Synthesis and Surface Properties of Novel Cationic Gemini Surfactants

A series of novel cationic gemini surfactants, p-[C _n H_2n+1N⁺(CH₃)₂CH₂CH(OH)CH₂O]₂C₆H₄·2Cl^? [A(n = 12), B(n = 14) and C(n = 16)], containing a spacer group with two flexible and hydrophilic groups (2-hydroxy-1,3-propylene) on both sides of a rigid and hydrophobic group (1,4-dioxyphenylene) has been synthesized by the reaction of hydroquinone diglycidyl ether with N,N-dimethylalkylamine and N,N-dimethylalkylamine hydrochloride. Their surface-active properties have been investigated by surface tension measurement. The critical micelle concentration (cmc) values of the synthesized cationic gemini surfactants are one order of magnitude lower than those of their corresponding monomeric surfactants (C _n H_2n + 1N⁺(CH₃)₃·Cl^?). Both the cmc and surface tension at the cmc (γ_cmc) of A are lower than those of p-[C₁₂H₂₅N⁺(CH₃)₂CH₂]₂C₆H₄·2Cl^? (D). The novel cationic gemini surfactants A and B also show good foaming properties.     

Organic reactions at surfaces: A study of carnitine by secondary ion mass spectrometry

Carnitine inner salt, (CH₃)₃N⁺ CH₂CH(OH)CH₂COO^?, and carnitine hydrochloride, (CH₃)₃N⁺CH₂CH (OH)CH₂COOH Cl^?, in the solid state undergo ion-beam-induced intermolecular methyl transfer reactions as shown by (CH₃)₃N⁺ CH₂CH(OH)CH₂COOCH₃ ions at m/z 176 in their positive ion spectra. In the case of carnitine HCl, the product ion is three times as abundant as the intact cation. For the inner salt however, the product is less than one-tenth as abundant as [M + H] ⁺. In both cases, the reaction can be precluded by dissolution of the sample, supporting an intermolecular mechanism. The negative ion spectra for these compounds contain no [M ? CH₃]^? ions, suggesting that simple transmethylation does not occur. Rather it is proposed that the inner salt abstracts a methyl group from the intact carnitine cation to yield [M + CH₃]⁺ and a neutral species, the driving force being a minimization of the total number of charges desorbed into the gas phase. Thermodynamic data favor this mechanism as do data for other carnitine salts. The reaction appears to be inhibited when one reactant is present in excess. This is the case for carnitine HNO₃ and CH₃SO₃H, which tend to liberate the intact cation since the anions are large and polarizable. It is also the case for small, hard anions like fluoride, which appear to favor release of the inner salt, hence the cation at m/z 162 is of low abundance and the transmethylation product (m/z 176) is absent. The extent of the reaction is also dependent on the methods of preparation of the sample, and deposition of the salts from solution greatly reduces the extent of methyl transfer. [M ? CH₃]^? is observed when glycerol is used as a matrix, possibly due to a matrix-analyte methyl transfer reaction.     

Quelques precisions sur les effets catalytiques des micelles cationiques hydroxylees

The alkaline hydrolysis of p-nitrophenyl acetate and of CH₃CO₂(CH₂)₂N⁺(CH₃)₂C₁₆H₃₃, Br^? was studied in the presence of micelles C₁₆H₃₃N⁺(CH₃)₂CH₂CH₂OH, Br^? and CTAB, C₁₆H₃₃N⁺(CH₃)₃,Br^?. A pathway involving an intermediate is suggested for the hydrolysis of the ester. Hydrolysis rate of the intermediate in the presence of micelles is the same as hydrolysis rate for the ester in the absence of micelles. Consequently, hydrolysis of p-nitrophenyl acetate is not catalysed by one type of micelle, while it is enhanced by another type of micelle.     

Unusual crystal and molecular structure of tris(2-hydroxyethyl)ammonium fluoride

According to the X-ray diffraction data, the crystal and molecular structure of tris(2-hydroxyethyl) ammonium fluoride (F^?N⁺H(CH₂CH₂OH)₃, fluoroprotatrane, substantially differs from other halo protatranes X^?N⁺H(CH₂CH₂OH)₃ (X = Cl, Br, and I). At X = F, to the endo-molecular LP of the nitrogen atom the HF molecule having the minimum ionic radius in a series of X^? anions is bonded. The geometry of fluoroprotatrane and the cation packing in the crystal are analyzed.     

