1-偶氮苯-3-(3-硝基-5-氯-2-吡啶)-三氮烯的合成及其与汞的显色反应

合成了显色剂1-偶氮苯-3-(3-硝基-5-氯-2-吡啶)-三氮烯(ABNCPyT),并用元素分析法和红外光谱法对其分子结构作了鉴定.研究了ABNCPyT与汞的显色反应,在pH 10.5的Na2B4O7-NaOH缓冲溶液中和聚氧乙烯烷基酚(Triton X-100)表面活性剂存在下,试剂与汞(Ⅱ)生成4:1型红色配合物.配合物的最大吸收峰位于525 nm,表现摩尔吸光率为1.92×105L·mol-1·cm-1.汞(Ⅱ)质量浓度在600 靏稬-1以内符合比耳定律.用拟定方法测定废水中微量汞,所得结果与原子吸收光谱法的结果一致,测得其相对标准偏差(n=5)≤2.5%,方法的回收率在97.5%～103.0%.     

(2,6-二溴-4-硝基苯)-3-(4-硝基苯)-三氮烯与银(Ⅰ) 的显色反应及其应用

研究了1-(2,6-二溴-4-硝基苯)-3-(4-硝基苯)-三氮烯(DBNPNPT)与Ag(Ⅰ)的显色反应。在Na2B4O7-NaOH缓冲溶液(pH=10.0)中和在Triton X-100存在下,试剂与Ag(Ⅰ)生成1∶1的配合物。该配合物在波长445 nm处有正吸收峰,在530 nm有负吸收峰,用双峰双波长法测得配合物的表观摩尔吸光系数为2.06×105L.mol-1.cm-1,符合比耳定律的范围为0~12μg/25mL。该法已用于回收定影液中银(Ⅰ)的测定,结果满意。     

新试剂(2,6-二氯-4-硝基苯)-3-(4-硝基苯)-三氮烯的合成及其与汞的显色反应研究

合成了新试剂(2,6-二氯-4-硝基苯)-3-(4-硝基苯)-三氮烯(DCNPNPT),测定了试剂的亚氨基离解常数pKa＝9．2。在TritonX-100存在下,pH9．8～11．0范围内,试剂与Hg2+形成14黄色型配合物,用双波长法测得其表观摩尔吸光系数为2．27×105L·mol-1·cm-1。汞含量在0～10μg／25ml范围内符合比耳定律,用此法测定了天然水和实验室废水中微量汞含量,结果满意。     

1-(2-苯并咪唑)-3-[4-(苯基偶氮)苯基]-三氮烯的合成及与镉(Ⅱ)的显色反应

报道了1-(2-苯并咪唑)-3-[4-(苯基偶氮)苯基]-三氮烯(PIPAPT)的合成及与镉(Ⅱ)的显色反应。在非离子表面活性剂OP存在下,于pH 11.0 Na2B4O7-NaOH缓冲体系中,试剂与镉(Ⅱ)形成4∶1的橘红色配合物,其最大吸收波长位于523 nm,表观摩尔吸光系数为1.19×105L.mol-1.cm-1。镉质量浓度在0~0.7μg/mL范围内符合比尔定律。方法可用于水中微量镉的测定。     

4-(4-氯苯重氮基)氨基-4′-氯偶氮苯的合成及其与汞(Ⅱ)的显色反应

合成了新显色剂4-(4-氯苯重氮基)氨基-4′-氯偶氮苯(简称CDACAB),并研究了其与汞(Ⅱ)的显色反应。结果表明,在非离子表面活性剂OP存在下,在pH=10.5的Na2B4O7-NaOH缓冲介质中,汞(Ⅱ)与CDACAB形成1∶2橙红色络合物,其最大吸收波长位于498nm处,表观摩尔吸光系数ε=1.15×105 L.mol-1.cm-1。汞(Ⅱ)质量浓度在0～7.0μg/10mL范围内遵守比耳定律。所拟方法用于废水中微量汞(Ⅱ)的测定,相对标准偏差为1.6%～3.1%,回收率为96.5%～103.8%。     

1-(4-硝基苯基)-3-(3,5-二溴吡啶)三氮烯的合成及其与汞的显色反应

合成了1-(4-硝基苯基)-3-(3,5-二溴吡啶)三氮烯(NPDBPDT),并研究了NPDBPDT与汞的显色反应.在Na2B4O7-NaOH缓冲溶液(pH11.0)介质中,在Triton X-100存在下Hg(Ⅱ)与试剂生成络合物(1∶2).络合物在450 nm处有最大正吸收峰,表观摩尔吸光系数为1.36×105 L·mol-1·cm-1,在535 nm处有最大负吸收峰,表观摩尔吸光系数为1.57×105 L·mol-1·cm-1,以535 nm为参比波长,以450 nm为测量波长进行双波长测定,表观摩尔吸光系数为2.93×105 L·mol-1·cm-1.汞量在0～0.48 μg/mL范围内符合比耳定律.     

