Preparation and chromatographic behavior of acetate-fiber filter rods with dye affinity ligands

Summary The dyes cibacron blue F3GA and reactive red 120 have been immobilized on acetate fiber filter rods to produce potential affinity matrixes. The isothermal adsorption of bovine serum albumin or human serum albumin on these matrixes was investigated and proved to conform to the Freundlich equation. In the static adsorption of human plasma the adsorption capacity for human serum albumin was 12.5 mg g⁻¹ fiber filter and one band was observed in SDS-PAGE electrophoresis of human serum albumin isolated by the immobilized cibacron blue F3GA filter rod. Ligand utilization efficiencies and breakthrough volumes were obtained for adsorption of HSA on the cibacron blue F3GA filter rod when the feed-rates were from 0.5 to 6 mL min⁻¹. In the affinity chromatography of human plasma the yield of human serum albumin was 1.27 g per 100 mL plasma.     

Determination of 4-methylbenzilidene camphor in sunscreen by square wave voltammetry in media of cationic surfactant

The voltammetric behavior of 4-methylbenzelidene camphor (MBC) was studied by square wave voltammetry (SWV) using mercury electrode. The experimental condition that provided the highest peak current with the best reduction signal definition of MBC was found in Britton-Robinson buffer and cationic surfactants, cetyltrimethylammoniun bromide (CTABr). A single peak of MBC reduction was observed at − 1.21 V versus Ag/AgCl. The developed methodology was applied for determination of MBC in commercial sunscreen SPF 15, 20 and 30 and for the simultaneous determination when other protection agents were associated, such as benzophenone-3 (BENZO) and octyl methoxycinammate (OMC). Both methodologies had shown good determination values for the analyzed samples. The calculated detection limit was 2.99 × 10^− 9 mol L^− 1 and the quantification limit was 9.98 × 10^− 9 mol L^− 1.     

4-Amino-1,8-naphthalimide-based anion receptors: employing the naphthalimide N-H moiety in the cooperative binding of dihydrogenphosphate

The 4-amino-1,8-naphthalimide-based anion receptor 3 binds dihydrogenphosphate with 1:1 stoichiometry through cooperative hydrogen bonding to a naphthalimide N-H and thiourea N-H groups. This was clearly established from ¹H NMR titration experiments in DMSO-d₆ where a substantial shift in the resonance for the naphthalimide N-H was observed concomitant with the expected thiourea N-H chemical shift migration upon successive additions of H₂PO₄⁻. However, whilst ¹H NMR titration experiments indicate that 3 was capable of binding other anions such as acetate, the naphthalimide N-H does not participate and the N-H resonance was essentially invariant during the titration. The lack of cooperative binding in this instance was justifiable on steric grounds.     

Structure and Crystallographic Disorder of [Mo2(O2CCF3)2I4](HPPh3)2

The reaction of Mo₂(O₃CCF₃)₄ with (CH₃)₃SiI and PPh₃ gave the title complex [Mo₃(O₂CCF₃)₂I₄]-(HPPh₃)₂ which was characterized by X-ray crystallography. Crystal data for [Mo₂(O₂CCF₃)₂I₄](HPPh₃)₂: space group $ {\rm P}\bar 1 $, a = 10.953(4) Å, b = 12.784(3) Å, c = 19.829(4) Å, α = 100.68(2)°, β = 91.16(2)°, γ = 112.98(2)°, V = 2498.6(10) ų, Z = 2, with final residuals R = 0.0887 and Rw = 0.0965. There are two independent molecules in each asymmetric unit. The molybdenum, oxygen, and fluoride atoms in one of the two independent molecules are disordered, such that the primary set is 53% occupied, and the secondary set 47%.     

Syntheses,Structures and Spectroscopic Studies of Quadruply Bonded Complexes Containing Bridging Acetate and η3-etp Ligands (etp = Ph2PCH2CH2P(Ph)CH2CH2PPh2)

The quadruply bonded complexes containing bridging acetate and polydentate phosphine ligands of the type Mo₂(O₂CCR₃)X_J(η³-etp) (R = H, X = Br, 1; R = F, X = CI, 2; R = F, X = Br, 3; etp = Ph₂PCH₂CH₂P(Ph)CH₂CH₂PPh₂) were prepared by reactions of Mo₂(O₂CCR₃)X₂(PPh₃)₂ with etp in CH₂X₂. Their UV-vis and ³¹P{¹H}-NMR spectra have been recorded, and the structure of 1 has been determined by X-ray crystallography. Crystal data for 1·2CH₂Br₂: space group P2₁/c, a = 13.924(7) Å, b = 21.157(4) Å, c = 14.427(5) Å, β = 101.82(3)°, V = 4159(2) ų, Z = 4, with final residuals R = 0.0797 and Rw = 0.0793. The absorption wavelengths of the δ → δ* transitions and the chemical shifts and the coupling constants of the ³¹P{¹H}-NMR spectra of these complexes are dependent on the natures of the halogen atoms and the acetate ligands.     

