Crystal structure of a bulky cyclic sulfite

The structure of the cyclic sulfite derived from the reaction of thionyl chloride withendo-8-hydroxy-exo-8-(endo-8-hydroxypentacyclo[5.4.0.0.^2,6.0^3,10.0^5,9]undec-exo-8-yl)pentacyclo-[5.4.0.0.^2,6.0^3,10.0^5,9]undecane is reported. All bond lengths and angles are consistent with the strained cage geometry. A static disorder of the terminal oxygen was found to be present.     

Crystal and molecular structure ofanti,exo,exo-5,10,12-tribromo-13-oxa-exo-tricyclo [7.3.1.02,6] tridecane

For the first time, a transannular II-cyclization and subsequent transannularO-heterocyclization is obtained during an electrophilic addition to a large-ring triene. The structure of the product—anti,exo,exo-5,10,12-tribromo-13-oxa-exo-tricyclo[7.3.1.0^2,6]tridecane—was determined by X-ray analysis.     

2,8,10,11-tetrachloro-12-oxahexacyclo-[7.2.1.02,8.03,7.04,11.06,10]dodeca-1,9-diol and disorder and mixed crystals in a system of tetracyclo-[6.3.0.04,11.05,9]undecanone and undecanol derivatives

2,8,10,11-Tetrachloro-12-oxahexacyclo[7,2.1.0^2.8.0^3.7.0^4.11.0^6.10]dodeca-1,9-diol is a strained cage molecule containing six five-membered rings and a four-membered ring. Twenty-five of the internal angles are less than 105° with 6 ranging from 89.5(3) to 97.4(3)°. The base promoted reaction of 3,6-dipyridyl-1,2,4,5-tetrazine with tetracyclo[6.3.0.0^4.11.0^5.9]undecane-3,6-dione yields the monoketone 6,7-[3,6-di(2-pyridyl)-4,5-pyridizino]tetracyclo[6.3.0.0^4.11.0^5.9]-undecan-2-one. This compound crystallizes in the centrosymmetric space group P2₁/n with enantiomers related by a center of symmetry. In the crystal investigated the molecules are disordered with each site containing about 80% of one isomer and 20% of the enantiomer. When the ketone is hydrogenated and the product isolated, two different crystals were found to have a ratio of alcohol to ketone of .71/.29 and .75/.25 or about 3/1. The alcohol and ketone occupy the same sites, but with opposite stereochemistries.     

Synthesis and crystal structure of 4,5-dibromo[2.1.1]triblattene

Reaction of 4-bromopentacyclo[7.3.0.0^2,7.0^3,11.0^6,10]dodec-11-ene (1) with Br₂—CCl₄ afforded 4,4,5-tribromopentacyclo[7.3.0.0^2,7.0^3,11.0^6,10]dodecane (2) in 89–94% yield. Subsequent treatment of 2 with KOt-Bu-t-BuOH resulted in competitive elimination of the elements of HBr and of Br₂ with concomitant formation of 4,5-dibromopentacyclo[7.3.0.0^2,7.0^3,11.0^6,10]dodec-11-ene (3, 76%) and 1 (17%), respectively. The structure of 3 was established unequivocally via application of X-ray crystallographic methods. Crystal data for 3: monoclinic, C2/c, a = 9.895(1), b = 9.0963(7), c = 12.471(1) Å, = 106.875(8)°, z = 4.     

