Synthesis of β-cyclodextrin-calix[4]arene coupling product and its adsorption of basic fuchsin and methylene blue from water

Two new β-CD-calix[4]arene coupling products 3,4 which contained one or two β-CD units in molecules were synthesized by ammonolysis of p-tert-butyl-25,27-dihydroxyl-26,28-di (ethoxy carbonyl methoxyl) calix[4]arene 1 and mono-6-ethylenediamino-6-deoxy-β-CD 2, and their structures were confirmed by ¹H NMR, IR and MS (Maldi-Tof). The probable mechanism for forming 3 was discussed also. Using water-insoluble coupling product 3 as an adsorbent, the influences of the adsorption capacities of 3 including initial concentration, temperature and pH onto basic fuchsin (BF) and methylene blue (MB) from aqueous solution were investigated. Results showed that the adsorption capability of 3 to BF was obviously higher than that to MB at similar adsorption conditions. The values of %sorption to BF were over 90 % in range of initial concentrations from 20 to 140 mg L^?1 whenas those to MB dropped rapidly from 92 to 58 %. The adsorptions of 3 to both BF and MB obeyed Freundlich adsorption isotherm well.     

Novel deep-cavity calix[4]arene derivatives with large s-triazine conjugate systems: synthesis and complexation for dyes

Two novel deep-cavity calix[4]arenes 3 and 4 with large s-triazine π-conjugate systems were designed and synthesized in high yields by reacting calix[4]arene with mono phenyl-substituted cyanuric chloride or further substitution with aniline. The liquid–liquid extraction experiment showed that they possessed excellent extraction abilities towards one cationic and three anionic dyes (Orange I, methylene blue, neutral red, brilliant green). The highest extraction percentage of compound 4 was 88.8 % for brilliant green. The complexation UV–Vis spectra of compounds 3 and 4 with four dyes indicated the existences of complexation action between hosts and guests with 1:1 ratio of complexation in DMSO solution. The association constants suggested that the larger π-conjugate system of compound 4 possessed the stronger complexation abilities than that of compound 3. The association constant of compound 4 with BG was as high as 8.1 × 10⁶ M^?1.     

Adsorption and corrosion inhibitive properties of piperidine derivatives on mild steel in phosphoric acid medium

The present study describes the inhibition effect of 4-benzyl piperidine (P1), 1,6-bis(4-benzylpiperidine-1-carboxamide)hexane (P2) and bis(4-benzylpiperidine)thiuram disulfide (P3) towards the corrosion of mild steel in 5.5 M H₃PO₄ solution using weight loss measurements and polarization technique. The influence of inhibitor concentration and temperature on the inhibitory behavior of P2 and P3 was investigated. Meanwhile, the inhibition efficiency (IE) was found to depend on the molecule structure and the concentration of piperidine derivatives. The IE for 10^?3 M P2 and P2 in 5.5 M H₃PO₄ is around 90 %. Polarization studies clearly revealed that all the compounds used act as mixed-type inhibitors. Adsorption isotherms were fitted by the Langmuir isotherm. Adsorption energies ( $ \Updelta {\text{G}}^\circ_{\text{ads}} $ and $ \Updelta {\text{H}}^\circ_{\text{ads}} $ ) and kinetic parameters were evaluated. Significant correlations are obtained between inhibition efficiency with the calculated chemical indexes, indicating that the variation of inhibition with structure of the inhibitor may be explained in terms of electronic properties.     

Effects of axial ligands on the intercalation of tetraphenylporphyrinatoantimony(V) into smectite clay layers

Adsorption and intercalation of +1-charged cationic dihydroxo(tetraphenylporphyrinato)-antimony(V) bromide (1a) into an artificially synthesized smectite clay was investigated. The red shift of the Soret band of 1a was observed in an aqueous clay colloidal solution owing to the adsorption onto the clay. Analyses of the X-ray diffraction of the complex obtained between 1a and the clay indicate the intercalation of 1a into the clay interlayer. The hydroxo group as an axial ligand led to the effective intercalation of 1a into the clay.     

