Complexes of yttrium, lanthanum, and erbium halides with carbamide: Syntheses and structures

New complexes of yttrium and lanthanum bromides and erbium chloride with carbamide (Ur), [Y(Ur)₄(H₂O)₄]Br₃ (I) and [La(Ur)₄(H₂O)₄]Br₃ (II), [La(Ur)₆(H₂O)₂]Br₃ (III), and [Er(Ur)₆Cl]Cl₂ (IV), are synthesized and studied by X-ray diffraction analysis. In structures I?CIII, the coordination of the ligands (water and carbamide) by the metal occurs through the oxygen atoms. The coordination polyhedron of the rare-earth metal atoms is a distorted square antiprism (coordination number 8), and the bromide ions are not included into the internal coordination sphere of the complexes. In compound IV, the internal coordination sphere of the complex includes six carbamide molecules and one chloride ion, and the coordination polyhedron of Er is a distorted pentagonal bipyramid (coordination number 7). Specific features of the structures of the crystalline carbamide derivatives of chlorides, bromides, and iodides of the considered rare-earth metals are compared. A distortion of the planar structure of some carbamide ligands, depending on their number in the complex cation and on the nature of the complex, is observed.     

Structural features of the crystalline iodide complexes of some rare-earth elements with carbamide and acetamide

New acetamide and carbamide complexes LnI₃ · 4Ur · 4H₂O (Ln = La, Eu, Dy, Ho, Y; Ur is carbamide) and LnI₃ · 4AA · 4H₂O (Ln = Nd, Eu, Dy, Ho, Y; AA is acetamide) are synthesized. The complexes are characterized by the data of chemical analysis, IR spectroscopy, and X-ray diffraction analysis. The ligands (water, carbamide, and acetamide molecules) are coordinated by the rare-earth element atoms through the oxygen atom, and the coordination polyhedron is a distorted square antiprism. The iodide ions are not coordinated and are located in the external sphere. The structural characteristics of the complexes are compared in the series [Ln(L)₄(H₂O)₄]I₃ (Ln = La, Nd, Eu, Gd, Dy, Ho, Er; L = AA, Ur).     

On the complexes of yttrium chloride with carbamide and acetamide

Data on the synthesis and the IR spectroscopic and X-ray diffraction analyses of new complexes of yttrium chloride with carbamide (Ur), [Y(Ur)₄(H₂O)₄]Cl₃ (I) and [Y(Ur)₆(H₂O)₂]Cl₃ (II), and with acetamide (AA), [Y(AA)₅(H₂O)₂]Cl₃ (III), are presented. The coordination of the ligands occurs through the oxygen atoms. For complexes I and II, the coordination polyhedra of the Y atoms are distorted tetragonal antiprisms. For structure III, the coordination polyhedron of the Y atom is a distorted pentagonal bipyramid. The coordination of four Ur molecules in complex I does not change their planar structure, and two Ur molecules in structure II have the dihedral angle N-C(O)-N different from 180°. The chloride ions are in the external sphere. Many hydrogen bonds are observed in the structures of complexes I–III.     

Complexes of gadolinium and erbium iodides with carbamide: Synthesis and structures

The novel carbamide complexes of gadolinium and erbium iodides of the composition LnI₃4Ur·4H₂O (Ln = Gd, Er; Ur = carbamide) were synthesized and studied by X-ray diffraction and IR spectroscopy. The ligands are coordinated to the central Gd or Er atom through the O atoms of water or carbamide molecules. The coordination polylhedron of Ln atoms is a distorted square antiprism. The iodide ions are not coordinated and lie in the outer sphere.     

