Simplified bicyclic cage-type molecule as a C 3 -symmetric host: X-ray and FTIR characterization of encapsulation of a nitrile molecule

We synthesized a new amine-type host molecule 2 by 2 steps, using 1,3,5-tris(aminomethyl)-2,4,6-trimethylbenzene and 2,6-pyridinedicarboxaldehyde as starting materials. Recrystallization of 2·6H₂O from hot acetonitrile, hot propionitrile and hexane/benzonitrile solutions gave colorless crystals of MeCN@2·MeCN·2H₂O, EtCN@2·EtCN, and 8H₂O@2·PhCN. In the former two crystals, the nitrile compounds were captured inside of the cavity of 2. On the other hand, in the latter one, the benzonitrile was laid outside 2. Infrared spectral measurements of MeCN@2·MeCN·2H₂O, EtCN@2·EtCN, and 8H₂O@2·PhCN showed that absorption bands assignable to the C ≡ N stretching vibrations of nitrile compounds were observed at 2240, 2241, and 2226 cm^?1 for MeCN@2·MeCN·2H₂O, EtCN@2·EtCN, and 8H₂O@2·PhCN, respectively. The former two peaks shifted to a lower energy region by 6–13 and 21–26 cm^?1 than those of liquid and gas phases of MeCN and EtCN, respectively. That for 8H₂O@2·PhCN shifted to a slightly lower region by 2 and 12 cm^?1 those of liquid and gas states of PhCN, respectively, indicating that the outer benzonitrile molecule dose not so much interact with 2 in the crystal.     

Zur Kenntnis der Struktur der Chalkon-Guanidin-Kondensate Über Heterocyclen, 75. Mitt.

Guanidine reacts with chalkone1 a, 4-methylchalkone1 b and 4′-methylchalkone1 c resp. to yield mixtures of pyrimidinamines2 a,3 b and3 c (=3 b) resp. with (2:1)-condensatesA,B andC resp. The structures of the compoundsA-C (whicha priori could be dihydropyrimidopyrimidines4 a-c or5 a-c or6 a-c) are elucidated. NMR-investigations show that the saltsA-C · HCl must be symmetrically substituted pyrimidopyrimidinyliumchlorides4 a-c · HCl or5 a-c · HCl (and not6 a-c · HCl). Furthermore, it is proved by chemical methods that the condensatesB · HCl andC · HCl are pyrimidopyrimidinyliumchlorides4 b andc · HCl (and not5 b andc · HCl): The structure ofB · HCl (=4 b · HCl) was established by total synthesis of dimethylpyrimidopyrimidinyliumpicrate9 b-Pi from10 c (via13 c · HI-18 · HCl) and transformation ofB · HCl into an identical salt9 b-Pi via hexahydropyrimidopyrimidine8 b · HCl. The structure ofC · HCl (=4 c · HCl) was determined by comparison of its hydrogenation product (=8c · HCl) with8 b · HCl. The structure of condensateA · HCl (=4 a · HCl) results from conclusion by analogy. The spatial structure of4 a-c · HCl and8 a-c · HCl is discussed; it was established by NMR that the salts are racemic mixtures of stereoisomers4 a-c K · HCl and8 a-c K · HCl resp. and their antipodes (with C₂ symmetry).     

Crystal structures of 3-phenylpropenal thiosemicarbazone and its nickel and zinc chelates