Crystal structures of four dibromomethylene-functionalized cage compounds

Crystal structures of four dibromomethylene-functionalized hexa- and heptacyclotetradecane cages are reported. 7-(Dibromomethylene)heptacyclo[6.6.0.0^2,6.0^3,13.0^4,11.0^5,9.0^10,14]tetradecane (3): orthorhombic, Pnma, a = 14.744(1), b = 11.237(1), c = 7.4625(7) Å Z = 4; R = 0.0531 for 504 observed reflections. 7,12-Bis(dibromomethylene)heptacyclo[6.6.0.0^2,6.0^3,13-0^4,11 .0^5,9.0^10,14]tetradecane (4): monoclinic, I2/a, a = 11.257(1), b = 9.5844(8), c = 13.884(2) Å, = 92.254(8)° Z = 4; R = 0.0413 for 663 observed reflections. 10,14-bis(dibromomethylene)hexacyclo[6.6.0.0^2,6.0^3,13.0^4,11.0^5,9]tetradecane (6): monoclinic, P2₁/n, a = 8.118(1), b = 15.273(4), c = 12.826(3) Å, = 104.20(1)° Z = 4; R = 0.0384 for 1392 observed reflections. 14-(dibromomethylene)hexacyclo[6.6.0.0^2,6.0^3,13.0^4,11.0^5,9]tetradecan-10-one (7): monoclinic, P2₁/n, a = 8.2879(7), b = 15.273(1), c = 10.0565(9) Å, = 92.271(8)° Z = 4; R = 0.0320 for 1402 observed reflections. The functional groups lead to slight shortening of bond lengths.     

Crystal Structure of a Rearranged Cage Compound, 3-Hydroxy-4-aza-8-oxoheptacyclo [9.4.1.0<Superscript>2,10</Superscript>.0<Superscript>3,14</Superscript>.0<Superscript>4,9</Superscript>.0<Superscript>9,13</Superscript>.0<Superscript>12,15</Superscript>]tetradecane

Abstract  Polycyclic hydrocarbon compounds exhibit a wide variety of biological activities, ranging from antiviral to Parkinson’s disease. Several structures such as the adamantanes have reached clinical status and are used therapeutically to treat, amongst others, neurodegenerative disorders such as Alzheimer’s. Polycyclics have also been utilised as carrier molecules to facilitate entry of drugs into the brain. The synthesis, molecular and crystal structure of a new polycyclic compound, 3-hydroxy-4-aza-8-oxoheptacyclo[9.4.1.0^2,10.0^3,14.0^4,9.0^9,13.0^12,15]tetradecane, are reported. NMR spectroscopy was applied for structure elucidation of the novel compound and a rearrangement mechanism is proposed for its formation. This compound crystallises in the orthorhombic system, space group Pbca (no. 61). The unit cell parameters are: a = 12.3763 (7), b = 11.6597 (6), c = 15.0539 (8) ?, V = 2172.3 (2) ?³ , and Z = 8 molecules in the unit cell. The reported structure was confirmed by X-ray analysis, which showed that the title molecules associate into centrosymmetric dimers via N–H···O hydrogen bonding. Index Abstract  The synthesis and structure of a new polycyclic compound, 3-hydroxy-4-aza-8-oxoheptacyclo[9.4.1.0^2,10.0^3,14.0^4,9.0^9,13.0^12,15]tetradecane, are reported in this article.      

Generation and intermolecular trapping of a cage-annulated cycloalkylidenecarbene

Base-promoted reaction of 11-methylenepentacyclo[5.4.0.0^2,6.0^3,10.0^{5, 9}]undecan-8-one (5) with diethyl diazomethylphosphonate when performed in the presence of excess cyclohexene, resulted in the formation of the corresponding cycloalkylidenecarbene, 6, which subsequently was trapped in situ to afford 8-methylene-11-(7-bicyclo[4.1.0]heptylidene)pentacyclo-[5.4.0.0^{2, 6}.0^{3, 10}.0^{5, 9}]undecane (7, obtained in 44% yield as a mixture of exo, endo isomers). Subsequent reaction of 7 with dichlorocarbene (generated under phase transfer catalytic conditions) produced the corresponding mono- and di-:CCl₂ adducts [i.e., 8 (64% yield) and 9 (5% yield), respectively]. The structure of 9 was established unequivocally via application of single crystal X-ray analysis: Triclinic, P1¯, a = 6.276(2), b = 8.700(2), c = 18.550(3) Å, = 76.52(3), = 87.59(3), = 70.88(4)° Z = 2; D _calc 1.486 g cm^–3.     

