Structure of the pinacol formed via sodium-promoted reductive dimerization of 12-methyleneheptacyclo-[6.6.02,6.03,13.04,11.05,9.010,14]tetradecan-7-one

The pinacol resulting from sodium promoted reductive coupling of a methyleneheptacyclo-[6.6.0^2,6.0^3,13.0^4,11.0^5,9.0^10,14]tetradecanone possesses a conformation in which equivalent groups on the pinacol carbon are virtually perpendicular to each other. This rotation minimizes steric interactions, thus the geometries of all the fragments in the molecule are within expected values.     

The preparation and crystal structures of some tricarbonylmanganese(I) octahedral complexes containing the 1,1-dimethylamino-2,2-diphenylphosphinoethane ligand

Four new complexes of (pn) the titled ligand have been prepared and characterized: (CO)₃Mn(pn)Br, 1; (CO)₃Mn(pn)N₃, 2; the triazalato (tz) complex, (CO)₃Mn(pn)(tz), 3 and [(CO)₄Mn(pn)]BF₄, 4. Crystal structures for the first three of these were determined. Crystal data for 1, monoclinic crystal system, space group = C2, a = 17.8587(6) Å, b = 7.9611(3) Å, c = 14.2349(4) Å, = 90.281(1)°, V = 2023.82(12) ų, Z = 4; for 2, monoclinic crystal system, space group = P2₁/c, a = 8.8933(14) Å, b = 13.844(2) Å, c = 16.361(3) Å, = 95.712(3)°, V = 2004.4(6) ų, Z = 4; for 3, orthorhombic crystal system, space group = Pbca, a = 17.9097(4) Å, b = 13.1308(4) Å, c = 21.2838(6) Å, V = 5005.3(2) ų, Z = 8.     

Synthesis, spectroscopy, and X-ray structures of fac-(CO)3(dppe)MnSC(S)H, fac-(CO)3(dppe)ReSC(S)H, fac-(CO)3(dppp)ReSC(S)H, and fac-(CO)3(dppb)ReSC(S)H

The monodentate dithioformato complexes, fac-(CO)₃(dppe)MnSC(S)H (1), fac- (CO)₃(dppe)ReSC(S)H (2), fac-(CO)₃(dppp)ReSC(S)H (3), and fac-(CO)₃ (dppb)ReSC(S)H (4), where dppe is 1,2-bis(diphenylphosphino)ethane, dppp is 1,3-bis(diphenylphosphino)propane, and dppb is 1,4-bis(diphenylphosphino)butane, were synthesized from the treatment of the corresponding hydrides, fac-(CO)₃ (P-P)MSC(S)H with CS₂. Compounds 1–4 crystallize in the monoclinic crystal system: for 1, space group = P2₁/c, a = 15.3139(3) Å, b = 9.7297(4) Å, c = 19.0991(6) Å, = 105.928(1), V = 2736.5 ų, Z = 4; for 2, space group = P2₁/c, a = 15.6395(8) Å, b = 9.8182(5) Å, c = 19.4153(11) Å, = 106.741(1), V = 2854.9(3) ų, Z = 4; for 3, space group = P2₁/n, a = 11.3570(10) Å, b = 19.465(2) Å, c = 15.5702(14) Å, = 104.776(2), V = 3328.3(5) ų, Z = 4; and for 4, space group = C2/c, a = 32.078(2) Å, b = 10.4741(6) Å, c = 19.0608(9) Å, = 94.315(2), V = 6386.1(6) ų, Z = 8.     

Crystal structures of three 1-arylpropane-1,2-diol 2-aryl ether derivatives and the acetate of 2,6-dimethoxy-4-(1-(E)-propenyl)phenol