3-Phenylpropenal thiosemicarbazone hydrate C₆H₅-HC=CH-CH=N-NH-C(S)-NH₂ · H₂O (HL · H₂O, I) and two chelates [Ni(L)₂] · nCH₃OH (II) and [Zn(L)₂] (III) are studied by X-ray diffraction. The crystals of I are orthorhombic: a = 6.227(1) Å, b = 7.763(2) Å, c = 25.585(5) Å, β = 90°, space group P2₁2₁2₁, Z = 4, R = 0.0426. A nonplanar molecule of I has an E conformation. The crystals of II are triclinic: a = 6.551(2) Å, b = 10.752(3) Å, c = 10.885(3) Å, α = 64.751(5)°, β = 82.753(5)°, γ = 89.857(5)°, space group, Z = 1, R = 0.0661. In a centrosymmetric molecule of II, the central atom coordinates two deprotonated ligands L through the immine nitrogen atom and thioamide sulfur atom at the vertices of a distorted square. The crystals of III are monoclinic: a = 25.342(2) Å, b = 9.150(2) Å, c = 21.340(3) Å, α = 90°, β = 111.84(2)°, γ = 90°, space group C2/c, Z = 8, R = 0.0556. In a molecule of complex III, two deprotonated bidentate ligands L are coordinated by the zinc ion through the immine nitrogen atoms and thioamide sulfur atoms to form a distorted tetrahedron at the central atom. In both II and III, ligand L after coordination by the metal ion changes the E conformation with respect to the N(1)-C(2) bond for the Z conformation. In crystals I-III, molecules are packed to form infinite layers parallel to the planes (001) and (010).     

Syntheses and characterization of a new class of vanadia precursors of oxime-modified oxovanadium(V) isopropoxide,crystal and molecular structure of [VO{ONC10H16}3]

Modification of [VO(OPrⁱ)₃] with oximes in different molar ratios, yielded new class of vanadia precursors, [VO{OPrⁱ}_3?n{L}_n] {where, n = 1–3 and LH = C₉H₁₆C=NOH (1–3) and (CH₃)₂C=NOH (4–6)}.All the products are yellow in colour. (1) and (2) are liquid/viscous liquid, while others are solids. Molecular weight measurements of all these derivatives and the ESI-mass spectral studies of (1), (2), (3) and (5) indicate their monomeric nature. ¹H and ¹³C{¹H} NMR spectra suggest that the oximato moieties are monodentate in solution which was further confirmed by the ⁵¹V NMR signals, appeared in the region expected for tetra-coordinated oxo-vanadium atoms. On ageing, a disproportionation reaction occurs in (1) and some crystals appeared. Single crystal X-ray diffraction analyses of the crystals obtained from (1) as well as from (3) were found to be the same and indicate the presence of side-on {dihapto η ²-(N, O)} binding modes of the oximato ligands, leading to the formation of seven coordination environment around the vanadium atom. Thermogravimetric curve of (1) exhibits multi-step decomposition with the formation of V₂O₅ as the final product at ~850 °C. Sol–gel transformation of (3) yielded (a) VO₂ sintered at 300 °C and (b) V₂O₅ at 600 °C. Similarly, sol–gel transformations of (1) and (2) yielded V₂O₅ (c) and (d) at 600 °C, respectively. Formation of monoclinic phase in (a) and orthorhombic phase in (b), (c) and (d) were confirmed by powder XRD patterns.     

Complexes built with a scorpion-type tripodal ligand and metal ions: syntheses, structural features, electrochemical properties and magnetic properties

The complexes [Fe(bpz*mpy)₂](ClO₄)₂ (1a), [Cu(bpz*mpy)₂](ClO₄)₂ (1b) and [Ag(bpz*mpy)(Ph₃P)](ClO₄) · H₂O (2) (bpz*mpy = pyridin-2-yl-bis(3,5-dimethylpyrazol-1-yl)methane) have been synthesized and characterized by physicochemical and spectroscopic methods. X-ray crystallographic analysis reveals that the central Fe^II and Cu^II ions in complexes 1a and 1b are located on a twofold rotation axis and have a distorted octahedral coordination sphere, while the Ag^I center in complex 2 is tetrahedrally coordinated. The electrochemical properties of complex 1b have been investigated. Furthermore, a variable temperature magnetic susceptibility study of complex 1a has also been performed over the measured temperature range 2–300 K.     

