All-Z-hexabenzo[24]annulene with a triangular benzene cluster substructure

All-Z-hexabenzo[24]annulene was synthesized via a poly-cis-stilbene intermediate. The single crystal of the annulene has a chiral C₃-symmetry with a central benzene trimer substructure. Although the compound is highly flexible in solution, the C₃-symmetric structure is stabilized by three concurrent CH/π interactions.     

Annulated Azuleno[2,1,8-ija]azulenes: Synthesis and Properties

Non-alternant non-benzenoid hydrocarbons exhibit very different optical and electronic properties than their well-studied benzenoid analogues. However, preparing such structures with extended conjugation length, remains challenging. Herein, we report the synthesis and properties of azuleno[2,1,8-ija]azulene derivatives using a two-step sequence involving a four-fold aldol condensation between aromatic dialdehydes and readily available tetrahydropentalene-2,5-(1H,3H)-dione. Molecules with band gap values ranging from 1.69 to 2.14 eV and molar extinction coefficients (ϵ) of nearly 3×10⁵ M⁻¹ cm⁻¹ have been prepared. These annulene-like structures exhibit significant diatropic ring currents (aromatic), as supported by ¹H NMR spectroscopy and DFT calculations. Field-effect transistors (OFETs) using azuleno[2,1,8-ija]azulene derivatives as semiconductors exhibit charge mobility values of up to 0.05 cm² V⁻¹ s⁻¹.     

(6Z,9Z,12Z)-6,9,12-Octadecatriene and (3Z,6Z,9Z,12Z)-3,6,9,12-icosatetraene, the novel sex pheromones produced by emerald moths

(6Z,9Z,12Z)-6,9,12-Octadecatriene and (3Z,6Z,9Z,12Z)-3,6,9,12-icosatetraene, hydrocarbons unsaturated more highly than usual lepidopteran Type II pheromones, were identified from geometrid females of Hemithea tritonaria and Thalassodes immissaria intaminata, respectively. The triene was synthesized by a double Wittig reaction between hexanal and an ylide derived from (Z)-1,6-diiodo-3-hexene, and the tetraene was synthesized by a coupling between (Z)-3-undecenal and an ylide derived from (3Z,6Z)-1-iodo-3,6-nonadiene. Each synthetic compound attracted males of the corresponding emerald moths in a field.     

Silver(I) complex of 5,6,11,12-tetradehydrodibenzo[a,e]cyclooctene

The reaction of 5,6,11,12-tetradehydrodibenzo[a,e]cyclooctene with silver(I)triflate yielded a 1:2 complex. X-ray investigations revealed that each silver ion is tetrahedrally coordinated to one triple bond and three oxygen atoms of the triflate anion.     

Stereoselective synthesis of (E)-N,N-diethyl-3-(imidazo[1,2-a]pyrid-2-yl)-2-(phenylsulfonyl)propenamide

The title compound, gem-amidovinylsulfone 3, was synthesized stereoselectively by aldolic condensation of N,N-diethylphenylsulfonylacetamide 1 on imidazo[1,2-a]pyridine-2-carbaldehyde 2 adding Et₃N at the end. The X-ray crystal structure of 3 [C₂₀H₂₁N₃O₃S: M_r=383.5, monoclinic, P2₁, a=8.191(4) Å, b=21.132(2) Å, c=11.752(1) Å, β=96.40(2)°, V=2022(1) Å³, Z=4 (two molecules per asymmetric unit), D_calc=1.260 g cm⁻³, λ(Mo Kα)=0.71073 Å, μ=0.184 mm⁻¹, F(000)=808, T=293(2)K, R=0.059 for 5105 observed reflections with I≥2σ(I)] was determined, and confirmed the (E) configuration.     

Azomacrocyclic derivatives of imidazole: synthesis, structure, and metal ion complexation properties

New azocrown ethers comprising imidazoles in the macrocycle have been synthesized. Imidazole, 2-methyl-, 4-methyl-, and 4-phenylimidazole were incorporated to form macrocyclic units by coupling with the appropriate bis-diazonium salts. The syntheses were performed under high dilution conditions. The X-ray structure of a water adduct of the 21-membered crown ether derivative of 4-methylimidazole 8 has been solved. Metal cation binding was investigated with the use of UV-vis spectroscopy in acetonitrile, methanol, and methanol-water mixtures. The obtained chromoionophores were tested as ion-carriers in ion-selective membrane electrodes.     

Spirobicyclic diamines. Part 3: Synthesis and metal complexation of proline-derived [4.4]-spirodiamines

The syntheses of racemic and homochiral [4.4]-spirolactams, starting from l-proline, in good yields are described. Reduction of the lactam carbonyl group of spirolactams, containing chiral substituents on the lactam nitrogen, with lithium aluminium hydride, gives a series of homochiral [4.4]-spirodiamines. The crystal structure of one of these spirodiamines on complexation with zinc chloride was obtained. Interestingly it showed a hydrogen-bonded dimeric structure, where the monomers are diastereoisomeric diamines.     