Studies on the inhibitive effect of potassium ferrocyanide on the corrosion of steel in phosphoric acid

In this work, the effect of potassium ferrocyanide (Pf) on the corrosion of mild steel in solutions of phosphoric acid (H₃PO₄) has been investigated in relation to the concentration of the inhibitor by weight loss, potentiodynamic polarization and AC impedance (EIS) measurements. The results obtained revealed that this compound is good a mixed-type inhibitor. The effect of temperature on the corrosion behavior with the addition of optimal concentration of Pf was studied in the temperature range 298–328 K. The value of inhibition efficiency decreases slightly with the increase in temperature. Changes in impedance parameters (charge transfer resistance, R _t, and double layer capacitance, C _dl) were indicative of adsorption of Pf on the metal surface, leading to the formation of a protective film. Adsorption of Pf on the C38 steel surface was found to obey the Langmuir adsorption isotherm. Some thermodynamic functions of dissolution and adsorption processes were also determined.     

Hydrothermal and sonochemical synthesis of a nano-sized nickel(II) Schiff base complex as a precursor for nano-sized nickel(II) oxide; spectroscopic, catalytic and antibacterial properties

The Ni(II) complexes [Ni(L)₂](ClO₄)₂ (1) and [Ni(L)₂(NO₃)₂] (2), where L is the Schiff base ligand of 4,5,9,13,14-pentaaza-benzo[b] triphenylene, were synthesized and characterized by physico-chemical and spectroscopic methods. Nano-sized particles of (1) were prepared both by sonochemistry (3) and solvothermal (4) methods. NiO nanoparticles were obtained by calcination of the nano-structure complexes at 500 °C. The structures of the nano-sized compounds were characterized by X-ray powder diffraction and scanning electron microscopy. The thermal stabilities of the bulk complexes (1–2) and nano-sized particles (3–4) were studied by thermogravimetric and differential scanning calorimetry. The catalytic activities of complexes of (1–4) are reported. The free Schiff base and its Ni(II) complexes have been screened for antibacterial activities against three Gram-positive bacteria. The metal complexes are more active than the free Schiff base. Electrochemical studies show that the Ni complexes undergo irreversible reduction in MeCN solution.     

Experimental and theoretical study for corrosion inhibition of mild steel 1 M HCl solution by some new diaminopropanenitrile compounds

The inhibition of the corrosion of mild steel 1 M HCl solution by some diamine compounds has been investigated in relation to the concentration of the inhibitor as well as the temperature using weight loss and electrochemical measurements. The effect of the temperature on the corrosion behavior with the addition of different concentrations of new diamine compounds (3-[2-(2-cyano-ethylamino)-methylamino]-propionitrile (P1); 3-[2-(2-cyano-ethylamino)-ethylamino]-propionitrile (P2), and 3-[6-(2-cyano-ethylamino)-hexylamino]-propionitrile (P3), respectively, was studied in the temperature range 40–80 °C. Polarization curves reveal that (P1, P2, and P3) are mixed type inhibitors. The inhibition efficiency of organic compounds is temperature independent, but increases with the inhibitor concentration. Adsorption of inhibitor on the carbon steel surface is found to obey the Langmuir adsorption isotherm. Some thermodynamic functions of dissolution and adsorption processes were also determined. On the other hand, and in order to determine the relationship between the molecular structure of these compounds and inhibition efficiency, quantum chemical parameters were calculated. The theoretically obtained results were found to be consistent with the experimental data.     

Synthesis and thermal behavior study of complexes of the type [Pd(μ-X)(4-eb-p-phen)]2 (X = Cl,Br, I,N3, NCO,SCN) and 4-eb-p-phen [bis(4-ethylbenzyl)p-phenylenediimine]

The Schiff base bis(4-ethylbenzyl) p-phenylenediimine, 4-eb-p-phen (1), and six new dimeric Pd(II) complexes of the type [Pd(μ-X)(4-eb-p-phen)]₂ {X = Cl (2), Br (3), I (4), N₃ (5), NCO (6), SCN (7)} have been synthesized and characterized by elemental analysis, IR spectroscopy, and ¹H and ¹³C{¹H}-NMR experiments. The thermal behavior of the complexes 2–7 has been investigated by means of thermogravimetry and differential thermal analysis. From the final decomposition temperatures, the thermal stability of the complexes can be ordered in the following sequence: 3 > 4 > 7 > 2 ≈ 5 > 6. The final products of the thermal decompositions were characterized as metallic palladium by X-ray powder diffraction (XRD).     

