Crystal structure of M4[(UO2)2C2O4(SO4)2(NCS)2] ( M = K+, Rh+) and K4[(UO2)2C2O4(SeO4)2(NCS)2]

Three heteroacidoligand uranyl complexes M ₄[(UO₂)₂C₂O₄(SO₄)₂(NCS)₂] (M = K⁺ (I), Rb⁺ (II)) and K₄[(UO₂)₂C₂O₄(SeO₄)₂(NCS)₂] (III) have been synthesized and their crystal structure has been determined by X-ray diffraction analysis. The compounds I–III are isostructural and crystallized in the monoclinic system, sp. gr. P2₁/c, Z = 2, a = 11.5548(3) ?, b = 7.0847(1) ?, c = 13.5172(3) ?, β = 93.130(1)°, V = 1104.90(4), R = 0.015 (I); a = 11.5854(9) ?, b = 7.3841(6) ?, c = 13.9072(9) ?, β = 95.754(3)°, V = 1183.74(15), R = 0.0235 (II); a = 11.6715(3) ?, b = 7.1418(2) ?, c = 13.8546(1) ?, β = 93.539(1)°, V = 1152.66(5), R = 0.0126 (III). Basic structural units of these crystals are [(UO₂)₂C₂O₄(XO₄)₂(NCS)₂]⁴⁻ chains, which belong to the crystallochemical group A ₂ K ⁰² B ₂² M ₂¹ (A = UO₂²⁺, K ⁰² = C₂O₂₋⁴, B ² = SO₄²⁻ or SeO₄²⁻, M ¹ = NCS⁻) of uranyl complexes. Uranium-containing chains are connected into a 3D framework via a system of electrostatic interactions with potassium or rubidium cations from outer spheres. Original Russian Text ? I.V. Medrish, E.V. Peresypkina, A.V. Virovets, L.B. Serezhkina, 2008, published in Kristallografiya, 2008, Vol. 53, No. 3, pp. 495–498.     

Solvothermal Syntheses and Crystal Structures of Neodymium Thiostannates [Nd(dien)3]2[(Sn2S6)Cl2] and [Nd(dien)3]2[(Sn2S6)(SH)2]

Abstract  

Two neodymium thiostannates [Nd(dien)₃]₂[(Sn₂S₆)Cl₂] (1) and [Nd(dien)₃]₂[(Sn₂S₆)(SH)₂] (2) (dien = diethylenetriamine) were synthesized by the reaction of tin and sulfur in the presence of NdCl₃ and Nd₂O₃, respectively under solvothermal conditions. Compounds 1 and 2 crystallize in monoclinic space group P2₁/n. Crystallographic data for 1: a = 11.6722(16), b = 15.119(2), c = 14.1566(19) ?, β = 96.213(3)°, V = 2483.6(6) ?³, Z = 4. For 2: a = 11.7190(14), b = 15.2168(19), c = 14.2209(18) ?, β = 95.775(4)°, V = 2523.1(5) ?³, Z = 4. The nine-coordinate [Nd(trien)₃]³⁺ complex cation formed in situ acts as the counter ion to the [Sn₂S₆]⁴⁻ anion. The [Nd(dien)₃]³⁺, [Sn₂S₆]⁴⁻ and Cl^– (or SH^–) ions form a 3-dimensional network structure through the N–H···S and N–H···Cl hydrogen bonds.     

Syntheses, Characterizations and Crystal Structures of Two Copper Coordination Polymers Both Having Cu2Cl2 Bridging Subunit [CuI(bipy)1/2Cl]n(1) and {[(CuII)4(phen)4(SSA)2Cl2](H2O)2(DMF)2}n(2)

Abstract  

Two copper coordination polymers [Cu^I(bipy)_1/2Cl] _n (1) and {[(Cu^II)₄(phen)₄(SSA)₂Cl₂] (H₂O)₂(DMF)₂} _n (2)(bipy = 4,4′-bipyridine, phen = 1,10-phenanthroline, H₃SSA = 5-sulfosalicylic acid, DMF = N,N-dimethylformamide) have been prepared and characterized by X-ray diffraction, elemental analysis, IR spectrum and 2 was also studied by cyclic voltammetric method. X-ray analysis indicates that both of them have Cu₂Cl₂ bridging subunit. Complex 1 is a two dimensional network structure. While 2 shows a one dimensional zigzag chain. Electrochemistry studies reveal that complex 2 undergo a quasi reversible one-electron metal-centered redox process at E _1/2 = +0.062 V.     