Synthesis of methyl (5Z,8Z,10E,12E,14Z)-eicosapentaenoate

The first total synthesis of methyl (5Z,8Z,10E,12E,14Z)-eicosapentaenoate has been achieved in seven steps and in 16% overall yield. The synthesis confirmed the assigned structure of this polyunsaturated natural product.     

Novel thiophene-substituted tetrathia[22]annulenes[2,1,2,1]: synthesis,physical properties,and improvement in field-effect behavior

Novel conjugated macrocycles, thiophene-substituting tetrathia[22]annulenes[2,1,2,1] (TTAs, and 5b), were synthesized through a convenient four-step procedure. They were evidenced to have high aromaticity by NMR, UV–vis absorption spectra, and calculation. Their UV–vis absorption spectra, thermal stability, electrochemical properties, thin film morphology were studied and the field-effect transistors based on 5a and 5b through a vapor deposition method performed good with reproducible bulk-like carrier mobilities (as high as 0.53 cm² V⁻¹ S⁻¹) and high on/off ratios (as high as 9.0×10⁵), which was among the best records in this series.     

Guest-binding properties of functionally porous crystal based on metal complex of p-tert-butylthiacalix[6]arene

A potassium salt of p-tert-butylthiacalix[6]arene shows highly-extensive coordination nature to give rise to zeolitic crystal which has huge cavity with the widest span of ca. 19 Å and is capable of crystalline phase guest-addition and -removal.     

f-Element/crown ether complexes. 27. The synthesis and crystal structure of [Ce(NO3)3 (OH2)(12-crown-4)] -12-crown-4

A unique cerium nitrate complex, [Ce(NO₃)₃(OH₂)(12-crown-4)]-12-crown-4, has been crystallized from the reaction of hydrated cerium nitrate and 12-crown-4. It crystallizes in the orthorhombic space group,Pnma, with (at –150°C)a = 22.901(5),b = 13.547(3),c = 8.422(1)Å, andD _x = 1.77 g cm^–3 forZ = 4 formula units. A finalR value of 0.048 was obtained utilizing 2059 unique observed [F _o 5(F _o)] reflections. The Ce atom resides on a crystallographic mirror plane and is 11-coordinate, coordinated to three bidentate nitrate groups, one water molecule and the four oxygens of one 12-crown-4 molecule. The water molecule hydrogen bonds a second 12-crown-4 unit. Both unique crown molecules and one of the nitrate anions are severely disordered.For part 26, see reference [1].     

Cooperative C-H…N and C-H…π bonded molecular dimers of 5-aryl-7,8,13,14-tetrahydro-dibenzo[a,i]phenanthridine

As a result of our new high-yielding one-pot reaction procedure, the investigation on a series of heterocyclic 5-aryl-7,8,13,14-tetrahydro-dibenzo[a,i]phenanthridine compounds was possible and reported: 5-(4-ethyl-phenyl)-7,8,13,14-tetrahydro-dibenzo[a,i]phenanthridine, 5-(4-cyano-phenyl)-7,8,13,14-tetrahydro-dibenzo[a,i]phenanthridine, and 5-(2-ethyl-phenyl)-7,8,13,14-tetrahydro-dibenzo[a,i]phenanthridine. Half-chair conformation of alicyclic rings gives rise to a slightly folded structure of central tricyclic phenanthridine. The structure analysis showed the formation of a well-defined dimeric unit in the crystals. Dimeric association essentially involves cooperative C-H…N and C-H…π close contacts between molecules related by a center of inversion. The first two compounds are isomorphous with noticeable differences in steric packing. The first structural elucidation on 5-aryl-7,8,13,14-tetrahydro-dibenzo[a,i]phenanthridine compounds indicates the prominent mode of interactions, which has use in structure-based drug discovery and optoelectronic applications.     

Fused pyrazino[2,3-b]indolizine and indolizino[2,3-b]quinoxaline derivatives; synthesis, structures, and properties

The synthesis of six new compounds incorporating either a pyrazino[2,3-b]indolizine or indolizino[2,3-b]quinoxaline core are reported in good yield (58-87%). The intermediates for the key cyclization reaction for one set of compounds (5a-c), with a sterically demanding 3,5-dimethylpyrazole group in the 5-position of the core, were found to be mono-substituted. These intermediates could be isolated and cyclized by heating under acid-catalyzed conditions. To further demonstrate the versatility of the chemistry, compounds 6a-c were synthesized in 58-68% yields. Compounds 5a-c are non-planar in solution and the solid-state, while 6a-c have close to planar conformations, pointing to weak hydrogen bonds between the acidic C-Hs and the adjacent azine nitrogen atoms. The cytotoxicity of the six newly synthesized and three previously prepared compounds was assessed against a human glioblastoma multiforme cell line.     