Inclusion of Cl− or Br− anions within host framework formed by second-sphere interactions

In this study, we have deliberately utilized the second-sphere coordination approach into the construction of supramolecular inclusion solids Cl ? [H₂ L1]·[InCl₄] (Crystal I) and Br ? [H₂ L1]·[TeBr₆] (Crystal II). The chloride or bromine anions can be encapsulated inside the host assemblies formed by the diamine molecule (4,6-dimethyl-1,3-phenylene) bis(N,N-dibenzylmethane) (L1) and the metal complexes ([InCl₄]^? and [TeBr₆]^2?) via second-sphere interactions. The inclusion complexes have been structurally characterized by X-ray crystallography, indicating that weak C–H···Cl and C–H···Br hydrogen bonding synthons play a significant role in the construction of host framework. 2-D networks are formed in both complexes by the interconnection of 1-D networks through the multiple weak hydrogen bonding interactions with [InCl₄]^? or [TeBr₆]^2?. The guest Cl^? or Br^? anions are encapsulated inside the host cages through N–H···Cl hydrogen bonds. The inclusion selectively was studied for the two host assemblies.     

Anion-directed organized assemblies of protonated pyrazole-based ionic salts

The reactions of 3(5)-(4-methoxyphenyl)-5(3)-phenyl-1H-pyrazole (L ¹ ) with nitric acid and 5-(4-benzyloxyphenyl)-3-(furan-2-yl)-1H-pyrazole(L ² ) with hydrochloric acid produced [HL ¹ · NO₃] (Salt-1) and [HL ² · Cl] (Salt-2). The structures of Salt-1 and Salt-2 were determined by single crystal X-diffraction. In Salt-1, HL ¹ showed [2 + 2] binding of NO₃ ^? ions in the solid state to form dimer architecture with R ₁ ² (4) and R ₄ ⁴ (14) graph sets. An anion directed one-dimensional anion-assisted helical chain with active participation of the chloride ion and protonated pyrazole via N–H···Cl hydrogen bonding in Salt-2. In addition, the protonated HL ² molecules interacted with each other through weak C–H···π interactions resulting in the formation of another one-dimensional helical chain.     

Synthesis, crystal structures and electrochemical properties of CoIII complexes with hexadentate ligand containing thioether-amidopyridyl donor set

Two new cobalt(III) complexes of the hexadentate ligand [1,4-bis[o-(pyridine-2-carboxamidophenyl)]-1,4-dithiobutane] (H₂bpctb) with N₄S₂ donor set atoms have been synthesized. A reaction of Co(CH₃COO)₂·4H₂O with (H₂bpctb) leads to the formation of [Co^III(bpctb)]PF₆ (1) having a CoN₂(pyridine)N′₂(amide)S₂(thioether) coordination by symmetric bpctb^2? ligand. A similar reaction under slightly different conditions, however, gives [Co^III(L ^a )(L ^b )] (2), resulting from a C–S bond cleavage reaction triggered by an acetate ion as a base, having CoN₂(pyridine)N′₂(amide)S(thioether)S′(thiolate) coordination. These two Co(III) complexes have been characterized by elemental analyses and spectroscopic methods, and the crystal and molecular structures of [Co^III(bpctb)]PF₆ (1) in the form of the solvate (1·MeOH·H₂O) and of [Co^III(L ^a )(L ^b )] (2) have been determined by X-ray crystallography. The Co atoms of both complexes exhibit distorted octahedral geometry. The electrochemical investigation of [Co(bpctb)]PF₆·MeOH·H₂O (1·MeOH·H₂O) and [Co^III(L ^a )(L ^b )] (2) by cyclic voltammetry reveals a reversible Co^III–Co^II redox process at E _1/2 = ?0.32 V (ΔE _p = 80 mV); for 1, and E _1/2 = ?0. 87 V (ΔE _p = 70 mV) for 2.     