Thin-layer chromatography of inorganic lons phosphate on cellulose in acetic acid and in acetic acid-ammonium acetate media

Summary Systematic study for the chromatographic behaviour of 49 inorganic ions has been carried out on cellulose phosphate layer in acetic acid and acetic acid — ammonium acetate media. Feasibilities for the effective separations of analytical interest are demonstrated on the 0.25 mm layer in both media.     

Formation of anionic palladium(0) complexes ligated by the trifluoroacetate ion and their reactivity in oxidative addition

As established previously for Pd(OAc)₂, Pd⁰ complexes are formed in situ from Pd(OCOCF₃)₂ and n equiv. triarylphosphines (4-Z-C₆H₄)₃P (Z = CF₃, F, Cl, H, CH₃; n ? 3). The phosphines are the intramolecular reducing agents and are oxidized to triarylphosphine oxides. The generated Pd⁰ complexes are anionic species ligated by the trifluoroacetate anion: Pd⁰(PAr₃)_n(OCOCF₃)⁻ (n = 2 or 3). Pd⁰(PAr₃)₂(OCOCF₃)⁻ is the reactive species involved in the oxidative addition to PhI. This leads to trans-PhPd(OCOCF₃)(PPh₃)₂, involved in equilibrium with the cationic complex trans-[PhPd(PPh₃)₂(DMF)]⁺, instead of the expected trans-PhPdI(PPh₃)₂ complex. The existence of anionic Pd⁰ complexes ligated by the acetate or trifluoroacetate ions delivered by the precursors Pd(OAc)₂ or Pd(OCOCF₃)₂, respectively, as well as their comparative reactivity in oxidative additions are consistent with theoretical DFT calculations.     

Micellar Effects on the Reaction between an Arenediazonium Ion and the Antioxidants Gallic Acid and Octyl Gallate

The effect of sodium dodecyl sulfate (SDS) micelles on the reaction between the 3‐methylbenzenediazonium (3MBD) ion and either the hydrophilic antioxidant gallic acid (GA) or the hydrophobic analogue octyl gallate (OG) have been investigated as a function of pH. Titration of GA in the absence and presence of SDS micelles showed that the micelles do not alter the first ionization equilibrium of GA. Analysis of the dependence of the observed rate constant (k_obs) with pH shows that the reactive species are GA^2? and OG^?. Kinetics results in the absence and presence of SDS micelles suggest that SDS aggregates do not alter the expected reaction pathway. SDS Micelles inhibit the spontaneous decomposition of 3MBD as well as the reaction between 3MBD and either GA or OG, and upon increasing the SDS concentration, with k_obs approaching the value for the thermal decomposition of 3MBD in the presence of SDS. Our results are consistent with the prediction of the pseudophase model and show that the origin of the inhibition for the reaction with GA is different to that for the reaction with OG; in the former case, the observed inhibition can be rationalized in terms of the micelle‐induced electrostatic separation of reactants in the micellar Stern layer, whereas the observed inhibition in the reaction with OG is a consequence of the dilution effect caused by increasing SDS concentration, decreasing the local OG^? concentration in the Stern layer.     

烟用醋纤丝束气味的嗅觉测试方法研究

研究并建立了醋酸纤维素丝束（醋纤丝束）气味的感官分析方法。对丝束的主要气味物质丙酮和乙酸进行测定，嗅阈值分别为丙酮46mg／L，乙酸0．074mg／L。本法检测灵敏度高，能对正常丝束气味和混有其它物质的异常丝束气味进行准确辨别。用该法对厂家生产的醋纤丝束进行嗅味测试，结果显示质量合格的丝束气味强度为2～3，当强度大于4时应引起厂家高度重视。     

Remarkable ESIPT induced NIR emission by a selective colorimetric dibenzimidazolo diimine sensor for acetate

A new dibenzimidazolo diimine sensor (DDS) has been designed and synthesized for selective detection of acetate ion. Significant naked eye recognized color change of DDS solution from light yellow to pink upon addition of only acetate ion is accompanied with near infra red (NIR) emission exploiting excited state intramolecular proton transfer (ESIPT).