Synthesis and characterization of heteronuclear germanium(IV) and lanthanum(III) (chromium(III)) complexes with 1,3-diamino-2-propanoltetraacetic acid: Crystal and molecular structure of [Ge(OH)(μ-Hpdta)(μ-OH)La(H2O)4] · H2O

Two heteronuclear germanium(IV) and lanthanum(III) (chromium(III)) complexes with 1,3-diamino-2-propanoltetraacetic acid (H₅Hpdta) have been synthesized. The compounds have been characterized by elemental analysis and X-ray powder diffraction data. The structure of [Ge(OH)(??-Hpdta)(??-OH)La(H₂O)₄] · H₂O (I) has been determined by X-ray crystallography. The crystals are monoclinic, a = 9.3805(3) ?, b = 10.3023(4) ?, c = 21.6527(6) ?, ?? = 94.829(2)°, V = 2085.10(12) ?³, Z = 4, space group P2₁/n, R1 = 0.0294 based on 5480 reflections with I > 2??(I). Compound I is composed of binuclear [Ge(OH)(??-Hpdta)(??-OH)La(H₂O)₄] molecules and crystal water molecules. In the dimeric molecule, the germanium and lanthanum atoms are linked by the bridging oxygen atom of the hydroxo ligand and the oxygen atom of the deprotonated isopropanol group of Hpdta^5?. The coordination spheres of germanium and lanthanum each contains one nitrogen atom and two carboxyl oxygen atoms of the four acetate arms of the heptadentate Hpdta^5? ligand. The Ge coordination polyhedron is completed to a distorted octahedron by the oxygen atom of the terminal hydroxo group, and the lanthanum coordination polyhedron is completed to a nine-vertex polyhedron by the oxygen atoms of four water molecules. In crystal, the complex molecules and crystal water molecules are combined by a system of hydrogen bonds.     

Synthesis and characteristics of the dioxonium salt based on tartratogermanate acid. Crystal and molecular structure of (H5O2)[(H2O)2Ge(μ-Tart)2Ge(OH)] · 4H2O

Tartratogermanate acid was obtained for the first time as the dioxonium complex (H₅O₂)[(H₂O)₂Ge(??-Tart)₂Ge(OH)] · 4H₂O (I) by the reaction of germanium tetrachloride with D-tartaric acid (H₄Tart) in 85% acetic acid. The complex was characterized by elemental analysis data, thermogravimetry, and IR spectroscopy. X-ray diffraction analysis for I was performed. The crystals are orthorhombic, a = 15.862(3) ?, b = 13.401(3) ?, c = 8.6800(17) ?, V = 1845.1(6) ?³, Z= 4, space group P2₁2₁2, R1= 0.0520 for 5152 reflections with I > 2??(I). Compound I is composed of the dimeric complex anions [(H₂O)₂Ge(??-Tart)₂Ge(OH)]^?, dioxonium cations, and water molecules of crystallization. In the anion, the Ge(1) (CN = 6) and Ge(2) (CN = 5) atoms are linked by two chelating bridging fully deprotonated tartaric acid ligands through two carboxyl (average Ge-O, 1.883(4) and 1.893(4) ?, respectively) and two alcohol (average Ge-O, 1.859(4) and 1.779(4) ?, respectively) oxygen atoms. The coordination polyhedron of Ge (1) is completed to a distorted octahedron by the oxygen atoms of two water molecules (Ge(1)-O(H₂O), 1.933(4) and 1.854(3) ?). The Ge(2) coordination polyhedron is trigonal bipyramid. Its base is formed by two alcohol oxygen atoms of two bridging Tart^4? ligands and the oxygen atom of the terminal hydroxy group (Ge-O, 1.764(4) ?). The axial positions are occupied by the carboxyl oxygen atoms of the Tart^4? ligands (the O(5)Ge(2)O(11), 176.84(16)°). In the crystal, the structural units are combined by hydrogen bonds to a three-dimensional framework.     

