Synthesis and crystal structure of supramolecular adduct of tetranuclear uranyl chloride aquacomplex with macrocyclic cavitand cucurbituril

Crystals of supramolecular compound {[(UO₂)₄O₂Cl₄(H₂O)₆](H₂OC₃₆H₃₆N₂₄O₁₂)}·4H₂O were obtained under conditions of hydrothermal synthesis from solutions of uranyl(vi) nitrate and cucurbituril in the presence of rubidium chloride. The crystal and molecular structure were determined by X-ray diffraction analysis.     

Syntheses and crystal structures of SmIII and ThIV complexes with macrocyclic cavitand cucurbituril

Slow evaporation of solutions of samarium nitrate and thorium chloride in hydrochloric acid containing the macrocyclic cavitand cucurbituril (C₃₆H₃₆N₂₄O₁₂) afforded crystals of the [{Sm(H₂O)₅(NO₃)}₂(C₃₆H₃₆N₂₄O₁₂)](NO₃)₄·6.5H₂O and [{Th(H₂O)₅Cl}₂(C₃₆H₃₆N₂₄O₁₂)]Cl₆·13H₂O complexes, respectively. The [Sm(C₃₆H₃₆N₂₄O₁₂)(H₂O)₅(SO₄)][Sm(H₂O)₅(SO₄)₂]·17H₂O complex was generated upon heating (130 °C) of a mixture of samarium sulfate, cucurbituril, and water in a sealed tube. X-ray diffraction analysis demonstrated that the metal atoms in these complexes are bound to the portal oxygen atoms of the cucurbituril molecules. In addition, the portal oxygen atoms of cucurbituril are linked to the coordinated H₂O molecules via hydrogen bonds.     

Synthesis and crystal structures of supramolecular adducts of molybdenum and tungsten selenide aqua complexes with macrocyclic cavitand cucurbituril

The supramolecular compounds {[W₃Se₄Cl₃(H₂O)₆]₂[PyHC₃₆H₃₆N₂₄O₁₂]}Cl₃·18H₂O (1) and {[Cl₃SnMo₃Se₄Cl₃(H₂O)₆][Cl₃SnMo₃Se₄Cl₂(H₂O)₇](C₃₆H₃₆N₂₄O₁₂)}Cl·26H₂O (2) were isolated from solutions of the selenium-containing tungsten and molybdenum clusters [W₃Se₄(H₂O)₉]⁴⁺ and [Cl₃SnMo₃Se₄(H₂O)₉]³⁺, respectively, and organic cavitand cucurbituril. X-ray diffraction analysis demonstrated that the macrocylcic cucurbituril molecule is coordinated on both sides by the cluster cations through the formation of complementary hydrogen bonds. Compound 1 has a chain structure stabilized by Se...Se interactions between the adjacent cluster cores. In compound 2, the bridging ₂-selenium atoms of the cluster fragment Mo₃Se₄ are coordinated to the tin atom of the SnCl₃ ^– ligand, thus losing the ability to be involved in Se...Se interactions.     

Synthesis and the crystal structure of a supramolecular adduct of the [Mo3O4(H2O)6Cl3]+ cluster complex with macrocyclic cavitand cucurbituril

The crystalline supramolecular compound of composition {(C₃₆H₃₆N₂₄O₁₂)[Mo₃O₄(H₂O)₆Cl₃]₂}Cl₂·14H₂O was obtained by slow concentration of a hydrochloric solution of the cluster aqua complex [Mo₃O₄(H₂O)₉]⁴⁺ and macrocyclic cavitand cucurbituril (C₃₆H₃₆N₂₄O₁₂). The molecular and crystal structure of the supramolecular adduct was established by X-ray diffraction analysis.     

Synthesis and crystal structures of supramolecular compounds of polynuclear aluminum(III) aqua hydroxo complexes with cucurbit[6]uril

Supramolecular compounds of the di-, trideca-, and triacontanuclear aluminum aqua hydroxo complexes, viz., [Al₂(OH)₂(H₂O)₈]⁴⁺, [Al₁₂(AlO₄)(OH)₂₄(H₂O)₁₂]⁷⁺, and [Al₃₀O₈(OH)₅₆(H₂O)₂₆]¹⁸⁺, respectively, with the organic macrocyclic cavitand cucurbit[6]uril (C₃₆H₃₆N₂₄O₁₂) were prepared by evaporation of aqueous solutions of aluminum nitrate and cucurbit[6]uril after the addition of pyridine, ammonia, KOH, or NaOH at pH 3.1–3.8. X-ray diffraction study demonstrated that the aqua hydroxo complexes are linked to the macrocycle through hydrogen bonds between the hydroxo and aqua ligands of the polycations and the portal oxygen atoms of cucurbit[6]uril. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 261—268, February, 2006.     