Exchange of boryl ligand substituents in Os[B(OEt)2]Cl(CO)(PPh3)2

Reaction between Os[B(OEt)₂]Cl(CO)(PPh₃)₂ and 1,2-ethanediol in the presence of Me₃SiCl (1 equivalent) leads to the tethered boryl complex, Cl(CO)(PPh₃)₂ (1), in which one ethoxy substituent on the boryl ligand is exchanged with one hydroxy group of the 1,2-ethanediol leaving the other OH group available to coordinate to osmium, so giving a six coordinate complex. This formulation is confirmed by crystal structure determination. The same reactants, but with 2 equivalents of Me₃SiCl, lead to the yellow, coordinatively unsaturated complex, OsCl(CO)(PPh₃)₂ (2). Complex (2) adds CO to give OsCl(CO)₂ (PPh₃)₂ (3). Crystal structure determinations of 2 and 3 reveal a very marked difference in the Os-B distances found in the five coordinate complex 2 (2.043(4) Å) and the six coordinate complex 3 (2.179(7) Å). In a reaction similar to that used for forming 2 but with 1,3-propanediol replacing 1,2-ethanediol, the product is OsCl(CO)(PPh₃)₂ (4). The crystal structure for 4 is also reported.     

Intra- vs. intermolecular configurations in the three-legged, piano-stool compounds (o, m and p-xylene)Mo(CO)3

The three (η6-xylene)Mo(CO)₃ complexes have been prepared and crystallographically characterized to determine the rotational relationship of the arene ring to the undercarriage, as has been suggested by theoretical studies. In fact, no such relationship can be seen, especially when combined with eight examples of structures with Z′ > 1, where both staggered and eclipsed forms are found.     

Synthesis and Structure of a Novel Macrocyclic Complex [Cd2(phen)4(phth)2]·4H2O

A novel complex [Cd2(phen)4(phth)2]·4H2O has been synthesized by the reaction of H2phth(phthalic acid) and phen(1,10-phenanthroline) with Cd(Ⅱ) in ethanol-water solution. X-ray crystal structure analysis shows it crystallizes in triclinic, space group P1 with a = 10.619(3), b =12.560(4), c = 12.651(4) A, α = 98.775(5), β = 109.035(5), γ = 113.576(5)°, C32H24CdN4O6, Mr=672.95, V= 1381.7(7) A3, Rint = 0.0358, Z= 2, Dc= 1.618 g/cm3, μ = 0.845 mm-1, -6 ≤h≤13, -15≤k ≤13, -15≤l≤14, F(000) = 680, S = 1.038, R = 0.0480 and wR = 0.0849 for 3992 observed reflections (I ＞ 2σ(Ⅰ)). Phth bridges Cd(Ⅱ) to form a macrocyclic compound, and a 2D supramolecular motif is formed through hydrogen bonds and π-π interaction.     

C12H12 interconversions: Two non-pyrolytic syntheses of tricyclo[5.3.2.04,8]dodeca-2,5,9,11-tetraene

Herein, we describe two independent and non-pyrolytic syntheses of an important C₁₂H₁₂ hydrocarbon which had been prepared previously by gas phase thermolysis of compound 6. The first method is based on an unusual dipolar cycloaddition of dichloroketene onto bullvalene. After reductive dechlorination, a Shapiro-Heath reaction of the tosylhydrazone gave the title compound. Alternatively, compound 13 is also obtained from its isomer 6 by a Ag⁺ catalyzed reaction.     

Synthesis and properties of p-benzoquinone-fused hexadehydro[18]annulenes

A series of hexadehydro[18]annulenes fused with different numbers of p-benzoquinone, 4-6, were synthesized by stepwise transformation of the p-dimethoxybenzene moiety of the precursor dehydroannulene 3 fused with three 3,6-dimethoxy-4,5-dimethylbenzene units at 1,2-positions into p-benzoquinone using ceric ammonium nitrate. The UV-vis spectra of compounds 4 and 5, which have both electron-donating p-dimethoxybenzene unit(s) and electron-accepting p-benzoquinone unit(s) in the π-systems, showed the maximum absorption bands bathochromically shifted in comparison with 3 having only p-dimethoxybenzene units and 6 having only p-benzoquinone units. However, the solvatochromism expected for 4 and 5 was found to be quite weak possibly because the HOMO and LUMO (B3LYP/6-31G(d)) are not localized but rather delocalized over the whole π-systems.     

配合物[Cu(H2biim)2]Br2的合成和晶体结构

The complex [Cu(H₂biim)₂]Br₂ (H₂biim=2,2′-biimdazole) has been synthesized and structurally charac-terized. It crystallizes in the Monoclinic system, space group C2/c with a=1.422 5(4) nm, b=0.931 2(2) nm, c=1.343 1(3) nm, β=116.227(4)°, V=1.595 9(7) nm^-3, R₁=0.060 2, wR₂=0.152 8 and Z=4. The copper ion has a sligh-tly distorted square planar coordination configuration with four nitrogen atoms from two H₂biim ligands. The complex has a one-dimensional chain structure, which is formed by hydrogen bonds and semi-coordinate bonds. CCDC: 624679.