Tetrameric complexes of germanium(IV) and cobalt(II), Nickel(II), or Zinc(II) with 1,3-Diamino-2-propanol-tetraacertic acid: crystal and molecular structures of [(OH)2Ge2(μ-Hpdta)2Zn2(H2O)4] · 12H2O

Heteronuclear germanium(IV) and Zn(II) (Co(II), Ni(II)) complexes with 1,3-diamino-2-propanol-tetraacetic acid (H₅Hpdta) were synthesized. The compounds were characterized by elemental analysis, thermogravimetry, and IR spectroscopy. X-ray diffraction analysis of the crystals of [(OH)₂Ge₂(??-Hpdta)₂Zn₂(H₂O)₄] · 12H₂O (I) was performed. The crystals are tetragonal, a = 15.2022(9)?, c = 20.932(3) ?, V = 4837.5(7) ?³, Z = 4, space group P4₃, R1 = 0.0449 over 11399 reflections with I > 2??(I). The structural units of the crystal are tetrametric complex molecules [(OH)₂Ge₂(??-Hpdta)₂Zn₂(H₂O)₄] and water molecules of crystallization. The tetramer is composed of two similar neutral dimeric molecules [(OH)Ge(??-Hpdta)Zn(H₂O)₂]. The germanium and zinc atoms in the dimer are linked by the bridging oxygen atom of the deprotonated isopropanol group of the Hpdta^5? ligand (average Ge-O, 1.844(2)?; Zn-O, 2.192(3)?). The coordination sphere of the Ge and Zn atoms contains also one nitrogen atom (average Ge-N, 2.074(4)?; Zn-N, 2.156(3)?), four oxygen atoms belonging to four acetate branches of the octadentate Hpdta^5? ligands including two carboxyl O atoms for each Ge atom (average Ge-O, 1.912(3)?) and two carbonyl O atoms for each Zn (average Zn-O, 2.065(3)?). The coordination polyhedron of each Ge atom is completed to a distorted octahedron by the oxygen atom of the terminal hydroxy group (average Ge-O, 1.772(2)?) and the carboxyl oxygen atom of the bridging acetate branch (average Ge-O, 1.926(3)?) coordinated through carbonyl oxygen to Zn atom (average Zn-O, 2.148(3)?) of the second dimeric molecule. The distorted octahedron around each Zn atom is completed by oxygens of two water molecules at substantially different distances (average Zn-O, 1.984(3) and 2.100(3)?). The structural units are combined by O-H??O hydrogen bonds to form a framework.     

Synthesis and characterization of heteronuclear germanium(IV) lanthanide 1,3-diamino-2-propanoltetraacetates: Crystal and molecular structure of the [Ge(OH)(μ-Hpdta)(μ-OH) Ln(H<Subscript>2</Subscript>O)<Subscript>3</Subscript>] · 2H<Subscript>2</Subscript>O complexes (Ln = Tb,Yb)