The crystal structures ofthreo-2-[2,6-dimethoxy-4-(1-(Z)-propenyl)phenoxy]-1-(4-hydroxy-3,5-dimethoxyphenyl)-1-propanol (7b),threo-2-(2,6-dimethoxy-4-propylphenoxy)-1-(3,4-5-trimethoxyphenyl)-1-propanol (7c), the diacetate oferythro-2-[2,6-dimethoxy-4-(1-(Z)-propenyl)phenoxy]-1-(4-hydroxy-3,5-dimethoxyphenyl)-1-propanol (8d) and the acetate of 2,6-dimethoxy-4-(1-(E)-propenyl)phenol (9) have been determined by single-crystal X-ray diffraction methods;7b,7c, and8d are structurally closely related to a class of optically-active neolignans of 1-arylpropane-1,2-diol 2-aryl ether type occurring in plant extracts. The reflection intensities were recorded at room temperature for7b and8d, at -140°C for7c and at -120°C for9. Compound7b crystallized as needles in the orthorhombic space groupPna2₁ witha=27.055(3),b=11.850(8),c=6.717(4)Å andZ=4.R became 0.041 for 1792 observed [I>3(I)] reflections used in the refinement of the structure. Compound7c crystallized as prisms in the monoclinic space groupP2₁/a witha=12.565(4),b=13.96(1),c=12.846(7)Å,=93.86(3)° andZ=4. The refinement gaveR=0.051 for 2101 observed [I>3(I)], unique reflections. Compound8d crystallized as prisms in the monoclinic space groupP2₁/n witha=13.182(4),b=8.518(5),c=23.322(5)Å,=106.12(2)° andZ=4. The finalR-valuebecame 0.042 for 2131 observed [I>3(I)], unique reflections. Compound9 crystallized as prisms in the orthorhombic space groupPca2₁ witha=18.216(4),b=9.483(3),c=7.416(2)Å andZ=4. TheR-value became 0.038 for 1502 observed [I>3(I)], unique reflections. The crystals of7b are stabilized by moderately strong hydrogen bonds. All the 1-arylpropane-1,2-diol 2-aryl ethers examined adopted conformations in which the aromatic groups tend to be as remote as possible. Observed double bond lengths in the propenyl groups of the compounds examined (1.30 Å) deviate significantly from the expected value (1.34 Å). The cause of this discrepancy is discussed.     

Structural studies of N(4)-substituted thiosemicarbazones prepared from 4-formylantipyrine and a thiourea derived from 4-aminoantipyrine

Reaction of 4-formylantipyrine with N(4)-dimethylthiosemicarbazide and 3-piperidylthiosemicarbazide produces the N(4)-dimethylthiosemicarbazone (1), and the 3-piperidyl-thiosemicarbazone (2), respectively. Compound 1 is triclinic, space group P-1 with a = 6.329(1) Å, b = 11.699(1) Å, c = 11.943(1) Å, = 65.83(1)°, = 80.83(1)°, = 84.90(1)°, and V = 796.1(1) ų with Z = 2, for D _calc = 1.324 g/cm³. Compound 2 is triclinic, space group P-1 with a = 6.784(1) Å, b = 10.485(2) Å, c = 13.462(3) Å, = 102.05(2)°, = 98.61(2)°, = 101.32(2)°, and V = 899.8(5) ų with Z = 2, for D _calc = 1.319 g/cm³. Reaction of 4-aminoantipyrine with phenyl isothiocyanate produced N-antipyrine-N-phenylthiourea (3). Compound 3 is monoclinic, space group P2₁/n with a = 6.863(7) Å, b = 15.361(3) Å, c = 16.332(5) Å, = 90.35(6)°, and V = 1720.7(18) ų with Z = 4, for D _calc = 1.306 g/cm³. Compounds 1 and 2 have intermolecular hydrogen bonding between the carbonyl oxygen of the antipyrine moiety and the NH hydrogen of the thiosemicarbazone moiety. In 3 the two unique molecules are held together as a dimer by interactions of the two thiourea NH's and the antipyrine moiety's\break oxygen.     

The synthesis and structural characterization of silyl-substituted fluorenes

Three silyl-substituted fluorenes have been prepared by direct synthetic methods and structurally characterized by X-ray diffraction. The three silyl-substituted fluorenes studied were 9-trimethylsilylfluorene (1), 9-(tert-butyldimethyl)silylfluorene (2), and 2,7-di-tert-butyl-9-trimethylsilylfluorene (3). Complex 1 is orthorhombic, P2₁2₁2₁, a = 6.2681(14) Å, b = 14.329(3) Å, c = 15.231(4) Å, Z = 4. Complex 2 is monoclinic, P2₁/c, a = 12.1953(10) Å, b = 6.9977(6) Å, c = 19.6536(17) Å, = 93.818(2), Z = 4. Complex 3 is monoclinic, P2₁/c, a = 11.9954(9) Å, b = 9.8978(7) Å, c = 18.5464(13) Å, = 92.456(2), Z = 4. The long carbon–silicon bonds effectively remove any significant intramolecular interactions as little distortion is exhibited around the sp ³-carbon atom and the fluorenyl backbone demonstrates near planarity. The bulky silicon substituents also prevent intermolecular interactions, as only a few close contacts less than 4.0 Å exist in all three solid state structures.     