Supramolecular compounds of cucurbituril with molybdenum and tungsten chalcogenide cluster aqua complexes

The review surveys the synthesis and structures of a new class of supramolecular compounds composed of the macrocyclic cavitand cucurbituril and molybdenum or tungsten chalcogenide clusters. The structural motifs of supramolecular compounds and factors influencing their formation are considered.     

Synthesis and crystal structures of PrIII and NdIII complexes with the macrocyclic cavitand cucurbit[6]uril

The [{Pr(NO₃)₂(H₂O)₃}{Pr(NO₃)(H₂O)₄} (C₃₆H₃₆N₂₄O₁₂)](NO₃)₃·4H₂O and [{Nd(NO₃)(H₂O)₄} ₂(NO₃@C₃₆H₃₆N₂₄O₁₂)][Nd(NO₃)₆] complexes were prepared by heating a mixture of lanthanide nitrates, cucurbit[6]uril, and water in a sealed tube. X-ray diffraction study demonstrated that the metal atoms in the former complex are linked to the macrocycle through tridentate coordination of the portal oxygen atoms of cucurbit[6]uril to the praseodymium(III) cation. The neodymium(III) complex is the first example of lanthanide compounds with cucurbit[6]uril belonging to coordination polymers. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1511–1517, September, 2006.     

Synthesis and crystal structure of a supramolecular adduct of the cubane cluster [CIPdMo3Se4(H2O)7Cl2]+ with macrocyclic cavitand cucurbituril

A new heterometallic selenide-bridged 60-electron complex containing the cubane cluster fragment [M0₃(μ₃-Se)₄Pd]^4τ was prepared by heating a solution of [Mo₃Se₄(H₂O)₉]Cl₄ and palladium black in 2M HCl. The cluster complex was isolated from aqueous solutions as a hydrolytically stable supramolecular adduct with macrocyclic cavitand cucurbituril. The molecular and crystal structure of {[ClPdMo₃Se₄(H₂O)₇Cl₂](C₃₆H₃₆N₂₄O₁₂)Cl}·7H₂O were established by X-ray diffraction analysis. Published inIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 1905–1909, November, 2000.     

Synthesis and crystal structures of sumpramolecular compounds of cucurbit[n]urils (n = 6, 8) with polynuclear strontium aqua complexes

Crystals of the {[Sr₄(H₂O)₁₂(NO₃)₄](C₃₆H₃₆N₂₄O₁₂)}(NO₃)₄·3H₂O and {[Sr₂(H₂O)₁₂][Sr(H₂O)₃(NO₃)₂]₂(C₄₈H₄₈N₃₂O₁₆)}(NO₃)₄·8H₂O were prepared by slow concentration of aqueous solutions containing strontium nitrate and macrocyclic cavitands, viz., cucurbit[6]uril and cucurbit[8]uril ([C₆H₆N₄O₂] _n , n = 6 and 8), respectively. According to the results of X-ray diffraction analysis, the crystal structures of these supramolecular compounds are built from polymeric chains, which consist of the alternating cucurbit[n]uril molecules and Sr²⁺ cations linked through the bridging aqua ligands and nitrate anions. The supramolecular compound of cucurbit[8]uril provides the first example of compounds in which this macrocycle is bound to metal aqua complexes.     

Adducts of aqua complexes of Ln3+ with a symmetrical octamethyl-substituted cucurbituril: potential applications for isolation of heavier lanthanides

Interaction of a series of lanthanide cations (Ln³⁺) with a symmetrical octamethyl-substituted cucurbituril (OMeQ[6]) has been investigated. X-ray single-crystal diffraction analysis has revealed that the interaction results in the formation of adducts of OMeQ[6] with aqua complexes of lanthanide cations ([Ln(H₂O)₈]³⁺), Ln = Eu, Gd, Tb, Dy, Ho, Er, Tm and Yb in OMeQ[6]–Ln(NO₃)₃–H₂O systems. However, no solid crystals were obtained from systems containing La, Ce, Pr, Nd and Sm. X-ray diffraction analysis has revealed that although the solid adducts fall into two isomorphous groups, there are no significant differences in the interactions between OMeQ[6] and [Ln(H₂O)₈]³⁺ complexes and in the corresponding supramolecular assemblies. Thermodynamic parameters for the interaction between OMeQ[6] and [Ln(H₂O)₈]³⁺ complexes based on isothermal titration calorimetry experiments show two periods corresponding to the above two systems, with the lighter lanthanide cations preferring to remain in solution and the heavier lanthanide cations forming crystalline solids. Electron spectroscopy has shown that interaction of OMeQ[6] with lanthanide cations could provide a means of isolating heavier lanthanide cations from their lighter counterparts.     