In the course of systematic studies, heteronuclear germanium lanthanide complexes based on 1,3-diamino-2-propanoltetraacetic acid (H₅Hpdta) have been synthesized (Ln = Pr (I), Nd (II, the structure was described in [1]), Sm (III), Eu (IV), Gd (V), Tb (VI), Dy (VII), Ho (VIII), Er (IX), Tm (X), Yb (XI), Lu (XII)). Comparative analysis of their structure as a function of the lanthanide ion has been performed. The analysis is based on a combination of physicochemical data on complexes I–XII, including X-ray crystallographic data for two heteronuclear [Ge(OH)(μ-Hpdta)(μ-OH)Ln(H₂O)₃] · 2H₂O complexes (Ln = Tb (VI) and Yb (XI). Isostructural crystals of VI and XI are monoclinic, Z = 4, space group P2₁/n, a = 9.340(4) and 9.3133(10) Å, b = 10.4839(14) and 10.4561(10) Å, c = 20.246(2) and 20.1222(10) Å, β = 95.12(3)° and 95.275(10)°, V = 1974.5(10) and 1951.2(3) A³, R1 = 0.0277 and 0.0241 for 4527 and 4751 reflections with I > 2σ(I). Crystals of VI and XI are composed of binuclear [Ge(OH)(μ-Hpdta)(μ-OH)Ln(H₂O)₃] molecules and crystal water molecules. The Ge and Ln atoms in VI and XI are linked by the bridging oxygen atom of the hydroxo group (Ge-O, 1.806(2) and 1.812(2) Å; Ln-O, 2.445(3) and 2.405(2) Å, respectively) and by the deprotonated oxygen atom of the isopropanol group of the Hpdta5-ligand (Ge-O, 1.865(2) and 1.864(2) Å; Ln-O, 2.302(2) and 2.255(2) Å in VI and XI, respectively). The coordination sphere of each of the Ge and Ln atoms involves one nitrogen atom (Ge-N, 2.097(3) and 2.096(3) Å; Ln-N, 2.670(3) and 2.628(3) Å in VI and XI, respectively) and two carboxyl oxygen atoms of four acetate arms of the completely deprotonated heptadentate Hpdta^5? ligand (av. Ge-O, 1.922(3) and 1.920(3) Å; Ln-O, 2.349(2) and 2.298(2) Å in VI and XI, respectively). The coordination polyhedron of the Ge atom is completed to a distorted octahedron by the oxygen atom of the terminal hydroxo group (Ge-O, 1.811(2) Å in VI and 1.810(2) Å in XI), and the coordination polyhedron of the Ln atom is completed to an eight-vertex polyhedron by the oxygen atoms of three water molecules (av. Ln-O, 2.378(3) Å in VI and 2.342(3) Å in XI). In the crystals of VI and XI, complex molecules and crystal water molecules are combined by a system of hydrogen bonds into a three-dimensional framework.     

Synthesis, properties, and crystal structure of the tin(IV) complex with N-(2-hydroxyethyl)ethylenediaminetriacetic acid [Sn(μ-Hedtra)(μ-OH)SnCl3(H2O)] · 3H2O

The binuclear tin(IV) complex with N-(2-hydroxyethyl)ethylenediamine-N,N′,N′-triacetic acid (H₄Hedtra) is synthesized. The compound is characterized by elemental analysis, thermogravimetry, and IR spectroscopy. An X-ray diffraction analysis of complex Sn(μ-Hedtra)(μ-OH)SnCl₃(H₂O)] · 3H₂O (I) is carried out. Structure I is formed by the binuclear complexes and molecules of water of crystallization. One of the tin atoms coordinates six “active” sites Hedtra^4? (the alcohol branch is deprotonated and forms a bridge between two tin atoms) and the bridging hydroxo group. The polyhedron is a pentagonal bipyramid. The octahedral environment of the second tin atom is formed by two bridging oxygen atoms, three chlorine atoms (fac isomer), and a coordination water molecule.     

Neodymium(III) triaquatrihydroxo(1,3-diamino-2-propanoltetraacetato)germanium(IV) hydrate [Ge(OH)(μ-HHpdta)(μ-OH)Nd(OH)(H<Subscript>2</Subscript>O)<Subscript>3</Subscript>] · H<Subscript>2</Subscript>O: Synthesis and crystal and molecular structure

The heteronuclear germanium(IV) and neodymium(III) complex with 1,3-diamino-2-propanoltetraacetic acid (H₅Hpdta) [Ge(OH)(μ-HHpdta)(μ-OH)Nd(OH)(H₂O)₃] · H₂O has been synthesized for the first time and characterized by physicochemical methods (elemental analysis, X-ray powder diffraction, thermogravimetry, IR spectroscopy, X-ray crystallography). The crystals are monoclinic: a = 9.331(3) Å, b= 10.279(4) Å, c = 21.474(7) Å, β = 94.59(3)°, V = 2053.0(12) ų, Z = 4, space group P2₁/n, R1 = 0.0245 for 4060 reflections with I > 2σ(I). The compound is built of complex binuclear molecules [Ge(OH)(μ-HHpdta)(μ-OH)Nd(OH)(H₂O)₃] and water molecules of crystallization. The germanium and neodymium atoms are bridged by the oxygen atom of the hydroxo group (Ge-O, 1.798(2) Å; Nd-O, 2.539(2) Å) and the deprotonated oxygen atom of the isopropanol group of the HHpdta^4? ligand (Fe-O, 1.858(2)Å; Nd-O, 2.420(2) Å) to form a dimeric molecule. Each coordination sphere (of the Ge atom and of the Nd atom) contains one nitrogen atom (Ge-N, 2.096(3) Å; Nd-N, 2.807(2) Å) and two carboxylic oxygen atoms from four acetate branches of the octadentate HHpdta^4? ligand (av. Ge-O, 1.928(2) Å; Nd-O, 2.391(2) Å). The coordination polyhedron of the Ge atom is completed to a distorted octahedron by the oxygen atom of the terminal hydroxo group (Ge-O 1.811(2) Å), and the polyhedron of the Nd atom is completed to a nine-vertex polyhedron by the oxygen atoms of the terminal hydroxo group (Nd-O 2.494(3) Å) and three water molecules (Nd-O, 2.512(3), 2.520(3), and 2.723(3) Å). In the crystal structure, the complex molecules and the water molecules of crystallization are joined by a hydrogen bond system.     

