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.     

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 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.     

Syntheses and crystal structures of supramolecular compounds of tetranuclear ZrIV and HfIV aqua hydroxo complexes with macrocyclic cavitand cucurbituril

Slow evaporation of hydrochloric acid solutions of zirconium(iv) or hafnium(iv) oxochlorides and cucurbituril in air afforded compounds with composition [M₄(OH)₈(H₂O)₁₆]Cl₈·(C₃₆H₃₆N₂₄O₁₂)·16H₂O, where M = Zr (1) or Hf (2). According to the X-ray diffraction data, complexes 1 and 2 are isostructural. Their crystal structures can be described as packings of polymer chains consisting of alternating cucurbituril molecules and tetranuclear cations [M₄(OH)₈(H₂O)₁₆]⁸⁺ linked to each other via an extensive network of hydrogen bonds. Compound 2 is the first structurally characterized tetranuclear hafnium aqua complex.     

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 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 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.     

Heteroligand Cobalt(III) Complexes with Triethanolamine and Aminoacetic Acid

Heteroligand cobalt(III) chelates with triethanolamine and glycine, [Co(HTetm)GlyH₂O] · 2H₂O (I) and [Co(HTetm)GlyNH₃] · 2H₂O (II) (H₃Tetm is N(C₂H₄OH)₃ and HGly is glycine), were synthesized. The acidity constants of complex I were determined at an ionic strength of 0.1. The reactions of I with alcoholic solutions of acids, ammonia, and ammonium nitrate were studied. Binuclear complexes were obtained upon the interaction of I and II with CoCl₂ · 6H₂O. The complexes were characterized using UV–VIS (in aqueous and alcoholic solutions) and IR (in the solid state) spectroscopy. The ¹³C NMR spectra of solutions of Iand II were recorded. The plausible structures of the complexes are discussed.     

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.     

New supramolecular adducts of chloroaquacomplexes [M3(μ3-S)S3?xSexCly(H2O)9?y](4?y)+ (M = Mo, W) with cucurbit[6]uril

New supramolecular adducts of cucurbit[6]uril with triangular cluster chloroaquacomplexes of Mo and W with mixed sulfido-selenido bridging ligands, {[W₃S₃Se(H₂O)₇Cl₂]₂(C₃₆H₃₆N₂₄O₁₂)}Cl₂·15H₂O (1), {[W₃S_1.5Se_2.5Cl_1.5(H₂O)_7.5]₂(C₃₆H₃₆N₂₄O₁₂)}Cl₅·18.5H₂O (2), and {[Mo₃SSe₃(H₂O)_7.5Cl_1.5]₂× (C₃₆H₃₆N₂₄O₁₂)}C_l5·11H₂O (3) are obtained treating the mixture of products in Mo-S-Se-Br and W-S-Se-Br systems, isolated, and structurally characterized. In all compounds, the supramolecular structure is based on hydrogen bonded associates of cucurbit[6]uril molecule with two cluster cations.     

Anion encapsulation by Ln(III)/K(I) heterobismetal-capped cucurbit[5]uril

Three Ln(III)/K(I) (Ln = La, Ce and Nd) heterobismetal-capped cucurbit[5]uril molecular capsules, {[LaK(C₃₀H₃₀N₂₀O₁₀)Cl]Cl(H₂O)₃}Cl₂·8H₂O (1), {[CeK(C₃₀H₃₀N₂₀O₁₀)Cl]Cl(H₂O)₃}Cl₄(H₃O)₂ ^2 + ·8H₂O (2) and {[NdK(C₃₀H₃₀N₂₀O₁₀)Cl]Cl(H₂O)₃}Cl₂·12.5H₂O (3), were synthesised by self-assembly in aqueous solution, and their anion encapsulation property was confirmed by X-ray crystallography. The effect of the lanthanide cation radius on the structure of the heterobismetal-capped cucurbit[5]uril molecular capsules has been investigated.     