Crystallographic characterization of N,N′-diarylformamidines bearing an alkoxy substituent at either the meta- or ortho-position

Crystal structures of four diphenylformamidines bearing phenyl substituents ortho-CH₃O (1), ortho-C₂H₅O (2), meta-CH₃O (3), and meta- ⁿ BuO (4) are reported. In each of the structures, formamidine exists as an unsymmetrical cyclic hydrogen bond dimer, and the geometry of the amidine unit is consistent with the localized C–N and C=N bonds. Interesting conformations due to the orientation of aryl groups were also observed. Crystal Data: 1, orthorhombic, Pbca, a = 11.297(1) Å, b = 15.092(1) Å, c = 16.380(2) Å, V = 2792.6(4) ų, Z = 8; 2, triclinic, P , a = 9.651(1) Å, b = 11.974(1) Å, c = 14.583(2) Å, = 101.789(2)°, = 99.320(2)°, = 99.048(2)°, V = 1595.9(3) ų, Z = 4; 3, orthorhombic, Pbca, a = 15.562(2) Å, b = 8.626(1) Å, c = 20.110(2) Å, V = 2699.4(5) ų, Z = 8; 4, monoclinic, P2₁/c, a = 14.525(2) Å, b = 15.534(2) Å, c = 8.818(1) Å, = 93.113(2)°, V = 1986.6(4) ų, Z = 4.     

Influence of the spectator cation on the structure of anionic pyridine-2,6-dicarboxylato complexes of cobalt(II), nickel(II), and copper(II)

The structures of anionic pyridine-2,6-dicarboxylato (pdc^2–) complexes of cobalt, nickel, and copper have been studied. The stoichiometries and structures are very much dependent on whether KOH, Et₄NOH, or NaOH is used in the synthesis to deprotonate the H₂pdc ligand. Crystallographic results are: (1) K₂[Co(pdc)₂] · 7H₂O, orthorhombic, Pnna, Z = 4, a = 20.637(2)Å, b = 13.480(1)Å, c = 8.200(1)Å (2) K₂[Ni(pdc)₂] · 7H₂O, orthorhombic, Pnna, Z = 4, a = 20.648(1)Å, b = 13.375(1)Å, c = 8.2393(8)Å (3) [Co₂(H₂O)₅(pdc)₂] · 2H₂O, monoclinic, P2₁/c, Z = 4, a = 8.3880(6)Å, b = 27.384(2)Å, c = 9.6110(8)Å, = 98.271(6)° (4) [Ni(Hpdc)₂] · 3H₂O, monoclinic, P2₁/c, Z = 4, a = 13.679(1)Å, b = 10.0450(9)Å, c = 13.767(2)Å, = 115.184(7)° (5) Na₆[Co(H₂O)₆][Co(pdc)₂]₄ · 28H₂O, monoclinic, P2₁/n, Z = 2, a = 13.363(1)Å, b = 8.437(1)Å, c = 40.689(3)Å, = 91.288(5)° (6) Na[Ni(Hpdc)(pdc)] · 11.5H₂O, monoclinic, C2/m, Z = 4, a = 15.200(2)Å, b = 22.299(2)Å, c = 8.3596(7)Å, = 118.894(7)° (7) Na[Cu(Hpdc)(pdc)] · 3H₂O, monoclinic, P2₁/n, Z = 4, a = 9.516(4)Å, b = 14.917(6)Å, c = 12.247(5)Å, = 92.00(5)°. The potassium and sodium complexes have extensive K⁺—H₂O and Na⁺—H₂O networks. The fact the Et₄N⁺ ion does not appear in any of the complexes is likely due to the fact that it is incapable of forming the intricate cation—water and hydrogen-bonding networks observed in all of the other structures.     

