Neutral Paddlewheel Diruthenium Complexes with Tetracarboxylates of Large π-Conjugated Substituents: Facile One-Pot Synthesis, Crystal Structures, and Electrochemical Studies

A one-pot reaction of a cationic diruthenium complex, [Ru2II,III(O2CCH3)4(THF)2](BF4), with arylcarboxylic acids, ArCO2H, (PhCO2H = benzoic acid, NapCO2H = 1-naphthoic acid, AntCO2H = 9-anthracenecarboxylic acid) in NDMA (NDMA = N,N-dimethylaniline) has led to isolation of neutral paddlewheel-type diruthenium complexes, [RuII2(O2CAr)4(THF)2] (Ar = Ph (1), Nap (2), Ant (3)). Paramagnetic variable temperature (VT) 1H NMR studies and GC-MS studies show that the reaction consists of two steps:  a one-electron reduction of the Ru2 core by NDMA and a simple carboxylate-exchange reaction. All compounds 1−3 were structurally characterized by X-ray crystallography. While the structural features of the Ru2 core are very similar in all the compounds, the dihedral angles between the carboxylate plane and the aromatic ring are larger with the expanding of aryl groups from phenyl to anthracene. The effect of π−π stacking leads to the formation of a 1-D chain structure in compound 3, whereas compounds 1 and 2 are fully isolated from each other. The electrochemical measurements show that the quasireversible one-electron oxidation step is observed at +0.06, +0.09, and +0.17 V (vs Ag/Ag+) for 1−3, respectively, assigned to the RuII2/RuII,III2 redox couple. These potentials are found to demonstrate a linear relationship with the substituent constants for aryl compounds,

Neutral Paddlewheel Diruthenium Complexes with Tetracarboxylates of Large π-Conjugated Substituents: Facile One-Pot Synthesis, Crystal Structures, and Electrochemical Studies

A one-pot reaction of a cationic diruthenium complex, [Ru2II,III(O2CCH3)4(THF)2](BF4), with arylcarboxylic acids, ArCO2H, (PhCO2H = benzoic acid, NapCO2H = 1-naphthoic acid, AntCO2H = 9-anthracenecarboxylic acid) in NDMA (NDMA = N,N-dimethylaniline) has led to isolation of neutral paddlewheel-type diruthenium complexes, [RuII2(O2CAr)4(THF)2] (Ar = Ph (1), Nap (2), Ant (3)). Paramagnetic variable temperature (VT) 1H NMR studies and GC-MS studies show that the reaction consists of two steps:  a one-electron reduction of the Ru2 core by NDMA and a simple carboxylate-exchange reaction. All compounds 1−3 were structurally characterized by X-ray crystallography. While the structural features of the Ru2 core are very similar in all the compounds, the dihedral angles between the carboxylate plane and the aromatic ring are larger with the expanding of aryl groups from phenyl to anthracene. The effect of π−π stacking leads to the formation of a 1-D chain structure in compound 3, whereas compounds 1 and 2 are fully isolated from each other. The electrochemical measurements show that the quasireversible one-electron oxidation step is observed at +0.06, +0.09, and +0.17 V (vs Ag/Ag+) for 1−3, respectively, assigned to the RuII2/RuII,III2 redox couple. These potentials are found to demonstrate a linear relationship with the substituent constants for aryl compounds,

Supramolecular Isomerism, Framework Flexibility, Unsaturated Metal Center, and Porous Property of Ag(I)/Cu(I) 3,3‘,5,5‘-Tetrametyl-4,4‘-Bipyrazolate

Template-controlled reactions of 3,3‘,5,5‘-tetramethyl-4,4‘-bipyrazole (H2bpz) with [Ag(NH3)2]+ or [Cu(NH3)2]+ give binary metal bipyrazolates [M2(bpz)] (M = Ag, Cu) as two supramolecular isomers (1 and 2). Isomer 1 possesses four-fold interpenetrated (10,3)-a coordination networks, two-fold interpenetrated (10,3)-a channel networks, and guest-accessible coordinatively unsaturated metal clusters. Isomer 2 possesses eight-fold interpenetrated (62·10)(6·102) coordination networks and isolated, small pores. These metal bipyrazolates are chemically stable and thermally stable up to 300−500 °C. Their exceptional framework flexibilities have been demonstrated by adsorption measurements and single-crystal diffraction analyses. The guest-accessible Ag(I)/Cu(I) UMC clusters have also been demonstrated to facilitate the accommodation of unsaturated hydrocarbons such as benzene, toluene, mesitylene, and acetylene via weak metal···π interactions