The Structure and Fluorescence Property of a 3D Supramolecular Network [Cd2(2-mBIM)2Cl2(C4H4O4)(H2O)2(H2O)]n

Abstract  

A cadmium(II) coordination polymer [Cd₂(2-mBIM)₂Cl₂(C₄H₄O₄)(H₂O)₂(H₂O)] _n (1) (wherein 2-mBIM = bis(2-methylimidazo-1-yl) methane, C₄H₄O₄ = succinate anion) has been synthesized and characterized by X-ray diffraction. Complex 1 crystallizes in the monoclinic space group C2/c with a = 23.5265(15) ?, b = 7.3558(5) ?, c = 17.4771(11) ?, β = 90.3560(10)°, V = 3024.5(3) ?³, Z = 4. Each Cd(II) atom is octahedrally coordinated and connected with two adjacent Cd(II) atoms by two individual 2-mBIM ligands in a trans-configuration to form one-dimensional (1D) helical structure. Such 1D helical chain structures were connected to each other via the succinate anion ligands and result in the formation of a two-dimensional (2D) framework. Meanwhile, an overall three-dimensional (3D) supramolecular network was formed via the weak hydrogen bond interactions between metal-coordination and free water molecules.     

Synthesis and crystal structure of (NH4)3[UO2(CH3COO)3]2[UO2(CH3COO)(NCS)2(H2O)]

Single crystals of the compound (NH₄)₃[UO₂(CH₃COO)₃]₂[UO₂(CH₃COO)(NCS)₂(H₂O)] (I) are synthesized, and their structure is investigated using X-ray diffraction. Compound I crystallizes in the monoclinic system with the unit cell parameters a = 18.3414(6) ?, b = 16.3858(7) ?, c = 12.4183(5) ?, β = 92.992(1)°, space group C2/c, Z = 4, V = 3727.1(3) ?³, and R = 0.0253. The uranium-containing structural units of crystals I are mononuclear complexes of two types with an island structure, i.e., the [UO₂(CH₃COO)₃]⁻ anionic complexes belonging to the crystal-chemical group (AB ₃⁰¹ = UO₂²⁺, B ⁰¹ = CH₃COO⁻) of the uranyl complexes and the [UO₂(CH₃COO)(NCS)₂(H₂O)]⁻ anionic complexes belonging to the crystal-chemical group AB ⁰¹M₃¹ (A = UO₂²⁺, B ⁰¹ = CH₃COO⁻, M ¹ = NCS⁻ or H₂O).     

Hydrothermal Synthesis, Structural Characterization and Luminescent Property of a New 1-D Chain-like [Er(NC6H4O2)3(H2O)2]n

Abstract  

Erbium (III) coordination compound with the formula [Er(IN)₃(H₂O)₂]_n 1 (HIN = isonicotinic acid) was synthesized by mixing Er₂O₃ with isonicotinic acid under hydrothermal condition. The structure of the title compound was determined by single crystal X-ray diffraction analysis, which reveals that the 1-D chain-like structure is formed by the erbium polyhedra through the carboxyl groups of IN. It crystallizes in the monoclinic system, possesses space group C2/c, with lattice parameters: a = 20.229(10) ?, b = 11.594(6) ?, c = 9.871(5) ?, α = γ=90°, β = 115.509(6)°, V = 2089.3(18) ?³, and D _calc = 1.811 mg/cm³ for Z = 4, F(000) = 1108, GOF = 1.109, R1 = 0.0675. Compound 1 has been characterized by IR absorption spectroscopy, ultraviolet excitation and emission spectrum.     