Copper complexes with N-allylisoquinolinium halides: Synthesis and crystal structures of [C9H7N(C3H5)]2CuIICl2.86Br1.14, [C9H7N(C3H5)CuIBr2] · H2O, and [C9H7N(C3H5)CuIBr2]

Crystals of the copper bromide complexes with N-allylisoquinolinium halides of the composition [C₉H₇N(C₃H₅)]₂Cu^IICl_2.86Br_1.14 (I), [C₉H₇N(C₃H₅)]Cu^IBr₂ · H₂O (II), and [C₉H₇N(C₃H₅)]Cu^IBr₂ (III) are prepared by ac electrochemical synthesis, and their structures are studied by X-ray diffraction analysis (DARCh-1 (for I) and KUMA/CCD (for II and III) diffractometers). The crystals of compound I are monoclinic: space group P2₁/n, a = 15.053(5) Å, b = 10.486(4) Å, c = 17.179(10) Å, γ = 109.77(3)°, V = 2552(4) ų, Z = 4. The crystals of complex II are triclinic: space group P $\overline 1 $ , a = 7.040(1) Å, b = 7.610(2) Å, c = 12.460(2) Å, α = 79.54(3)°, β = 86.73(3)°, γ = 89.51(1)°, V = 655.4(2) ų, Z = 2. The crystals of complex III are monoclinic: space group P2₁/n, a = 12.799(1) Å, b = 7.692(1) Å, c = 13.491(1) Å, β = 111.08(1)°, V = 1239.3(2) ų, Z = 4. The structure of compound I is built of the Cu^IIX ₄ ^2? tetrahedra and N-allylisoquinolinium cations united by the C-H···X contacts into corrugated layers. The crystal structure of π-complex II is formed of dimers of the composition [C₉H₇(C₃H₅)]₂ Cu ₂ ^I Br₄ forming layers in the direction of the z axis due to the C-H···X contacts. An important role in structure formation belongs to water molecules that cross-link the organometallic layers through the O-H···X contacts into a three-dimensional framework. When kept in the mother liquor for 6 months, the crystals of compound II transformed into crystals of compound III, whose structure consists of {[C₉H₇(C₃H₅)]₂Cu ₂ ^I Br₄} _n columns united through the C-H···Br contacts (H···Br 2.84(3)?2.92(4) Å) into a three-dimensional framework.     

Long, multicenter bonding in π-[terthiophene] 2 2+ dimers

The repulsive nature of the interaction between the cation radicals of the π-[terthiophene] ₂ ²⁺ dimers, 1 ₂ ²⁺ , found in crystals has been concluded from B3LYP/6-31+G(d) calculations. Hence, the bonding component is weaker than the Coulombic repulsion, consistent to recent findings for [TTF]^·+–[TTF]^·+ interactions (TTF = tetrathiafulvalene). The existence of 1 ₂ ²⁺ dimers originates from the cation⁺–anion^? electrostatic interactions, which exceeds the combined effect of the 1 ^.+–1 ^.+ plus (SbF₆)^?–(SbF₆)^? repulsions in 1 ₂(SbF₆)₂, similar to what is found for [TTF]^·+–[TTF]^·+ interactions in [TTF]₂(ClO₄)₂ aggregates and in crystals. The long, multicenter bond in 1 ₂ ²⁺ is characterized as a 2e^?/10c bond from an Atoms-in-molecules analysis.     

