Synthesis, crystal structure, and spectral studies of the molecular complex of [60]fullerene with chloro(triphenylphosphine)gold(I), C60·2[(Ph3P)AuCl]

The molecular complex C₆₀·2[(Ph₃P)AuCl] (1) was synthesized. The crystal and molecular structure of1 was established by X-ray diffraction analysis. At room temperature, the [60]fullerene molecules in complex1 are ordered due to π—π interactions between C₆₀ and the phenyl rings of the chloro(triphenylphosphine)gold(1) molecules. The satellite structure, which accompanies the Cls photoelectron peak of complex1, is indicative of a partial suppression of a channel of losses due to π→π transition in the phenyl ring. The 1R spectral data indicate that either a charge is absent or the charge transfer to the fullerene molecule is negligible. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 365–369, February, 2000.     

Circular dichroism of optically active organometallic derivatives of fullerenes C<Subscript>60</Subscript> and C<Subscript>70</Subscript>

Palladium and platinum complexes of fulleienes C₆₀ and C₇₀ containing the axially chiral ligand (—)-BITIANP (BITIANP is 2,2’-bis(diphenylphosphino)-3,3’-bi(benzo[b]thiophene)) and pynolidino[60]fullerene bearing a planar chiral organometallic π-complex substituent in the heteiocyclic ring were studied by circular dichroism (CD) spectroscopy.     

Synthesis and anion recognition of neutral receptors based on multiamide calix[4]arene

Two multiamide calix[4]arenes (5, 6) were synthesized and characterized by NMR, MS and elemental analysis. The binding properties of receptors with some anions (π-O₂NPhOPO₃²⁻, π-O₂NPhO⁻, H₂PO₄⁻, Ac⁻, Cl⁻, Br⁻ and I⁻) were studied by UV-Vis spectra. The results indicate that the tetraamide calix[4]arenes (5, 6) have a good selectivity to the anions containing aromatic ring (π-O₂NPhOPO₃ ²⁻, π-O₂NPhO⁻). The 1 : 1 complexes between host and guest were formed through multiple hydrogen bonding and π-π interactions. The hosts 5 and 6 also show a definite binding ability for the anions (H₂PO₄⁻, Ac⁻, Cl⁻) that have no ultraviolet absorption, which provides a simple method of spectrum detection for these anions.     

Cycloaddition of diazoketones to [60]fullerene in the presence of the catalytic system Pd(acac)2—PPh3—Et3Al

A method for the selective and efficient synthesis of methanofullerenes by cycloaddition of diazoketones to [60]fullerene in the presence of a three-component catalytic system Pd(acac)₂—PPh₃—Et₃Al has been developed.     

Stable complexes of tertiary ammonia derivative of phenothiazine with tertramethylsulfonated resorcin[4]arenes obtained under substoichiometric conditions

Eight water insoluble complexes of tetramethylsulfonated calix[4]resorcinarenes 1 and 2 (–CH₃ and –C₅H₁₁) with phenothiazine derivative, 3, were obtained under substoichiometric conditions by mixing aqueous solutions of the initial reagents. It was found that complexation of cationic 3 by macrocycles was provided by both Coulomb interaction with the negative sulfonato-groups on the upper rim and by cation-π interactions with the aromatic cavity. The complexes precipitated and, therefore, were studied in organic solvents—DMSO, CD₃OD, and CDCl₃ using IR-, UV-, and NMR- spectroscopy. Formation of the complexes accompanied by gradual dehydratation of the host—estimated quantity of water in the complexes decreased with increase of the initial concentration of 3. Driving forces of precipitation and complexation, the role of water coordinated by the hosts, and distribution of phenothiazine derivative between two kinds of binding sites are discussed.     

An oxacalix[2]arene[2]pyrimidine-bis(Zn-porphyrin) tweezer as a selective receptor towards fullerene C70

An oxacalix[2]arene[2]pyrimidine-bis(Zn^II-porphyrin) conjugate was readily prepared via nucleophilic aromatic substitution of a phenolic AB₃-Zn-porphyrin on the upper rim of a (1,3-alternate) 5,17-bis(methylsulfonyl)oxacalix[4]arene precursor. Efficient 1:1 complex formation between the ‘jaws’ bisporphyrin tweezer and fullerene C₇₀ was evidenced by ¹H NMR titrations (K = 3.0 × 10⁴ M⁻¹), while no detectable complexation could be observed with C₆₀. On the other hand, an analogous oxacalix[4]arene-bis(Cu-corrole) conjugate did not show any measurable (C₆₀ or C₇₀) fullerene binding.     