Positive and negative methanol cluster ions using a direct fast atom bombardment technique

Positive and negative cluster ions in methanol have been examined using a direct fast atom bombardment (FAB) probe technique. Positive ion (CH₃OH)_IIH ⁺ clusters with n = 1-28 have been observed and their clusters are the dominant ions in the low-mass region. Cluster-ion reaction products (CH₃OH)_II(H₂O)H⁺ and (CH₃OH)_II(CH₃OCH₃)H⁺ are observed for a wide range of n and the abundances of these ions decrease with increasing n. The negative ion (CH₃OH)_II(CH₃O)^? clusters are also readily observed with n = 0-24 and these form the most-abundant negative ion series at low n. The (CH₃OH)_II(CH₂O)^?, (CH₃OH)_II(H_IIO)(CH₂O)^? and (CH₃OH)_II(H₂OXCH₃O)^? cluster ions are formed and the abundances of these ions approach those of the (CH₃OH)_II(CH₃O)^? ion series at high n. Cluster-ion structures and energetics have been examined using semi-empirical molecular orbital methods.     

Crystal and molecular structure of N-methyl-bis(2-hydroxyethyl)ammonium (4-chlorphenylsulfonyl)acetate

By X-ray diffraction the crystal and molecular structure of N-methyl-bis(2-hydroxyethyl)ammonium (4-chlorphenylsulfonyl)acetate 4-ClC₆H₄SO₂CH₂COO^?·CH₃N⁺H(CH₂CH₂OH)₂ synthesized by the interaction of (4-chlorphenylsulfonyl)acetic acid with N-methyl-bis(2-hydroxyethyl)amine is studied.     

Theoretical kinetic investigation of thermal decomposition of nitropropane

The thermal decomposition of nitropropane (CH₃CH₂CH₂NO₂) has been investigated at the CBS-QB3 level of theory. The pyrolysis of CH₃CH₂CH₂NO₂ mainly includes the simple bond ruptures mechanism, hydrogen abstraction processes, isomerization and secondary reactions. As a result, for the simple bond ruptures mechanism, the formation of \({\text{CH}}_{3} {\text{CH}}_{2} {\text{CH}}_{2}^{\cdot} +\,^{\cdot}{\text{NO}}_{2}\) products is dominant with the energy barrier of 49.77 kcal mol^?1. The process of H atom on the β–CH₂ abstracted by one O atom of NO₂ moiety in CH₃CH₂CH₂NO₂(CH₃CH₂CH₂NO₂ → CH₃CH=CH₂ + HONO) needs to overcome lower energy barrier than that of the rate-determining step (one of H atom on the α-CH₂ and γ-CH₃ abstracted of reaction) of the other hydrogen abstraction reactions. Therefore, we predict that the corresponding alkenes and HONO are the main products in the hydrogen abstraction reaction of nitroparaffin. Besides, the channel of the CH₃CH₂CHO + HNO formations (CH₃CH₂C(α)H₂NO₂ → CH₃CH₂C(α)H₂ONO → CH₃CH₂CHO + HNO), occurring through the H atom of C(α) abstracted by the N atom of NO₂ moiety after the isomerization reaction from CH₃CH₂CH₂NO₂ to CH₃CH₂CH₂ONO, is favorable in the isomerization secondary reactions. Rate constants and branching ratios are estimated by means of the conventional transition state theory with zero curvature tunneling over the temperature range of 400–1500 K. The calculation shows that the overall rate constant in the temperature of 400–1500 K is mainly dependent on the competitive channels of formations of CH₃CH=CH₂ + HONO and \({\text{CH}}_{3} {\text{CH}}_{2} {\text{CH}}_{2}^{\cdot} +\,^{\cdot}{\text{NO}}_{2}\) The three-parameter expression for the total rate constant is fitted to be k _total = 1.74 × 10^?13 T ^8.20exp(17038.7/T) (s^?1) between 400 and 1500 K.     