Crystal and molecular structure of [(4-picolineN-oxide)2H]+ [AuCl4]−: A diadduct revealing a short hydrogen bond

The crystal structure of the [AuCl₄]^–-stabilized hydronium ion diadduct of 4-picolineN-oxide has been determined using 1388 reflections collected on a CAD4 diffractometer. The structure was refined to anR value of 0.46. Two 4-picolineN-oxide molecules form a short hydrogen-bonded hydronium ion diadduct [H(4-picNO)₂]⁺ with an OO distance of 2.442(4) Å. The planar [AuCl₄]^– acts as a counter anion. Due to the nonbonding packing interactions, the Au(III) ion appears to be in an unusual six-coordinate distorted octahedral environment in the solid state. The changes in the N=O distance, the shifts in the infrared absorptions, and the downfield NMR chemical shifts for the bridged protons are explained in terms of inductive effects of the substituents on the pyridineN-oxide ring.     

Infrared spectra of silver complexes with 2-aminopyridine and crystal structure of the 4:3 aminopyridine-silver nitrate compound

The 43 complex formed between 2-aminopyridine (ampy) and AgNO₃ belongs to the orthorhombic space groupPccn. The unit cell of dimensionsa=7.992(4),b=16.788(5),c=21.034(8) Å contains four formula units. The structure was refined on 998 nonzero reflections toR=0.038. The crystal contains the dimeric [Ag₃(ampy)₄]³⁺ cation. Two of the three independent Ag atoms are each coordinated to two ampy ligandsvia the heterocyclic nitrogen lone pair (mean Ag-N=2.18 Å), and the N-Ag-N angle in this [ampy-Ag-ampy]⁺ unit is 154.0°. By using the two available amino groups, the [ampy-Ag-ampy]⁺ unit acts as a bidentate ligand, and two such units related by a twofold axis achieve a roughly tetrahedral environment of NH₂ lone pairs about the third Ag atom (mean Ag-N=2.39 Å). The infrared spectra of [Ag₃(ampy)₄](NO₃)₃, [Ag(ampy)₂]ClO₄, [Ag₃(ampy-H)₂]NO₃, and [Ag₃(ampy-H)₂]ClO₄, and those of their amino-deuterated derivatives, are discussed. Diagnostic regions are proposed to identify coordinationvia the amino group and the heterocyclic nitrogen atom.     

Synthesis and Crystal Structure of 2,13-Bis(acetamido)-3,14-dimethyl-2,6,13,17-tetraazatricyclo[14,4,0<Superscript>1.18</Superscript>,0<Superscript>7.12</Superscript>]docosane Tetrachlorocobalt(II)dihydrate

Abstract The novel ionic compound [H₂bdtd][CoCl₄] · 2H₂O (1) was prepared by the reaction between CoCl₂ and 2,13-bis(acetamido)-3,14-dimethyl-2,6,13,17-tetraazatricyclo[14,4,0^1.18,0^7.12]docosane (bdtd) in adjusted to pH 3.0 by 1.0 M HCl and structurally characterized. The crystals are monoclinic C2/c with a = 18.7777(9), b = 9.7356(4), c = 20.0884(9) ?, β = 109.6340(10)°, V = 3458.9(3) ?³, Z = 4. The dication H₂bdtd occupies a special position about an inversion center. The cobalt(II) atom in the anion is in a distorted tetrahedral environment with four chloride ligands. The crystal structure is stabilized by a variety of hydrogen-bonding contacts involving the dication, chloride anions and solvent water molecules. Cyclic voltammetry of [CoCl₄]²⁻ anion in 1 undergoes irreversible one-electron reduction to the Co^II/Co^I. Graphical abstract The crystal structure of the ionic compound [H₂bdtd][CoCl₄] · 2H₂O (1) consists of [H₂bdtd]²⁺ cation, [CoCl₄]²⁻ anion and water molecules joined together by ionic interaction and hydrogen bonds. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

The effect of nitrogen atom on double bond pyramidalization

The title compound 6-phenyl-4,6,8-triazatetracyclo[9.2.1.0^2,10.0^4,8]tetradec-2(10)-ene-5,7-dione (6) has been synthesized by the addition of 4-phenyl-1,2,4-triazole-3,5-dione (PTAD) to 2,3-dimethylenebicyclo[2.2.1]heptane. The cell parameters are a = 9.991(5), b = 11.754(9), c = 6.549(5) Å, = 101.08(7)°, = 103.31(5)°, = 98.24(5)°. The crystal structure of 6 was determined. The obtained geometrical parameters were highly correlated with the DFT calculations. The experimentally determined folding angle of the double bond was found to be 8.44°. The effect of the electron-withdrawing ability of nitrogen atom on the degree of pyramidalization is discussed.     