Stability and structure in solution of potassium and barium complexes with N,N’-diaryldiaza-18-crown-6: Crystal structure of N,N’-Bis(4-dimethylaminophenyl)diaza-18-crown-6 and its complex with barium perchlorate

It has been shown that N,N’-diaryldiaza-18-crown-6 ethers with p-dimethylamino-and p-methoxy groups in the benzene ring (aryl is 4-Mc₂NC₆H₄) (I) and 4-MeOC₆H₄ (II) form complexes with potassium and barium salts. The influence of these salts on the UV and ¹H NMR spectra of crown ethers I and II has been studied. The stability constants (logβ) of the complexes increase in the series II · Ba(ClO₄)₂ (2.0), I · Ba(ClO₄)₂ (2.3), II · KBr (2.8), I · KBr (3.0). N,N’-bis(4-dimethylphenylamine)diaza-18-crown-6 (L, I) and its complex with barium perchlorate Ba(ClO₄)₂ · L (III) are characterized by X-ray crystallography. The crystals of I are monoclinic: a = 13.778(2) Å, b = 5.9731(9) Å, c = 17.542(3) Å, β = 106.65(1)°, V = 1383.1(4) ų, Z = 2, space group P2₁/n, R = 0.0374 for 990 reflections with I > 2σ(I). The crystals of III are monoclinic: a = 17.275(4) Å, b = 8.017(2) Å, c = 26.935(4) Å, β = 100.47(2)°, V = 3669(1) ų, Z = 4, space group C2/c, R = 0.0320 for 1897 reflections with I > 2σ(I). The molecules of I and III are centrosymmetric. In III, the Ba atom is in the center of substituted diaza-18-crown-6 (DA18C6). The Ba atom is coordinated by all six donor atoms of diaza-18-crown-6 (av. Ba-O, 2.779(3) Å; Ba-N, 3.004(4) Å) and four oxygen atoms of two asymmetrically bound perchlorate groups (Ba-O, 2.832(4) and 3.031(4) Å) arranged below and above the plane of substituted diaza-18-crown-6. The conformations of the macrocycle in free and coordinated L are different.     

Crystalline inclusion compounds derived from bulky organosilicon hosts – design, synthesis, structure and stability

New organosilicon compounds 1–3 featuring bulky triphenylsilyl moieties attached to rigid linear or trigonal spacer units have been synthesized and demonstrated to act as clathrate hosts, yielding crystalline inclusion compounds mostly with apolar and aprotic dipolar guest molecules, while the nonbulky dimethylphenylsilyl or trimethylsilyl substituted analogous compounds 4 and 5, which were also synthesized, proved inefficient. X-ray crystal structures of the inclusion compounds 1·DMF (1:1), 1·pyridine (1:1), 2·1,4-dioxane (2:1), 2·pyridine (2:1), 2·p-xylene (2:1), 2·H₂O (2:1) as well as of the unsolvated compounds 2 and 5 are described, and thermal stability studies of selected clathrates are reported.     

Synthesis and study of hydrogen hexamolybdonickelate and hydrogen hexamolybdozincate with the cobaltammine cation

[Co(NH₃)₆] · H₂[NiMo₆O₁₈(OH)₆] · 6H₂O (I) and [Co(NH₃)₆] · H₂[ZnMo₆O₁₈(OH)₆] · 6H₂O (II) have been synthesized and studied by mass spectroscopy, thermogravimetry, and X-ray powder diffraction. The crystals of compounds I and II are monoclinic, Z = 1; for compound I: a = 16.10 Å, b = 5.58 Å, c = 12.22 Å, β = 117.86°, V = 1045.14 ų, and ρ_calcd = 2.26 g/cm³; for compound II: a = 16.12 Å, b = 5.52 Å, c = 12.12 Å, β = 117.90°, V = 1043.21 ų, and ρ_calcd = 2.21 g/cm³.     