Synthesis,crystal structures,and magnetic properties of methoxido-bridged dinuclear MnIII complexes derived from tri-dentate chelating ligands

Two new doubly methoxido-bridged Mn^III dinuclear complexes, [Mn^III(mphp)(μ-OCH₃)(CH₃OH)]₂·2CH₃OH (1) and ([Mn^III(ahbz)(μ-OCH₃)(CH₃OH)]₂·2CH₃OH (2), have been synthesized by using the tridentate ligands H₂mphp (H₂mphp = 2-methyl-6-(pyrimidin-2-yl-hydrazonomethyl)-phenol) and H₂ahbz (H₂ahbz = N-(2-amino-propyl)-2-hydroxy-benzamide). The complexes have been characterized by single-crystal X-ray diffraction analysis and magnetic measurements. Complexes 1 and 2 have a similar dimeric molecular structure. Two [Mn(L)(CH₃OH)]⁺ moieties (L^2? = mphp^2? or ahbz^2?) are bridged by two μ-OCH₃^? groups in the axial-equatorial asymmetric manner. The coordination geometry of Mn^III is an axially elongated octahedron with two oxygens of a methanol ligand and a methoxido ligand situated at the axial positions. Magnetic measurements indicate that 1 and 2 exhibit antiferromagnetic behavior with the fitting parameter of J = ?1.49(3) cm^?1, D = ?1.3(1) cm^?1, g = 1.98(1) and zJ′ = ?0.18(4) cm^?1 for 1, and J = ?1.6(2) cm^?1, D = 4.5(3) cm^?1, g = 2.06(1) and zJ′ = 1.4(1) cm^?1 for 2 on the basis of the spin Hamiltonian ? = ?2J?_Mn1?_Mn2.     

The ions [CH3S]+, [C2H5S]+ and [CH3O]+ formed by electron-impact

The mass spectra of deuterated species shows that both the isomeric ions [CH₂?SH]⁺ and [CH₃? S]⁺ are formed in the ratio 2:1 from CH₃SH; the ions [CH₃CH?SH]⁺ and [CH₃CH₂S]⁺ in the ratio 0·8:1 from CH₃CH₂SH; and [CH₂?OH]⁺ and [CH₃? O]⁺ in the ratio 6·7:1 from methanol. The heats of formation of [CH₃S]⁺ and [C₂H₅S]⁺ are of the order of 222 and 203 Kcal.mole^?1 respectively. The isomeric ions cannot be distinguished on thermodynamic grounds.     

Structure and formation of gaseous [C4H6O]+˙ ions: 1—The enolic ions [CH2C(OH)?CHCH2]+˙ and [CH2CH?CHCH(OH)]+˙ and their relationship with their keto counterparts

The [C₄H₆O]^+˙ ion of structure [CH₂?CHCH?CHOH]^+˙ (a) is generated by loss of C₄H₈ from ionized 6,6-dimethyl-2-cyclohexen-1-ol. The heat of formation ΔH_f of [CH₂?CHCH?CHOH]^+˙ was estimated to be 736 kJ mol^?1. The isomeric ion [CH₂?C(OH)CH?CH₂]^+˙ (b) was shown to have ΔH_f, ? 761 kJ mol^?1, 54 kJ mol^?1 less than that of its keto analogue [CH₃COCH?CH₂]^+˙. Ion [CH₂?C(OH)CH?CH₂]^+˙ may be generated by loss of C₂H₄ from ionized hex-1-en-3-one or by loss of C₄H₈ from ionized 4,4-dimethyl-2-cyclohexen-1-ol. The [C₄H₆O]^+˙ ion generated by loss of C₂H₄ from ionized 2-cyclohexen-1-ol was shown to consist of a mixture of the above enol ions by comparing the metastable ion and collisional activation mass spectra of [CH₂?CHCH?CHOH]^+˙ and [CH₂?C(OH)CH?CH₂]^+˙ ions with that of the above daughter ion. It is further concluded that prior to their major fragmentations by loss of CH₃˙ and CO, [CH₂?CHCH?CHOH]⁺˙ and [CH₂?C(OH)CH?CH₂]^+˙ do not rearrange to their keto counterparts. The metastable ion and collisional activation characteristics of the isomeric allenic [C₄H₆O]^+˙ ion [CH₂?C?CHCH₂OH]^+˙ are also reported.     

