1-（2′-苯并噻唑）-3-（4′-羧基苯）三氮烯固相萃取分光光度法测定钯

根据新试剂1-(2′-苯并噻唑)-3-(4′-羧基苯)三氮烯(BTCBT)与钯的显色反应及C8固相萃取小柱对显色络合物的固相萃取,建立了一种测定痕量钯的新方法,在pH为5.0~6.3的柠檬酸氢二钠-NaOH缓冲介质中,在乳化剂OP和SDBS存在下,钯与BTCBT发生反应形成1∶2的稳定络合物,该络合物可用C8固相萃取小柱富集,小柱上富集的络合物用乙醇洗脱后用分光光度法测定,在富集后的测定液中,络合物最大吸收波长为490 nm,摩尔吸光系数ε=1.16×105L.mol-1.cm-1,Pd2 量在0.1~1.2μg/mL内符合比尔定律,方法适用于测定催化剂中的钯。     

2-(4-羧基苯偶氮)苯并噻唑固相萃取分光光度法测定铂的研究

根据新试剂2-(4-羧基苯偶氮)苯并噻唑(CPABT)与铂的显色反应及C8固相萃取小柱对显色络合物的固相萃取,建立了一种测定痕量铂的新方法,在pH为3.8~5.5的乙酸-乙酸钠缓冲介质中,在Tween-80存在下,铂与CPABT发生反应形成1∶1的稳定络合物,该络合物可用C8固相萃取小柱富集,小柱上富集的络合物用二甲基甲酰胺洗脱后用分光光度法测定,在富集后的测定液中,络合物最大吸收波长为508 nm,摩尔吸光系数ε=2.29×105L.mol-1.cm-1,Pt4 量在0.1~1.2μg/mL内符合比尔定律,方法已用于测定催化剂中的铂。     

2-(2-喹啉偶氮)-1,5-二氨基苯固相萃取光度法测定痕量钯

根据2-(2-喹啉偶氮)-1,5-二氨基苯(QADAB)与钯的显色反应及MCI-GEL反相固相萃取小柱对显色络合物的固相萃取,建立了一种测定痕量钯的方法.在0.2～3.0 mol·L-1高氯酸介质中,溴化十六烷基三甲胺(CTMAB)存在下,QADAB与钯反应生成2:1稳定络合物,该络合物可被MCI-GEL反相固相萃取小柱萃取富集,富集的络合物用丙酮洗脱后用光度法测定,在丙酮介质中体系的最大吸收波长为600 nm,表观摩尔吸光率为9.63×104L·mol-1·cm-1.钯质量浓度在0.01～L 5 mg·L-1内符合比耳定律,方法用于几种实样中痕量钯的测定,测得回收率在86%～96%间.     

钯与对若丹宁偶氮苯甲酸络合物的固相萃取和光度测定

根据新试剂对若丹宁偶氮苯甲酸(RABA)与钯的显色反应及C18固相萃取小柱对显色络合物的固相萃取,建立了一种测定痕量钯的新方法,在pH为2.0～4.0的HCl-邻苯二甲酸氢钾(HCl-KHP)缓冲介质中,在CTMAB存在下,钯与RABA发生反应形成1:1的稳定络合物,该络合物可用C18固相萃取小柱富集,小柱上富集的络合物用乙醇洗脱后用光度法测定,在富集后的测定液中,络合物最大吸收波长为500 nm,摩尔吸光系数ε=1.36×105 L·mol-1·cm-1,Pd2 量在0.1～1.0 μg/mL内符合比尔定律,方法用于催化剂中钯的测定.     

微波消解和固相萃取光度法测定氰化渣中痕量钯

根据 2_(2_喹啉偶氮 )_5_二甲氨基苯甲酸 (QADMAB)与钯的显色反应及C18固相萃取小柱对显色络合物的固相萃取 ,并结合微波消解样品 ,建立了一种测定氰化渣中痕量钯的方法。即在pH为 3 5的HAc_NaAc缓冲介质中 ,溴化十六烷基三甲胺 (CTMAB)存在下 ,QADMAB与钯反应生成 2 1稳定络合物 ,该络合物可被C18小柱萃取富集 ,富集的络合物用乙醇洗脱后用光度法测定 ,在乙醇介质中体系λmax=63 0nm ,ε=1 2 0× 1 0 5L·mol-1·cm-1。钯含量在 0 0 1～ 1 5mg L内符合比尔定律 ,方法用于氰化渣中钯含量的测定 ,结果令人满意。     