Synthesis and catalytic activity of DI-μ-methoxo-bis[(2-aminopyridine)(chloro)copper(II)] and m-xylylenediamine Zn(OAc)2

Compound I, [di-μ-methoxo-bis[(2-aminopyridine)(chloro)copper(II)], was obtained by two different synthetic routes. In synthetic route 1, we first obtained intermediate by the addition of two equivalents of o-aminopyridine to copper chloride in an ethanolic solution, and then we recrystallized the intermediate from methanol and n-hexane to give compound I. Synthetic route 2 involved the reaction of o-aminopyridine with copper chloride in a methanol solution directly. The crystal structure of compound I was obtained. The reaction of m-xylylenediamine with Zn(OAc)₂ · 2H₂O in THF resulted in the production of one novel zinc complex C₁₂H₁₈N₂O₄Zn, bis(m-xylenediamine)zinc (II) and its structure was determined by X-ray diffraction analysis. Complexes I and II were also characterized by elemental analysis, and IR. Then they were applied as catalysts for the Henry reaction, and they achieved good conversions (64 and > 99%, respectively).     

Synthesis of a vinylcarbynetetrairon complex. Crystal and molecular structure of [(C5H5)2(CO)2Fe2(μ-CO)]2- (μ-C5H3)+BF4−

The diiron vinyl ether carbyne complex [(C₅H₅)(CO)Fe]₂(μ-CO)- (μ-CCHCHOCH₂CH₃)⁺ BF₄⁻ (1) reacted with the diiron ethenylidene complex [(C₅H₅)(CO)Fe]₂(μ-CO)(μ-CCH₂) (2) to yield the tetrairon complex [(C₅H₅)₂(CO)₂Fe₂(μ-CO)]₂(μ-C₅H₃⁺BF₄⁻ (3) which was characterized by spectroscopy and by single crystal X-ray diffraction.     

Synthesis,structure, and DNA-binding of a new binuclear copper(II) complex: [Cu2(heap)(H2O)2](pic)2 · 2H2O

In this study, a new μ-oxamido-bridged binuclear copper(II) complex [Cu₂(heap)(H₂O)₂](pic)₂ ? 2H₂O, where heap and pic stand for the anion of N,N′-bis(N-hydroxyethylaminopropyl)oxamide and 2,4,6-trinitrophenol, respectively, has been synthesized and characterized by elemental analyses, IR, UV, molar conductance, and single-crystal X-ray diffraction. The complex has an embedded inversion center at the middle of the C–C bond of the oxamido group. Each copper(II) is in a square-pyramidal coordination geometry. The bridging ligand (heap) adopts a bis-tetradentate trans conformation and the oxamido group is in an imidic acid configuration. Hydrogen bonds contribute to a 3-D supramolecular structure in the crystal. The interaction of the binuclear complex with herring sperm deoxyribonucleic acid (HS-DNA) has been investigated by using absorption and emission spectra, electrochemical techniques, and viscometry. The results suggest that the binuclear copper(II) complex interacts with HS-DNA by electrostatic interaction with intrinsic binding constant of 2.67 × 10⁴ (mol L^?1)^?1. The influence of anions on the structure and the interaction of the binuclear complex with HS-DNA were preliminarily discussed.     