Isomorphous crystal structures of 4,7,13,16,21,24-hexaoxo-1,10-diaziniabicyclo[8.8.8]·hexacosane bis(tribromide) and bis(bromoiodide)

Two compounds, 7,13,16,21,24-hexaoxa-1,10-diazoniabicyclo[8.8.8]hexacosane bis(tribromide) and bis(bromodiiodide) — [H₂(Crypt-222)]²⁺·2Br ₃ ^? (I) and [H₂(Crypt-222)]²⁺·1.45(BrI₂)^?·0.4(Br₂I)^?·0.15 I ₃ ^? (II) — are prepared and characterized by single crystal XRD; the refinement of the second compound was more accurate. Isomorphous monoclinic structures (I, space group C2/c, Z = 4, a = 12.090, b = 15.833 Å, c = 15.732 Å, β = 95.83°; II, a = 12.548 Å, b = 16.417 Å, c = 15.748 Å, β = 94.53°) are solved by a direct method and refined in the anisotropic full-matrix approximation to R = 0.057 (I) and 0.044 (II) using all 2635 (I) and 2852 (II) measured independent reflections (automated CAD-4 diffractometer, λMoK _α). In the structures of I and II one of the trihalide anions sits at the inversion center i(000), and the second trihalide anion and the dication [H₂(Crypt-222)]²⁺ are situated at crystallographic axis 2. In the structure of II iodine is located in the center of trihalide anions, while the terminal atoms are disordered and are represented by a statistical combination of iodine and bromine atoms.     

Über die Reaktionen von monosubstituierten Guanidinen mit 1-Phenyl-1,3-butandion

Methyl-, benzyl- and phenylguanidine (2 b–d) react with 1-phenyl-1,3-butanedione to yield exclusively N²-substituted 4-methyl-6-phenyl-2-pyrimidinamines10 b–d. The formation of isomeric N¹-substituted 2(1H)-pyrimidinimines11 or12 cannot be observed. The structural formulae of10 b and c were proved by spectroscopical methods. The structure of the phenylguanidine-phenylbutanedione-condensate was determined by comparison and establishment of the identity of its picrate with an authentical sample of10 d-picrate, which had been synthetized from pyrimidinthione13 (via methylthiopyrimidine16 · HI). Boiling13 with aniline in butanol yields thiodipyrimidine15 (and not10 d).     

Oxidation of coordinated ethylenediamine in platinum(IV) complexes with bromine. Crystal structures of [Pt(en)Py2Br2]Br2 · H2O, [Pt(HN-C(O)-C(O)-NH)Py2Br2] · H2O, and [Pt(en)PyBr3]NO3

Heating of an aqueous solution of [Pt(en)Py₂Cl₂]Cl₂ · 2H₂O (I) with KBr excess leads to the formation of [Pt(en)Py₂Br₂]Br₂ · H₂O (II). The interaction of a solution of II with bromine water results in the precipitation of polybromide ([Pt(en)Py₂Br₂]Br₂ · Br₂), which within a few days in the reaction solution partly transforms into oximide platinum(IV) complex, [Pt(HN-C(O)-C(O)-NH)Py₂Br₂] · H₂O (III). Complex [Pt(en)PyBr₃]Br · H₂O (IV) with an impurity of II was prepared by reacting KBr excess and the product of [Pt(en)Py₂]Cl₂ oxidation with chlorine in 0.05 N HCl. The action of HNO₃ on the solution of IV produced a nitrate derivative ([Pt(en)PyBr₃]NO₃, V). Complex IV, unlike II, does not react with bromine. The IR spectra of all the obtained compounds were recorded. Complexes II, III, and V were studied by X-ray crystallography. The crystals of II are monoclinic, space group P2₁/c, a = 15.640(2) Å, b = 9.345(1) Å, c = 14.167(2) Å, β = 102.63(1)°, V = 2020.5(5) ų, Z = 4, R _hkl = 0.033. The crystals of III are triclinic, space group P $\bar 1$ , a = 7.108(1) Å, b = 10.946(1) Å, c = 11.020(2) Å, α = 83.63(1)°, β = 80.31(1)°, γ = 75.02(1)°, V = 814.4(2) ų, Z = 2, R _hkl = 0.033. In the near-planar five-membered chelate ring (torsion angle NCCN is 7°), the C-O distances (1.23(1) Å) correspond to double bonds; the C-C (1.53(1) Å) and C-N (1.31(1) Å), distances correspond to ordinary bonds. The crystals of V are monoclinic, space group P2₁/c, a = 8.306(2) Å, b = 8.995(2) Å, c = 20.231(4) Å, β = 97.48(2)°, V = 1498.6(6) ų, Z = 4, R _hkl = 0.037.     