Supramolecular approach to crystallization of polynuclear chromium(III) aqua hydroxo complexes: synthesis and crystal structures of complexes [Cr2(OH)2(H2O)8]4+ and [Cr4(OH)6(H2O)12]6+ with cucurbit[n]uril (n = 7, 8)

Supramolecular compounds of the compositions {[Cr₂(OH)₂(H₂O)₈](C₄₂H₄₂N₂₈O₁₄)₂}-(NO₃)₄·18.75H₂O (1) and {[Cr₄(OH)₆(H₂O)₁₂](C₄₈H₄₈N₃₂O₁₆)₃(NO₃)₆·55H₂O (2) were synthesized from aqueous solutions of chromium(III) nitrate and the macrocyclic cavitand cucurbit[n]uril (C_6n H_6n N_4n O_2n , where n = 7 or 8, respectively). According to the X-ray diffraction study, the polynuclear chromium aqua complexes are disposed in cavities formed by the cucurbit[n]uril molecules and are linked to these molecules through hydrogen bonds between the hydroxo and aqua ligands of the polycations and the portal oxygen atoms of the macrocycles. Compound 1 is the first example of supramolecular compounds of cucurbit[7]uril with metal aqua complexes. The isolation of the supramolecular adduct with cucurbit[8]uril 2 in the single-crystalline state allows the determination of the structure of the tetranuclear chromium aqua complex having an adamantane-like structure, [Cr₄(μ₂-OH)₆(H₂O)₁₂]⁶⁺, which has been previously unknown in the solid state.     

A ternary complex of aqua(18‐crown‐6)bis(o‐nitrophenolato)barium(II), the triaqua(18‐crown‐6)(o‐nitrophenolato)barium(II) cation and the o‐nitrophenolate anion

In the title compound [systematic name: tri­aqua(1,4,7,10,13,16‐hexaoxa­cyclo­octa­decane‐κ⁶O)(2‐nitro­phenolato‐κO)­barium(II)–aqua(1,4,7,10,13,16‐hexaoxa­cyclo­octa­decane‐κ⁶O)‐ bis(2‐nitro­phenolato‐κ²O,O′)­barium(II)–2‐nitro­phenolate (1/1/1)], [Ba(C₁₂H₂₄O₆)(C₆H₄NO₃)(H₂O)₃][Ba(C₁₂H₂₄O₆)(C₆H₄NO₃)₂(H₂O)](C₆H₄NO₃), the two Ba^II atoms encapsulated by the 18‐crown‐6 rings have different coordinations. Although both Ba^II atoms are coordinated to the six O atoms of the crowns, in the neutral moiety, the Ba^II atom is coordinated to one terminal O atom from a water mol­ecule, two phenolate O atoms and two nitro‐group O atoms, while in the cationic moiety, the Ba^II atom is coordinated to three terminal O atoms from water mol­ecules and one phenolate O atom. Both the crowns are eclipsed and translated along the b direction. In the asymmetric unit, the three components are interconnected by four O—H?O interactions. The packing is stabilized by two intermolecular C—H?O interactions and by one O—H?O interaction.     

A polymeric cobalt(II) complex derived from citric acid (H4cit) and 2,6‐diaminopurine (dap): {[Co4(cit)2(dap)4(H2O)4]·6.35H2O}n

Poly[[tetraaquadi‐μ₄‐citrato‐tetrakis(2,6‐diaminopurine)tetracobalt(II)] 6.35‐hydrate], {[Co₄(C₆H₄O₇)₂(C₅H₆N₆)₄(H₂O)₄]·6.35H₂O}_n, presents three different types of Co^II cations in the asymmetric unit, two of them lying on symmetry elements (one on an inversion centre and the other on a twofold axis). The main fragment is further composed of one fully deprotonated citrate (cit) tetraanion, two 2,6‐diaminopurine (dap) molecules and two aqua ligands. The structure is completed by a mixture of fully occupied and disordered solvent water molecules. The two independent dap ligands are neutral and the cit tetraanion provides for charge balance, compensating the 4+ cationic charge. There are two well defined coordination geometries in the structure. The simplest is mononuclear, with the Co^II cation arranged in a regular centrosymmetric octahedral array, coordinated by two aqua ligands, two dap ligands and two O atoms from the β‐carboxylate groups of the bridging cit tetraanions. The second, more complex, group is trinuclear, bisected by a twofold axis, with the metal centres coordinated by two cit tetraanions through their α‐ and β‐carboxylate and α‐hydroxy groups, and by two dap ligands bridging through one of their pyridine and one of their imidazole N atoms. The resulting coordination geometry around each metal centre is distorted octahedral. Both groups are linked alternately to each other, defining parallel chains along [201], laterally interleaved and well connected via hydrogen bonding to form a strongly coupled three‐dimensional network. The compound presents a novel μ₄‐κ⁵O:O,O′:O′,O′′,O′′′:O′′′′ mode of coordination of the cit tetraanion.     