New copper(II) 2-(alkylamino)troponates

The copper aminotropones Cu[ON(R′)C₇H₄R-4]₂ [R = H, R′ = Me (13), Et (14), n-Pr (15), n-Bu (16), Bz (17), MenOCH₂CH₂ (20); R = i-Pr, R′ = Me (18), n-Pr (19), MenOCH₂CH₂ (21)] have been prepared from the corresponding aminotropones HN(R′)OC₇H₄R-4 (1–7) by reacting with copper(II) acetate in aqueous ethanol. 20, 21 contain the flavourant, menthol, as part of the ligand. The structures of 5 (R = H, R′ = Bz), a hydrogen-bonded dimer, 14 and 20, both incorporating square-planar, four-coordinate copper centres, have been determined by X-ray crystallography. The antibacterial activities of complexes 13, 17, 20 and 21 have been assayed against Staphylococcus waneri, an in vitro model of plaque inhibition effects, and found to be more active than a commercial toothpaste formulation, but less active than the O,O-chelated copper(II) complex of ethylmaltol.     

Development of oxygen selective adsorbents for gas separation and purification

Development, characterization, and testing of oxygen selective chemical adsorbents (chemisorbents) for cyclic gas separation and purification applications using pressure cycling are described herein. Three structurally related compositions, designated IA-1, IA-2, and IA-3 offer high oxygen capacities and selectivities coupled with fast uptake kinetics. Extended lifetime tests for IA-3 indicate a half-life of 17 years with 0.01 % oxygen at 60 °F under cycling conditions. Hazard testing results are presented and these data impose some restrictions on handling and use. For practical applications using packed beds of adsorbent in pressure-swing cycles, agglomeration is required to produce larger particles using formulations and methods that minimize the impact on oxygen binding. Methods are described herein using polymeric binders that provide the necessary physical features while maintaining adequate adsorption performance characteristics. Proof of concept oxygen removal test results are also described.     

Theoretical study on the singlet and triplet potential energy surfaces of NH (X3Σ−) + HCNO reaction

Both the singlet and triplet potential energy surfaces (PESs) of the NH (X³Σ^?) + HCNO reaction have been investigated at the BMC-CCSD level based on the UB3LYP/6-311++G(d, p) structures. The results show that the title reaction is more favorable through the singlet potential energy surface than the triplet one. For the singlet potential energy surface of the NH (X³Σ^?) + HCNO reaction, the most feasible association of NH (X³Σ^?) with HCNO is found to be a non-barrier nitrogen-to-carbon attack forming the adduct a (trans-HNCHNO), which can isomerize to the adduct b (cis-HNCHNO). The most feasible channel is that the 1, 3-H shift with N2–H2 and C–N1 bonds cleavage associated with the N1–H2 bond formation of adduct a leads to the product P ₁ (HCN + HNO). Moreover, P ₂ (HNC + HNO) should be the competitive product. The other products, including P ₃ (NH₂ + NCO) and P ₄ (N₂H₂ + CO), are minor products. The product P ₁ can be obtained through two competitive channels Path 1: R → a → P ₁ and Path 3: R → b → d → P ₁ , whereas the product P ₂ can be formed through Path 2: R → b → d → P ₂ . At high temperatures, the nitrogen-to-nitrogen approach may become feasible. For the triplet potential energy surface of the NH (X³Σ^?) + HCNO reaction, the Path 10: R → ³ a → ³ a ₁ → P ₁ should be the most feasible pathway due to the less reaction steps and lower barriers. These conclusions will have impacts on further experimental investigations.     

Synthesis and characterization of glycol ether and oxime modified precursors of niobium(V) for soft transformation to niobia

A glycol ether modified precursor, [Nb{O(CH₂CH₂O)₂}(OPrⁱ)₃] (A) was prepared by the reaction of Nb(OPrⁱ)₅ with O(CH₂CH₂OH)₂ in 1:1 molar ratio in anhydrous benzene. Further reactions of A with a variety of internally functionalized oximes in different molar ratios, yielded heteroleptic complexes of the type, [Nb{O(CH₂CH₂O)₂}(OPrⁱ)_3?n{ON = C(CH₃)(Ar)}_n] (1–9) {where Ar = C₄H₃O-2, n = 1 [1], n = 2 [2], n = 3 [3]; C₄H₃S-2, n = 1 [4], n = 2 [5], n = 3 [6]; C₅H₄N-2, n = 1 [7], n = 2 [8], n = 3 [9]}. All the above derivatives have been characterized by elemental analyses, FT-IR, NMR (¹H, ¹³C {¹H}) and FAB mass studies. Spectral studies of 1–9 suggest the presence of mono- and bi-dentate mode of oxime moieties, in the solution and in the solid states, respectively. FAB mass studies indicate monomeric nature for 3 and dimeric nature for A. TG curves of A and 6 show their low thermal stability. Soft transformation of A and 3 to pure niobia, a and b, respectively have been carried out by sol–gel technique. The XRD patterns of niobia a and b suggest the formation of nano-size crystallites of average size of 10.8 and 19.5 nm, respectively. The XRD patterns also indicate the formation of monoclinic phase of the niobia in both the cases. Absorption spectra of a and b suggest energy band gaps of 4.95 and 4.39 eV, respectively.     

