N，N-二丁基辛酰胺从硝酸介质中萃取铀(Ⅵ)和钍(Ⅳ)

合成了N,N-二丁基辛酰胺(简称DBOA)。以甲苯为稀释剂研究了DBOA萃取硝酸的平衡,认为低酸度下形成HNO₃·DBOA,得到萃取平衡常数为0.2 mol^-2·L²;研究了水相酸度和萃取剂浓度对DBOA萃取硝酸铀酰平衡的影响,得到萃合物组成UO₂(NO₃)₂·(DBOA)₂,25℃下萃取平衡常数为4.93 mol^-4·L⁴;利用红外光谱分析并确定了萃合物的结构;考察温度对萃取平衡的影响,得到萃取反应热为-29.1 kJ·mol^-1。实验结果表明相同条件下DBOA萃取Th⁴⁺、 Fe³⁺的能力很弱,UO²⁺₂能与之有效地分离,表明DBOA在钍-铀分离方面具有应用前景。     

2-乙基己基辛基硫醚树脂固相萃取钯的研究

合成和鉴定了新萃取剂2-乙基己基辛基硫醚(EHOS),研究了EHOS树脂萃取钯的性能。实验表明,在0.1 mol·L^-1盐酸介质中,EHOS树脂萃Pd(Ⅱ)的萃取率＞99%,研究了EHOS树脂萃取钯的机理,结果表明,EHOS树脂通过EHOS分子上的硫原子与钯(Ⅱ)配位,形成2∶1配合物。硫脲是有效反萃剂,从萃合物的晶体结构看出,硫脲通过S原子与Pd(Ⅱ)配位,萃合物以Pd原子为中心构成平面正方型结构。选择了汽车催化剂浸出液进行固相萃取分离试验,钯回收率＞97%。     

穿心莲内酯NO供体衍生物的合成

利用协同前药原理, 在穿心莲内酯衍生物的结构上引入硝酸酯, 合成了硝酸酯NO供体新化合物9个, 以期找到生物利用度更高、抗癌作用更好的新药; 目标化合物结构经¹H NMR, ¹³C NMR和MS确证.     

醇-水体系中HPMBP萃取钬的机理及萃合物晶体结构

本文报道研究了在醇-水混合体系中用HPMBP-三氯甲烷萃取Ho³⁺的机理。在萃取条件下,得到了固态萃合物Ho(PMBP)₃·2H₂O,并用X-射线衍射方法测定了固态萃合物的晶体结构。晶体属于单斜晶系,空间群P2₁/n, a=1.5035(4) nm,b=1.4710(2)nm, c=2.4391(4)nm, β=101.407(1)°,     

两个取代苄基锡配合物的合成、抗癌活性及其与DNA相互作用

利用二（2,4-二氯苄基）二氯化锡分别与对甲基苯甲酰肼或对叔丁基苯甲酰肼、丙酮酸钠在甲醇中发生反应,合成了2个二（2,4-二氯苄基）锡配合物（C1、C2）,通过元素分析、IR、¹H NMR、¹³C NMR、¹¹⁹Sn NMR、HRMS以及X射线单晶衍射表征了配合物结构。测试了配合物C1、C2的热稳定性以及配合物对NCI-H460（人肺癌细胞）、HepG2（人肝癌细胞）和MCF7（人乳腺癌细胞）的体外抑制活性,发现配合物C1对癌细胞均表现较好的抑制作用。利用UV-Vis光谱、荧光光谱以及黏度法研究了2个配合物与ct-DNA之间的相互作用,结果表明配合物是以经典的嵌入模式与DNA结合。     

meso-四(对烷氧苯基)卟啉金属配合物的合成和性能研究(IV)

合成了系列卟啉乙酸合锰配合物9个, 其中6个为未见文献报道的新化合物. 用UV, ¹H NMR, IR, MS, 元素分析等表征确证了配合物的结构, 总结了锰与卟啉类配体配合的IR, UV, ¹H NMR判据. 采用差示扫描量热法(DSC)和偏光显微镜(PM)研究了该系列配合物的液晶性能, 发现8个配合物具有液晶性. 考察了烷氧基链长、配位金属离子和分子空间结构对液晶性能的影响.     

一类新型手性烷基氨基酚类配体的合成

利用Mannich反应, 高对映选择性地以中等产率合成了三个新型烷基氨基苯酚类配体及6个具有C₂对称轴的烷基氨基萘酚类配体. 合成的9个新化合物的结构经元素分析, IR, ¹H NMR, ¹³C NMR和MS等确定, 其中两个化合物4和7通过X射线单晶衍射确定了新生成的手性中心的绝对构型.     