Mixing Behavior of Conventional and Gemini Cationic Surfactants

Micellization behavior of cationic monomeric surfactants, hexadecyltrimethylammonium bromide (CTAB), cetylpyridinium bromide (CPB), cetylpyridinium chloride (CPC), tetradecyltrimethylammonium bromide (TTAB), and dimeric (gemini) cationic surfactant pentamethylene‐1, 5‐bis(hexadecyldimethylammonium bromide) with formula C₁₆H₃₃(CH₃)₂N⁺(CH₂)₅N⁺(CH₃)₂C₁₆H₃₃ · 2Br^?, abbreviated as 16‐5‐16, in mixed states (binary) have been studied by conductivity. The micellar compositions, activities of the components, and their mutual interactions have been estimated from Rubingh's theory. The mixtures show nonideal behavior with favorable interactions.     

Synthetic,spectral as well as in vitro antimicrobial studies on some bismuth(III) bis(N,N‐dialkyldithiocarbamato) alkylenedithiophosphates

Mixed sulfur donor ligand complexes of the type bismuth(III) bis(N,N‐dialkyldithiocarbamato) alkylenedithiophosphate, [R₂NCS₂]₂BiS₂POGO [where R = CH₃ and C₂H₅; G = ‐CH₂‐C(C₂H₅)₂‐CH₂‐, ‐CH₂‐C(CH₃)₂‐CH₂‐, ‐CH(CH₃)‐CH(CH₃)‐ and ‐C(CH₃)₂‐C(CH₃)₂‐] were synthesized in 1:1 molar ratio of bismuth(III) bis(N,N‐dialkyldithiocarbamate) chloride and ammonium alkylenedithiophosphate in refluxing benzene and characterized by melting point, molecular weight determinations, elemental analysis (C, H, N, Bi and S) and spectral [UV, IR,NMR (¹H,¹³C and ³¹P) and powder X ray diffraction] studies; all these studies were in good agreement with the synthesized complexes. These newly synthesized derivatives are yellow and brown colored solids and are soluble in common organic solvents like benzene, chloroform, dichloromethane and DMF. Based on the physicochemical and spectral studies, a tentative structure of these newly synthesized complexes was assigned and the average particle size of the synthesized complexes determined by powder XRD, showing that nano range polycrystalline particles were formed with a monoclinic crystal system. These complexes were also screened for their antimicrobial activities using the well diffusion method. The free ligands as well as their mixed metal complexes were tested in vitro against four bacterial strains: two Gram‐positive, Staphylococcus aureus (ATCC 9144) (G⁺) and Bacillus subtilis (ATCC 6051), (G⁺) and two Gram‐negative, Escherichia coli (ATCC 9637) (G^?) and Pseudomonas aeruginosa (ATCC 25619) (G^?) to assess their antimicrobial properties. The results were indeed positive and exhibited good antibacterial effects. Chloroamphenicol used as a standard for comparison and synthesized complexes showed good antibacterial effects over chloroamphenicol. On the basis of these studies, the synthesized complexes help to understand the different structural and biological properties of main group elements with sulfur donor ligands. Copyright © 2010 John Wiley & Sons, Ltd.     

Base Catalysed Racemization of Ethylenediamine-N,N,N′-triacetato-aqua-cobalt(III)

The kinetics of the base catalysed racemization of [Co(EN3A)H₂O]

1 Abbreviations: EN3A^3?=(^?OOCCH₂)₂N(CH₂)₂NHCH₂COO^?; ME3A^3?=(^?OOCCH₂)₂N(CH₂)₂ N(CH₃)CH₂COO^?; EDDA^2?=^?OOCCH₂NH(CH₂)₂NHCH₂COO^?; EDTA^4?=(^?OOCCH₂)₂N(CH₂)₂N(CH₂COO^?)₂;TNTA^4?=(^?OOCCH₂)₂N(CH₂)₃N(CH₃COO^?)₂; HETA^3?=(^?OOCCH₂)₂N(CH₂)₂N(CH₂COO^?)CH₂CH₂OH; en=H₂N(CH₂)₂NH₂; Meen=H₂N(CH₂)₂NHCH₃; sar^?=^?OOCCH₂NHCH₃.

were studied polarimetrically in aqueous buffer solution. The reaction rate is first order in OH^? and in complex, in weakly acidic medium. Activation parameters are ΔH≠=22 kcal · mol^?1, ΔS≠=26 cal · K^?1. The results are discussed in terms of an S_N1CB mechanism involving exchange of the ligand water molecule. The N-methylated analogue [Co(ME3A)H₂O] does not racemize in the pH-range investigated. Loss of optical activity occurs at a rate which is about 1,000 times slower than the racemization of [Co(EN3A)H₂O](60°) and coincides with the decomposition of the complex.     