A new double asymmetric μ 1,1-azido bridged binuclear copper(II) complex: crystal structure and magnetic properties

A new double asymmetric μ_1,1-azido bridged binuclear copper(II) complex, [Cu₂(μ_1,1-N₃)₂(Him2-py)₂(N₃)₂] (Him2-py?=?2-(2′-pyridyl)-4,4,5,5-tetramethylimidazoline-1-hydroxy), has been synthesized and characterized structurally and magnetically. The crystal structure shows this complex is binuclear with copper(II) in a distorted square-pyramidal geometry, bridged by double asymmetric end-on azide ligands. The variable temperature magnetic susceptibility analyses reveal weak antiferromagnetic interaction mediated by the bridge.     

Synthesis,crystal structure,and magnetic properties of a new end-to-end thiocyanato-bridged dicobalt(II) complex CoII(dien)(H2O)(NCS)(μ1,3-NCS)CoII(dien)(NCS)2 (dien = diethylenetriamine)

Synthesis, characterization, crystal structure, and magnetic properties of the first single µ_1,3-thiocyanato-bridged dicobalt(II) compound, [Co^II(dien)(H₂O)(NCS)(µ_1,3-NCS)Co^II(dien)(NCS)₂] (1; dien = diethylenetriamine), are described. In 1, cobalt(II) is six coordinate with distorted-octahedral geometry. The Co(1) ··· Co(2) distance is 5.99 Å. The magnetic properties of 1 have been investigated by variable-temperature magnetic susceptibility measurements. The metal centers are coupled by weak ferromagnetic interaction (J = 1.14 cm^?1). The structure and magnetic properties are compared with related thiocyanate-bridged compounds.     

Synthesis and Crystal Structure of Bis[(2,6-pyridinedicarboxylato)(methanol)dibenzyltin(IV)]

ＩｎｔｒｏｄｕｃｔｉｏｎＤｉｏｒｇａｎｏｔｉｎｄｅｒｉｖａｔｉｖｅｓｏｆ 2 ,6 ｐｙｒｉｄｉｎｅｄｉｃａｒｂｏｘｙｌｉｃａｃｉｄｅｘｈｉｂｉｔｈｉｇｈｉｎｖｉｔｒｏａｎｔｉｔｕｍｏｕｒａｃｔｉｖｉｔｉｅｓ .1 5Ｔｈｅｓｅｃｏｍｐｏｕｎｄｓｈａｖｅｂｅｅｎｓｙｎｔｈｅｓｉｚｅｄｂｙｔｈｅｒｅａｃｔｉｏｎｏｆｄｉｏｒｇａｎｏｔｉｎｄｉｃｈｌｏｒｉｄｅｓｏｒｄｉｏｒｇａｎｏｔｉｎｏｘｉｄｅｓｗｉｔｈ 2 ,6 ｐｙｒｉｄｉｎｅｄｉｃａｒｂｏｘｙｌｉｃａｃｉｄ ,ｂｕｔｔｈｅｒｅａｃｔｉｏｎｂｅｔｗｅｅｎｔｒｉ …     

Crystal structure and catalytic properties of a vanadium complex cis-[VO2(Him-py)(im-py)]2·3H2O

Abstract

The coordination behavior of Him-py (2-(1H-imidazol-2-yl)pyridine) toward vanadium has been explored. The six-coordinate complex, cis-[VO₂(Him-py)(im-py)]₂·3H₂O (1), was synthesized by the coordination reaction of NH₄VO₃ and Him-py in the aqueous methanol solution, which was characterized by single-crystal X-ray technology. It belongs to the monoclinic space group P2₁/n with a?=?8.0756(6), b?=?19.3531(15), c?=?11.4433(8), β?=?106.905(2), V?=?1711.2(2), and Z?=?2. The crystal structure shows that the six-coordinate vanadium is bonded to two cis-oxido ligands and two bidentate ligands, Him-py and im-py. Interestingly, when crystals of 1 were immersed in H₂O₂, a peroxovanadium compound, (H₂im-py)[OV(O₂)₂(Him-py)] (2), was obtained, which crystallizes in the orthorhombic space group Fdd2 with a?=?22.600(2), b?=?22.7259(13), c?=?18.0146(11), V?=?9252.4(12), and Z?=?16, and consists of a seven-coordinate peroxovanadate(V) ion, one Him-py and one H₂im-py ligand. Moreover, we also studied the catalytic activity of 1 in the oxidative bromination of phenol/aniline-like compounds towards mimicking bromoperoxidase reactivity.     