Aquadimethylsulfoxide complexes of rare earth elements Pr,Eu, and Tm with the [Mo3S7Br7]3− cluster anion

New complexes of rare earth elements [Ln(DMSO)_m(H₂O)_n][Mo₃S₇Br₇], Ln=Pr, Eu, Tm were synthesized and investigated by X-ray diffraction analysis. In [Pr(DMSO)₆(H₂O)₂]³⁺ and [Eu(DMSO)₇(H₂O)]³⁺, the coordination polyhedra of Ln are distorted, square antiprisms (coordination number is 8); in [Tm(DMSO)₆(H₂O)]³⁺, the coordination polyhedron of Ln is a distorted pentagonal bipyramid (coordination number is 7). In all complexes, DMSO is coordinated via oxygen atoms. Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences. Swiss Technological Institute, Zurich, Switzerland. Translated fromZhurnal Strukturnoi Khimii, Vol. 36, No. 6, pp. 1046–1069, November–December, 1995. Translated by L. Smolina     

Different Types of Coordinated Urea Molecules in its Complexes with Rare‐Earth Iodides and Perchlorates

An earlier reported series of the [Ln(Ur)₄(H₂O)₄]I₃ (Ln = Y, La, Nd, Eu, Gd, Dy, Ho, Er; Ur = urea) complexes was completed with seven new compounds (Ln = Ce, Pr, Sm, Tb, Tm, Yb, Lu); one of them, [Ce(Ur)₄(H₂O)₄]I₃, was studied by X‐ray diffraction. The most striking feature of the [Ln(Ur)₄(H₂O)₄]I₃ structures is the presence of two types of coordinated urea molecules. There are two planar symmetric and two non‐planar asymmetric urea molecules. The Ln–O–C bond angles vary in the ranges 163.06–165.71° and 148.42–152.42° for symmetric and asymmetric urea ligands, respectively, correlating with the ionic mode of urea coordination. To elucidate the role of aqua ligands for the urea coordination mode, two water‐free perchlorate complexes, [La(Ur)₈](ClO₄)₃ · 2Ur and [La(Ur)₇(OClO₃)](ClO₄)₂ were synthesized and structurally characterized. In these complexes, all urea molecules are planar symmetric; however, both covalent and ionic types of urea coordination with the La–O–C bond angles varying in the 132.4–142.3° and 145.5–159.1° ranges, respectively can be observed.     

Hydrothermal syntheses,crystal structures and luminescence properties of two lanthanide dinuclear complexes with hexafluoroglutarate

Two complexes [Ln₂(hfga)₂(phen)₄(H₂O)₆] · hfga · 2H₂O (H₂hfga = hexafluoroglutaric acid, phen = 1, 10-phenanthroline, Ln=Tb, 1; Eu, 2) were synthesized under hydrothermal conditions and their structures determined by X-ray crystallography. The complexes consist of dinuclear units with an inversion center. Each Ln(III) is nine-coordinate with two carboxylate oxygens from two hfga ligands, three oxygens from water and four nitrogens from two phen molecules. Two carboxylate groups of one hfga adopt monodentate coordination to Ln(III) as a long bidentate bridge linking two Ln(III) ions to form a dimer. Ln(III) ··· Ln(III) distances of 9.027(3) Å for 1 and 9.043(3) Å for 2 were observed. Both complexes emit strong fluorescence and show characteristic emission of Tb(III) and Eu(III) ions, respectively.     

Ionic acetamide coordination in its complexes with rare-earth iodides

A series of [Ln(CH₃CONH₂)₄(H₂O)₄]I₃ (Ln?=?rare-earth metal) complexes was completed with seven new compounds (Ln?=?Ce, Pr, Sm, Tb, Tm, Yb, Lu); two (Ln?=?Ce, Tm) were studied by X-ray diffraction. The coordination polyhedron of eight oxygen atoms is a distorted square antiprism. No tetrad effect was found for Ln–O bond lengths. The structure is stabilized by a system of intermolecular hydrogen bonds. The most striking feature of the structures is the recently predicted ionic acetamide coordination. The acetamide molecules are non-planar (the Ln–O–C–N torsion angles are 159–170°) and Ln–O–C bond angles vary in the 146.0–156.8° range.     