Crystal structures of diphosphinated group 6 Fischer alkoxy carbenes

The crystal structures of four diphosphinated Group 6 Fischer alkoxy carbenes with the compositions fac-(dppe)(CO)₃M–C(OR)(R) (R = Me, R = Et, M = Cr, 1; R = Ph, R = Me, M = Cr, 2; R = Me, R = Me, M = W, 3; R/OR = 3-methyl-2-oxacyclopentylidenyl, M = Cr, 4) have been determined at 243 K. Compound 1 crystallizes in the monoclinic system, space group P2₁/c with a = 11.2243(11) Å, b = 18.5998(18) Å, c = 15.1260(15) Å, = 107.056(4), V = 3019.0(5) ų, and Z = 4. Compound 2 crystallizes in the monoclinic system, space group P2₁/c with a = 11.8102(9) Å, b = 18.3152(14) Å, c = 15.0262(12) Å, = 93.753(3), V = 3243.3(4) ų, and Z = 4. Compound 3 crystallizes in the monoclinic system, space group P2₁/c with a = 11.3458(6) Å, b = 18.5772(9) Å, c = 15.3883(8) Å, = 108.576(6), V = 3074.5(3) ų, and Z = 4. Compound 4 crystallizes in the orthorhombic system, space group Pna2₁ with a = 22.6509(14) Å, b = 9.8118(6) Å, c = 13.7507(8) Å, V = 3056.0(3) ų, and Z = 4. Steric repulsions with the dppe ligand favor a conformation with the alkoxy moiety directed toward the dppe backbone, in an E geometry, in 1–4.     

The preparation and crystal structures of a covalent tetrafluoroborato complex, (CO)<Subscript>3</Subscript>(dppfe)MnFBF<Subscript>3</Subscript>, and of a related ionic complex, [(CO)<Subscript>4</Subscript>(dppfe)Mn]BF<Subscript>4</Subscript> [(dppfe) = bis-(1,1′-diphenylphosphino)ferrocene]

The titled covalent tetrafluoroborato dppfe complex was prepared by treating the precursor hydride, (CO)₃(dppfe)MnH, with tetrafluoroboric acid. Similar treatment of analogous hydrido complexes with other chelating phosphines always gave ionic tetrafluoroborates, presumably via similar intermediate FBF₃ covalent complexes, which however could not be isolated. Crystal structures for the covalent complex (CO)₃(dppfe)MnFBF₃.3/2CH₂Cl₂, 3, and the ionic complex [(CO)₄(dppfe)Mn]BF₄.CH₂Cl₂, 4, were determined. Crystal data for 3, monoclinic crystal system, space group = P2₁/n, a = 11.458(2) Å, b = 19.348(3) Å, c = 17.810(3) Å, = 104.410(4), V = 3823.9(12) ų, Z = 4; for 4, monoclinic crystal system, space group = P2₁/n, a = 15.6521(2) Å, b = 14.3107(4) Å, c = 17.0933(5) Å, = 95.075(1), V = 3813.8(2) ų, Z = 4.     

Synthesis and characterization of a novel pentacyclic C16 diketone and derivatives

The syntheses and crystal structures of pentacyclo[9.4.1.0^5,14.0^7,13.0^12,15]hexadecane-3,9-dione (2), a novel C₁₆ diketone with potential inclusion ability, and the products of the reaction of2 withn-butyllithium andmeso-erythritol (i.e.,meso-1,2,3,4-butanetetrol) are described. Crystal data:2·H₂O, orthorhombic,Pmmn,a=10.7385(8),b=9.0188(6),c=6.8411(4)Å,V=662.55(7)ų, andR=0.039 (379 reflections);3 (product from reaction withn-butyllithium), triclinic,P¯1,a=8.7192(7),b=10.9351(8),c=12.1842(8)Å,=68.933(5),=75.850(6), =80.309(6)°,V=1047.0(1)ų, andR=0.081 (1811 reflections);4 (product from reaction with erythritol), triclinic,P¯1,a=7.7224(8),b=10.1976(8),c=10.7021(9)Å,=85.405(7),=85.766(8), =76.056(7)°,V=814.0(1)ų, andR=0.052 (1471 reflections).     

