Conformational studies on complexes of a diimine containing a (CH2)2 spacer: crystal structures of a double-stranded Zn(II) meso-helicate and an enantiopure Δ-Cu(II) monohelicate
摘要:
Ni(II), Cu(II), Zn(II) and Cd(II) complexes of an N-4-donor Schiff base, containing (CH2)(2) as spacer, have been prepared. The X-ray crystal structures of monohelical Ni(ETs) . H2O and the homochirally crystallised Delta-Cu(ETs), as well as the meso-helicate Zn-2(ETS)(2) . MeCN [H2ETs: N,N'-bis(2-tosylaminobenzylidene)-1,2-diaminoethane] have been solved. In the latter, the ligand behaves as bis-bidentate, displaying a "C"-type arrangement, instead of the typical "S"-type fashion present in bis-helical dinuclear complexes. (C) 2004 Elsevier B.V. All rights reserved.
Sulfonamide-imines as selective fluorescent chemosensors for the fluoride anion
摘要:
报告了有机介质中的两种新型磺酰胺类荧光化学传感器。这两种受体[N,N′-双(2-对甲苯磺酸氨基亚苄基)-1,2-二氨基乙烷和 N,N′-双(2-对甲苯磺酸氨基亚苄基)-1,3-二氨基-2-丙醇]在碱性阴离子的去质子化作用下显示出明显的荧光发射强度变化,并且对氟化物的选择性高于其他无机阴离子,如醋酸盐或磷酸二氢盐。这些结果表明,与以前的文献实例相比,亚胺基团作为分子内氢键受体的存在提高了这些传感器的选择性。分光光度法和分光荧光滴定法以及核磁共振光谱法都证明了这种去质子化机制。此外,还讨论了这两种受体的 X 射线结构。