Jorge Balmaseda

The existence of ferrous ferricyanide

Evidence in the literature on the synthesis of ferrous ferricyanide is critically discussed. Pyrolysis and pressure effects on Prussian Blue lead to ferrous ferrocyanide together with decomposition by-products, and not to ferrous ferricyanide. The latter compound could be a precursor in the formation of Turnbulls Blue or an excited state of Prussian Blue, but it is not a stable chemical species.

Water adsorption properties of a Sc(III) porous coordination polymer for CO2 capture applications

Water adsorption at room temperature in NOTT-400 was investigated along with its ability to perform CO2 capture under relative humidity (RH) conditions. Thus, the CO2 capture was increased from 4.2 wt% (anhydrous conditions) to 10.2 wt% at 20% RH and 30 °C.

Water Adsorption Properties of NOTT-401 and CO2 Capture under Humid Conditions

The water-stable material NOTT-401 was investigated for CO2 capture under humid conditions. Water adsorption properties of NOTT-401 were studied, and their correlation with CO2 sequestration at different relative humidities (RHs) showed that the CO2 capture increased from 1.2 wt % (anhydrous conditions) to 3.9 wt % under 5% RH at 30 °C, representing a 3.2-fold improvement.

Transformation of cadmium ferricyanide by heating, milling and sonication

Abstract On heating, milling and sonication, cadmium ferricyanide decomposes and reduces to cadmium ferrocyanide. Two compositions were studied, pure cadmium ferricyanide and mixed potassium-cadmium ferricyanide. The role of reducing agent is played by the CN− anions liberated during the decomposition process. The solid decomposition product is composed by several phases of cadmium ferrocyanide, an Fe3+ phase and also potassium ferrocyanide in the case of the mixed complex salt. The decomposition process was monitored using DTA, XRD, IR and Mossbauer techniques. No occurrence of linkage isomerization in cadmium ferricyanide was detected.

Synthesis and crystal structure of three new cadmium tartrates with open frameworks

Four metal–organic coordination polymers: {[Cd3(C4H4O6)3(H2O)]·H2O}nI, {[Cd3(C4H3O6)2(H2O)2]·5.5H2O}nII, {[Cd2(C4H4O6)2(H2O)]·3H2O}nIII, and [Cd(C4H4O6)]nIV were obtained under hydrothermal conditions and characterized by IR spectroscopy and single crystal X-ray diffraction. The structural analysis reveals that compounds I–III exhibit new 3D open frameworks filled with water molecules, which according to thermogravimetric analysis evolve at temperatures significantly lower than onset temperatures for decomposition. Compound I exhibits an 8-c net; uninodal net (eci net) with Schlafli symbol {36·412·510}, where Cd atoms are connected by μ4,κ6-mode and μ4,κ5-mode tartrate ligands. Compound II is a rare example of a tartrate trianion complex formed by μ5,κ6-mode ligands creating a (6,3)-connected net with Schlafli symbol (4·62)2(42·610·83). Compound III exhibits a 3,3,4,4-connected, 4-nodal net with Schlafli symbol {4·82}{4·84·10}, built up by dimers of two octahedral Cd atoms linked by μ4,κ6-mode and μ3,κ5-mode tartrate ligands. Compound IV was previously reported although being obtained under different synthetic conditions and can be described as a 5,5,11-connected, 3-nodal net with the Schlafli symbol of {32·46·52}2{34·414·516·618·72·8}{34·43·52·6}. None of the compounds reported here are topologically related, evidencing the versatility of the tartrate ligand for the framework formation of coordination polymers.

Highly reversible sorption of H2S and CO2 by an environmentally friendly Mg-based MOF

Mg-CUK-1, an ecologically friendly material synthesised in water is found to be a high-capacity, highly reversible adsorbent for acidic gases including H2S and CO2. Furthermore, Mg-CUK-1 is demonstrated to retain long-range crystallinity upon sorption cycling; its sorption performance is maintained over multiple cycles, even in the presence of high relative humidity (95%). Reversible H2S adsorption by Mg-CUK-1 is rare among MOFs studied for this purpose to date. The joint experimental and computational studies presented here show that Mg-CUK-1 is an effective solid adsorbent for applications in the field of acid gas capture, an application that is highly relevant for the purification of many industrial gas streams.

Synthesis, characterization, and crystal structure of two zinc linear dicarboxylates

Two different crystalline structures corresponding to a zinc adipate and a zinc succinate were determined combining: X-ray powder and single-crystal diffraction, infrared spectroscopy, thermal analysis, and true densities experiments. The zinc succinate crystal structure was determined by single-crystal X-ray diffraction. This compound crystallizes in the orthorhombic space-group Cccm with unit-cell parameters a = 4.792(1) A, b = 21.204(6) A, c = 6.691(2) A, V = 679.8(3) A 3 , and Z = 8. Zinc adipate crystal structure was refined from the laboratory X-ray powder diffraction data by the Rietveld method. It crystallizes in the monoclinic space group P 2/ c with unit-cell parameters, a = 16.2037(17)A, b = 4.7810(2)A, c = 9.2692(6)A, β = 90.329(3)°, V = 718.07(9) A 3 , and Z = 4. The thermal expansion of it was estimated in 5.40 × 10 −5 K −1 . This contribution is a step on the way to systematize the regularities in the coordination diversity between linear dicarboxylates and transition metal–inorganic buildings units of metal–organic frameworks.