Polymeric aqua(glutarato)(hydrogen glutarato)lanthanum(III) monohydrate

Abstract

The structure of the title compound, [La(C5H6O4)(C5H7O4)‐(H2O)]·H2O, consists of dense layers formed by chains of one‐edge‐sharing LaO9(H2O) polyhedra, linked together by the glutarate ligand. The three‐dimensional polymeric structure, built up through connection of these layers by the hydrogen glutarate ligand, exhibits cavities accommodating a guest water mol­ecule. The lanthanum ion is tenfold coordinated by four glutarates, acting as bridging–chelating carboxyl­ate groups, by three hydrogen glutarates, three times monodentate, and by one water mol­ecule. Its coordination polyhedron is highly distorted and intermediate between a bicapped dodecahedron and a tetracapped trigonal prism. Hydro­gen bonding links the two water mol­ecules and the framework built up from this polynuclear coordination polymer. A very short hydrogen bond, D⋯A = 2.484 (3) Å, links the proton­ated with the deprotonated acid groups in the hydrogen glutarate.

Synthesis, Structure and Thermal Behavior of Oxalato-Bridged Rb+ and H3O+ Extended Frameworks with Different Dimensionalities

“…Although it was generally found that an increase in reaction temperature favors anhydrous compounds formation, the two isostructural crystals 1 and 2 , obtained hydrothermally, contain water molecules, whereas 3 resulting from soft chemical route at room temperature is completely anhydrous. Moreover, the partially deprotonated ligand appeared to depend roughly on the metal ligand ratio and probably on reaction time [18,20,25,37]. As shown in a comparative study in the series of α,ω-aliphatic dicarboxylic acids [16,17,18,19,20,21,22,23,24,25,26,37], the optimal hydrogen bonding patterns should be more determining in the deprotonation of these acids than their corresponding pKa.…”

“…Moreover, the partially deprotonated ligand appeared to depend roughly on the metal ligand ratio and probably on reaction time [18,20,25,37]. As shown in a comparative study in the series of α,ω-aliphatic dicarboxylic acids [16,17,18,19,20,21,22,23,24,25,26,37], the optimal hydrogen bonding patterns should be more determining in the deprotonation of these acids than their corresponding pKa. The nature of alkali salts used as starting materials has probably a great effect on the formation of this kind of material, through the pH value of the mixture [38,39,40,41,42,43,44].…”

Synthesis, Characterisation and Luminescent Properties of Lanthanide‐Organic Polymers with Picolinic and Glutaric Acids

“…This is particularly notable for the bridging groups which appear as syn,anti bridges while in those related 1D compounds [12,13] one oxygen atom is simultaneously involved in a syn,syn chelate and in a syn,anti bridge. Moreover, this structural aspect exhibited by one carboxylato oxygen atom is repeatedly found in all the remaining known 2- [14] and 3D [15][16][17][18][19][20][21] lanthanide-organic materials containing glutaric acid residues, thus rendering the present compound the first example of a glutaratolanthanide material in which an inter-lanthanide bridge via a carboxylato group is enforced by a syn,anti bridge. Apart from structurally creating the aforementioned bimetallic units, the glutarato anionic residues further establish physi- (Figure 1, c and d).…”

“…As reported by Zhang et al [13] for the 1D 2 ] molecular tape present in the crystal structure also contains, external to the glu/Sm core, chelating aromatic organic ligands (picolinato residues) which seem to prevent the growth of the hybrid polymer in more than one direction by removing available coordination sites in the metallic centres (Figure 1). Indeed for all known and related compounds, when these chelating moieties are not present, 2- [14] and 3D [15][16][17][18][19][20][21][22] materials are typically isolated. The picolinic acid residues appear coordinated to the Sm 3+ metallic centres in a typical N,O-chelating fashion (Scheme 1) with a bite angle of 64.97(10)°, a value consistent with those reported for similar compounds [23][24][25][26] (10 entries in the CSD, with values spanning from 60.5 to 67.6°; median of 64.0°).…”

“…On the one hand, strong and highly directional [all interaction angles Ͻ(DHA) are well above 150°-see Table 2] O-H···O hydrogen bonds involving the coordinated water molecules and the carboxylato groups interconnect neighbouring tapes in the bc plane of the unit cell leading to a 2D supramolecular framework (Figure 2, a). One of these interactions is particularly important for the structural integrity of the binuclear secondary building unit of the molecular tape, as represented in Figure 2 In fact, for all other closely related compounds, connections between adjacent lanthanide centres are usually assured by four carboxylato groups, either belonging to the glutarato [12][13][14]16,[18][19][20][21] or oxalato [15,17] anions in a pseudo-paddlewheel motif. For the ϱ 1 [Sm(glu)(pic)(H 2 O) 2 ] molecular tape, only two carboxylato groups bridge the metallic centres (Figure 2, b) with structural stability being achieved [a] (4) 172 (4) [a] Symmetry transformations used to generate equivalent atoms: Table 2.…”