水峰调制下的3,4-Seco-olean-11,13-dien-4,15α,22β,24-tetraol-3-oic Acid的NMR结构解析

对海南半红树植物黄槿(Hibiscus tiliaceus)内生菌中提取的一个新化合物进行核磁共振结构解析的研究. 在核磁共振测试时发现水峰信号与部分样品信号发生了重叠, 直接影响了该化合物谱图数据的分析. 本工作通过实验确证了在氘代二甲亚砜(DMSO-d₆)溶剂中水峰化学位移与含水量之间的变化规律. 依据该规律, 利用定量加入纯水的方法对实际样品中的水峰信号进行了调制, 解决了水峰信号与样品信号的重叠问题, 得到了较理想的¹H NMR, ¹³C NMR一维谱和COSY, HMQC, HMBC等二维谱. 利用核磁共振提供的信息完成了对新化合物结构的解析, 确定该化合物为齐墩果烷三萜类化合物3,4-seco-olean-11,13-dien-4,15α,22β,24-tetraol-3-oic acid.     

N, N, N′, N′-四丁基丙二酰胺萃取Pr3+的研究

利用丙二酸二乙酯与二正丁胺反应高收率的制备了N，N，N′，N′-四丁基丙二酰胺(TBMA)萃取剂。研究了硝酸浓度、硝酸锂浓度、萃取剂浓度以及温度等对萃取Pr(Ⅲ)分配比的影响，确定了萃合物的组成，得到了不同稀释剂中萃取反应的热力学数据。结合红外光谱和摩尔电导数据初步推断了萃合物的结构。     

1,10-双(1′-苯基-3′-甲基-5′-氧代吡唑-4′-基)癸二酮-[1,10]对希土、钍和铀萃取行为的研究

本文研究了新型的双酰代吡唑酮类整合萃取剂1,10-双(1′-苯基-3′-甲基-5′-氧代吡唑-4′-基)癸二酮-[1,10](H₂A)的氯仿溶液从硝酸介质中对11个希土离子,钍和铀的萃取行为。测定了pH_1/2值,用斜率法求得萃合物的组成,确定了各自的萃取平衡反应,计算了萃取平衡常数,合成了希土固态萃合物,并对其组成、UV、IR及TG-DTA谱进行了研究。     

Liquid-liquid extraction of rhodium(III) from hydrochloric acid solutions with 1,2,4-triazole derivative

Liquid-liquid extraction of rhodium(III) from hydrochloric acid solutions with a 1,2,4-triazole derivative was studied. Optimal conditions for its recovery were found. Rhodium(III) was shown to be recovered in extraction system by ion-exchange reaction at the time of phase contact not longer than 5 min. When phase contact time increased, rhodium(III) is extracted by a mixed mechanism with simultaneous insertion of two extractant molecules into the inner coordination sphere of rhodium(III) ion. Composition of coordination species of recovered compounds was established by electronic, IR, ¹H and ¹³C NMR spectroscopy and functional analysis, the structure of the coordination species is proposed.     

Extraction of rhodium(III) by a bisacylated diethylenetriamine derivative from hydrochloric acid solutions

The extraction of rhodium(III) with a bisacylated diethylenetriamine derivative from hydrochloric acid solutions was studied. Optimum conditions for rhodium(III) extraction were determined. It was found that, at a contact time to 10 min, the extraction occurred by an ion-association mechanism. At a contact time longer than 10 min, rhodium(III) was extracted by a mixed mechanism with the insertion of an extractant molecule into the inner coordination sphere of the rhodium(III) ion. The composition of the extracted compound was determined using electronic, ¹H and ¹³C NMR, and IR spectroscopy and elemental analysis, and the structure of this compound was proposed.     

Iridium(IV) extraction with petroleum sulfoxides from hydrochloric acid solutions

Iridium(IV) extraction with petroleum sulfoxides (PSO) from hydrochloric acid solutions is studied. Optimum conditions of extraction are chosen. It is shown that in the investigated extraction systems for a phase contact time of 30 min, iridium(IV) is extracted by the ion-associative mechanism. Electronic, ¹H NMR, and IR-spectroscopy, and elemental analysis are used to establish the structure of the extracted compound.     

Biopolymers from the Mauritian Marine Environment

To the best of our knowledge, the extraction of biopolymers from algae and seaweeds still remains untapped. Prior studies in this area have been limited to a taxonomic survey of algae and seaweeds found around our coastal regions. In this paper, we report on the extraction of biopolymers from Hypnea, Eucheuma and Gracilaria species collected around the coastal regions of Mauritius. Various extraction conditions were used and their effects on yield and structure of the corresponding biopolymers were investigated. The extracted polysaccharides were characterized by a combination of IR, NMR, SEC, viscometry and elemental analyses. These revealed that polysaccharide extracted from Gracilaria is a highly methylated agar and Hypnea/Eucheuma contain κ-carrageenan.     