Chloride Metathesis and Dimethylamide Transfer in the Reaction of TaCl(NMe2)4 with ZnMe2 and MeMgCl: Spectroscopic Studies and X-ray Diffraction Structures of TaCl(Me)(NMe2)3 and ZnCl2(NHMe2)2

Abstract  

Treatment of TaCl(NMe₂)₄ with ZnMe₂ in pentane furnishes a mixture of TaCl(Me)(NMe₂)₃, TaMe(NMe₂)₄, and Ta(NMe₂)₅ as the principal reaction products based on ¹H NMR spectroscopy. Depending upon the work-up conditions employed, the compounds TaCl(Me)(NMe₂)₃ and ZnCl₂(NHMe₂)₂ have been isolated and their molecular structures established by X-ray crystallography. TaCl(Me)(NMe₂)₃ crystallizes in the orthorhombic space group Pna2₁, a = 13.644(4) ?, b = 12.934(4) ?, c = 6.992(2) ?, V = 1233.9(7) ?³, Z = 4, and d _calc = 1.958 Mg/m³; R = 0.0316 and wR ₂ = 0.0707 for 2630 reflections with I > 2σ(I). The molecular structure of TaCl(Me)(NMe₂)₃ consists of a trigonal bipyramidal core and contains axial and equatorial chlorine and methyl groups, respectively. ZnCl₂(NHMe₂)₂ crystallizes in the orthorhombic space group P2₁2₁2₁, a = 5.759(1) ?, b = 10.810(2) ?, c = 15.174(3) ?, V = 944.1(3) ?³, Z = 4, d _calc = 1.593 Mg/m³; R = 0.0213 and wR ₂ = 0.0494 for 1872 reflections with I > 2σ(I). ZnCl₂(NHMe₂)₂ exhibits a tetrahedral motif and represents the first reported four-coordinate zinc(II) compound containing acyclic monodentate secondary amine groups. The reaction between TaCl(NMe₂)₄ and MeMgCl afforded a mixture of tantalum products, of which TaCl(Me)(NMe₂)₃ and Ta(NMe₂)₅ were found as the major products by ¹H NMR spectroscopy.     

X-ray Crystal Structure of Trans -UO2(N(SiMe3)2)2(THF)2: One in a Series of Uranyl(VI) Complexes Supported by Bis(trimethylsilyl)amido Ligands

Abstract The title compound trans-UO₂(N(SiMe₃)₂)₂(THF)₂ (1) was synthesized and characterized by X-ray crystallography. The complex crystallizes in the monoclinic space group C2/c (#15) with lattice parameters a = 16.0771(5) ?, b = 13.1196(4) ?, c = 16.9391(6) ?, β = 116.853(1)°, V = 3187.61(18) ?³, Z = 4, D _calc = 1.532 g cm^-3. The six-coordinate uranium(VI) center adopts an all-trans octahedral geometry consisting of mutually trans oxo groups, silylamido ligands, and neutral THF donors. Structural comparisons of this uranyl(VI) bis(amido) complex with a related tris(amido) derivative within the series are made based on symmetry, charge, and coordination number. Graphical Abstract The X-ray crystal structure of the title complex is reported, providing comparisons based on symmetry, charge, and coordination number with a related uranyl(VI) amido derivative within this series.      

Synthesis and crystal structure of Cu3(Bipy)2(L1)2(L2)2? 4H2O(Bipy = 2,2′-bipyridine, L1 =1-((2-sulfonateethylimino)methyl)-2-naphthol), L2 = 2-hydroxy-1-naphthaldehyde)

The title compound, Cu₃(Bipy)₂(L¹)₂(L²)₂⋅4H₂O, was synthesized in the methanol solution of Bipy and Cu(II) in the presence of 1-((2-sulfonate-ethylimino)-methyl)-2-naphthol (L¹), which was condensation compound of taurine and 2-hydroxy-1-naphthaldehyde. This complex crystallized in the space group P-1 with a = 9.825(2) ?, b = 12.626(2) ?, c = 14.342(3) ?, α = 90.29(1)^∘, β = 100.67(1)^∘, γ = 101.67(2)^∘, and Z = 2. In the trinuclear Cu(II) complex, there are two type Cu atoms which have square and square pyramid geometries, respectively. The Cu–N distances vary from 1.965(3) to 2.000(4) ?, while the Cu–O distances are between 1.896(3) and 2.337(4) ?.     

