An unusual Pd(iii) oxidation state in the Pd–Cl chain complex with high thermal stability and electrical conductivity

Abstract

A thermally stable and highly electrically conductive Pd(iii) 1D complex [Pd(dabdOH)2Cl]Cl2 was newly synthesized.

Ni(III) Mott–Hubbard-like State Containing High-Spin Ni(II) in a Semiconductive Bromide-Bridged Ni-Chain Compound

“…Additionally, TG-DTA of 1 ·solvent indicated a small weight loss (−4.8 wt %) at 435 K under a N 2 atmosphere (Figure S4). A similar small weight loss has been reported in MX-Chains with the dabdOH ligands, i.e., [Pd­(dabdOH) 2 Br]­Br 2 and [Pd­(dabdOH) 2 Cl]­Cl 2 , at the same temperature region. These MX-Chain compounds have no solvent molecules.…”

“…The peak-to-peak line width (Δ H pp ) was 85 G at 4 K, whereas that at 150 K was broadened to 127 G. Above 150 K, the signal was extremely broadened and difficult to detect. This broadening has been reported to be a common property of the MH state of MX-Chains. ,,, Therefore, the magnetic properties exhibited both mixed-valence and MH-like nature, indicating the coexistence of the MH-like state and the mixed-valence state.…”

“…The polarized Raman spectrum for a single crystal of 1 ·solvent showed a peak at 145 cm –1 (Figure b). This peak can be assigned as a symmetric stretching mode of Br–Ni–Br, which is a forbidden mode in the MH state. − ,, Thus, 1 ·solvent appeared to be in an MH-like state based on X-ray diffraction; however, it also contained a CDW-like state, as revealed by these spectra.…”

“…In addition, the Ni(1) chains have two Br counter ions per Ni complex moiety, forming a 2D sheet structure [Ni­(dabdOH) 2 Br]­Br 2 via the triple hydrogen-bonding network of NH···Br (N···Br = 3.519(8) and 3.560(8) Å) and OH···Br (O···Br = 3.266(6) Å), as shown in Figure b. Such 2D sheet structures are typical among MX-Chains, e.g., [Ni­(bn) 2 Br]­Br 2 (bn: 2 S ,3 S -diaminobutane), [Ni­(chxn) 2 Br]­Br 2 , and [Pd­(dabdOH) 2 X]­X 2 (X = Br, Cl). , …”

“…As there has only been one report of this type of system so far, further studies are desired in this field. Additionally, we have previously reported Pd- and Pt-based MX-Chains having (2 S ,3 S )-2,3-diaminobutane-1,4-diol (dabdOH) ligands. − [Pd­(dabdOH) 2 Br]­Br 2 was revealed to have the Pd­(III) MH state and to exhibit the highest electrical conductivity (3–38 S cm –1 ) among all reported MX-Chains . On the other hand, [Pt­(dabdOH) 2 Br]­Br 2 was revealed to have the Pt­(II)/Pt­(IV) CDW state and to show the smallest optical gap (1.19 eV) among the reported Pt–Br-type MX-Chains .…”