Synthesis and crystal structure of the nanosized supramolecular SmIII complex with macrocyclic cavitand cucurbituril {[Sm(H2O)4]2(C36H36N24O12)3}Br6·44H2O

The supramolecular compound {[Sm(H₂O)₄]₂(Cuc)₃}Br₆·44H₂O (Cuc = C₃₆H₃₆N₂₄O₁₂) was synthesized. Its crystal and molecular structure was established by X-ray diffraction analysis. The binuclear complex cation {(Cuc)[Sm(H₂O)₄](Cuc)[Sm(H₂O)₄](Cuc)}⁶⁺ built from the alternating cucurbituril molecules (C₃₆H₃₆N₂₄O₁₂) and the [Sm(H₂O)₄]³⁺ aqua ions is a triple-decker nanosized (33 ) sandwich.     

Synthesis and guest exchange reactions of inclusion compounds of cucurbit[8]uril with nickel(II) and copper(II) complexes

Inclusion compounds of the macrocyclic cavitand cucurbit[8]uril (CB[8]) with the nickel(II) complex, {trans-[Ni(en)₂(H₂O)₂]@CB[8]}Cl₂ · 23.5H₂O, the copper(II) complex, {2[Cu(dien)(bipy)(H₂O)]@CB[8]}(ClO₄)₄ · 11H₂O, and the organic molecules, 2(pyCN)@CB[8]} · 16H₂O and {2(bpe)@CB[8]} · 17H₂O, where bipy is 4,4′-bipyridyl, pyCN is 4-cyanopyridine, and bpe is trans-1,2-bis(4-pyridyl)ethylene, were synthesized. The inclusion compounds with organic molecules were synthesized starting from inclusion compounds of cucurbit[8]uril with cyclam and ethylenediamine complexes of copper(II) and nickel(II) by the guest exchange method, which is based on the replacement of one guest with another in the cavity of the cavitand The resulting compounds were characterized by X-ray diffraction, ESR, ¹H NMR, IR, and electronic absorption spectroscopy, and electrospray mass spectrometry. Photochemically induced [2+2]-cycloaddition of two 1,2-bis(4-pyridyl)ethylene molecules included in cucurbit[8]uril was studied. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 25–34, January, 2006.     

Synthesis and structures of two supramolecular complexes constructed via hydrogen bond linking

Two supramolecular complexes,[Ni(rac-L)]3[CrO4]2[ClO4]2-4H2O (1) and [meso-H2L]0.5[VO3]-0.16H2O (2) (L= 5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetra-decane),have been prepared in an aqueous solu-tion,and detected by elemental analysis,IR,TG,and single crystal X-ray diffraction analyses. Com-pound 1 shows a one-dimensional hexagonal prism formed by the hydrogen bonding interactions between the secondary amines of rac-L and CrO42-anion/water molecules. Compound 2 displays a three-dimensional structur...     

Crystal structure of a La(III) complex with macrocyclic cavitand cucurbit[6]uril

Slow evaporation in air of a lanthanum nitrate solution containing macrocyclic cavitand cucurbit[6]uril yields a complex of the composition of [La(H₂O)₆(X@C₃₆H₃₆N₂₄O₁₂)(NO₃)](NO₃)₂· 6.96H₂O (X = 0.5C₅H₅N + 0.5H₂O). The complex is structurally characterized using single crystal X-ray diffraction. Lanthanum atoms are coordinated with oxygen atoms of carbonyl groups of cucurbit[6]uril portals. The compound crystallizes in the orthorhombic crystal system, space group Pnn2, unit cell parameters (150 K): a = 11.997(2) Å, b = 17.093(3) Å, c = 14.133(3) Å, V = 2899.3(10) ų, Z = 2. Lanthanum atoms are disordered, alternative positions being related by the two-fold axis. The complex has an island structure. A pyridine molecule occupies an internal cavity of one half of cucurbit[6]uril molecules, while a water molecule occupies the other.     

Synthesis and the crystal structure of the supramolecular complex [Cl3InW3S4(H2O)9]2+ with cucurbituril

The supramolecular complex {[Cl₃InW₃S₄(H₂O)₉]₂(C₃₆H₃₆N₂₄O₁₂)}Cl₄·28H₂O was prepared by mixing solutions of [Cl₃InW₃S₄(H₂O)₉]²⁺ and cucurbituril in hydrochloric acid. The molecular and crystal structure of the resulting complex was established by X-ray diffraction analysis.     

