Synthesis and characterization of indolocarbazole-quinoxalines with flat rigid structure for sensing fluoride and acetate anions.
A new series of indolocarbazole-quinoxalines (ICQ, receptors 6 and 7) are prepared and characterized for effective fluoride and acetate anion sensing. The new indole-based system has a highly flat rigid structure with a large pi system, and exhibits high binding affinity and sensitivity for acetate and fluoride anions. Receptors 6 and 7 give abundant and unique spectral features in dimethyl sulfoxide (DMSO). Both fluoride and acetate anions cause a bathochromic shift of the absorption peaks of receptor 7 in DMSO, whereas only fluoride anion results in a remarkable shift of the absorption peak of receptor 6 in DMSO. Receptors 6 and 7 can also operate as efficient colorimetric sensors for naked-eye detection of fluoride and acetate anions, and their combined use also offers a simple way for distinguishing these two anions by the naked-eye. The analysis of a Job's plot for the binding of receptor 7 and F(-), single crystal structures of 7.TBACl and 7.TBACH(3)COO confirm 1:1 binding stoichiometry. Notably, the ICQ system offers novel and excellent receptors for acetate anion both in solution and in crystalline solid through the formation of two hydrogen bonds.
Wang
Ting
T
Research Center for Analytical Sciences, College of Chemistry, Nankai University, 94 Weijin Road, Tianjin, 300071, China.
Bai
Yu
Y
Ma
Liang
L
Yan
Xiu-Ping
XP
D000085:Acetates / Q000737:chemistry*; D000838:Anions / Q000737:chemistry; D002227:Carbazoles / Q000737:chemistry*; D005459:Fluorides / Q000737:chemistry*; D007211:Indoles / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D011810:Quinoxalines / Q000138:chemical synthesis* / Q000737:chemistry; D013053:Spectrophotometry; D014961:X-Ray Diffraction
D000085:Acetates; D000838:Anions; D002227:Carbazoles; D007211:Indoles; D011810:Quinoxalines; C041514:carbazole; C030374:indole; D005459:Fluorides