Cadmium(II) thio‐ and selenocyanate complexes of 3,3′‐bis(1,2,4‐triazol‐4‐yl)‐1,1′‐biadamantane,a ligand designed with an `extended nanodiamond' aliphatic platform

In the structures of the Cd^II pseudohalide coordination polymer poly[[diaquabis[μ₂‐3,3′‐bis(1,2,4‐triazol‐4‐yl)‐1,1′‐biadamantane‐κ²N¹:N^1′]cadmium(II)] dithiocyanate dihydrate], {[Cd(C₂₄H₃₂N₆)₂(H₂O)₂](NCS)₂·2H₂O}_n, (I), and the isomorphous selenocyanate analogue, {[Cd(C₂₄H₃₂N₆)₂(H₂O)₂](NCSe)₂·2H₂O}_n, (II), the Cd^II cations occupy inversion centres and have octahedral CdN₄O₂ environments, completed by four N atoms of the organic ligands [Cd—N = 2.316 (2) and 2.361 (2) Å for (I), and 2.313 (3) and 2.372 (3) Å for (II)] and two trans‐coordinated aqua ligands [Cd—O = 2.3189 (15) Å for (I) and 2.323 (2) Å for (II)]. In each compound, the ligand displays a bidentate N¹:N^1′‐bridging mode, connecting the metal centres at a distance of 14.66 Å into two‐dimensional nets of (4,4)‐topology, while the uncoordinated thio(seleno)cyanate anions reside inside the net cavities. Hydrogen bonding between the water molecules, anions and 1,2,4‐triazole N atoms supports the tight packing, with an interlayer distance of 6.09 Å.     

Protonated Co(III) Complexes with Ethylenediaminetetraacetic and S-Proline-N-Mono-3-propionic Acids. Crystal Structures of (H3O)[Co(HEdta)(CN)] · H2O and [Co(Promp)(HPromp)] · H2O

Crystal structures of [Co(Promp)(Hpromp)] · H₂O (I) (where Promp and Hpromp are deprotonated and monoprotonated anions of S-proline-N-mono-3-propionic acid) and (H₃O)[Co(Hedta)(CN)] · H₂O (II) (where HEdta is monoprotonated anion of ethylenediaminetetraacetic acid) are determined by X-ray diffraction method. The Co coordination octahedron in compound I is formed by two N atoms in trans-positions and by four O atoms of two tridentate ligands, i.e., anions of H₂Promp acid, one of which is fully deprotonated, while the other one has protonated carboxyl group of a six-membered aminopropionate metal cycle. Neutral [Co(Promp)(Hpromp)] complexes and water molecules are united by hydrogen bonds into chains along 2₁ screw axis. Crystals II consist of the complex anions [Co(Hedta)(CN)]⁻, hydroxonium cations, and water molecules. The Co coordination octahedron includes two N atoms and three O atoms of ion of ethylenediaminetetraacetic acid, whose one acetate group is not coordinated but protonated; cyanide ion lies in the NCoN plane. Crystals II contain two types of H₃O⁺ ions that are involved in hydrogen bonds in different way.__________Translated from Koordinatsionnaya Khimiya, Vol. 31, No. 8, 2005, pp. 596–605.Original Russian Text Copyright © 2005 by Poznyak, Burshtein.     