Two copper(II) complexes of curcumin derivatives: synthesis,crystal structure and in vitro antitumor activity

Two Cu(II) complexes of curcumin derivatives, formulated as CuL ₂ ^a (1) and CuL ₂ ^b (2) [HL^a = 1,7-bis(4-ethyloxy-3-methoxy-phenyl)-1,6-heptadiene-3,5-dione and HL^b = 1,7-bis(4-butyloxy-3-methoxy-phenyl)-1,6-heptadiene-3,5-dione], have been synthesized and characterized by single-crystal X-ray diffraction, along with physicochemical and spectroscopic methods. In both complexes, each Cu(II) center is surrounded by four oxygen atoms from two β-diketone ligands in a square planar geometry. Complex 1 forms a 2D layer structure through intermolecular π–π stacking interactions, as well as weak coordination interactions between the Cu and O atoms of the solvent 1,4-dioxane molecules. Complex 2 displays a 1D column structure stabilized by intermolecular π–π stacking interactions. MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assays were used to evaluate the cytotoxicities of these complexes against three human cancer cell lines. The results show that the Cu(II) complexes exhibit more potent inhibition tumor growth in comparison with the free ligands.     

3-(diallylamino)propanenitrile ((C3H5)2NC2H4CN, L) π-complexes with copper(I) ionic salts. Syntheses and crystal structures of compounds [Cu(H+L)ClO4]ClO4 · H2O, [Cu(H+L)BF4]BF4 · H2O, and [Cu(H+L)(H2O)]SiF6 · H2O

Qualitative single crystals of ??-complexes Cu(H⁺L)(ClO₄)]ClO₄ · H₂O (I), Cu(H⁺L)(BF₄)]BF₄ · H₂O (II), and [Cu(H⁺L)(H₂O)]SiF₆ · H₂O (III) are synthesized from solutions of 3-(diallylamino)propanenitrile (L) in propanol, ethanol, and methanol-water acidified with the corresponding acid to pH 3.5?C5 and from the copper(II) salts (Cu(ClO₄)₂ · 6H₂O, Cu(BF₄)₂ · 6H₂O, and CuSiF₆ · 4H₂O) using the alternating-current electrochemical method on copper wire electrodes. The crystal structures of the complexes are determined. All compounds crystallize in the monoclinic crystal system: complexes I and II are isostructural, space group P2₁/n, Z = 4. For compound III, space group P2₁/c, Z = 8. Unit cell parameters: for I a =7.8153(3), b = 16.7824(7), c = 12.4426(5) ?, ?? = 93.410(2)°, V = 1629.1(1) ?³; for II, a = 7.6755(4), b = 16.7119(7), c = 12.3784(6) ?, ?? = 94.354(2)°, V = 1583.2(1); and for III a = 9.826(2), b = 24.009(3), c = 12.061(2) ?, ?? = 91.820(6)°, V = 2843.9(7) ?³. The trigonal pyramidal coordination of the copper atom in complexes I-III is formed by two C=C bonds of the allyl groups of H⁺L, the nitrile N atom of the adjacent cation of the ligand, and the O or F atom of the ClO ₄ ^? or BF ₄ ^? anions. In structure III, the apical position of the pyramid is occupied by the O atom of the water molecule, since the SiF ₆ ^2? anion is considerably remote from the copper(I) atom. However, this anion is bound to the organic cation by hydrogen bonds F??H (2.05?C2.51 ?).     