Sorbents based on calix[4]arenes for extraction of technetium(vii) from acidic and alkaline media

Sorption of Tc^VII from solutions of various compositions with new sorbents prepared by the noncovalent immobilization of (thia)calix[4]arenes on the Amberlite XAD-7™ support was studied. The sorbents studied efficiently extract technetium(vii) from both acidic and alkaline media. The sorption capacity of the sorbent with thiacalix[4]arene groups is superior to that of the sorbents with calix[4]arene groups and several times higher than that of the sorbents previously proposed for the sorption of Tc^VII. Technetium(vii) is sorbed by this sorbent as 1: 1 and 1: 2 thiacalix[4]arene—NH₄TcO₄ and 1: 1 and 1: 2 thiacalix[4]arene—NaTcO₄ complexes.     

Effect of the Counter Anion and Solvate on the Structure,Stability and Spectral Properties of a Ruthenium(II) Complex Containing Group 15 Donors and 2,2′ :6′,2′′-terpyridine

Ruthenium complexes [Ru(κ³−tpy)(AsPh₃)₂C1]PF₆ · 0.42H₂O (tpy =2,2′:6′,2′′-terpyridine) (1) and a new crystal form of [Ru(κ³−tpy)(AsPh₃)₂Cl]BF₄ (2), which crystallized without water solvate, and their comparative studies on spectral, structure and stability aspects are reported. The complexes have been characterized by elemental analyses, FAB-MS, i.r., ¹H n.m.r. and electronic spectral studies. In these complexes weak C—H···Fπ and face-to-face π–π interactions lead to a single helical motif while, C—H···FX (X=F, Cl) interactions result in linear chains. Various studies on the stability of the complexes suggested that the compound containing the counter anion PF₆^- is more stable than the other containing BF₄^- as the counterpart.     

Addition of diphenylphosphinoyl azide to [60]fullerene

The reaction of [60]fullerene with diphenylphosphinoyl azide in toluene or ino-dichlorobenzene in the presence of traces of water affords 2-[N-(diphenylphosphoryl)amino]-1-hydroxy[60]fullerene This reaction in THF gives a mixture of (N-diphenylphosphoryl)[60]fullerenol[1,2-b]aziridine and a product of partial hydrolysis of the bisadduct of phosphorylated azide and fullerene. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2168–2172, November, 1999.     

A [2+3] fragment coupling approach to N,O-bridged calix[1]arene[4]pyridines and their complexation with C60

Functionalized N,O-bridged calix[1]arene[4]pyridines, first examples of the odd-numbered heterocalixaromatics containing mixed heteroatom bridges and mixed aromatic units, have been synthesized from the Pd₂(dba)₃/dppp-catalyzed 2+3 macrocyclic fragment coupling reaction between readily available staring materials. These novel macrocyclic compounds, which adopted distorted 1,3-alternate conformation in solid state, were powerful host molecules able to form 1:1 complex with fullerene C₆₀ in solution, giving binding constant up to 49,494 M⁻¹.     

Novel addition in trifluoromethylation of [70]fullerene

Pyrolytic trifluoromethylation of [70]fullerene with CF₃CO₂Ag at 300 °C results in the addition of up to 12 CF₃ groups to the fullerene cage. Forty-six C₇₀(CF₃)_n derivatives (numbers in parentheses) were separated by two-stage high pressure liquid chromatography (HPLC) as follows: n = 2(2), 4(16), 6(9), 8(14) 10(5), some being characterised by NMR. The range of derivatives is much greater than for other [70]fullerene reactions, and as with [60]fullerene trifluoromethylation, no single derivative is dominant, indicating that kinetic stability mainly controls product formation. NMR spectra show most derivatives to be unsymmetrical, with combinations of quartets and septets (overlapping quartets) due to contiguous (‘linear’) addend arrays, having significantly different coupling constants of the ‘terminal’ quartets of between 9.1 and 17.7 Hz. These differences, together with those observed previously in trifluoromethylation of [60]fullerene are consistent with addition across both 6:6- and 5:6-ring junctions. Of the two C₇₀(CF₃)₂ isomers, one has either C_s or C₂ symmetry, the other has C₁ symmetry, whilst the C₇₀(CF₃)₄ derivatives fall into four categories: (i) symmetrical compounds (one gives only two singlets in the NMR); (ii) unsymmetrical compounds that show a ‘linear’ coupling sequence; (iii) unsymmetrical compounds having a remote pairs of adjacent groups; (iv) compounds having a coupled array of three CF₃ groups, together with a remote group suggesting sterically-driven migration. The first evaluation of differential NMR couplings across 6:6- and 5:6-bonds in a fullerene has been made using C₆₀F₆ as a model.     