A Novel 1:1 Co-Crystal of Bis(1,10-Phenanthroline)(1,10-Phenanthroline-5,6-Dione)Nickel(II) Hexafluorophosphate and Tris(1,10-Phenanthroline)Nickel(II) Hexafluorophosphate Complexes, [Ni(phen)2(phen-dione)] [Ni(phen)3] (PF6)4

Abstract  

The purpose of this study was to investigate whether co-crystals form by simply mixing pure solutions of [Ni(phen)₃](PF₆)₂ and [Ni(phen)₂(phen-dione)](PF₆)₂ where phen is 1,10-phenanthroline and phen-dione is 1,10-phenanthroline-5,6-dione. The 1:1 cocrystal, [Ni(phen)₂(phen-dione)][Ni(phen)₃](PF₆)₄·CH₃CN has been characterized by elemental analysis, IR, paramagnetic NMR, and UV–vis spectroscopies, cyclic voltammetry, and single crystal X-ray structure analysis. The title complex crystallized in triclinic crystal system (z = 2) with space group of Pī, a = 13.201(2) ?, b = 14.782(3) ?, c = 22.294(4) ?, α = 81.575(15)^o, β = 88.756(15)^o, γ = 88.032(15)^o and V = 4300.1(14) ?³. A careful inspection of the packing pattern in the lattice reveals that non-covalent interactions of three different types, viz. C–H···F, C=O···H−C and C−H···π interactions, are active in the lattice. The coordination around the Ni(II) centers is a distorted octahedral, with bite angles of 78.3−79.8^o for the chelating phen and phen-dione ligands. Cyclic voltammetry of this co-crystal shows that the Ni(III/II) couple is quasi-reversible. The effective magnetic moment (μ_eff) of the co-crystal was measured to be 2.87 BM per Ni(II) ion by Evans method. The magnitude of μ_eff is consistent with magnetic moment for octahedral Ni(II) complexes.     

Synthesis and Crystal Structure of Copper II and Silver I Complex with 1,4-diazabicyclo[2.2.2]octane[Cu(CBC)2(Dabco)(H2O)] n (1) and [Ag2(HBC)2(Dabco)] n (2)

Two 1D polymeric complex, [Cu(CBC)₂(Dabco)(H₂O)] _n (1) and [Ag₂(HBC)₂(Dabco)] _n (2) have been synthesized and characterized by X-ray single crystal analysis, where CBCH is p-chlorobenzoic acid, HBCH 2 is 2-hydroxybenzoic acid and Dabco is 1,4-diazabicyclo[2.2.2]octane. Complex 1 has been obtained in high yield by hydrothermal synthesis from CuO and CBCH and Dabco, and complex 2 has been obtain by evaporation of the solvent from silver salicylate and Dabco, 1 crystallizes in the orthorhombic space group Pmn2 ₁ with a = 24.3310(5) ?, b = 6.9050(6) ?, c = 5.9980(5) ?, Z = 2, V = 1007.70(4) ?³ and Dx = 1.657 g cm⁻³, 2 crystallizes in the monoclinic space group P2 ₁ /m with a = 10.292(3) ?, b = 6.913(2) ?, c = 14.417(4) ?, β = 95.660(5), Z = 2, V = 1020.8(5) ?³ and Dx = 1.959 g cm⁻³. The final R value is 0.0302 for 1323 measured reflections for 1 and the final R value is 0.0684 for 1545 measured reflections for 2. The atomic arrangement is built by infinite one-dimensional polymeric chain in both complexes. These chains are cross-linked by hydrogen bonds involving the coordinated water molecules to form a two-dimensional framework in complex 1.     

