Synthesis, structures and full characterization of p-tert-butylcalix[5]arene mono-, di-, tri- and pentaanionic ligand precursors

Interaction of para-tert-butylcalix[6]arene molecules in Langmuir films with cadmium ions and their effects on molecular conformation and surface potential

“…[1][2][3] Due to their cone-like structure [1][2][3] and the presence of phenol oxygen donor atoms, [1][2][3][4] calixarenes may be complexed with metal ions or incorporate charged and neutral molecules. [1][2][3][4][5] With such properties, calixarenes have been used in detecting metallic ions, such as alkaline [6][7][8] and alkaline earth [8][9][10] metals, cadmium, [10][11][12] copper, 7,13,14 and for incorporating neutral molecules, [15][16][17][18][19][20] including dopamine, 15 volatile organic compounds 16 and aminoacids. 17 They have also been studied in biological membranes, [18][19][20] and in the formation of molecularly organized films using self-assembled monolayers [21][22][23] and LangmuirBlodgett (LB) [6][7][8][9][10...…”

“…10 Ye et al 13 observed trimers of p-tert-butylthiacalix [4]arene and Cu 2+ ions in Langmuir and LB films, where the area per molecule at the air/water interface increased due to electrostatic repulsion among Cu 2+ ions bound to the complex. Hg 2+ ions coordinated with p-tert-butylthiacalix [4]arene through the bridgingsulfur atom and its phenolic oxygen atoms, and were not located inside the calixarene cavities.…”

“…10 Ye et al 13 observed trimers of p-tert-butylthiacalix [4]arene and Cu 2+ ions in Langmuir and LB films, where the area per molecule at the air/water interface increased due to electrostatic repulsion among Cu 2+ ions bound to the complex. Hg 2+ ions coordinated with p-tert-butylthiacalix [4]arene through the bridgingsulfur atom and its phenolic oxygen atoms, and were not located inside the calixarene cavities. 24 The presence of Cu 2+ ions in the subphase induced a shift to lower areas per molecule and a decrease in collapse pressure of tetraoxocalix [2]arene [2]triazine, with the corresponding LB films being used as voltammetric sensors to detect Cu 2+ ions.…”

“…24 The presence of Cu 2+ ions in the subphase induced a shift to lower areas per molecule and a decrease in collapse pressure of tetraoxocalix [2]arene [2]triazine, with the corresponding LB films being used as voltammetric sensors to detect Cu 2+ ions. 25 Dong et al 11 produced a sensor to measure trace levels of Tl + and Cd 2+ made with an LB film of p-tertbutylthiacalix [4]arene, where the use of differential pulse stripping voltammetry led to a detection limit for Cd 2+ of 2 Â 10 À8 mol L À1 . Recognition of metal ions through calixarenes has been studied theoretically 26,27 and experimentally, [6][7][8][9][10][11][12][13][14]24,25 in many cases motivated by the concern with the environment as heavy metals accumulate in biological systems.…”

Cu-Catalyzed Arylation of Bromo-Difluoro-Acetamides by Aryl Boronic Acids, Aryl Trialkoxysilanes and Dimethyl-Aryl-Sulfonium Salts: New Entries to Aromatic Amides

“…All used boronic acids 2 and some aryl trialkoxysilanes 3 are commercially available and were purchased from appropriate vendors. 2-Bromo-2,2-difluoroacetamides [ 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 ], 1, 2-iodo-2,2-difluoroacetamides [ 54 ], aryl trialkoxysilanes 3 [ 58 , 59 , 60 , 61 , 62 , 63 , 64 ], sulfonium salts 4 [ 65 , 66 , 67 ], and calixarenes L1 , L2 [ 68 , 69 ] are known compounds in the literature and were prepared according to the known literature, and the spectral data are identical with the corresponding literature. Copies 1 H and 13 C-NMR spectra are placed in Supplementary Materials .…”