Syntheses,crystal structures and characterization of divalent transition metal sulfonate complexes with O-phenanthroline

Two new complexes, [Zn(phen)₂(H₂O)₂]2L·H₂O (1) and [Cu(phen)(L)(H₂O)₂]L·3H₂O (2), where HL?= 4-aminobenzenesulfonic acid and phen = o-phenanthroline, have been synthesized and their crystal structures determined by X-ray diffraction. In the complexes the Cu(II) and Zn(II) atoms revealed two different coordination environments. Complex 1 consists of a cation [Zn(phen)₂(H₂O)₂]²⁺, in which Zn(II) is six-coordinated by four nitrogen atoms from two o-phenanthroline molecules and by two water molecules. Complex 2 has two crystallographically unique Cu(II) ions, where Cu(II) ion is five-coordinate with two nitrogen atoms of o-phenanthroline, two water molecules and one sulfonate oxygen atom. The electrochemical behavior and FT-IR of the two compounds have also been studied in detail.     

Two 2-D lanthanide coordination polymers constructed from hydroquinone-O,O′-diacetic acid

Two new coordination polymers, {Ln₂(hqda)₃(H₂O)₄·6H₂O}_n (H₂hqda = hydroquinone-O,O′-diacetic acid, Ln = Dy, 1; Ho, 2), were prepared and characterized by elemental analysis, IR spectroscopy, TG-DTA, fluorescence spectroscopy, and single-crystal X-ray diffraction. The two complexes are isomorphous with similar crystal structures. In 1 and 2, each Ln(III) ion is nine coordinate with seven oxygen atoms from hqda ligands and two oxygen atoms from water molecules. Two adjacent Ln(III) ions are bridged by–COO^? groups from hqda ligands in bidentate-bridging and chelating-bridging modes. These building blocks cross link through ^–OOCCH₂OC₆H₄OCH₂COO^? spacers to form a 2–D network structure. The adjacent 2-D layers are further interlinked by hydrogen bonds to form a 3-D supermolecular structure.     

Two- and three-dimensional coordination polymers of lanthanide tartrate: synthesis,crystal structures and luminescence

Several new coordination polymers of lanthanide tartrate with three types of topological structures, namely [Ln₂(DL-tart)₃(H₂O)₃] · 1.5H₂O [Ln = La (1), Nd (2), and Sm (3)], [Ln₂(D-tart)₃(H₂O)₂] · 3H₂O [Ln = Eu (4), Tb (5), and Dy (6)], and [Lu(C₄H₄O₆)(C₄H₅O₆)] · 2.5H₂O (7), have been synthesized by hydrothermal synthesis. X-ray crystallographic analysis reveals that 1 is a unique 3-D network, whereas 5 with a 3-D network and 7 with a 2-D network are isomorphous with their analogs. All lanthanide ions are nine-coordinate through oxygen donors. Four different coordination modes of tartrate occur in these complexes. Luminescence spectra reveal that 4, 5, and 6 emit characteristic luminescence of corresponding lanthanide ions.     

On the reaction products of lanthanide chlorides with biurete

The synthesis and results of IR spectroscopy and X-ray diffraction analysis of new complexes of biurete NH₂CONHCONH₂ (BU) with the composition LnCl₃ · 2BU · 4H₂O, where Ln = La (I), Pr (II), Ho (III), Er (IV), and Lu (V), are presented. Crystals of complexes I–V include complex cations [Ln(H₂O)₄(BU)₂]³⁺ and uncoordinated chloride ions. The coordination mode of biurete molecules is bidentate through the oxygen atoms, and upon coordination the BU molecules are transformed from the initial trans to cis configuration. Water molecules are also coordinated through the oxygen atom (the shape of the polyhedron of the Ln atoms is a two-capped trigonal prism). The oxygen atoms of both BU molecules and the oxygen atoms of the first and second water molecules form a trigonal prism, whereas the oxygen atoms of the third and fourth water molecules form two caps of the coordination polyhedron. The coordinated BU molecules are joined with the chloride ions and water molecules of the adjacent complex cations by hydrogen bonds. The degree of conversion of trans-BU to cis-BU in the lanthanide series of complexes of this type is discussed.     