Synthesis and X-ray structural investigation of K2(H5O2)[UO2(C2O4)2(HSeO3)]

The synthesis and X-ray diffraction analysis of K₂(H₅O₂)[UO₂(C₂O₄)₂(HSeO₃)] single crystals have been performed. This compound crystallizes in the triclinic system with the unit-cell parameters a = 6.7665(4) ?, b = 8.8850(4) ?, c = 12.3147(7) ?, α = 94.73°, β = 90.16°, γ = 92.11°, sp. gr. P[`1]P\bar 1, Z = 2, and R = 0.019. The basic structural units are island [UO₂(C₂O₄)₂(HSeO₃)]³⁻ groups, which belong to the AB ₂⁰¹ M ¹ crystallochemical group of uranyl complexes (A = UO₂²⁺, B ⁰¹ = C₂O₄²⁻, and M ₁ = HSeO₃⁻). Uraniumcontaining complexes are linked through K⁺ and H₅O₂⁺ ions and via a system of hydrogen bonds with the participation of oxonium hydrogen atoms in this structure.     

Reactions of triosmium clusters with indole: X-ray structures of [Os3(CO)10(μ-OH)(μ-OMeCO)] and [Os3(μ-H)(CO)10(μ-1, 2-η2-NC8H6)]

Treatment of [Os₃(CO)₁₂] with indole in presence of a methanolic solution of Me₃NO⋅2H₂O at 60^∘C afforded the previously reported compounds [(μ-H)Os₃(CO)₁₀(μ-OMe)] 2, [(μ-H)Os₃(CO)₁₀(μ-OH)] 3 and [Os₃(CO)₁₀(μ-OH)(μ-OMeCO)] 4 in 10, 5 and 20% yields, respectively. The reaction of [Os₃(CO)₁₀(MeCN)₂] with indole at room temperature gave [(μ-H)Os₃(CO)₁₀(μ-1,2-η²-NC₈H₆)] 5 in 40% yield. Compounds 4 and 5 have been characterized by single crystal X-ray diffraction studies. Compound 4 crystallizes in the monoclinic space group P2(1)/c with a = 23.1239(3), b = 9.8087(4), c = 16.9017(6) ?, β = 92.6998(14)^∘, Z = 8 and V = 3829.3(2) ?³ and 5 crystallizes in the monoclinic space group P2(1)/c with a = 9.009(3), b = 9.764(4), c = 24.906(6) ?, β = 93.452(14)^∘, Z = 4 and V = 2186.9(13) ?³. Compound 4 consists of an open cluster of three osmium atoms with the hydroxy and methoxycarbonyl ligands bridging the open Os–Os edge. Compound 5 consists of an isosceles triangle of osmium atoms with one elongated Os–Os edge which is bridged by the hydride and the indolyl ligands.     

Synthesis, characterization and crystal structure of [Ni(DACH)2](H2O)2(CH3COO)2 (DACH = 1,4-diazacycloheptane): a three-dimensional (3-D) hydrogen-bonded network embodying 1-D water chains

The mononuclear complex [Ni(DACH)₂](H₂O)₂(CH₃COO)₂ (DACH = 1,4-diazacyclo-heptane) has been synthesized and characterized by IR, UV-Vis, elemental analysis and single crystal X-ray diffraction. The complex crystallizes in monoclinic system, P2₁/n space group with a=7.500(3) ?, b=8.788(3) ?, c=16.429(6) ?, β=93.395(5)°, D _c =1.269 g cm⁻³, μ=0.930 mm⁻¹, V=1080.9(6) ?³, Z=2. The central Ni^II atom is in a square-planar coordination geometry formed by four N atoms of two DACH chelated ligands. The notable feature of the title compound resides in the formation of a three-dimensional network through hydrogen bonds between the [Ni(DACH)₂]²⁺ cations, the CH₃COO⁻ counter anions and the guest water molecules trapped in the crystal lattice.     

