Crystal structure of a new basic nitrate of neodymium(III), [Nd6O(OH)8(H2O)14(NO3)6](NO3)2 · 2H2O

Isolated Hexanuclear Hydroxo Lanthanide Secondary Building Units in a Rare-Earth Polymeric Framework Based on p-Sulfonatocalix[4]arene

“…This arrangement gives rise to the formation of hexameric clusters, in which the octahedrally disposed lanthanide atoms are joined through eight μ 3 -OH − groups to give rise to a rhombic dodecahedron (Figure ). This type of cluster, which has already been reported in other lanthanide compounds, is depicted in most of cases with a central oxygen atom coordinated to the six Ln atoms. − There are also some examples in which this central atom does not appear in the cluster. , In the present metal−organic frameworks (MOFs), a high electronic density was located at the center of the cluster, which was effectively assigned to an oxygen atom. The structure of three different Pr crystals and one Nd crystal were refined, finding this atom in all of them, and its thermal parameters showed in all cases relatively high values, which is unexpected for a hexacoordinated O atom (see Figure , left).…”

Lanthanide, Y and Sc MOFs: where amazing crystal structures meet outstanding material properties

“…This cluster has a rhombic-dodecahedron geometry, but its overall connectivity is eight, and it is formed with presence of a central oxygen atom. The chemical nature of this atom ''oxygen or hydroxyl group'' is discussed on the base of the calixarene protonation state and supported by bond valence calculations 33 when compared with other reported clusters, [34][35][36][37][38] The point symbol of this layer forming the RPF9 structure type is (4 20 $6 8 )(4 6 ) 2 , with 4-connected nodes at the calixarenes positions, and 8 connected nodes for the hydroxo lanthanide clusters (Fig. 13).…”

Syntheses and crystal structures of rare earth basic nitrates hydrates

“…Type [9,10] belong, according to their lattice parameters and the space group, also to the type A I . However, there is a small difference in the coordination of Ln atoms.…”

“…Metallic distances of Eu and Yb are out of range of the graph due to a different structure of the metals. The values for Pr and Nd are taken from [9,10]. Table 4 Exact lattice parameters of all LnBN.…”

“…This can be performed either by a careful increase of pH by an addition of diluted NaOH to Ln(NO 3 ) 3 solution [8,10] or by a spontaneous hydrolysis of the solution of the first hydrolytical product of thermally decomposed Ln(NO 3 ) 3 in the solution of appropriate Ln nitrate [2,3,18,19]. Recently, two papers dealing with the synthesis of Pr and Nd octahedral complex salts with the formula Ln 6 ( 6 -O)( 3 -OH) 8 3 in the presence of di-thienyl ketone [9], the paper [10] describes the synthesis of Pr and Nd salts of the same formula by a controlled hydrolysis of Ln(NO 3 ) 3 with diluted solution of NaOH. Furthermore, it seems that octahedral complex salts (regardless of their structure type, vide infra), are formed only in specific pH ranges depending on the Ln [10].…”