2-(2-喹啉偶氮)-1,5-二氨基苯固相萃取光度法测定钴

合成了新试剂2 (2 喹啉偶氮) 1,5 二氨基苯(QADAB),研究了其与钴的显色反应及C18固相萃取小柱对显色络合物的固相萃取,在pH3.5磷酸盐缓冲介质中,CTMAB存在下,QADAB与钴反应生成2∶1稳定络合物,该络合物可用C18固相萃取小柱富集,小柱上富集的络合物用乙醇(内含2%乙酸)洗脱后用光度法测定,λmax=590nm,ε=8.36×104L·mol-1·cm-1。钴含量在0.01～0.80mg·L-1内符合比耳定律,方法用于环境样品中钴含量的测定,结果满意。     

2-（2-喹啉偶氮）-1，5-二氨基苯固相萃取光度法测定痕量钯

根据2-（2-喹啉偶氮）-1,5-二氨基苯（QADAB）与钯的显色反应及MCI—GEL反相固相萃取小柱对显色络合物的固相萃取,建立了一种测定痕量钯的方法。在0．2～3.0mol·L^-1高氯酸介质中,溴化十六烷基三甲胺（CTMAB）存在下,QADAB与钯反应生成2：1稳定络合物,该络合物可被MCI—GEL反相固相萃取小柱萃取富集,富集的络合物用丙酮洗脱后用光度法测定,在丙酮介质中体系的最大吸收波长为600nm,表观摩尔吸光率为9．63×10^4L·mol^-1·cm^-1。钯质量浓度在0．01～1.5mg·L^-1内符合比耳定律,方法用于几种实样中痕量钯的测定,测得回收率在86％～96％间。     

氰化渣中痕量钯的微波消化-固相萃取光度法的研究

合成了新试剂2-(2′-喹啉偶氮)-5-二乙氨基苯甲酸(QADEAB),试验了该试剂与钯(Ⅱ)的显色反应及C18固相萃取小柱对显色配合物的固相萃取。钯(Ⅱ)在pH 2.5的氯乙酸-氢氧化钠缓冲介质中,溴化十六烷基三甲胺(CTMAB)存在下与QADEAB生成1∶2稳定配合物。该配合物可被C18小柱萃取富集,富集的配合物用乙醇洗脱;富集倍数达50倍,洗脱液经定容后用光度法测定。最大吸收波长为635 nm,ε=1.53×105L.mol-1.cm-1,钯(Ⅱ)含量在0.01~1.5 mg.L-1内符合比耳定律。该方法用于氰化渣中钯含量的测定,结果满意。     

4,5-二甲基-2-噻唑偶氮重氮氨基偶氮苯固相萃取-分光光度法测定银

研究了4,5-二甲基-2-噻唑偶氮重氮氨基偶氮苯(DMTDAA)与银的显色反应,在pH 11．0的硼砂-氢氧化钠缓冲介质中,乳化剂-OP存在下,DMTDAA与银反应生成2:1稳定络合物,该络合物可用Waters XterraTM RP18固相萃取小柱富集,小柱上富集的络合物用乙醇(内含0．01 mol．L-1pH为11．0的四氢吡咯-乙酸缓冲盐)洗脱后用光度法测定,在洗脱剂介质中λmax =518 nm,ε=1．39×105L·mol-1·cm-1。银含量在0．01～2．0 mg·L-1范围内符合比耳定律。方法用于环境水样中银含量的测定,结果的RSD在2．2％～2．8％,回收率在96％～104%。     

8-氨基喹哪啶固相萃取光度法测定水中痕量铁(Ⅲ)的研究

根据8-氨基喹哪啶（AQ）与铁（Ⅲ）的显色反应及固相萃取小柱对显色配合物的固相萃取,建立了一种测定水样中μg／L级铁（Ⅲ）的新方法在pH=5．5HAc-NaAc缓冲介质中AQ与铁（Ⅲ）反应,生成分子比为3：1的稳定配合物,该配合物可用Waters Porapak SepPak C18固相萃取小柱富集,富集物用含1％醋酸的乙醇溶液洗脱后用光度法测定。采用该方法测定了儿种水样中微量铁（Ⅲ）的含量,结果令人满意。     

(S)-(-)-5-对苄氧基苄基-2,4-噁唑烷二酮的合成

L-酪氨酸经O-苄基化和重氮化反应得到关键中间体--手性3-(对苄氧基苯基)-α-羟基丙酸(4); 4经酯化、氨化和环化反应合成了(S)-(-)-5-对苄氧基苄基-2,4-噁唑烷二酮,总收率10%, 95.4%e.e.,其结构经1H NMR和HR-MS表征.     