Synthesis and characterisation of phosphinothiolate tin(IV) complexes. Crystal structure of [SntBu2(OPPh2C6H4S)(OH2)]ClO4·H2O

[SnR₂Cl₂] (R=Me, ^tBu) react with OPPh₂C₆H₄SH in the presence of NaOEt affording mononuclear derivatives [SnR₂(OPPh₂C₆H₄S)₂] (1,  2) with two units of the oxide of the thiophenylphosphine. The loss of one of such units is achieved by the reaction of 1 and 2 with HCF₃SO₃ or HClO₄ giving rise to complexes with the formula [SnR₂(OPPh₂C₆H₄S)]A (A=CF₃SO₃, ClO₄) (3a–b, 4a–b). The crystal structure of [Sn^tBu₂(OPPh₂C₆H₄S)]ClO₄ (4b) has been determined by X-ray diffraction.     

Crystal structure and magnetic properties of catena-μ-(pyrazine-N,N′)bis[(p-nitrobenzoyl)trifluoroacetonato-O,O′]copper(II)

The X-ray crystal structure, variable-temperature magnetic susceptibilities and e.s.r. spectra are reported for the title complex. The complex crystallises as infinite chains in which the copper(II)-β-diketonate units are bridged axially by ambidentate pyrazine ligands with a Cu⋯Cu separation of 7.6700(2) Å. The magnetic susceptibility measurements in the range 5–325 K are consistent with the ferromagnetic intrachain exchange. The S=1/2 Heisenberg ferromagnetic linear chain analysis results in magnetic parameters of g=2.12 and J/k=0.6 K.     

Metallation of the methyl group ino-nitrosotoluene: synthesis and the molecular structure of the binuclear complex [o-(NO)(CH2)C6H4)]2Pd2(μ-OOCCF3)2

The reaction of the tetranuclear cluster Pd₄(CO)₄(OOCCF₃)₄ witho-nitrosotoluene afforded the Pd¹¹-containing complex [o-(NO)(CH₂)C₆H₄]₂Pd₂(μ-OOCCF₃)₂. The elimination of CO₂ and the formation of organic products of transformation of tolylnitrene species (azotoluene, ditolylamine, and tolylisocyanate) were observed in the course of the reaction. The title complex was characterized by IR and¹H NMR spectroscopy. Its structure was established by X-ray diffraction analysis. It was suggested that the reaction proceeds through intermediate formation of nitrene complexes. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 147–150, January, 2000.     

Crystal and molecular structure and ion selective and complexing properties of 1,5-bis[2-(dioxyphosphoryl-4-methoxy)phenoxy]-3-oxapentane dihydrate [(OH)2(O)P(C6H3OCH3)(OCH2CH2)2 O(C6H4OCH3)P(O)(OH)2] · 2H2O

Ion selective and complexing properties of 1,5-bis[2-(dioxyphosphoryl-4-methoxy)phenoxy]-3-oxapentane dihydrate H₄M² · 2H₂O (I) were described. X-ray diffraction analysis for compound I was performed. The crystals are orthorhombic, a = 7.9818(16) ?, b = 30.553(6) ?, c = 9.0559(17) ?, V = 2208.5(8) ?³, Z = 4, space group Pnma, R = 0.0500 over 1372 reflections with I > 2??(I). In I, the H₄M² molecules are combined by hydrogen bonds (HB) with two crystallographically independent H₂O(7) and H₂O(8) molecules to give neutral H₄M² · 2H₂O aggregates. The HB between the phosphoryl and hydroxyl oxygen atoms of the aggregates and the donor O(7)-H??O(8) HB give rise to a layered structure. Conclusions about the Cu(H₂M²) compound structure were drawn based on the X-ray diffraction, DTA, and vibrational spectroscopy data.     