Synthesis,crystal structure and characterization of a series of complexes constructed from coordinated Lanthanides(III) and the heteropolyanion [SiMo12O40]4−

The reaction of α-[SiMo₁₂O₄₀]^4? with trivalent cations Ln³⁺ and N-methyl-2-pyrrolidone leads to a series of complexes of formula [Ln(NMP)₄(H₂O) _n ]H[SiMo₁₂O₄₀]?·?2NMP?·?mH₂O [where Ln?=?La (1), Pr (2), Nd (3), Sm (4), Gd (5), n?=?4, Ln?=?Dy (6), Er (7), n?=?3. NMP?=?N-methyl-2-pyrrolidone]. The syntheses, X-ray crystal structures, IR, and ESR spectra and thermal properties of the complexes 1, 2, 4, 6, 7 have been reported previously. Here, we report X-ray crystal structures, IR, UV, ESR spectra and thermal properties of the complexes [Nd(NMP)₄(H₂O)₄]H[SiMo₁₂O₄₀]?·?2NMP?·?1.5H₂O (3), and [Gd(NMP)₄(H₂O)₄]H[SiMo₁₂O₄₀]?·?2NMP?·?H₂O (5). In addition, the electrochemical behaviour of this series of complexes in aqueous solution and aqueous-organic solution has been investigated and systematic comparisons have been made. All these complexes exhibit successive reduction process of the Mo atoms.     

4-磺基苯甲酸镍配合物结构多样性与性质研究

本文报道2个镍/4-磺基苯甲酸/1,10-邻菲咯啉配合物的合成、表征、结构和性质。配合物[Ni(4-sb)(phen)(H₂O)₂]·(2H₂O) (1)是单核结构,配合物[Ni(phen)₃]·(4-Hsb)(OH)(8H₂O) (2)是1个阳离子与阴离子复合物。在这2个配合物中金属镍的配位形式均是六配位八面体构型,Ni-N键长相近。2个配合物的扩展结构均为三维网络结构。配合物2中阳离子占据由阴离子与水分子形成的三维网络孔道。配合物2是一个羧基氢未脱去同时又有氢氧根的分子。     

Syntheses and structures of layered compounds based on lanthanides(iii) and cubane molybdenum and tungsten telluride cyano complexes

Eight isostructural polymeric coordination compounds of the general formula [Ln(DMF)(H₂O)₄][Ln(DMF)₂(H₂O)₄][M₄Te₄(CN)₁₂]·DMF·nH₂O (Ln = Er, Ho, Gd, or Sm; M = W or Mo) were prepared for the first time by evaporation in air of aqueous solutions containing the cuboidal telluride anionic complex of tungsten [W₄Te₄(CN)₁₂]^6– or molybdenum [Mo₄Te₄(CN)₁₂]^7–, lanthanide chlorides, and dimethylformamide. The resulting polymeric coordination complexes with layered structures were characterized by X-ray diffraction analysis and IR spectra. The magnetic susceptibilities of the gadolinium complexes were measured.     

Syntheses and characterization of three lanthanide(III) complexes containing pyridine-3,5-dicarboxylic acid and oxalic acid ligands

Direct reaction of pyridine-3,5-dicarboxylic acid (H₂PDA) and oxalic acid (H₂ox) with Ln(ClO₄)₃ · nH₂O under hydrothermal conditions gave three 3-D coordination networks, [Ln(PDA)(ox)_0.5(H₂O)₂] · H₂O [Ln = La(1), Nd(2), and Eu(3)]. The complexes were characterized by elemental analysis (EA), X-ray single-crystal diffraction, infrared spectroscopy (IR), and thermogravimetric analysis (TGA). Single crystal X-ray diffractions shows that the compounds are isomorphous and have 3-D framework structures, in which pyridine-3,5-dicarboxylates (PDA^2?) link lanthanides to give 2-D layers, which are further fabricated into a 3-D network via bis-bidentate oxalate bridging. Luminescence of 3 is investigated.     