单加成环丙烷富勒烯膦酸酯衍生物的合成与电化学性能

在Mn(OAc)₃•2H₂O催化下, C₆₀分别和亚甲基二膦酸四乙酯、氰基亚甲基膦酸二乙酯或乙氧羰基亚甲基膦酸二乙酯在氯苯中回流, 生成3个单加成环丙烷富勒烯膦酸衍生物C₆₀C(R)PO(OEt)₂ [1, R＝PO(OEt)₂; 2, R＝COOEt; 3, R＝CN]. 与以前报道的Bingel反应法相比, 该方法副产物少并且缩短了反应时间. 采用循环伏安法发现1, 2的还原电位相对于C₆₀发生负移, 而3的还原电位相对于C₆₀却正移40 mV, 表明引入象氰基一样具有很强吸电子能力的取代基团, 可以改善富勒烯球的电化学性能, 合成电子接受能力较强的富勒烯衍生物.     

Catalytic polymerization of ethylene by non-metallocene Zirconium(IV) calix[4] pyrrole complexes

Some zirconium compounds containing chelating diamido dipyrrole or tetra-amido tetra-pyrrole ligands were synthesized and used as polymerization catalyst with high polymerization activity of ethylene at 40 °C and 1 bar, in presence of MAO or B(C₆F₅)₃ as co-catalyst. The maximum catalytic activity reached 1100 Kg/mol bar h for ethylene polymerization by Zr₂(octa-phenyl calix[4]pyrrolidine)Cl₄. These results reveal that half-zirconocene like complexes including four terminal chlorine and one calix[4]pyrrolidine in middle with both π and σ-interaction have the highest ethylene polymerization turnover (compounds 13, 14).     

Inhibition of J-aggregation of meso-tetra(4-sulfonatophenyl)porphyrin by an ionic liquid with π-conjugated character

Abstract  

UV–visible spectral observations indicate that the J-aggregation of protonated meso-tetra(4-sulfonatophenyl)porphyrin ([H₂TSPP]²⁺) under acidic conditions is completely inhibited by the π–π counteraction between 1-butyl-pyridinium tetrafluoroborate ([bpy]BF₄) and [H₂TSPP]²⁺. The studies also suggest that the intermolecular π–π force is of relative importance for the J-aggregates of [H₂TSPP]²⁺ and the intermolecular electrostatic force for the H-aggregates.     

Exploring the photoinduced electron transfer reactivity of aza[60]fullerene iminium cation

Photolysis of (C₅₉N)₂ solutions in the presence of neutral π-donors, such as arenes and electron-rich alkenes leads to a series of novel aza[60]fullerene monoadducts. The key step of the reaction involves a photoinduced electron transfer from the donor molecule to the iminium cation of aza[60]fullerene, followed by radical coupling of the resulting aza[60]fullerenyl radical with an intermediate stabilized radical derived from the substrate. This type of reactivity has been proven efficient with arenes having oxidation potential higher than about 1.5 V. Simple olefins, such as tri- and tetra-methylethylene, as well as cyclohexene, can also participate in this kind of photoinduced electron transfer-initiated reaction with C₅₉N⁺, affording the corresponding aza[60]fullerene derivatives. In the case of 2-methoxyprop-1-ene, 2,4-hexadiene, and β,β-dimethylstyrene, [2+2] cycloaddition reactions with the aza[60]fullerene carbon shell dominate, leading to a mixture of unidentified multiadducts.     