Synthesis and X-ray structural analysis of (2<Emphasis Type="Italic">Z</Emphasis>)-3(4-hydroxyphenyl)-2-pyridin-4-ylacrylonitrile and (2<Emphasis Type="Italic">Z</Emphasis>)-3-(3,5-di-<Emphasis Type="Italic">tert</Emphasis>-butyl-4-hydroxyphenyl)2-pyridin-4-ylacrylonitrile

Synthesis and X-ray structural investigations have been carried out for the two title compounds C₁₄H₁₀N₂O (3a) and C₂₂H₂₆N₂O (3b). Compound 3a crystallizes in the monoclinic space group P2₁/c, with a = 3.843(1) Å, b = 24.618(5) Å, c = 11.318(2) Å, = 92.61(3), V = 1069.7(4) Å,³ and Z = 4. Compound 3b crystallizes in the triclinic space group P-1, with a = 9.004(2) Å, b = 9.447(2) Å, c = 11.713(2) Å, = 76.70(3), = 83.12(3), = 82.16(3), V = 956.5(3) Å,³ and Z = 2. Both stilbazole derivatives have Z-geometry about the ethylene bridge which links the heterocyclic and aromatic rings. The molecular skeleton of 3a is slightly non-planar: the dihedral angles between the acrylonitrile linkage and the pyridine ring, and between this linkage and the p-hydroxyphenyl ring are 7.2(2) and 4.1(2), respectively. The molecular skeleton of 3b is less planar: the values of similar dihedral angles are 17.0(2) and 20.8(2), respectively. In the crystal of 3a, the molecules are packed in stacks along the a axis with head-to-head orientation. Intermolecular hydrogen bonds O=H s N and C=H s N link molecules into sheets parallel to (100) plane. In the crystals of 3b, the molecules have a head-to-tail orientation and intermolecular hydrogen bonds O=H s N link the molecules into infinite chains along [01-1] direction.     

Syntheses and X-ray structures of new phenoxy imino compounds

Four new phenoxy imino compounds were synthesized, and the solid-state structures of 1–3 were determined by single-crystal X-ray diffraction study, giving crystallographic data as follows. 2-Acetyl-6-[1-(2,6-diisopropylphenylimino)ethyl]-4-methylphenol (1): a = 13.5893(5) Å, b = 10.5781(4) Å, c = 15.6778(4) Å, = 113.1804(18), P2₁/c. 2,6-[1-(2,6-Diisopropylphenylimino)ethyl]-4-methylphenol (2): a = 12.1909(5) Å, b = 16.3324(6) Å, c = 15.9456(7) Å, = 96.990(2), P2₁/c. 2-Acetyl-6-[1-(4-bromine-2,6-dimethylphenylimino)ethyl]-4-methylphenol (3): a = 7.5337(4) Å, b = 10.0457(5) Å, c = 12.6163(4) Å, = 90.139(3), = 104.003(3), = 106.485(2), P–1. Their molecular structures show that the 2,6-substituted phenyl ring is located approximately orthogonal to the hydroxyphenyl ring with the dihedral angle varying from 85.2 to 101.4.for X-ray Diffraction     

Syntheses and structures of N-phenylmaleimidetriazoles and by-products

The syntheses, properties, and structures of N-phenylmaleimidetriazole derivatives are described. Intermediates and by-products are also discussed. 1b. a = 43.997(7) Å, 5.7610(9) Å, 8.245(1) Å, = 99.339(4), C₂/c; 2a. a = 13.646(4) Å, b = 7.744(2) Å, c = 10.612(3) Å, = 91.979(6), P2₁/c. 3a. a = 22.245(1) Å, b = 22.245(1) Å, 10.010(1) Å, P42/n. 3a. a = 11.727(2) Å, b = 14.075(3) Å, c = 16.080(3) Å, = 105.859(3), = 105.331(3), = 98.187(3), P-1. 3b. a = 8.561(3) Å, b = 14.755(5) Å, c = 22.771(7) Å, = 97.006(5), P2₁/c. 3c. a = 10.500(2) Å, b = 12.189(2) Å, c = 13.040(2) Å, = 109.091(3), = 106.089(3), = 101.022(3), P-1. 8a. a = 16.389(8) Å, b = 5.749(3) Å, c = 19.316(3) Å, = 97.467(9), P2₁/n. 8b. a = 5.822(2) Å, b = 10.114(3) Å, c = 16.705(4) Å, = 84.681(5), = 82.840(5), = 75.769(4), P-1. 9b. a = 11.251(1) Å, 13.335(3) Å, 13.376(3) Å, = 102.456(4), P2₁/n. 9c. a = 15.836(3) Å, b = 8.236(2) Å, c = 5.447(3) Å, = 92.551(3), P2₁/c. 10a. a = 13.177(2) Å, b = 14.597(2) Å, c = 5.5505(8) Å, = 110.979(2), Cc. 11a. a = 14.720(2) Å, b = 13.995(2) Å, c = 38.245(6) Å, = 94.430(3), P2₁/n. 12b. a = 15.067(5) Å, b = 20.378(6) Å, c = 8.669(5) Å, = 99.16(4), = 99.32(3), = 105.23(3), P-1. 13b. a = 8.2824(6) Å, b = 10.5245(7) Å, c = 15.518(1) Å, = 92.305(1), = 100.473(1), = 100.124(1), P-1. 15a. a = 15.357(3) Å, b = 7.778(2) Å, c = 22.957(2) Å, Pbca. 16b. a = 18.0384(4) Å, b = 12.474(3) Å, c = 20.078(5) Å, Pbca.     