Synthesis and Crystal Structure of Macrocyclic Cavitand Cucurbit[5]uril and Its Supramolecular Adduct with Cu（Ⅱ）

The first supramolecular adduct (H₃O)₂[Cu(H₂O)₄](SO₄)₂·2(C₃₀H₃₀N₂₀O₁₀)·₂₄(H₂O) based on cucurbit[5]uril was synthesized and characterized by single crystal X‐ray diffraction analysis. In the adduct, copper ion is coordinated by four oxygen atoms from H₂O. The latter links two cucurbit[5]uril molecules due to a complicated hydrogen bonding containing lattice water molecules.     

Use of the macrocyclic ligand cucurbit[6]uril for isolation of tetranuclear lanthanide aquahydroxo-carboxylate complexes from aqueous solutions

The tetranuclear lanthanide complexes {[Ln₄(μ₃-OH)₄(μ₂-OH)₂(C₅NH₄COO)₂ (H₂O)₄-(C₃₆H₃₆N₂₄O₁₂)₂][Ln(H₂O)₈]_1.5[Ln(H₂O)₆(NO₃)₂]_0.5} (NO₃)₉·nH₂O (Ln = Ho, Gd, or Er) were prepared by heating (130 °C) aqueous solutions of lanthanide nitrates, cucurbit[6]uril (C₃₆H₃₆N₂₄O₁₂), and 4-cyanopyridine. The tetradentate coordination of the macrocyclic cucurbit[6]uril ligands through the portals leads to the formation of sandwich compounds, in which the tetranuclear hydroxo complex is located between two macrocyclic molecules. The polynuclear complexes are additionally stabilized by the chelating effect of the isonicotinate ligands generated by hydrolysis of 4-cyanopyridine. In the complexes, the aromatic moiety of the isonicotinate ion is encapsulated into the hydrophobic inner cavity of cucurbit[6]uril. In the absence of cucurbit[6]uril, the reaction with 4-cyanopyridine produces only the polymeric complexes [Nd(C₅NH₄COO)₃(H₂O)₂] and [Ln(C₅NH₄COO)₂(H₂O)₄]NO₃ (Ln = Pr, Sm, or Gd), whose structures were established by X-ray diffraction. In water and aqueous solutions of nonionic and cationic surfactants, irreversible changes of the tetranuclear fragment of the complex (Ln = Gd) were observed after storage for two days, whereas the anionic surfactant stabilizes the complexes. Dedicated to Academician O. M. Nefedov on the occasion of his 75th birthday. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 1885–1894, November, 2006.     

Syntheses and supramolecular structures of two 5‐nitrosalicylate titanocene complexes

Two 4‐coordinated titanocene complexes, [(η⁵‐C₅H₅)₂Ti(O,O′)(5‐NO₂‐OCC₆H₃)] (I) and [(η⁵‐C₅H₅)₂Ti(2‐OH‐5‐NO₂‐O₂CC₆H₃)₂] (II), have been synthesized by reaction of Cp₂TiCl₂ and 5‐nitrosalicylic acid in aqueous media. Single‐crystal X‐ray analyses of I and II display the mononuclear forms of Ti^IV, and geometries at titanium atoms are distorted tetrahedrons, while the coordination environment at Ti^IV in complex I is different from that in complex II. Crystallographic characterization revealed that each of the complexes exhibits a three‐dimensional framework constructed through weak interactions, which are H‐bonding, π–π stacking and C–H·π interactions, but they differ greatly when forming the three‐dimensional network structure in both complexes. The results show that the dramatic change of conditions has great effect on the molecular structure of 5‐nitrosalicylate titanocene, thereby significantly influencing the weak interactions and the specific framework structure. Copyright © 2005 John Wiley & Sons, Ltd.     

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.     

Cadmium iodide complexes with dimethylsulphoxide,and their crystal structures

The crystalline compounds [{CdI₂(dmso)}_n] ( 1 ,) and [Cd₂I₄(dmso)₄] ( 2 ,) provide a structural sequence illustrating the conversion of CdI₂ into the ionic derivatives [Cd(dmso)₆]²⁺ [Cd(dmso)I₃]₂^? · EtOH ( 3 ,) and [Cd(dmso)₆]²⁺ CdI₄^2? ( 4 ,), with increasing proportions of dmso. ( 1 ,) comprises polymeric chains with Cd centres linked by bridging iodide atoms, and alternately in four- and six-coordination. ( 2 ,) is a binuclear segment of the chains and can be seen as the structural forerunner of the ionic compounds ( 3 ,) and ( 4 ,). The ion packing in ( 3 ,) is loose, with lattice ethanol.