Syntheses and molecular structures of organo-tellurium(IV) halides trans-[(Ph2Te)(μ-Cl)2]n,cis-[(Ph2Te)(μ-Cl)2]n, [(p-MeC6H4)2TeBr2], and [{(p-MeC6H4)2TeBr}2(μ-O)]

Abstract

Treatment of Ph₂Te with aqueous hydrogen chloride under air in refluxing THF gave trans-[(Ph₂Te)(μ-Cl)₂]_n (1), whereas interaction of Ph₂Te with ammonium chloride under similar condition afforded cis-[(Ph₂Te)(μ-Cl)₂]_n (2). Reaction of (p-MeC₆H₄)₂Te and bromine in refluxing THF resulted in formation of a discrete complex [(p-MeC₆H₄)₂TeBr₂] (3) with a step-like tetrameric structure, which further reacted with sodium hydroxide in refluxing THF to give a dinuclear tellurium oxide [{(p-Me-C₆H₄)₂TeBr}₂(μ-O)] (4) with a bridging oxygen atom. Complexes 1–4 have been spectroscopically characterized and their crystal structures have been established by X-ray crystallography.     

Metal-phenoxyalkanoic acid interactions—XXIII. Complexes of copper(II) with the phenoxyisobutyric acids. The crystal structures of tetra-μ-[2-methyl-2-(4-chlorophenoxy)propanoato-O,O′)]-bis[(2-aminopyrimidine)copper(II)] and two polyaquacopper(II) tri-μ-[2-methyl-2-phenoxypropanoato-O,O′]-bis[(2-methyl-2-phenoxypropanoato)copper(II)] polymorphs

The crystal structures of three copper(II) complexes with phenoxyisobutyric acid (PIBAH) and p-chlorophenoxyisobutyric acid (PCIBAH) have been determined by X-ray diffraction. Tetra-μ-[2-methyl-2-(4-chlorophenoxy)-propanoato-O,O′]-bis[2-amino-pyrimidine)copper(II)], [Cu₂(PCIBA)₄(2-aminopyrimidine)₂]₂ (1) is a centrosymmetric tetracar☐ylate bridged dimer [Cu⋯Cu, 2.689(2)Å] with the nitrogens of the 2-aminopyrimidine molecules occupying the axial positions [CuN, 2.198(7)Å]. Tetraaquacopper(II) tri-μ-[2-methyl-2-phenoxypropanoato-O,O′]-bis[(2-methyl-2-phenoxypropanoato(copper(II)], [Cu(H₂O)₄]²⁺] {[Cu₂(PIBA)₅]⁻}₂, (2), is a disordered precursor of the stable structure (3), [Cu(H₂O)₅]²⁺ {[Cu₂(PIBA)₅]⁻·4H₂O, consisting of centrosymmetric square planar [Cu(H₂O)₄]²⁺ cations and tris(car☐ylate)-bridged dimer anions [Cu⋯Cu, 2.85(1)Å] (2). The fourth position of each square planar dimer ‘end’ is occupied by a car☐ylate oxygen of a PIBA molecule which also provides the ether oxygen capping each axial dimer site [CuO, 2.15(4), 2.19(5)Å]. This completes a five-membered chelate ring. A symmetrical array of eight hydrogen bonds link the four waters of the [Cu(H₂O)₄]²⁺ cation to the car☐yl oxygens of both the capping PIBA ligands of the two dimeric anions. Structure (3) has essentially identical [Cu₂(PIBA)₅]⁻ dimer anions [Cu⋯Cu, 2.929(1)Å] and hydrogen-bonding interactions with the tetraaquacopper(II) cations. However, water molecules partially occupy the octahedral sites of these cations [CuO, 2.46(1)Å], as well as a number of lattice sites in the crystal.