Synthesis of Pyrazolo[3,4‐d]pyrimidin‐4‐ones Catalyzed by Br?nsted‐acidic Ionic Liquids as Highly Efficient and Reusable Catalysts

A convenient and efficient method for the synthesis of pyrazolo[3,4‐d]pyrimidin‐4‐ones via heterocyclization reaction of 5‐amino‐1H‐pyrazole‐4‐carboxamides with triethyl orthoesters using two Br?nsted‐acidic ionic liquids, 3‐methyl‐1‐(4‐sulfonic acid)butylimidazolium hydrogen sulfate [MIM⁺(CH₂)₄SO₃H][HSO₄^?] or N‐(4‐sulfonic acid)butyl triethylammonium hydrogen sulfate [Et₃N⁺(CH₂)₄SO₃H][HSO₄^?], as efficient homogeneous catalysts under solvent‐free conditions is described.     

Formation and hydrolysis of gas‐phase [UO2(R)]+: R═CH3, CH2CH3, CH═CH2, and C6H5

The goals of the present study were (a) to create positively charged organo‐uranyl complexes with general formula [UO₂(R)]⁺ (eg, R═CH₃ and CH₂CH₃) by decarboxylation of [UO₂(O₂C─R)]⁺ precursors and (b) to identify the pathways by which the complexes, if formed, dissociate by collisional activation or otherwise react when exposed to gas‐phase H₂O. Collision‐induced dissociation (CID) of both [UO₂(O₂C─CH₃)]⁺ and [UO₂(O₂C─CH₂CH₃)]⁺ causes H⁺ transfer and elimination of a ketene to leave [UO₂(OH)]⁺. However, CID of the alkoxides [UO₂(OCH₂CH₃)]⁺ and [UO₂(OCH₂CH₂CH₃)]⁺ produced [UO₂(CH₃)]⁺ and [UO₂(CH₂CH₃)]⁺, respectively. Isolation of [UO₂(CH₃)]⁺ and [UO₂(CH₂CH₃)]⁺ for reaction with H₂O caused formation of [UO₂(H₂O)]⁺ by elimination of ·CH₃ and ·CH₂CH₃: Hydrolysis was not observed. CID of the acrylate and benzoate versions of the complexes, [UO₂(O₂C─CH═CH₂)]⁺ and [UO₂(O₂C─C₆H₅)]⁺, caused decarboxylation to leave [UO₂(CH═CH₂)]⁺ and [UO₂(C₆H₅)]⁺, respectively. These organometallic species do react with H₂O to produce [UO₂(OH)]⁺, and loss of the respective radicals to leave [UO₂(H₂O)]⁺ was not detected. Density functional theory calculations suggest that formation of [UO₂(OH)]⁺, rather than the hydrated U^VO₂⁺, cation is energetically favored regardless of the precursor ion. However, for the [UO₂(CH₃)]⁺ and [UO₂(CH₂CH₃)]⁺ precursors, the transition state energy for proton transfer to generate [UO₂(OH)]⁺ and the associated neutral alkanes is higher than the path involving direct elimination of the organic neutral to form [UO₂(H₂O)]⁺. The situation is reversed for the [UO₂(CH═CH₂)]⁺ and [UO₂(C₆H₅)]⁺ precursors: The transition state for proton transfer is lower than the energy required for creation of [UO₂(H₂O)]⁺ by elimination of CH═CH₂ or C₆H₅ radical.     

Supramolecular inclusion of a pillared double-layered host by an anion-directed second-sphere coordination

In this paper, we have illustrated the utilisation of a second-sphere coordination approach to construct supramolecular inclusion solids with varieties of guest molecules. A flexible molecule N,N,N′,N′-tetra-p-methylbenzyl-ethylenediamine (L1) bearing doubly protonated H-bond donors was designed, capable of forming N–H…Cl hydrogen bonds with a crystallographically unique chloride anion, to construct an anion-directed ligand. The pillared double-layered host framework was constructed by an anion-directed ligand and primary coordination sphere [CoCl₄]^2 ?  through weak C–H…Cl hydrogen-bonding interactions. A variety of guest molecules, such as p-anisaldehyde, 1,4-dimethoxy-2,5-bis(methoxymethyl)benzene, can be included, leading to the formation of novel supramolecular inclusion solids: [L1]·4[H]⁺·[CoCl₄]^2 ? ·2Cl^? ·1.5[C₈H₈O₂]·0.25[CH₃OH] (1) and [L1]·4[H]⁺·[CoCl₄]^2 ? ·2Cl^? ·1.5[C₁₂H₂₀O₄]·0.5[CH₃OH] (2).