Prussian Blue Nanoparticles Protected by Poly(vinylpyrrolidone)

Prussian blue (PB) nanoparticles protected by poly(vinylpyrrolidone) (PVP) were prepared by mixing aqueous Fe2+, Fe(CN)63-, and PVP solutions together and were characterized by UV−vis, IR, XRPD, and TEM. Averaged dimensions of the nanoparticles were controlled between 12 and 27 nm depending on initial Fe ion concentrations and feed ratios of Fe ion to PVP. Solubility of PB bulk in organic solvents is considerably low; nevertheless, formations of the PB nanoparticles dramatically increase the solubility in a variety of organic solvents. It is noteworthy that the PVP-protected PB nanoparticles stably maintain the cluster formations without further aggregations and dissociation in CHCl3 over 1 month. Measurement of the critical temperature (Tc) where PB nanoparticles exhibit a ferromagnetic property showed a gradual decrease of Tc for the nanoparticles as the particle sizes become smaller. This result could be ascribed to the reduction of the averaged numbers of magnetic interacted neighbors

Supramolecular Isomerism, Framework Flexibility, Unsaturated Metal Center, and Porous Property of Ag(I)/Cu(I) 3,3‘,5,5‘-Tetrametyl-4,4‘-Bipyrazolate

Template-controlled reactions of 3,3‘,5,5‘-tetramethyl-4,4‘-bipyrazole (H2bpz) with [Ag(NH3)2]+ or [Cu(NH3)2]+ give binary metal bipyrazolates [M2(bpz)] (M = Ag, Cu) as two supramolecular isomers (1 and 2). Isomer 1 possesses four-fold interpenetrated (10,3)-a coordination networks, two-fold interpenetrated (10,3)-a channel networks, and guest-accessible coordinatively unsaturated metal clusters. Isomer 2 possesses eight-fold interpenetrated (62·10)(6·102) coordination networks and isolated, small pores. These metal bipyrazolates are chemically stable and thermally stable up to 300−500 °C. Their exceptional framework flexibilities have been demonstrated by adsorption measurements and single-crystal diffraction analyses. The guest-accessible Ag(I)/Cu(I) UMC clusters have also been demonstrated to facilitate the accommodation of unsaturated hydrocarbons such as benzene, toluene, mesitylene, and acetylene via weak metal···π interactions

Supramolecular Isomerism, Framework Flexibility, Unsaturated Metal Center, and Porous Property of Ag(I)/Cu(I) 3,3‘,5,5‘-Tetrametyl-4,4‘-Bipyrazolate

Template-controlled reactions of 3,3‘,5,5‘-tetramethyl-4,4‘-bipyrazole (H2bpz) with [Ag(NH3)2]+ or [Cu(NH3)2]+ give binary metal bipyrazolates [M2(bpz)] (M = Ag, Cu) as two supramolecular isomers (1 and 2). Isomer 1 possesses four-fold interpenetrated (10,3)-a coordination networks, two-fold interpenetrated (10,3)-a channel networks, and guest-accessible coordinatively unsaturated metal clusters. Isomer 2 possesses eight-fold interpenetrated (62·10)(6·102) coordination networks and isolated, small pores. These metal bipyrazolates are chemically stable and thermally stable up to 300−500 °C. Their exceptional framework flexibilities have been demonstrated by adsorption measurements and single-crystal diffraction analyses. The guest-accessible Ag(I)/Cu(I) UMC clusters have also been demonstrated to facilitate the accommodation of unsaturated hydrocarbons such as benzene, toluene, mesitylene, and acetylene via weak metal···π interactions

Supramolecular Isomerism, Framework Flexibility, Unsaturated Metal Center, and Porous Property of Ag(I)/Cu(I) 3,3‘,5,5‘-Tetrametyl-4,4‘-Bipyrazolate