1-D Ln–Ag (Ln = Eu; Tb) heterometallic coordination polymers with pyridine-2,6-dicarboxylate as the single ligand: Synthesis,crystal structures,and luminescence

Two new 4d–4f heterometallic coordination polymers [AgLn(pydc)₂(H₂O)₃] · x(H₂O) [Ln = Eu, x = 1.25 (1); Ln = Tb, x = 1.25 (2); pydc = 2,6-pyridinedicarboxylate] have been synthesized and characterized by elemental analysis, IR spectroscopy, and single crystal X-ray diffraction. Both structures display the same unusual 1-D heterometallic coordination polymer based on Ln building blocks and Ag ions. Thermal stabilities and luminescent properties of 1 and 2 are presented.     

Mixed-ligand lanthanide complexes constructed by flexible 1,3-propanediaminetetraacetate and rigid terephthalate

Abstract

Coordination polymers (CPs) of mixed-ligand lanthanide complexes [Ln₂(1,3-pdta)(TPA)(H₂O)₂]_n·nH₂O [Ln?=?La, 1; Ce, 2; Pr, 3; Nd, 4] (1,3-H₄pdta = 1,3-propanediaminetetraacetic acid; H₂TPA?= terephthalic acid) were hydrothermally synthesized with flexible 1,3-pdta and rigid TPA ligands. Moreover, lanthanide propanediaminetetraacetates [Ln(1,3-Hpdta)(H₂O)]_2n·nH₂TPA·xH₂O [Ln?=?Sm, 5; Gd, 6] with multi-layered structures were also obtained. In 1–4, both 1,3-pdta and TPA coordinate with lanthanide ions through carboxyl oxygen and nitrogen atoms. In 5 and 6, only 1,3-Hpdta coordinates with the central lanthanide ion, where one nitrogen atom in 1,3-Hpdta is protonated, and TPAs are crystallized as H₂TPA with the central multi-layered structures of [Ln(1,3-Hpdta)(H₂O)]_2n through very strong hydrogen bonds [2.504(4) Å]. Solid-state ¹³C NMR analysis of 1 revealed the coordination of carboxyl groups. However, the methylene groups of 1,3-pdta showed an obvious upfield shift, which can be attributed to the effects of the phenyl ring in TPA ligand. The successful synthesis of these mixed-ligand lanthanides provides a rational design of such lanthanide CPs with flexible and rigid ligands.     

Syntheses,crystal structures and electrochemistry of divalent metal 4-methylbenzenesulfonate complexes with o-phenanthroline

Three new compounds, namely [Mn(phen)₂(L)₂] · EtOH (1), [Zn(phen)₂(H₂O)₂]2L · 6H₂O (2) and [Cd(phen)₂(H₂O)₂]2L · 6H₂O (3), where HL = 4-methylbenzenesulfonic acid and phen = o-phenanthroline, have been synthesized, and their crystal structures determined by X-ray diffraction. In the complexes the metal atoms have two different coordination environments. Complex (1) consists of neutral molecules, [Mn(phen)₂(L)₂], in which Mn^II is six-coordinated by four nitrogen atoms from two o-phenanthroline molecules and two oxygen atoms from two sulfonate ions. Complexes (2) and (3) are isomorphous, each consisting of cationic species [M(phen)₂(H₂O)₂]²⁺ [M = Zn (2), Cd (3)], in which M^II is six-coordinated by four nitrogen atoms from two o-phenanthroline molecules and two water molecules. The electrochemical behavior and FT-IR of these compounds were also studied in detail.     

Thiocarbamide derivatives of europium,holmium, and erbium iodides: Synthesis and structures

Data on the synthesis, IR spectra, and X-ray diffraction analysis of the thiocarbamide complexes of europium, holmium, and erbium iodides, [Ln(H₂O)₉]I₃ · 2CS(NH₂)₂ (Ln = Eu (I), Ho(II), Er (III)), are presented. The crystal structures of the complexes contain nonaaqualanthanide cations (the polyhedron shape is a monocapped tetragonal antiprism), outer-sphere thiocarbamide molecules, and uncoordinated iodide ions. The thiocarbamide molecules form hydrogen bonds with the aqua cations and join them into continuous layers or network ensembles. The thiocarbamide molecules are disordered in the crystal structures of complexes II and III.