We have presented herein the utilisation of a second-sphere coordination approach to construct supramolecular inclusion solids with a variety of guest molecules. A novel type of a pillared double-layered host framework was constructed by a second-sphere coordination between the anion-directed ligand (L1 = N,N,N′,N′-tetra-p-methylbenzyl-ethylenediamine) and [CoCl₄]^2 ?  through weak C–H…Cl hydrogen-bonding interaction, and a variety of guest molecules, such as p-anisaldehyde, 1,4-dimethoxy-2,5-bis(methoxymethyl)benzene, can be included, leading to the formation of supramolecular inclusion solids: [L1]·4[H]⁺·[CoCl₄]^2 ? ·2Cl^? ·1.5[C₈H₈O₂]·0.25[CH₃OH] (1) and [L1]·4[H]⁺·[CoCl₄]^2 ? ·2Cl^? ·1.5[C₁₂H₂₀O₄]·0.5[CH₃OH] (2)

     

Phosphoryl transfer from phenyl and 4-nitrophenyl phosphates in aprotic and protic solvents : Amine catalysis and formation of oxyphosphorane and metaphosphate intermediates

The behavior of 4-nitrophenyl dihydrogen phosphate, ArOPO₃H₂, and of its tetra-n-butylammonium and tetramethylammonium salts, ArOPO₃H^?R₄N⁺, ArOPO₃^2?2(R₄N⁺), was studied in aprotic solvents, in the absence and in the presence of increasing amounts of alcohols or water. The reactions were investigated in the absence of amines, and in the presence of hindered and unhindered amines, diisopropylethylamine and quinuclidine. The course of the reactions was followed at 35° or at 70° by ³¹P and ¹H NMR spectrometry. Values for the approximate half-times of the reactions were estimated (± 25 %) from the times at which reactant signal intensity becomes equal to product signal intensity. The mononitrophenyl ester transfers its phosphoryl group to alcohols and water from the diprotonated acid by the addition-elimination mechanism via oxyphosphorane intermediates, and from the monoanion and dianion by the elimination-addition mechanism via the monomeric metaphosphate intermediate, PO₃^?. Formation of PO₃^? is faster from dianion than from monoanion in acetonitrile and in alcohol solutions. Conversely, PO₃^? is generated at a faster rate from monoanion than from dianion in aqueous solution. This effect results from a decrease in the rate of formation of PO₃^? in the solvent series: acetonitrile > alcohols > water. The rate depression as a function of the medium is greater for the dianion than for the monoanion, and is attributed to greater solvation of the more polar phosphate ground state than of the less polar transition state in the more polar protic solvents. Unhindered amines add to 4-nitrophenyl phosphate monoanion, but not to the dianion. The oxyphosphorane intermediate thus formed collapses to aroxide ion and a protonated dipolar phosphoramide which is rapidly deprotonated by the relatively basic 4-nitrophenoxide: ArOPO₃H^? + CH(CH₂CH₂)₃N(acetonitrile ? CH(CH₂CH₂)₃N⁺P(O)(OH)O^? + ArO^?? CH(CH₂ CH₂)₃N⁺PO₃^2?+ ArOH → CH(CH₂CH₂)₃N + PO₃^?. The postulated formation of PO₃^? by this route explains why the addition of quinuclidine to an acetonitrile solution containing the monoanion salt, ArOPO₃H^?R₄N⁺, and t?BuOH produces t-butyl phosphate at a faster rate than the addition of diisopropylethylamine to the same solution. 2,4-Dinitrophenyl phosphate, which was previously studied by the same techniques, reacts via oxyphosphorane intermediates from the diprotonated and the monoanion forms, and via monomeric metaphosphate, from the dianion form.     