Synthesis, Spectroscopic Characterization and Crystal Structure of a New Acetyl phosphorylamidate P(O)[NHC(O)C6H4(4-NO2)][N(CH(CH3)2)(CH2C6H5)]2

Abstract  

A new acetyl phosphorylamidate P(O)[NHC(O)C₆H₄(4-NO₂)][N(CH(CH₃)₂)(CH₂C₆H₅)]₂ has been synthesized and characterized by elemental analysis, ¹H, ¹³C and ³¹P NMR, IR and single crystal X-ray diffraction. Single crystal X-ray analysis shows that it belongs to triclinic system, space group P[`1] P\bar{1} , with a = 10.5868(16) Å, b = 11.8058(18) Å, c = 12.4364(19) Å, α = 65.410(3)°, β = 67.492(4)°, γ = 85.879(3)°, V = 1,298.6(3) Å³, and Z = 2. The intermolecular PO···HN hydrogen bond makes H-bonded dimer of molecule with Ci symmetry. In the crystal network, the dimers are aggregated in the chain arrays through π-stacking between p-NO₂–C₆H₄–C(O)–NH– moieties. Moreover, weak C–H···O and C–H···π interactions exist in the crystal network.     

Crystal structure of R[UO2(CH3COO)3] (R = NH 4+ , K+, or Cs+)

The single crystal structure of NH₄[UO₂(CH₃COO)₃] (I), K[UO₂(CH₃COO)₃] (II), and Cs[UO₂(CH₃COO)₃] (III) is studied by X-ray diffraction. I and II crystallize in the tetragonal crystal system. The crystal data are as follows: a = 13.6985(3) and c = 27.5678(14) ?, V = 5173.1(3) ?³, space group I4₁/a, Z = 16, and R = 0.023 for I; a = 13.8890(5) and c = 26.0839(18) ?, V = 5031.7(4) ?³, space group I4₁/a, Z = 16, and R = 0.037 for II. Crystals III are orthorhombic, a = 18.176(2), b = 13.119(2), and c = 22.088(4) ?, V = 5267(1)?³, space group Pbca, Z = 16, and R = 0.0424. In structures I–III, the uranium-containing structural units are represented by discrete mononuclear [UO₂(CH₃COO)₃]⁻ groups, which belong to the AB ₃⁰¹ (A = UO₂²⁺, B ⁰¹=CH₃COO⁻) crystal chemical group of uranyl complexes.     

Synthesis and Characterization of Nickel(II) Complex of 3,14-Dimethyl-2,6,13,17-Tetraazatricyclo[14,4,01.18,07.12]Docosane Containing Pyrazine-2-Carboxylate Ligand

Abstract  

The reaction of [Ni(L)]Cl₂·2H₂O (L = 3,14-dimethyl-2,6,13,17-tetraazatricyclo[14,4,0^1.18,0^7.12]docosane) with pyrazine-2-carboxylic acid (H-pyc) yields mononuclear nickel(II) complex, [Ni(L)(pyc)₂]·2H₂O (1). This complex has been characterized by X-ray crystallography, electronic absorption and cyclic voltammetry. The crystal structure of 1 exhibits a distorted octahedral geometry with four nitrogen atoms of the macrocycle and two pyrazine-2-carboxylate ligands. It crystallizes in the triclinic system P-1 with a = 9.6643(17), b = 10.116(3), c = 16.99(4) ?, V = 1633(3) ?³, Z = 2. Electronic spectrum of 1 also reveals a high-spin octahedral environment. Cyclic voltammetry of 1 undergoes two waves of a one-electron transfer corresponding to Ni^II/Ni^III and Ni^II/Ni^I processes.     

