Nuclear magnetic resonance (NMR)
spectroscopy was done using a Bruker Avance II 600 MHz (Germany) spectrometer.
Electron impact ionization (EI) mass spectrometry was performed using
a Thermo Scientific DFS high-resolution GC/MS (Germany) mass spectrometer.
Electrospray ionization in high-resolution mode was done using a Waters
Xevo G2-S QToF, (Germany) LC MS/MS mass spectrometer. The single crystal
data collections were made on Bruker X8 Prospector (Germany) and Rigaku
Rapid II (Japan) diffractometers. ITC studies were carried out on
an Affinity ITC, TA Instruments. DLS analysis was done on a Zetasizer
Nano Range, Malvern PANalytical system (U.K.). Flash column chromatography
was performed using silica gel (Silica gel 60, 40–60 mesh ASTM,
EMD Millipore, Merck KGaA, Germany). DMF is distilled before use.
All other reagents and solvents were of reagent grade purity and used
without further purification. The synthesis of 1,4-bis(2-bromoethoxy)benzene,
1-(1,4-bis(2-bromoethoxy))-2,3,4,5-dimethoxy-pillar[5]arene, 1,1-Pillar-a, 1,2-(1,4-bis(2-bromoethoxy))-3,4,5-dimethoxy-pillar[5]arene, 1,2-Pillar-a, and 1,3-(1,4-bis(2-bromoethoxy))-2,4,5-dimethoxy-pillar[5]arene, 1,3-Pillar-a have been previously discussed.31 (link)