Crystal structures of 2,6- and 3,5-dichlorobenzoic acids: nonbonded Cl ⋅ ⋅ ⋅ Cl contacts

The crystal structures of 2,6-dichlorobenzoic acid (1) and 3,5-dichlorobenzoic acid (2) were obtained by single-crystal X-ray diffraction. Crystallization of 1 occurred in the centrosymmetric triclinic space group P1 (No. 2) with a = 7.2678(9), b = 9.8543(8), and c = 11.8290(11) Å = 95.000(7), = 104.262(10), and = 102.128(8); and Z = 4. Crystallization of 2 occurred in the monoclinic centrosymmetric space group P2₁/n (No. 14) with a = 3.7812(3), b = 13.996(2), and c = 14.514(2) Å = 95.183(8); and Z = 4. Chlorine substituents of four dimeric molecules of 2 formed square channels, ca. 3.54 Å on a side, which run parallel to the crystallographic a axis. Monomers of 1 and 2 formed centrosymmetric dimers via near-linear hydrogen bonds. Details of the structures and spectroscopic results are presented and discussed.     

Synthesis and structural characterization of five new coordination polymer chain structures using a new,Z-shaped ligand, 2,2′-bis-(4-pyridylethynyl)tolane

Using the new ligand, 2,2-bis-(4-pyridylethynyl)tolane we have synthesized five new coordination polymers: HgBr₂[2,2-bis-(4-pyridylethynyl)tolane] (1), HgI₂[2,2-bis-(4-pyridylethynyl)tolane] (2), Ni(acetylacetonate)₂[2,2-bis-(4-pyridylethynyl)tolane] (3), Zn(acetylacetonate)₂[2,2-bis-(4-pyridylethynyl)tolane] (4), and Cu(hexafluoro acetylacetonate)₂[2,2-bis-(4-pyridylethynyl)tolane]CHCl₃ (5). 2,2-Bis-(4-pyridyl ethynyl)tolane is a rigid ligand with a Z-shape that promotes the formation of zig-zag chains. Compounds 1– 5 were characterized by single crystal X-ray diffraction; and compounds 1– 3 were additionally characterized by IR, elemental analysis, and thermogravimetric analysis. Compound 1 crystallizes in the monoclinic space group C2/c with a = 29.761(3) Å, b = 5.0531(5) Å, c = 16.7823(15) Å, = 104.090(2), V = 2447.9(4) ų, Z = 4. Each mercury is bound to two tolane ligands and two bromine anions, resulting in a tetrahedral coordination environment. Compound 2 crystallizes in the monoclinic space group P2/c, with a = 20.3061(17) Å, b = 5.6303(5) Å, c = 24.5459(19) Å, = 110.338(2), V = 2631.4(4) ų, Z = 4. Here also, each mercury is bound to two tolane ligands and two iodine anions in a tetrahedral coordination environment. The ligand orientation differs in compounds 1 and 2 being trans oriented in 1 and cis oriented in 2. Compound 3 crystallizes in the monoclinic space group P2₁/c with a = 14.5947(14) Å, b = 6.3082(6) Å, c = 18.3939(18) Å, = 112.112(2), V = 1568.9(3) ų, Z = 2. Each nickel is bound to two tolane ligands and two bidentate AcAc anions, resulting in an octahedral coordination environment. Compound 4, which is isostructural with 3, also crystallizes in the monoclinic space group P2₁/c with a = 14.6990(9) Å, b = 6.2724(4) Å, c = 18.6433(11) Å, = 112.8610(10), V = 1583.86(17) ų, Z = 2. Compound 5 crystallizes in the triclinic space group P-1 with a = 6.5487(4) Å, b = 11.6471(7) Å, c = 14.3225(9) Å, = 70.1360(10), = 89.3990(10), = 88.7680(10), V = 1027.18(11) ų, Z = 1. Each copper in 5 is bound to two tolane ligands and two bidentate hfAcAc anions, resulting in an octahedral coordination environment identical to that found in 3 and 4.     

