Electrical Conducting Bis(Oxalato)platinate Complex with Direct Connection of Cu^II Ions

Abstract

Reactions of K1.62[Pt(ox)2].2H2O and [Cu(bpy)(H2O)3](NO3)2 yielded partially oxidized one-dimensional (1D) bis(oxalato)platinates of [Cu(bpy)(H2O)n]6[Pt(ox)2]7.7H2O (n = 2, 3, or 4) (1) and [Cu(bpy)(H2O)n]8[Pt(ox)2]10.8H2O (n = 3 or 4) (2). The average oxidation numbers of the platinum ions in 1 and 2 are +2.29 and +2.40, respectively. Complexes 1 and 2 crystallize in the triclinic P and monoclinic C2/c space groups, respectively, and the [Pt(ox)2]n- anions are stacked along the crystallographic b axis with 7-fold periodicity for 1 and 10-fold periodicity for 2. In 1, an oxalato ligand in the platinum chain directly coordinates to a paramagnetic [Cu(bpy)(H2O)3]2+ ion, whereas no such direct coordination was observed for 2. The electrical conductivity of 2 at room temperature along the platinum chain is approximately 3 orders of magnitude smaller (sigma||= 1.3 x 10(-3) S cm(-1)) than that of 1 (sigma|| = 0.9-0.5 S cm(-1)), and the activation energies of 1 and 2 are 29 and 67 meV, respectively. The longest inter-platinum distances in 1 and 2 are 2.762 and 3.0082 A, respectively, and this is responsible for the lower electrical conductivity of 2. An X-ray oscillation photograph taken along the b axis of 1 reveals the 7-fold periodicity in the 1D chain, consistent with the period of the Peierls distortion estimated from the degree of partial oxidation. The semiconducting state of 1 can therefore be regarded as a commensurate Peierls state. The magnetoresistance of 1 at ambient pressure indicates no interaction between conduction electrons in the platinum chain and local spins of the paramagnetic CuII ions. Application of hydrostatic pressures of up to 3 GPa enhances electrical conduction, as is often seen as the usual pressure effect on the electrical conductivity, which is due to enhanced orbital (Pt-5dz2) overlap by pressure application.

The Reactivity of [Zn2Cp*2]: Trapping Monovalent {.ZnZnCp*} in the Metal‐Rich Compounds [(Pd,Pt)(GaCp*)a(ZnCp*)4−a(ZnZnCp*)4−a] (a=0, 2)

“…[22,23] Similarly, infinite mixed-metal chains are known for various metal/ligand combinations in coordination polymers. [24,25] In comparison, compound 2 is among the very few examples [26] of molecular compounds featuring oligo (hetero) metal chains without stabilization of the internal chain atoms by ligands, similar to the ligand-free, infinite metal chains in some solid state compounds, for example, Hg 3 (AsF 6 ) 2 and Hg 4 (AsF 6 ) 2 ). [27,28] Notably, treatment of [(Pd,Pt)(GaCp*) 4 ] with a large excess of [Zn 2 Cp* 2 ] does not lead to products with a (Ga + Zn)/(Pd,Pt) coordination number of more than eight.…”

Three Distinct Silver(I) Coordination Polymers: Bridging‐­Ligand Directed Syntheses, Crystal Structures, Luminescence, and Nitrobenzene Sensing Properties

“…[25,32] At a concentration of 100 ppm, the quenching efficiency of 1-3 are 58. 33 2 ]·solvent, which represents the most sensitive for nitrobenzene detection. [25] In addition, the detection limits of the assay calculated with 3σ/k (k: slope, σ: standard) are about 0.841 ppm, 0.591 ppm, and 0.713 ppm, for 1-3, respectively ( Figures S3-S5 The luminescence sensing ability of CPs is due to the interaction between their backbones and the analyte molecules.…”

“…[2][3][4][5] It is well known that varieties of factors, for example the synthetic methods, solvents, counterions and coordination arrangements of the central metal ions etc., will affect the architectures of CPs. [6][7][8][9][10][11] Particularly, the bridging ligands with different symmetry, rigidity, and types of bridging units etc.…”

“…[21][22][23][24][25] Several CP-based luminescence sensors have been developed for the detection of nitrobenzene. [23][24][25][26] 2 ]·solvent {H 3 L = 2,4,6-tri[1-(3-carboxylphenoxy)ylmethyl]mesitylene and DMF = N,N-dimethylformamide}, and the emission intensity was quenched at δ = 100 ppm with a high quenching efficiency of 92.5 %. To the best of our knowledge, this is the most sensitive for nitrobenzene detection at present.…”

Chemie von [Zn2Cp*2]: einwertiges {.ZnZnCp*}, stabilisiert in den metallreichen Verbindungen [(Pd,Pt)(GaCp*)a(ZnCp*)4−a(ZnZnCp*)4−a] (a=0, 2)

“…[22,23] Darüber hinaus gibt es auch unendliche Metallketten für verschiedene Metall-Ligand-Kombinationen in Koordinationspolymeren. [24,25] Im Vergleich dazu zählt 2 zu den sehr seltenen Beispielen [26] …”