited number of radical gold dithiolene complexes reported so far, we are currently investigating other substitution patterns, and report here on the seven-membered 6,7-dihydro-5H-1,4-dithiepine-2,3-bis(thiolate) ligand, already found in [Au(F 2 pdt) 2 ] , 15 where the central carbon atom of the propylene group had been indeed replaced by a CF 2 one. .)…”