Synthesis and structure ofexo-11-cyano-endo-11-(trimethylsilyloxy)pentacyclo[5.4.0.02,6.03,10.05,9]undecan-8-one

The crystal structure of an asymmetric pentacyclo[5.4.0.0^2,6.0^3,10.0^5,9]undecan-8,11-dione derivative is reported, in which Me₃SiCN has been added across one of the keto groups. The cage structure demonstrates the expected effects of this addition.     

The crystal structure of [NBu 4 n ][AlI4]

The crystal structure of [NBu ₄ ⁿ ]f AlI₄] has been determined from counter data, and refined by full-matrix least-squares techniques. The crystals belong to the monoclinic space groupP2₁/n (an alternate setting ofP2₁/c-C _2h ⁵ , No. 14) witha=11.661(3),b=20.828(5),c=11.674(3) Å,=98.39(2)°, andD _calc=1.84 g cm^–3 forZ=4. The finalR value for 1587 observed reflections is 0.051. The structure consists of discreet [NBu ₄ ⁿ ]⁺and [AlI₄]^– ions. The [AlI₄]^– anion is approximately tetrahedral and exhibits an average Al-I bond length of 2.52(1) Å. The closest cation-anion, IC, contact is ¯4 Å. The compound was isolated from the reaction of I₂ with [NBu ₄ ⁿ ][Al₂Me₆I].     

Synthesis and structural characterization of 5,6,15,16-tetradehydrobenzo[a]phenanthro[9, 10-e]cyclooctene,C24H12

A benzo-phenanthro-fused planar cyclooctatetraene derivative, namely, 5,6,15,16-tetradehydrobenzo[a]phenanthro[9, 10-e]cyclooctene (5) was synthesized in two steps from the known benzo[a]phenanthro[9, 10-e]cyclooctene (6). Compound5 crystallizes in space groupPbam witha=9.828(2),b=19.466(4),c=15.901(3) Å, and Z=8. X-Ray analysis (MoK radiation,R=0.060 for 1233 observed data) has shown that both independent molecules have the same planarC _2v configuration with averaged bond lengths of 1.381(7) and 1.208(7) Å for the phenanthrene C_6a–C_14b bond and the acetylenic CC bond, respectively.¹H and¹³C NMR spectral results of 5 and 5,6,15,16-tetrabromo-5,6,15,16-tetrahydrobenzo[a]phenanthro[9, 10-e]cyclooctene (7) are also presented.     

Air-stable liquid clathrates. 1. Crystal structure of [NBu4][Br3] and reactivity of the [NBu4][Br3]·5 C6H6 liquid clathrate

[NBu₄][Br₃] interacts with C₆H₆ to form an air-stable liquid clathrate. The tribromide anion reacts with phenol to give para-bromophenol in>95% yield. The HBr which is generated in the reaction combines with the Br^– anion to form [Br-H-Br]^–. The latter forms the basis for a new liquid clathrate, [NBu₄][Br-H-Br]·n C₆H₆. The parent salt, [NBu₄][Br₃], crystallizes in the monoclinic space group C2/c witha=12.983(5),b=10.380(7),c=16.222(6) Å,=93.93(3)°, andD _c =1.47 g cm^–3 forZ=4. The final R value is 0.068 based on 787 observed reflections.     

Synthesis and structure of ditetrabutylammonium tetrachlorodioxoneptunium(VI)

The reaction of a stock solution of NpO₂² + in 2 M HCl with two equivalents of tetrabutylammonium chloride in 6 M HCl results in the preparation of the title compound. This compound, [NBu₄]₂[NpO₂Cl₄], is isostructural with the uranium analogue, [NBu₄]₂[UO₂Cl₄]. The anion of the complex, [NpO₂Cl₄]²–, adopts a pseudooctahedral geometry common to six-coordinate actinyl complexes in which the neptunium metal is coordinated by two trans axial oxo groups with NpO(oxo) bond lengths of 1.733(5)Å, and four equatorial chloride ligands with Np–Cl bond lengths in the range 2.637(2)–2.676(2)Å. The neptunyl ONpO bond angle is 178.6(3)°. Charge balance of the neptunyl tetrachloride anion is maintained by two tetrabutylammonium cations. This complex crystallizes in the monoclinic space group P2₁/n (a = 15.416(4), b = 15.362(4), c = 18.479(5)Å, = 108.147(6)°, V = 4158.4(19)ų, Z = 4).     