Crystal structure of [Cu2(Edta)(Py)2(H2O)2] · 2H2O and [Cu(Im)6]{;Cu(Im)4[Cu(Edta)(Im)]2} · 6H2O, Products of the interaction of (Ethylenediaminetetraacetato)diaquadicopper(II) with pyridine and imidazole

The crystals of [Cu₂(Edta)(Py)₂(H₂O)₂] · 2H₂O (I) and [Cu(Im)₆]{;Cu(Im)₄[Cu(Edta)(Im)]₂} · 6H₂O (II) were isolated as a result of the reaction of an aqueous solutions of Cu₂(Edta) · 4H₂O with pyridine or imidazole, respectively. The crystals were studied by X-ray diffraction. The crystals of I are monoclinic, a = 12.682 Å, b = 6.788 Å, c = 14.834 Å, β = 91.44°, Z = 2, space group P2₁/n. The crystals of II are triclinic, a = 9.118 Å, b = 14.889 Å, c = 15.130 Å, α = 72.59°, β = 72.94°, γ = 82.54°, Z = 1, space group P{ie241-1}. In the centrosymmetric binuclear complex molecule of I, an N atom and two O atoms of the Edta ligand are coordinated to each Cu atom (Cu-N, 2.046 Å; Cu-O, 1.941 and 1.954 Å). The N atom of the pyridine molecule (Cu-N, 1.993 Å) completes the base of an elongated tetragonal pyramid (4 + 1) with the O atom of the H₂O molecule in the apex (Cu-O(w), 2.244 Å). The crystals of II are built of centrosymmetric complex cations [Cu(Im)₆]²⁺ (Cu(1)-N, 2.469, 2.021, and 2.056 Å), centrosymmetric trinuclear complex anions {;Cu(Im)₄[Cu(Edta)(Im)]₂}^2?, and crystal water molecules. In the anion, the central fragment [Cu(Im)₄]²⁺ (Cu(2)-N, 1.985 and 2.023 Å) is bonded to two peripheral complexes [Cu(Edta)(Im)]^2? through atoms O of the Edta ligand (Cu(2)-O, 2.615 Å). In the [Cu(Edta)(Im)]^2? fragment of the complex anion, the Cu(3) atom is bonded to the Edta ligand through the two N atoms and three O atoms (Cu(3)-N, 1.970 and 2.071 Å; Cu(3)-O, 1.966, 1.969, and 2.238 Å) and with the imidazole molecule, through an N atom (Cu(3)-N, 2.397 Å). The coordination polyhedra of the three copper atoms (Cu(1)-Cu(3)) in the structure of II are elongated tetragonal bipyramids (4 + 2). In the structures studied, Edta^4? is a hexadentate chelating/bridging ligand. However, the coordination mode of the ligand in these structures is different: in the binuclear complex I, the Edta ligand is coordinated to each Cu atom through an N atom and two O atoms with the formation of two chelate rings (symmetric (trans) coordination mode), whereas, in the trinuclear complex II, the Edta ligand is coordinated to the Cu(2) atom through an O atom and to the Cu(3) atom through the two N atoms and three O atoms with the formation of three chelate rings (asymmetric (cis) coordination mode).     

Synthese,Kristallstruktur und Konformation vontrans-[2.2](1,2)Ferrocenophan und seinen 1-Hydroxyderivaten

Starting from1-(dimethylaminomethyl)-2-iodo-ferrocene (3) [2.2](1,2)ferrocenophane (2) was prepared in an 8-step synthesis with 17% overall yield. Both from the oxoderivative12 and the ferrocenophane2 puretrans-isomers (12b and2b, resp.) were obtained; the former (12b) was reduced to a separable mixture ofexo andendo 1-hydroxy-ferrocenophanes13a andb, resp. (～ 3:7), the configurations of which were assigned by the LIS-method. X-ray crystal structure analysis of2b revealed a centrosymmetrical chair conformation. From¹H- and¹³C-NMR spectra both for2b and for the hydroxyderivatives13 a rigidexo-exo chair conformation was deduced.