BEDT-TTF-based radical cation salt with the cyanurate anion: synthesis,structure, conductivity,and polarized reflection spectra

The new conducting radical cation salt, bis(ethylenedithio)tetrathiafulvalene cyanurate, was synthesized. This salt is an organic metal down to 4 K. The crystal structure, conductivity, and optical properties of the salt were studied. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 96–101, January, 2008.     

Electrochemistry of Cobalta Bis(dicarbollide) Ions Substituted at Carbon Atoms with Hydrophilic Alkylhydroxy and Carboxy Groups

In this study we explore the effect on the electrochemical signals in aqueous buffers of the presence of hydrophilic alkylhydroxy and carboxy groups on the carbon atoms of cobalta bis(dicarbollide) ions. The oxygen-containing exo-skeletal substituents of cobalta bis(dicarbollide) ions belong to the perspective building blocks that are considered for bioconjugation. Carbon substitution provides wider versatility and applicability in terms of the flexibility of possible chemical pathways. However, until recently, the electrochemistry of compounds substituted only on boron atoms could be studied, due to the unavailability of carbon-substituted congeners. In the present study, electrochemistry in aqueous phosphate buffers is considered along with the dependence of electrochemical response on pH and concentration. The compounds used show electrochemical signals around −1.3 and +1.1 V of similar or slightly higher intensities than in the parent cobalta bis(dicarbollide) ion. The signals at positive electrochemical potential correspond to irreversible oxidation of the boron cage (the C2B9 building block) and at negative potential correspond to the reversible redox process of (CoIII/CoII) at the central atom. Although the first signal is typically sharp and its potential can be altered by a number of substituents, the second signal is complex and is composed of three overlapping peaks. This signal shows sigmoidal character at higher concentrations and may be used as a diagnostic tool for aggregation in solution. Surprisingly enough, the observed effects of the site of substitution (boron or carbon) and between individual groups on the electrochemical response were insignificant. Therefore, the substitutions would preserve promising properties of the parent cage for redox labelling, but would not allow for the further tuning of signal position in the electrochemical window.     

Boron-Containing Lipids and Liposomes: New Conjugates of Cholesterol with Polyhedral Boron Hydrides

A series of boron-containing lipids were prepared by reactions of cyclic oxonium derivatives of polyhedron boranes and metallacarboranes (closo-dodecaborate anion, cobalt and iron bis(dicarbollides)) with amine and carboxylic acids which are derived from cholesterol. Stable liposomal formulations, on the basis of synthesized boron-containing lipids, hydrogenated soybean l -α-phosphatidylcholine and (HSPC) 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)-2000] (DSPE-PEG) as excipients, were prepared and then characterized by dynamic light scattering (DLS) that revealed the formation of particles to be smaller than 200 nm in diameter. The resulting liposomal formulations showed moderate to excellent loading and entrapment efficiency, thus justifying the design of the compounds to fit in the lipid bilayer and ensuring ease of in vivo use for future application. The liposomal formulations based on cobalt and iron bis(dicarbollide)-based lipids were found to be nontoxic against both human breast normal epithelial cells MCF-10A and human breast cancer cells MCF-7.     

Synthesis and structures of complexes ofN-(2-aminoethyl)diaziridines with transition metal salts

A series of complexes ofN-(2-aminoethyl)diaziridines with transition metal salts (Zn²⁺, Cd²⁺, Ni²⁺, Co²⁺, Mn²⁺, or Fe²⁺) were synthesized. Their structures were established by IR and NMR spectroscopy. The structure of bis[1,2-bis(2-aminoethyl)diaziridine]cadmium(II) diperehlorate was confirmed by X-ray diffraction analysis. Published inIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 1910–1914, November, 2000.     