Structure of a PCU-derived pinacol formed via sodiumpromoted reductive dimerization of pentacyclo[5.4.0.02,6.03,10.05,9]undecane-8,11-dione monoethylene ketal

The pinacol resulting from sodium promoted reductive coupling of pentacyclo[5.4.0.0^2,6.-0^3,10.0^5,9]undecane-8,11-dione monoethylene ketal possesses a conformation, dictated by intramolecular hydrogen bonding, that lies midway between eclipsed and staggered. The C–C and C–O distances in the pinacol unit are, respectively, longer and shorter than usual, and all parameters are as expected.     

Crystal structure of triethylentetraammonium bis monohydrogen-monophosphate dihydrate β-NH3(CH2)2NH2(CH2)2NH2(CH2)2NH3(HPO4)2·2H2O

The salt triethylentetraammonium bis monohydrogen-monophosphate dihydrate is orthorhombic Pbca with unit cell dimensions a = 8.963(2), b = 10.326(2), c = 17.381(4)Å; Z = 4; D_m = 1.540 g cm^–3; D _x = 1.562 g cm^–3. The examination of the structure shows a layer arrangement parallel to the axis: planes of [HPO₄]^2– tetrahedra alternate with planes of [(NH₃(CH₂)₂NH₂CH₂)₂]⁴⁺. The [HPO₄]^2– tetrahedra are connected through O(W)s--H···O hydrogen bonds, so that infinite chains of the composition [HPO₄(H₂O)]_n ^2n– are formed in the structure parallel to the axis. The structure of this compound is built from [HPO₄]^2– anions, [(NH₃(CH₂)₂NH₂CH₂)₂]⁴⁺ cations and zeolitic water molecules connected by hydrogen bonds.     

Palladium(II) and platinum(II) tetrakisthiourea dichloride bis(7-hydroxy-5-methyl[1,2,4]triazolo[1,5a]pyrimidine) dihydrate solvates

The title compounds palladium(II) and platinum(II) tetrakisthiourea dichloride bis(7-hydroxy-5-methyl[1,2,4]triazolo[1,5a]pyrimidine (Hmtpo)) dihydrate solvates, have been synthesized by reacting thecis-[MCl₂(Hmtpo)₂] (where M=Pt(II), Pd(II)) complexes with an excess of thiourea (tu) and the structure of the palladium compound was solved by X-ray diffraction. Crystals of [Pd(tu)₄]Cl₂·2Hmtpo·2H₂O are triclinic with space groupP and unit cell dimensionsa=7.972(1),b=9.049(1),c=11.808(2)Å, =88.20(1), =75.15(1), =76.54(1)^o. The cation [Pd(tu)₄]²⁺ is centrosymmetric involving four sulfur thiourea atoms in a near square planar environment. The triazolopyrimidine molecules, chloride anions and water molecules do not take part in the metal center coordination but interact by hydrogen bonding between them and the thiourea moieties. A comparison between powder diffraction data of palladium(II) and platinum(II) compounds clearly indicates that both compounds are isomorphous.     

Molecular associations of 5-membered benzofused heterocyclic donors with organic acceptors

Benzofused heterocycles like 10H-[1]benzo thieno[3,2-b] indole and thieno[3,2-b]benzo[b]thiophene form molecular associations with ^* organic acceptors. The weak interactions involved are viewed in terms of UV-Vis and IR techniques. The results, mainly in the case of complexes of 10H-[1]benzo thieno[3,2-b] indole, are in some disagreement with the literature. The structure of the complex 10H-[1]benzo thieno[3,2-b] indole/tetracyanoethylene is also reported. The four condensed rings constitute a conjugate system with significant lengthenings of the aromatic ring bonds and a shortening of those of the five-membered rings. The fragment as a whole is almost planar, and forms a dihedral angle of 39.9(1)° with the planar tetracyanoethylene molecule.