Theoretical study on the mechanism of C2Cl3 + NO2 reaction

The radical-molecule reaction of C₂Cl₃ with NO₂ is explored at the B3LYP/6-311G(d,p) and CCSD(T)/6-311+G(d,p) (single-point) levels. On the singlet potential energy surface (PES), the association between C₂Cl₃ and NO₂ is found to be carbon-to-nitrogen attack forming the adduct C₂Cl₃NO₂ (1) without any encounter barrier, followed by isomerization to C₂Cl₃ONO (2). Starting from 2, the most feasible pathway is the N–O1 bond cleavage which lead to P ₁ (C₂Cl₃O + NO). Much less competitively, 2 transforms to the three-membered ring isomer c-OCCl₂C–ClNO (4 ^a ) which can easily interconvert to c-OCCl₂C–ClNO 4 ^b . Then 4 (4 ^a , 4 ^b ) takes direct C1–C2 and C2–O1 bonds cleavage to give P ₂ (COCl₂ + ClCNO). The lesser competitive channel is the 4 ^a isomerizes to the four-membered ring intermediate O-c-CNClOCCl₂ (5) followed by dissociation to P₃ (CO + ClNOCCl₂). The concerted 1,2-Cl shift along with C1–O1 bond rupture of 4 ^b to form ONC(O)CCl₃ (6) followed by dissociation to P ₄ (ClNO + OCCCl₂) is even much less feasible. Moreover, some of P ₃ and P ₄ can further dissociate to P ₅ (ClNO + CO + CCl₂). Compared with the singlet pathways, the triplet pathways may have less contribution to the title reaction. Our results are in marked difference from previous theoretical studies which showed that two initial adducts C₂Cl₃–NO₂ and C₂Cl₃–ONO are obtained. Moreover, in the present paper we focus our main attentions on the cyclic isomers in view of only the chain-like isomers are considered by previous studies. The present study may be helpful for understanding the halogenated vinyl chemistry.     

Phytochemical Study of the Rhizome of Pinellia ternata and Quantification of Phenylpropanoids in Commercial Pinellia Tuber by RP-LC

Four phenylpropanoids, (E)-p-coumaryl alcohol (1), 3,4-dihydroxycinnamyl alcohol (2), sachaliside 1 (3), and coniferin (4) have been isolated from the rhizome of Pinellia ternata. Their structures were elucidated by spectroscopic methods. Compounds 1–3 were isolated from the genus Pinellia for the first time. Compound 4 was isolated from this plant for the first time. A rapid, sensitive, and accurate reversed-phase high-performance liquid chromatographic method with UV detection at 260 nm was established for simultaneous separation and determination of the four phenylpropanoids in nineteen batches of dried rhizomes of P. ternata. Compounds were separated on a 250 × 4.6 mm C₁₈ column with methanol–acetonitrile–water–phosphoric acid, 20:5:75:0.3, as mobile phase. The amounts of 1–4 in the rhizome of P. ternata could be easily determined within 30 min. The linear calibration ranges for 1–4 were 0.05–137.50, 0.66–1050.00, 0.06–30.00, and 0.05–67.50 μg mL^?1, respectively. Recovery of 1–4 was 97.43–103.73%, with RSD from 0.12 to 1.62%. Limits of quantification for 1–4 were 50, 660, 60, and 50 ng mL^?1, respectively. The method was successfully used for phytochemical analysis of phenylpropanoids from the rhizome of P. ternata.     

Naphthologs of overcrowded bistricyclic aromatic enes: (E)-bisbenzo[a]fluorenylidene