Crystal structures and spectroscopic properties of copper(II) and zinc(II) complexes with the macrocycle 1,4,7-tris(2-pyridylmethyl)-1,4,7-triazacyclononane

Two novel transition-metal copper and zinc complexes [(CuL)₂]·(ClO₄) (1) and [(ZnL)]·(ClO₄)₂ (2) (L = 1,4,7-tris(2-pyridylmethyl)-1,4,7-triazacyclononane) have been synthesized and structurally determined. The two complexes are both crystallized in monoclinic space group P2(1)/c with a = 14.318(4), b = 17.214(5), c = 22.403(7) Å, = 93.096(6)°, V = 5522(3) ų, and Z = 4 for 1 and a = 9.371(2), b = 17.615(4), c = 17.579(4) Å, =104.070(4)°, V = 2814.6(11) ų, and Z = 4 for 2. The center metal ions are coordinated to six nitrogen atoms, three of which are from triazacyclononane and other three from the pendant-arms 2-pyridylmethyl, forming a slightly distorted octahedral geometry. Two complexes have been characterized by element analysis, infrared spectroscopy, and the UV–Vis and ESR spectra for 1 have also been determined.     

Crystal and molecular structure of meso-2,9-dicyano-5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradeca-4,11-diene,C18H30N6

meso-2,9-Dicyano-5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradeca-4,11-diene (1) has been investigated by X-ray structural methods. The crystals are monoclinic, space groupP2₁/n, with cell dimensions=7.319(1),b=7.442(1),c=17.359(3)Å, and=98.30(1)°;Z=2. The structure was solved by direct methods and refined by a full-matrix, least-squares procedure against 1339 observed reflections givingR=0.0627. The [133133]_i macro-chair (m ¹ C ₄) was assigned to the macrocycle of1. The occurrence of intramolecular bifurcated hydrogen bonding NHN=C was postulated.     

Reactivity of 6α,7α-epoxyhimachal-2-ene and crystal structures of 2α,3α-dibromocyclopropanehimachal-5,7-diene and 2α,3α-dibromocyclopropane-6α,7α-epoxyhimachalane

We report here the reactivity of 6,7-epoxyhimachal-2-ene with dibromocarbene generated in situ by phase-transfer catalysis. The stereochemistry of products resulting from dibromocyclopropanation has been established by X-ray crystallography. Compound 3 is orthorhombic P2₁2₁2₁ with a = 7.549 (1), b = 8.432 (1), c = 24.469 (1) Å, V = 1559.8 (5) ų, Z = 4 and compound 5 is monoclinic P2₁ with a = 8.779 (1), b = 15.684 (1), c = 12.111 (1) Å, = 91.869 (1)°, V = 1666.7 (4) ų and Z = 4.     

Crystal structure of phenyl-substituted cyclopentenes

The crystal structures of two stereoisomers of tetraphenyl- and pentaphenyl-substituted cyclopentenes 1 and 2 have been determined by X-ray analysis. An envelope conformation ¹E has been ascertained for the cis isomer 1a, whereas the cis, cis isomer 2a, which crystallizes in two different space groups, P1¯ and P2₁/n, displays a twisted ²T₁ conformation. The phenyl substituents are all tilted with respect to the cyclopentene ring in both structures. Compound 1a crystallizes in the space group P2₁/a with a = 18.553(3), b = 6.006(2), c = 19.355(5), = 102.67(4)°, and V = 2104.2(g) ų for Z = 4; compound 2a ^I crystallizes in P2₁/n with a = 10.064(2), b = 20.756(5), c = 12.245(3) Å, = 95.21(2)°, and V = 2547(1) ų for Z = 4; compound 2aII crystallizes in P1¯ with a = 10.117(3), b = 11.750(2), c = 12.359(2) Å, = 111.25(2), = 94.84(2), = 108.78(2)°, and V = 1262.3(6) ų for Z = 2.