Diaqua­bis[4‐(4H‐1,2,4‐triazol‐4‐yl)­benzoato‐κ2O,O′]cobalt(II), and the cadmium(II) and copper(II) analogues: new self‐complementary hydrogen‐bond donor/acceptor modules for designing hydrogen‐bonded frameworks

In the isostructural title complexes, [M(C₉H₆N₃O₂)₂(H₂O)₂] [M = Co^II, (I), Cd^II, (II), and Cu^II, (III); the metal centres reside on a twofold axis in the space group C2/c for (I) and (II)], the metal centres are surrounded by four O atoms from two O,O′‐bidentate carboxyl­ate groups and by two trans‐coordinated aqua ligands, forming a distorted octa­hedral environment. The mol­ecules possess four hydrogen‐bond donor (two aqua ligands) and four hydrogen‐bond acceptor sites (two triazole groups), and aggregate by self‐association, forming two‐dimensional hydrogen‐bonded frameworks [via O—H⋯N inter­actions; O⋯N = 2.749 (3)–2.872 (3) Å]. The layers are parallel and are tightly packed with short inter­layer distances of 4.93, 4.95 and 5.01 Å for (I), (II) and (III), respectively.     

Crystal structures and thermal decomposition oftrans-Pd(Creat)2Cl2·2H2O andcis-Pt(Creat)2I2·3H2O

New complexes of the formulaetrans-Pd(Creat)₂Cl₂·2H₂O (I) andcis-Pt(Creat)₂I₂·3H₂O (II) have been prepared and their structures and stabilities studied by X-ray diffraction and thermal analysis. Both compounds have a squareplanar geometry, the two Cl atoms and N1 creatinine atoms are coordinated to Pd intrans configuration, while in compoundII the I atoms and N1 atoms are coordinated incis configuration. In spite of the earlier differences, the TG and DTA curves of the complexes show that their stability is very similar. Since an extended hydrogen bond system is present in the crystals, especially inII, the possible consequences in biological media are discussed briefly.

---

Kristallstrukturen und thermische Zersetzung vontrans-Pd(Creat)₂Cl₂·2H₂O undcis-Pt(Creat)₂I₂·3H₂O

Zusammenfassung Es wurden neue Komplexe der Formelntrans-Pd(Creat)₂Cl₂·2H₂O (I) undcis-Pt(Creat)₂I₂·3H₂O (II) hergestellt und ihre Strukturen und Stabilitäten mittels Röntgenstrukturanalyse bzw, thermischer Analyse untersucht. Beide Komplexe haben quadratisch-planare Struktur, die zwei Cl-Atome und die N1-Creatinin-Atome sind an Pd intrans-Konfiguration koordiniert, währenddessen in VerbindungII die I-Atome und die N1-Atome incis-Konfiguration zueinander stehen. Trotz früherer Differenzen zeigen die TG- und DTA-Kurven der Komplexe, daß ihre Stabilitäten sehr ähnlich sind. Da besonders inII ein ausgedehntes Wasserstoffbindungssystem vorhanden ist, werden auch mögliche Konsequenzen bezüglich biologischer Wirksamkeit kurz diskutiert.

     

Geometric Isomers of Cobalt(II) and Cobalt(III) Picolinates in Solution

Cobalt complexes with picolinic acid (HPic), namely, [Co^II(Pic)₂(H₂O)₂] · 2H₂O (I) and [Co^III(Pic)₃] · H₂O (II) are studied using ¹H and ¹³C NMR spectroscopy. Compound Iexists in solution as three geometric isomers, namely, trans-trans-trans, cis-trans-cis, and trans-cis-cis(molar ratio 4 : 2 : 1, respectively). According to ¹³C NMR data, compound IIexists in solution as a mer-isomer. The relative energy stability of the isomers was estimated using the molecular mechanics method.     

Bis[N-(isonitrosoacetophenone)-N′-benzoylhydrazonato-k<Superscript>3</Superscript>O,N,N′]nickel(II) dimethylformamide disolvate hemihydrate: Synthesis,crystal structure,and spectroscopic and electronic properties

In the title complex, [Ni(C₃₀H₂₄N₆O₄)]₂ · 4C₃H₇NO · H₂O (I), the Ni(II) atoms are six-coordinated by two N atoms and one O atom of each of the two tridendate benzoylhydrazone ligands, leading to a distorted octahedral geometry. In the environment of Ni(II) atoms, the equatorial planes are approximately perpendicular. The structure is stabilized by O-H...O, O-H...N, and C-H...O intra- and intermolecular hydrogen bonding, resulting in the formation of infinite chains running along the x axis of the triclinic cell. The structure of the compound was characterized by IR and UV spectra, elemental analyses, and X-ray diffraction techniques.