A,C-Bridged Calix[6]arene： Relationship between the Length of Bridge and Conformation

Three new A,C-diamide bridged p-tert-butylcalix[6]arenes were synthesized from p-tert-butylcalix[6]arenes by bridging ClCH2CONH(CH2)nNHCOCH2Cl(n=3,4,6) in acetonitrile using K2CO3 as a base in 17%-25% yields.It was found that the bridged calix[6]arenes with shorter bridges (n=2,3,4 in N′,N′-bischloroacetodiamines) adopt cone conformation, but the last one (n=6) adopts alternate conformation, i.e., accompanying the lengthening of bridge, the conformation of A,C-bridged calix[6]arenes changes from cone to alternate.     

化学电离–气相色谱–串联质谱法测定卷烟侧流烟气中的4种烟草特有亚硝胺

建立了化学电离–气相色谱–串联质谱法测定卷烟侧流烟气中4种烟草特有亚硝胺(TSNAs)的方法。采用吸烟机对卷烟进行抽吸,利用鱼尾罩和剑桥滤片对卷烟侧流烟气进行捕集,用稀盐酸溶液进行鱼尾罩洗涤和剑桥滤片萃取,萃取液经阳离子交换固相萃取柱净化,采用氨水甲醇溶液洗脱,洗脱液经氮气吹干后用二氯甲烷定容至1 mL,过滤膜后检测,利用色谱峰面积内标法定量。4种TSNAs的质量浓度在1～500 ng/mL范围内与各目标物和内标的色谱峰面积比线性关系良好,相关系数均大于0.999 1,检出限为0.16～0.35 ng/mL。加标回收率为80.8%～107.4%,检测结果的相对标准偏差为3.2%～6.8%(n=6)。     

杯[4]单硫(硒)杂冠-5的合成及其对金属离子的识别性能研究

从简单无机硫、硒化合物直接合成冠醚环上含硫、硒杂原子的杯[4]单硫杂冠-5及杯[4]单硒杂冠-5;化合物的结构经¹HNMR、MS及元素分析确证.并研究了它们对Na⁺,K⁺,NH⁴⁺,Co²⁺,Ni²⁺,Ag⁺及Hg²⁺的两相萃取性能,发现其对Ag⁺、Hg²⁺有较好的识别能力.