Preparation,molecular structures,and characteristic properties of (E)-1-(2-furyl)- and (E)-1-(2-thienyl)-2-(3-guaiazulenyl)ethylenes and (E)-1-(3-furyl)- and (E)-1-(3-thienyl)-2-(3-guaiazulenyl)ethylenes

Wittig reactions of 2-furaldehyde (20) [and thiophene-2-carbaldehyde (21)] with (3-guaiazulenylmethyl)triphenylphosphonium bromide (19) in ethanol containing NaOEt at 25 °C for 24 h under argon give (E)-1-(2-furyl)-2-(3-guaiazulenyl)ethylene (22E) and (E)-1-(2-thienyl)-2-(3-guaiazulenyl)ethylene (23E) in 53 and 36% yields. Similarly, Wittig reactions of 3-furaldehyde (29) [and thiophene-3-carbaldehyde (30)] with 19 under the same reaction conditions as for 20 and 21 afford (E)-1-(3-furyl)-2-(3-guaiazulenyl)ethylene (31E) and (E)-1-(3-thienyl)-2-(3-guaiazulenyl)ethylene (32E) in 32 and 46% yields. Molecular structures and characteristic properties as well as preparation of the title E (i.e., one of the geometrical isomers) forms, with a view to comparative study, are reported. Moreover, reactions of those conjugated π-electron systems with TCNE (=tetracyanoethylene) in benzene [and in DMF (=N,N-dimethylformamide)] at 25 °C for 24 h under argon yield unique products, possessing interesting molecular structures, respectively, whose characteristic properties and crystal structures are documented, also.     

(S)-(-)-norlaudanosine和(S)-(-)-O,O-dimethylcoclaurine的合成

以高藜芦胺为起始原料,经N-磺酰化反应制得高藜芦磺酰胺(2);2分别与芳乙烯甲醚经对甲苯磺酸催化的Pictet-Spengler反应后用金属钠脱除Ts基团合成了(±)-norlaudanosine(5a)和(±)-O,O-dimethylcoclaurine(5b);使用半量拆分法,以N-乙酰-L-苯丙氨酸为拆分剂,制得(S)-(-)-5a和(S)-(-)-5b,其结构经1H NMR,13C NMR,IR,MS和HR-ESI-MS确证。     

Synthesis and Crystal Structure of 1-（Trifluoromethyl）-1-（propioloyl）-（E）-3-oxo-（2-thienyl）-（2-naphthylamine）

1INTRODUCTIONTheSchiffbasesderivedfromb-diketonesandaliphaticamineshavebeenshowntoexistastheketo-amines.However,ifsubstituentseitherattheketooraminogrouparearomatic,itmaybeexpectedtheenoliminewillbethefavoredtautomericform[1].Recently,someSchiffbasesderivedfromTTA(4,4,4-trifluoro-1-(2-thienyl)-1,3-butanedione)andPMBPhavebeenstudiedbyWang[2]andYu[3]etal.Inordertostudytherelationshipbetweenthestructuresandperformancesofthesecompounds,thetitlecom-poundwillbereportedherein.2EXPERIMENT…     

Smectic A and smectic C materials: partially deuteriated chiral liquid crystals (S)-(-)-2-methylbuty 4-(4-(d13)-hexyloxyphenyl)benzoate and (S)-(-)-2-methylbutyl 4-(4-(d17)-octyloxyphenyl)benzoate

In order to study the difference in microscopic orientation of ferro- and antiferroelectric liquid crystalline molecules, we synthesized the partially deuteriated chiral compounds, (S)-(^-)-2-methylbutyl 4-(4-(d₁₃)-hexyloxy- and (S)-(^-)-2-methylbutyl 4-(4-(d₁₇)-octyloxy-phenyl)benzoates. Fundamental physical properties such as phase transition temperatures, spontaneous polarization and tilt angle were determined. Polarized FTIR measurements were also made to provide information on molecular structure and orientation.     

Synthesis of (S)-5-(1-aminoethyl)-2-(cyclohexylmethoxy)benzamide

Three short syntheses of the title compound, a peptidomimetic for the Glu-Glu-Ile-NH₂ portion of Ac-pTyr-Glu-Glu-Ile-NH₂, a high affinity peptide for the Src SH2 domain, are described. The most efficient route produces the title compound in a final enantiopurity of 94% ee.     

An Efficient Synthesis of Optically Pure (R)- and (S)-2-(aminomethyl)alanine ((R)- and (S)-ama) and (R)- and (S)-2-(aminomethyl)leucine ((R)- and (S)-aml)

An efficient synthesis of enantiomerically pure (R)- and (S)-2-(aminomethyl)alanine ((R)- and (S)-Ama) 1a and (R)- and (S)-2-(aminomethyl)leucine ((R)- and (S)-Aml) 1b is described (Schemes 1 and 2). Resolution of the racemic amino acids was achieved using L -phenylalanine cyclohexylamide ( 2 ) as chiral auxiliary. The free amino acids 1a, b were converted to the N^α-Boc,N^γ-Z-protected derivatives 11a, b (Scheme 3) ready for incorporation into peptides. Based on the three crystal structures of the diastereoisomeric peptides 8a, 8b , and 9b , the absolute configurations in both series were determined. β-Turn type-I geometries were observed for structures 8b and 9b , whereas 8a crystallized in an extended backbone conformation.