Template-controlled reactions of 3,3‘,5,5‘-tetramethyl-4,4‘-bipyrazole (H2bpz) with [Ag(NH3)2]+ or [Cu(NH3)2]+ give binary metal bipyrazolates [M2(bpz)] (M = Ag, Cu) as two supramolecular isomers (1 and 2). Isomer 1 possesses four-fold interpenetrated (10,3)-a coordination networks, two-fold interpenetrated (10,3)-a channel networks, and guest-accessible coordinatively unsaturated metal clusters. Isomer 2 possesses eight-fold interpenetrated (62·10)(6·102) coordination networks and isolated, small pores. These metal bipyrazolates are chemically stable and thermally stable up to 300−500 °C. Their exceptional framework flexibilities have been demonstrated by adsorption measurements and single-crystal diffraction analyses. The guest-accessible Ag(I)/Cu(I) UMC clusters have also been demonstrated to facilitate the accommodation of unsaturated hydrocarbons such as benzene, toluene, mesitylene, and acetylene via weak metal···π interactions

Supramolecular Isomerism, Framework Flexibility, Unsaturated Metal Center, and Porous Property of Ag(I)/Cu(I) 3,3‘,5,5‘-Tetrametyl-4,4‘-Bipyrazolate

Template-controlled reactions of 3,3‘,5,5‘-tetramethyl-4,4‘-bipyrazole (H2bpz) with [Ag(NH3)2]+ or [Cu(NH3)2]+ give binary metal bipyrazolates [M2(bpz)] (M = Ag, Cu) as two supramolecular isomers (1 and 2). Isomer 1 possesses four-fold interpenetrated (10,3)-a coordination networks, two-fold interpenetrated (10,3)-a channel networks, and guest-accessible coordinatively unsaturated metal clusters. Isomer 2 possesses eight-fold interpenetrated (62·10)(6·102) coordination networks and isolated, small pores. These metal bipyrazolates are chemically stable and thermally stable up to 300−500 °C. Their exceptional framework flexibilities have been demonstrated by adsorption measurements and single-crystal diffraction analyses. The guest-accessible Ag(I)/Cu(I) UMC clusters have also been demonstrated to facilitate the accommodation of unsaturated hydrocarbons such as benzene, toluene, mesitylene, and acetylene via weak metal···π interactions

Supramolecular Isomerism, Framework Flexibility, Unsaturated Metal Center, and Porous Property of Ag(I)/Cu(I) 3,3‘,5,5‘-Tetrametyl-4,4‘-Bipyrazolate

Template-controlled reactions of 3,3‘,5,5‘-tetramethyl-4,4‘-bipyrazole (H2bpz) with [Ag(NH3)2]+ or [Cu(NH3)2]+ give binary metal bipyrazolates [M2(bpz)] (M = Ag, Cu) as two supramolecular isomers (1 and 2). Isomer 1 possesses four-fold interpenetrated (10,3)-a coordination networks, two-fold interpenetrated (10,3)-a channel networks, and guest-accessible coordinatively unsaturated metal clusters. Isomer 2 possesses eight-fold interpenetrated (62·10)(6·102) coordination networks and isolated, small pores. These metal bipyrazolates are chemically stable and thermally stable up to 300−500 °C. Their exceptional framework flexibilities have been demonstrated by adsorption measurements and single-crystal diffraction analyses. The guest-accessible Ag(I)/Cu(I) UMC clusters have also been demonstrated to facilitate the accommodation of unsaturated hydrocarbons such as benzene, toluene, mesitylene, and acetylene via weak metal···π interactions

Supramolecular Isomerism, Framework Flexibility, Unsaturated Metal Center, and Porous Property of Ag(I)/Cu(I) 3,3‘,5,5‘-Tetrametyl-4,4‘-Bipyrazolate

Template-controlled reactions of 3,3‘,5,5‘-tetramethyl-4,4‘-bipyrazole (H2bpz) with [Ag(NH3)2]+ or [Cu(NH3)2]+ give binary metal bipyrazolates [M2(bpz)] (M = Ag, Cu) as two supramolecular isomers (1 and 2). Isomer 1 possesses four-fold interpenetrated (10,3)-a coordination networks, two-fold interpenetrated (10,3)-a channel networks, and guest-accessible coordinatively unsaturated metal clusters. Isomer 2 possesses eight-fold interpenetrated (62·10)(6·102) coordination networks and isolated, small pores. These metal bipyrazolates are chemically stable and thermally stable up to 300−500 °C. Their exceptional framework flexibilities have been demonstrated by adsorption measurements and single-crystal diffraction analyses. The guest-accessible Ag(I)/Cu(I) UMC clusters have also been demonstrated to facilitate the accommodation of unsaturated hydrocarbons such as benzene, toluene, mesitylene, and acetylene via weak metal···π interactions