Structures and Characterization of [Zn(n-chlorosalicylato)2(N-methylnicotinamide)2(H2O)2] (n?=?4 or 5) Ligand Isomers

Abstract  

Two ligand isomers [Zn{4-ClC₆H₃-2-(OH)COO}₂(Menia)₂(H₂O)₂] (I) and [Zn{5-ClC₆H₃-2-(OH)COO}₂(Menia)₂(H₂O)₂] (II) (Menia = N-methylnicotinamide) were prepared and characterized by elemental analysis, IR spectroscopy and thermal analysis. The X-ray crystal structures of complexes (I) and (II) were determined. Compound (I) crystallizes in the triclinic space group P[`1] P\bar{1} with a = 8.105(1) ?, b = 10.036(2) ?, c = 10.545(2) ?, α = 109.088(9)°, β = 91.416(8)°, γ = 102.757(9)°, V = 786.2(2) ?<sup>3</sup>, Z = 1. Compound (II) crystallizes in the triclinic space group P[`1] P\bar{1} . Its cell parameters are: a = 8.133(1) ?, b = 10.119(2) ?, c = 10.428(1) ?, α = 66.44(1)°, β = 74.32(1)°, γ = 80.16(1)°, V = 755.5(2) ?³, Z = 1. The molecular structure of both isomers is monomeric. Each Zn(II) atom is hexacoordinated by three pairs of unidentate ligands in trans-positions (ZnO₄N₂). The 5-Clsal complex is somewhat less distorted than 4-Clsal complex (Cl-sal = chlorosalicylate). The structural data are compared with those found in similar [Zn(RCOO)₂(NL)₂(H₂O)₂].     

Synthesis and X-ray diffraction study of (Cs0.5Ba0.25)[UO2(CH3COO)3] and Ba0.5[UO2(CH3COO)3]

Uranyl triacetate complexes (Cs_0.5Ba_0.25)[UO₂(CH₃COO)₃] (I) and Ba_0.5[UO₂(CH₃COO)₃] (II) are synthesized for the first time and their structures are determined by X-ray diffraction. Both compounds crystallize in the cubic crystal system. The crystal data are as follows: a = 17.3289(7) ?, V = 5203.7(4) ?³, space group I2₁3 and Z = 16 (I); a = 17.0515(8)?, V = 4957.8(4) ?³, space group I $ \bar 4 $ \bar 4 3d, and Z = 16 (II). In I and II, as in all uranyl triacetates studied earlier, the coordination polyhedron of the uranium atom is a hexagonal bipyramid whose vertices are occupied by the oxygen atoms of the uranyl and three acetate groups. The uranium-containing group belongs to the AB ₃⁰¹ (A = UO₂²⁺, B ⁰¹ = CH₃COO⁻) crystal chemical group of uranyl complexes. It was found that compound II is isostructural to the (Rb_0.50Ba_0.25)[UO₂(CH₃COO)₃] studied earlier.     

Self-Assembly of Two Isomorphous Thiocyanate Complexes of Co(II) and Ni(II) with 3-Hydroxypicolinamide

Abstract  

The synthesis, thermal and spectral characterization, and crystal structure of isomorphous thiocyanate cobalt(II) and nickel(II) complexes with 3-hydroxypicolinamide (3-OHpia), [M(C₆H₆N₂O₂)₂(NCS)₂]·2H₂O, are reported. The metal(II) ions are chelated by two cis-oriented 3-OHpia and two thiocyanate ligands in distorted octahedral geometry. The distortion within the coordination sphere is mainly imposed by formation of the chelate rings. The compounds crystallize in monoclinic space group P2/c with two symmetrically independent molecules and a = 14.4945(2) ?, b = 8.5906(1) ?, c = 16.3865(3) ?, β = 105.987(2)°, Z = 4 (1) and a = 14.4927(5) ?, b = 8.5912(3) ?, c = 16.2712(6) ?, β = 105.740(4)°, Z = 4 (2). Commonly observed supramolecular amide synthons are not robust enough to accommodate thiocyanate ions and H₂O molecules. But instead, neutral complexes are linked through hydrogen bonds leading to two different hydrogen bonding ribbon motifs involving amide moieties and H₂O molecules [C(8)R ₂²(12) along c axis] and amide moieties and thiocyanate ions [C(8)R ₂²(16) along b axis] for symmetrically related molecules labelled as 1 [Co1 (1) and Ni1 (2)] and 2 [Co2 (1) and Ni2 (2)], respectively.