Porous Siloxane-Silica Hybrid Materials by Sol-Gel Processing

Porous hybrid materials have been fabricated by sol-gel processing of tetraethoxysilane (TEOS) and 1,3,5,7-tetramethyl-tetrakis(ethyltriethoxysilane)-cyclotetrasiloxane (1) in the presence of the cationic surfactant, cetyltrimethylammonium bromide (CTAB). The chemical and physical properties of these materials have been analysed by FT-IR spectroscopy, solid state ²⁹Si NMR spectroscopy, powder X-ray diffraction and nitrogen adsorption-desorption studies. FT-IR spectroscopy established that the CTAB surfactant can be extracted from a crushed gel using ethanol as a solvent. Solid state ²⁹Si NMR spectroscopy showed the presence of D, T and Q species as expected from the structure of the precursors. Broad bands observed for the D units at –18 ppm and the T units at –63 ppm suggested that the cyclotetrasiloxane was held in a rigid environment and bound to the Q species of the silica matrix derived from the TEOS. NMR spectroscopy confirmed that solvent extraction resulted in further condensation of the silica matrix. Powder X-ray diffraction indicated that the materials possess short-range order and small domain sizes, as shown by broad diffraction peaks. The condensation induced by solvent extraction led to a decrease in the lattice and domain size of the samples, generally resulting in a less ordered material. Nitrogen adsorption-desorption isotherms were typical of microporous materials with pore diameters of 18 Å and a narrow size distribution.     

Extraction of Iridium(IV) by 1-(2-(2,4-Dichlorophenyl)-4-propyl-1,3-dioxolan-2-yl-methyl)-1H-1,2,4-triazole from Hydrochloric Solutions

Extraction of iridium(IV) by 1-(2-(2,4-dichlorophenyl)-4-propyl-1,3-dioxolan-2-yl-methyl)-¹H-1,2,4-triazole from hydrochloric solutions was studied. Optimal extraction parameters were determined. The mechanism of iridium(IV) extraction in this system is ion exchange (3.0 mol/L HCl and τ_cont = 5 min). Electronic, ¹H NMR, ¹³C NMR, and IR spectroscopy and elemental analysis were used to determine the composition of the extracted compound.     

Mössbauer and NMR characterization of tin octoate: Neat and residues in RTV foams

We have investigated hydrolysis and oxidation effects on tin octoate and on tin-octoate residues in RTV polysiloxane foams by means of Nuclear Magnetic Resonance (NMR) and Mössbauer spectroscopy (MS). ¹¹⁹Sn NMR showed the presence of various tin species whereas ¹¹⁹Sn MS detected the presence of two oxidation states: Sn(II) and Sn(IV). The relative abundance of Sn(IV) increased as both the tin octoate and the foam aged. Foams were also solvent extracted and no selective extraction of one tin oxidation state was observed; both oxidation states were detected. ¹³C NMR indicated that octanoic acid is present in the tin octoate and in the foams as a residue. MS data showed that aging treatments of the foams and of the neat catalyst have a great effect on the tin oxidation state. The two spectroscopic methods complement each other in following the effects of hydrolysis and oxidation.     

Extraction of rhodium(III) with sulfoxides from hydrochloric acid solutions

Extraction of rhodium(III) from hydrochloric acid solutions with dihexyl sulfoxide (DHSO) and with petroleum sulfoxides (PSOs) was studied, and the optimal conditions for its recovery were found. At a phase contact time of up to 0.5 h, the extraction of rhodium(III) with sulfoxides occurred mainly by an ionassociation scenario. If the phase contact time exceeds 0.5 h, a mixed extraction scenario predominated to form the extracted complexes (L · H⁺) · [RhCl₄L₂]-(DHSO)_o and PSO (LH⁺) · [RhCl₄(H₂O) · L]⁻. The protonation of the extraction agents occurred at the donor oxygen atoms of the sulfoxide group. When rhodium was extracted with PSOs, the coordination of the extractant molecule in the inner coordination sphere of the acido complex to the metal ion occurred through the donor sulfur atom of the sulfoxide group, while with the use of DHSO, through the donor atoms of sulfur and oxygen of the sulfoxide group. Electronic, ¹H NMR, and IR spectroscopy and elemental analysis were used to determine the composition of the extracted compounds and suggest their structure.     

Extraction of rhodium(III) by 1,3-diamyl-2-imidazolidinethione from hydrochloric acid solutions

The extraction of rhodium(III) with 1,3-diamyl-2-imidazolidinethione from hydrochloric acid solutions was studied. Optimum conditions for rhodium(III) extraction were determined. It was found that rhodium(III) was extracted from a 0.5 M solution of HCl at a phase contact time of 3 h by a coordination mechanism. The composition of the extracted compound was determined using electronic, ¹H and ¹³C NMR, and IR spectroscopy and elemental analysis. It was demonstrated that the extracting agent coordinated to the rhodium(III) ion through the sulfur atom.     

Vanadium(V) extraction from sulfuric acid solutions

We studied vanadium(V) extraction by di-2-ethylhexylphosphoric acid (DEHPA) from 1.0–12.0 M sulfuric acid. Optimal extraction parameters were determined. IR, ⁵¹V NMR, and electronic spectroscopy was used to determine the stoichiometry of the extracted complex and the reaction equation for vanadium(V) extraction by DEHPA. The equilibrium constant of vanadium(V) extraction by DEHPA was determined.