(E)-11H-Bisbenzo[a]fluorenylidene (E-6) was synthesized by Barton’s double extrusion diazo-thione coupling method from 11H-benzo[a]fluoren-11-thione (11) and 11-diazo-11H-benzo[a]fluorene (13). The reaction is probably thermodynamically controlled; in the event that the less stable Z -6 is also formed, it would rapidly undergo Z → E diastereomerization to give E -6. The B3LYP/6-311G(d,p) calculated diastereomerization barrier for Z -6 → E -6 is ΔG ₂₉₈ = 57.0 kJ/mol (13.6 kcal/mol). The calculated equilibrium constant K _eq(E -6 → Z -6) = 92:8 (at 298 K) is indicative of a marked diastereoselectivity of the reaction leading to E -6. The structure of E-6 was established by ¹H-NMR and ¹³C-NMR spectroscopies and by X-ray analysis. PAE E-6 crystallizes in the monoclinic space group C2/c. The unit cell of the crystal structure E -6 contains eight molecules, arranged as four pairs of enantiomers. PAE E -6 adopts a twisted conformation with the pure twist of the central C¹¹=C^11′ bond ω = 39°. The dihedral angle ν in E -6 is 60.6°, which is significantly higher than the respective dihedral angle in PAEs Z -6, 2, E -7, Z -7, 14, and 15. The large syn-pyramidalization angles at C¹¹ and C^11′ (χ = 12.6° and 14.8°) of E-6 indicates the enhanced strain in the fjord regions of the molecule. The enhanced twist is primarily attributed to the double benzo[a]annelation of the bifluorenylidene moiety at the fjord regions. The B3LYP/6-311G(d,p) calculated structure of E -6 is in a very good agreement with the experimental X-ray structure. PAE E -6 adopts a twisted conformation in solution, with the downfield chemical shift of H¹/H^1′ (8.31 ppm); H¹⁰/H^10′ (δ = 7.20 ppm) and H⁹/H^9′ (δ = 6.86 ppm) in E -6 are positioned above the planes of the opposing naphthalene rings. PAEs E -6 and Z -6 are significantly higher in energy than their corresponding benzo[b]annelated isomers E -7 and Z -7.     

Peculiarities of the phase behavior of 1,3,3′,5,5′-alkoxybenzoate biphenyls in mixtures with chiral and discotic mesogenes

A synthesis of 1,3,3′,5,5′-alkanoyloxy-(Ia) and 1,3,3′,5,5′-alkoxybenzoate biphenyls (Ib) has been performed. Peculiarities of phase behavior of liquid crystalline 1,3,3′,5,5′-alkoxybenzoate biphenyls (Ib) in mixtures with discotic (1-nitro-2,3,6,7,10,11-hexadecyloxytriphenylene — II and triphenylene 2,3,6,7,10, 11-hexaundecyloxybenzoate — III) and chiral (cholesterol undecylate — IV) were studied with the aim of identifying the type of mesomorphysm. Ib was found to be mutually soluble with II and III and partially soluble with IV. The construction and analysis of the phase diagram of the mixtures of I with II throughout the range of concentrations makes it possible to assign the studied biphenyl Ib to discotic mesogens. An area of the smectic phase, which is formed from the chiral nematic IV and the discotic mesogen Ib (which displays dimorphism in the mesophase) have been found for the first time in the mixtures of these compounds. During cooling, in the mixture with molar ratio 1:1 dendritic textures with grained branches are formed, which are similar to those described in literature for TGB (twist grain boundary) phases. Relying on our studies, we suggest that Ib has a columnar type of the structure in the low-temperature area and a nematic, probably chiral, type in the high-temperature area of the mesophase.     

How do phosphoramides compete with phosphine oxides in lanthanide complexation? Structural, electronic and energy aspects at ab initio and DFT levels

Novel comparison of the structural, electronic and energy aspects of lanthanide complexes of model phosphoramides (PAs) with those of phosphine oxides (POs), phosphate esters (PEs) and phosphoryl trihalides (PHs) has been carried out by ab initio and DFT calculations. Atoms in Molecules (AIM) and Natural Bonding Orbital (NBO) analyses were performed to understand the electronic structure of ligands L and related complexes, L–Ln³⁺. NBO analysis indicates that the negative charge on phosphoryl oxygen (O_P) and the p character of the phosphoryl lone pair, Lp(O_P), increase in the order PH < PE < PO < PA. Positive charge of the lanthanide cation in PA complexes is less than those of PH, PE and PO complexes, due to the more intense ligand to metal charge transfer (LMCT). The metal–ligand distance decreases in the order PH > PE > PO > PA, which is confirmed by the results of AIM analysis. Charge density at the bond critical point of L–Ln³⁺ follows the sequence PH < PE < PO < PA. The results of the Energy Decomposition Analysis (EDA) indicate that the donative interaction and LMCT increases in order PH < PO < PE < PA. The effect of basis set superposition error (BSSE) on the L···Ln³⁺ interaction energies was also studied in detail at DFT, MP2 and CCSD(T) levels using the counterpoise (CP) method. Trends in the CP-corrected L–Ln³⁺ bond energies are in good accordance with the optimized O_P···Ln³⁺ distances. The results show that the difference between CP-corrected and uncorrected interaction energies in PA complexes is larger than those in the others, because PAs are more deformable. It is depicted that PAs are comparable with POs in lanthanide complexation.     