1-偶氮苯-3-(4,6-二甲基-2-嘧啶)-三氮烯的合成及其与汞(Ⅱ)显色反应

报道了1-偶氮苯-3-(4,6-二甲基-2-嘧啶)-三氮烯(ABDMPDT)的合成及其与汞(Ⅱ)的显色反应研究,在pH10.5的Na2B4O7-NaOH缓冲溶液中,有Triton X-100存在下,该试剂与汞反应形成2∶1的橙红色络合物。其最大吸收波长在524nm处,表观摩尔吸光系数为1.986×105L·mol-1.cm-1,汞的质量浓度在0～0.48μg/mL范围内符合比耳定律。     

铑(Ⅲ)与5-(5-碘-2-吡啶偶氮)-2,4-二氨基甲苯配合物催化氢波研究及其应用

建立了催化极谱法测定超痕量铑(Ⅲ)的新方法,在0.1 mol· L-1 HAc-NaAc底液(pH＝4.8)中,铑(Ⅲ)与5-(5-碘-2-吡啶偶氮)-2,4-二氨基甲苯(5-I-PADAT)反应形成稳定配合物,并在适量HClO4底液中于-1.02 V(vs.SCE)处产生灵敏极谱催化波.该催化波一阶导数峰电流ip'与铑(Ⅲ)浓度在9.7×10-12～3.9×10-9 mol·L-1范围内成良好线性关系,检出限达3.0×10-12mol·L-1.研究证明该波为铑(Ⅲ)-5-I-PADAT配合物的催化氢波,其电极过程为不可逆过程.方法用于铑炭催化剂中铑的测定,结果较好.     

基于2-(4-甲基苯甲酰基)苯甲酸及2,2′-联吡啶的双核铜(Ⅱ)配合物的晶体结构、荧光和磁性(英文)

以2-(4-甲基苯甲酰基)苯甲酸(HL)及2,2′-联吡啶(2,2′-bipy)为配体合成了一个双核铜(Ⅱ)配合物[Cu2(L)4(2,2′-bipy)2]·H2O(1),并对其进行了晶体结构测定。测定结果表明,该配合物晶体属于三斜晶系,空间群为P1,晶胞参数:a=1.012 57(15)nm,b=1.312 5(2)nm,c=1.317 0(2)nm,α=82.985(2)°,β=76.437(2)°,γ=88.290(2)°,V=1.688 7(4)nm3,Dc=1.391 g·cm-3,Z=2,F(000)=732,GooF=1.027,最终偏离因子R1=0.037 5,wR2=0.091 4。在配合物分子中相邻的2个铜(Ⅱ)离子通过2个2-(4-甲基苯甲酰基)苯甲酸根桥联配位连接起来,其端位各与1个2-(4-甲基苯甲酰基)苯甲酸根和1个2,2′-联吡啶分子配位,整个分子形成了双核结构。测定了标题配合物的荧光和磁性,结果表明:当激发波长为608 nm时,配合物在472和476 nm处有2个较强的荧光发射峰;在2~100 K,配合物具有顺磁性。     

2,3,7-三羟基-9-(3,5-二氯)水杨基荧光酮与锰(Ⅱ)显色反应的研究及应用

研究了在阳离子表面活性剂溴化十六烷基三甲胺(CTAB)存在下,2,3,7-三羟基-9-(3,5-二氯)水杨基荧光酮(DCSAF)与Mn2+的显色反应和光谱性能。结果表明,在pH=9.07的Na2HPO4-KH2PO4缓冲溶液中,Mn2+与DCSAF形成摩尔比为1∶2的三元配合物。该配合物最大吸收峰位于550nm处,表观摩尔吸光系数ε=1.92×105L.mol-1.cm-1,Mn2+含量在0～0.70μg/5mL范围内符合比耳定律。建立的分析方法用于钢样中微量Mn2+的测定,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…     

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.     

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.