Synthesis, electrochemical properties, and thermal transformations of 1-(5-nitropyrimidin-2-yl)[60]fullereno[1,2-b]aziridine

The reaction of fullerene C₆₀ with 2-azido-5-nitropyrimidine afforded 1-(5-nitropyrimidin-2-yl)[60]fullereno[1,2-b]aziridine, whose electrochemical reduction proceeds more easily than the reduction of nonmodified C₆₀. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 484–488, March, 2006.     

Frontier-orbital analyses of ketene [2+2] cycloadditions

Twelve kinds of ketene [2+2] cycloadditions have been investigated by ab initio calculations. They are composed of four ketenes (Y–HC=C=O, Y=H, NH₂, Cl, and CN) and three isoelectronic ketenophiles (ethylene, methylenimine, and formaldehyde). All the transition state geometries obtained here are not different significantly, but the extent of formation of two covalent bonds differs appreciably. The difference is attributable to the degree of the charge transfer interactions. One is the interaction from the π orbital and/or the lone pair orbital of a ketenophile to the LUMO of a ketene (dominant charge transfer, CT1). The other is that from the HOMO of the ketene to the π* orbital of the ketenophile (second dominant charge transfer, ct1). CT1 contributes to the formation of only one covalent bond, and ct1 does to the formation of the other. This independent function is characteristic of ketene [2+2] cycloadditions. They are not concerned with the orbital phase. We also have examined Fukui's postulate that the deformation of particular frontier orbitals causes the reaction progress. The role has been verified both by configuration analyses along the intrinsic reaction coordinate of the ketene-ethylene reaction and by the examination of distortions of frontier-orbital shapes along the low-frequency vibrational modes. Received: 25 June 1998 / Accepted: 28 August 1998 / Published online: 11 November 1998     

[60]Fullerene diol issued from pentaerythritol derivatives

A new [60]fullerene diol is synthesized in good yield, in two steps starting from reaction of C₆₀²⁻ anion with the benzylideneacetal derived from 2,2-bis(iodomethyl)-1,3-propanediol. The corresponding [60]fullerene bis-mesylate is also formed in a similar way starting from bis-iodo bis-mesylate compound in the same series. The scope of this fullerene diol in synthesis is exemplified by its easy esterification with 4-formyl benzoyl chloride.     

Mechanism of the catalytic action of the mechanoactivated salt K2PTCL4 in the gas-phase hydrochlorination of acetylene

A heterogeneous catalyst for the hydrochlorination of acetylene by gaseous HCl is formed as a result of mechanical treatment of the solid salt K₂PtCl₄ in an atmosphere of acetylene, ethylene, or propylene by the formation of π complexes of platinum(II) as active centers in the surface layer under these conditions. The controlling stage of the catalytic reaction is chloroplatination of the π-coordinated acetylene by the HCl molecule. The reaction takes place as a concerted process, in which an intermediate β-chlorovinyl derivative of platinum(II), a complex of platinum with a coordination vacancy[PtCl ₃ ^* ]⁻, and a new molecule of HCl are formed simultaneously with cleavage of the H—Cl and Pt—Cl bonds in the metal complex adjacent to the π-acetylene complex. The catalytic cycle closes with rapid dissociation of the organoplatinum intermediate by the action of HCl, giving the final product and the initial complex [PtCl₄]²⁻. __________ Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 42, No. 5, pp. 306–311, September–October, 2006.     

The Mannich reaction in the synthesis of N,S-containing heterocycles. 7. Effective one-pot synthesis of derivatives of spiro[3,5,7,11-tetraazatricyclo-[7.3.1.0<Superscript>2,7</Superscript>]tridec-2-ene-13,4′-piperidine]

5,11-Disubstituted derivatives of 1′-isopropyl-8-thioxospiro[3,5,7,11-tetrazatricyclo[7.3.1.0^2,7]tridec-2-ene-13,4′-piperidine]-1,9-dicar bonitrile was obtained by the interaction of 10-amino-9-aza-3-azonia-7,11-dicyano-3-isopropylspiro[5,5]undeca-7,10-diene-8-thiolate with 2 equiv. of a primary amine and excess of formaldehyde. An anomalous reaction product was obtained with o-toluidine — 7,9-dicyano-1′-isopropyl-3-(2-methylphenyl)-1,2,3,4-tetrahydrospiro[pyrido[1,2-a][1,3,5]triazine-8,4′-piper idinium]-6-thiolate. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, 1709–1713, November, 2007.