NEW PHTHALOCYANINES FOR PHOTODYNAMIC VIRUS INACTIVATION IN RED BLOOD CELL CONCENTRATES

Abstract Cationic phthalocyanines with either aluminum or silicon as the central metal were evaluated for their ability to inactivate viruses in red blood cell concentrates (RBCC) photodynamically. In addition, the virucidal potential of a substituted anionic phthalocyanine, aluminum dibenzodisulfophthalocyanine hydroxide (AlN₂SB₂POH) was evaluated and compared with that of the much studied anionic aluminum tetrasulfophthalocyanine hydroxide (AIPcS₄OH). Based on the rate of inactivation of the lipid-enveloped vesicular stomatitisvirus (VSV), the viruci dal potential of these phthalocyanines was: HOSiP_COSi(CH₃)₂(CH₂)₃N⁺(CH₃)₃I- (Pc 5) = SiPC[OSi(CH₃)₂-(CH₂)₃N⁺(CH₃)₃I-]₂ (Pc 6) > AIP_COSi(CH,)₂(CH₂)_?N⁺(CH₃)₂(CH_?)₁₁CH₃I- (Pc 21) = A1N₂SB₂POH = AlPcS₄ > HOSiPc[OSi(CH₃)₂(CH₂)₃N⁺(CH₃)₂(CH₂)₁₁CH₃1–]₂(Pc 14) > AIPcOSi(CH₃)₂(CH₂)₃N+(CH_S)₃I- (Pc 2). Phthalocy anine ligand 14 and Pc 21 are new phthalocyanines, made by quaternizing known amino analogues. Compared to VSV, the rate of inactivation of Sindbis virus (another model lipid-enveloped virus) was identical when treated in red blood cells (RBC) with Pc 5 and slightly higher when treated with Pc 6 and AlPcS₄OH. Treatment of RBCC containing cell-free human immunodeficiency virus (HIV-1) with Pc 5 or AlPcS₄OH required 15 min of irradiation to inactivate (>5 log₁₀ reduction) the virus. The extent of HIV-1 inactivation with AlN₂SB₂POH was 3.7 log₁₀ after 60 min of red light exposure. The RBC integrity after photosensitization was measured by the ability of the cells to bind to plates coated with poly-L-lysine, (which reflects the retention of the RBC surface negative charges) and hemolysis of the cells over a 7 day storage period. The RBC damage using these criteria was most pronounced with Pc 5 and Pc 6 but could be reduced when treatment was in plasma instead of buffer. These data indicate that lipid-enveloped viruses differ in their sensitivity to phthalocyanine photosensitization. Therefore, for virus sterilization of RBCC for transfusion the ability to inactivate human pathogenic viruses completely will have to be evaluated for each virus. The cationic Pc 5 appears to be a potentially useful virucidal agent.     

Mass spectra of substituted thioglycollic acids and esters. Skeletal rearrangement upon electron-impact

The mass spectra of thioglycollic acids and esters are reported and discussed. The spectra of compounds of the type X·CH(Y)·S·CH₂·COOR(X > Y) contain skeletal rearrangement fragments with the composition R·Y·C₂H₃SO⁺. Ions produced by simple cleavage processes may be usefully correlated with structure.     

Three copper(II) complexes constructed from 4-(2-pyridyl)-<Emphasis Type="Italic">1H</Emphasis>-1,2,3-triazole ligands: syntheses,structures, optical,and electrochemical properties

Three Cu(II) complexes constructed from 4-(2-pyridyl)-1H-1,2,3-triazole (L), namely, [CuL₂Cl₂]·H₂O, [CuL₂(CH₃OH)(NO₃)]NO₃ and [CuL₂(H₂O)]SO₄, have been synthesized and characterized. X-ray crystal structure analyses revealed that [CuL₂Cl₂]·H₂O and [CuL₂(CH₃OH)(NO₃)]NO₃ have octahedral geometries, whilst [CuL₂(H₂O)]SO₄ adopts a square-pyramidal coordination geometry. In all three complexes, the Cu(II) atoms are chelated by two L ligands in the basal plane, whilst the apical positions are occupied by Cl^?, NO₃^?, CH₃OH or H₂O. The bandgaps between the HOMO and LUMO were estimated by cyclic voltammetry (CV) and diffuse reflectance spectroscopy (DRS) to be 3.43, 3.12, and 3.74 eV, respectively. Theoretical calculations on each structure gave similar results to the experiments. Frontier molecular orbital analyses showed that the higher electron density on the apical ligand, the lower the bandgap.