Sulfonyl-bridged oligo(benzoic acid)s: synthesis, X-ray structures, and properties as metal extractants

Sulfonyl-bridged oligo(benzoic acid)s 7 _n (n = 2–4) are prepared from the corresponding triflate esters (8 _n ) of sulfur-bridged oligophenols by palladium-catalyzed methoxycarbonylation of the triflate moieties, followed by hydrolysis of the resulting methyl esters, and subsequent oxidation of the sulfur bridges. X-ray analysis reveals that dimer 7 ₂ forms supramolecular zig-zag chains through intermolecular hydrogen bonds between the carboxy groups. As for the crystal of trimer 7 ₃ , two molecules are associated through two couples of intermolecular hydrogen bonds between terminal and central carboxy groups to form a cyclic dimer, which connects with two adjacent dimers with the remaining carboxy groups to construct an infinite columnar structure. Tetramer 7 ₄ adopts a monomolecular cyclic structure through intramolecular hydrogen bonds between the terminal carboxy groups, and a molecule connects with each of two adjacent molecules through two couples of intermolecular hydrogen bonds between inner carboxy and sulfonyl groups. Solvent extraction experiments reveal that the oligo(benzoic acid)s exhibit high extractability toward lanthanoid ions (Ln³⁺); the performance follows the order 7 ₄  ≈ 7 ₃  > 7 ₂ . Moderate extraction selectivity is observed for the extraction of Pr³⁺, Gd³⁺, and Yb³⁺ with 7 ₂ . X-ray crystallographic analysis of cluster [Tb₄L₄(H₂O)₆](Et₃NH)₄, which was prepared from 7 ₄ (H₄L) and Tb(NO₃)₃·6H₂O in the presence of Et₃N, reveals that no sulfonyl oxygens coordinate to the metal centers. This indicates that the high extractability of 7 ₄ originates from the electron-withdrawing nature of the sulfonyl function, which increases the acidity of two adjacent carboxy groups.     

Nickel(II)-α-diimine complexes containing naphthyl substituents for ethylene polymerization under low ethylene pressure

Two new α-diimine containing Ni(II) complexes, {bis[N,N′-(2,6-dimethyl-4-naphthylphenyl)imino]-1,2-dimethylethane}dibromonickel 3a and {bis[N,N′-(2-methyl-4-naphthylphenyl)imino]-1,2-dimethylethane}dibromonickel 3b were synthesized and characterized. The crystal structures of representative ligand 2a and its complex 3a were determined by X-ray crystallography. Complex 3a bearing 2,6-dimethyl and 4-naphthyl groups, activated by diethylaluminum chloride (DEAC), shows high catalytic activity for the polymerization of ethylene [4.43 × 10⁶ g PE/(mol Ni h bar)]. Interestingly, complexes 3a and 3b bearing the naphthyl substituent in the para-aryl position produced dendritic polyethylenes (branching degree, 3a: 112, 118, and 147; 3b: 113, 127, and 151 branches/1,000 C at 20, 40, and 60 °C, respectively). The dendritic polyethylene particle size obtained by 3a and 3b/DEAC can be controlled in the 1–20 nm range under low ethylene pressure (diameter, 3a: 18.31, 14.44, and 11.09; 3b: 12.29, 8.98 and 6.27 nm at 20, 40, and 60 °C, respectively) and could be expected to produce a nano-targeted drug carrier after modification with water-soluble oligo(ethylene glycol).     

Controlling the photochemical reactions of alkenes by light-path length effects of a microchannel reactor

Photoirradiation of Me₂CO–H₂O solution of pent-4-en-1-ol (1a) with a high-pressure mercury lamp in a test tube gave 8-hydroxyoctan-2-one (3a) in 66 % yield along with oxetane (4a) and the isomer (4a′) in 10 % yield. Irradiation of the running Me₂CO–H₂O solution of 1a in the flow system of a microchannel reactor (MCR) gave mainly 4a. The photoreaction of 1,1-diphenylethene (2a) with triethylamine gave a Markovnikov-type adduct (5a) and an anti-Markovnikov-type adduct (6a). The use of the MCR enhanced the production of 5a. These phenomena were explained by the light-path length effects of the MCR.