Structural and Spectral Study of Nickel(II) Complexes of Pyridyl bis{3‐piperidyl‐, bis{hexamethyleneiminyl‐, bis{N(4)‐diethyl‐, and bis{N(4)‐dipropylthiosemicarbazones}

Pyridyl bis(N(4)‐substituted thiosemicarbazones), in which the substituents replacing the NH₂ group on the thiosemicarbazone moieties are piperidyl, H₂Plpip; hexamethyleneiminyl, H₂Plhexim; diethylamino, H₂Pl4DE; and dipropylamino, H₂Pl4DP, have been synthesized. These bis(thiosemicarbazones) and their nickel(II) complexes have been characterized with IR, electronic, mass, and ¹H and ¹³C NMR spectra. Crystal structures have been solved for H₂Plpip and all four nickel(II) complexes. H₂Plpip does not possess hydrogen bonding between the thiosemicarbazone moieties, but is in the Z isomeric form with intramolecular hydrogen bonding from both thiosemicarbazone moieties to pyridine nitrogen atoms. The nickel(II) complexes possess square‐planar N₂S₂ (i. e., imine nitrogen and thiolato sulfur atoms) centers and the two pyridine ring nitrogen atoms are not coordinated.     

CO2 Hydroboration: Impact of the Boryl Moieties on the Reactivity of Four Bis(boryl)acetal Compounds toward 2,6-Diisopropylaniline

The hydroboration of CO₂ into bis(boryl)acetal (BBA) compounds is an important transformation, since it enabled to selectively reduce CO₂ by 4e^- and to subsequently use the BBA compounds as C₁ and C_n sources. However, the influence of the nature of the boryl moieties on the reactivity of BBA compounds has not been evaluated so far. In the present study, four BBA compounds – including two new ones – were reacted with 2,6-diisopropylaniline to afford the expected imine. Significant differences in the rate of the reaction from minutes to weeks have been observed depending on the BBA used, showing the importance of the nature of the boryl moieties. Theoretical investigations enabled to propose a mechanism involving the addition of the aniline to the BBA as the rate-determining step and to determine that the steric hindrance of the BBA compounds is the main factor driving the rate of this condensation reaction.     

H_2BPMPBD和DAM协同萃取部分Ln(Ⅲ)

4 酰代双吡唑啉酮是以吡唑酮为端基、脂肪族碳氢取代基联结而成的一类新型非环四齿酸性螯合剂[1 ,2 ] ,螯合功能团比普通的 4 酰代吡唑酮多一倍 ,对金属离子具有很强的萃取能力 ,其中对Ｆｅ(Ⅲ )、Ｃｏ(Ⅱ )、Ｎｉ(Ⅱ )、稀土离子的萃取分离以及稀土荧光配合物方面的研究已有报道[3～ 5] 。为了进一步探讨该类萃取剂的萃取性能 ,在合成萃取剂 1 ,4 双 ( 1′ 苯基 3′ 甲基 5′ 氧代吡唑 4′ 基 )丁二酮 [1 ,4]的基础上 ,研究了Ｈ2 Ａ与ＤＡＭ的氯仿溶液从硝酸介质中协同萃取Ｌｎ(Ⅲ )的性能。通过考察萃取剂浓度和溶液酸度等因素对Ｌｎ(Ⅲ …     

乙基二茂铁与乙酰丙酸甲酯的缩合反应

以多聚磷酸-浓硫酸-甲醇为催化剂和环已烷为溶剂,由乙基二茂铁与乙酰丙酸甲酯缩合合成4,4-双（乙基二茂铁基）成酸甲酯,转化率73%,产率84%。正交实验法获得的适宜反应条件：乙基二茂铁55mmol,乙酰丙酸甲酯75mmol,浓硫酸3.0mL,环已烷20mL,甲醇11mL。通过元素分析、IR、^1H NMR和^13C NMR确证了缩合产物的结构。     

Reductive mono- and diallylation of the bis(pyridine)dihydropyridyllithium dimer by triallylborane

Reductive allylation of the bis(pyridine)dihydropyridyllithium dimer containing the 1,2- and 1,4-dihydropyridine fragments by triallylborane results mainly in trans- and cis-2,6-diallylpiperidines (60—85%), their ratio depending on the nature of the solvent. The minor reactions products are 2-allyl-1,2,3,6-tetrahydropyridine and 4,10-diallyl-3,9-diazatricyclo[6.2.2.0^2,7]dodecane. The unexpected formation of the latter is due to hetero-Diels—Alder condensation of intermediate products formed in the allylboration of dihydropyridines. The stereochemistry of trans- and cis-2,6-diallylpiperidines was determined from the ¹H and ¹³C NMR spectra of the respective N,N-dimethylpiperidinium iodides. The structure of 4,10-diallyl-3,9-diazatricyclo[6.2.2.0^2,7]dodecane dipicrate was established by X-ray diffraction analysis.