1 6 diaminohexane

All solvents used were of Milli‐Q®, spectroscopic or HPLC‐grade. Absolute ethanol was purchased from VWR Chemicals. Tetrahydrofurane was dried and distilled over potassium. Trifluoroacetic acid was purchased from Carl Roth (Germany) in PEPTIPURE® ≥99,9 % quality. Sulfuric acid (≥95 %, Fisher Chemical), hydrochloric acid (37 %, Anal. Reag. Gr., Fisher Chemical), acetic acid (Anal. Reag. Gr., ChemSolute), methyl red (Alfa Aesar), carbonyldiimidazole (97 %, Alfa Aesar), 1,3‐diaminopropane (for synth., Merck), 1,6‐diaminohexane (98 %+, Alfa Aesar) and 1,8‐diaminooctane (98 %, Alfa Aesar) were used as received. 1,8‐Diazabicyclo[5.4.0]undec‐7‐ene was dried over calciumchloride (anhydrous, technical, Bernd Kraft) and distilled in vacuo. 1,2‐Diaminoethane was distilled in vacuo.
UV‐vis measurements were performed on a Thermo Scientific™ Evolution™ 220 UV‐Vis‐spectrophotometer. If not stated otherwise, the measurements were done with 100 nm/min and a resolution of 1 nm.
NMR‐measurements were performed on a Jeol EZC 500. ¹H‐¹H‐NOESY NMR spectra were measured with a mixing time of 500 ms. 1D‐Spectra were analysed with MestreNova 9. 2D‐Spectra were analysed with Delta 5.3 by JEOL. NMR spectra can be found in the ESI.

4,4′-Diaminodiphenyl methane and triethyl phosphate were received from Tokyo Chemical Industry (TCI), and were used as received without further purification. Epichlorohydrin(±) was purchased from Sigma Aldrich and used as purchased without further purification. 1,6-Diaminohexane was obtained from Alfa Aesar. Dimethylformamide (DMF) was purchased from Samchun Chemicals (Seoul, Korea). 2-CEES gas was supplied by Research institute of Gas Analytical Science (RIGAS).
Fourier transform infrared (FT-IR) spectra were recorded on a Vertex70 spectrometer (Bruker Optics, MA, USA) equipped with a diamond attenuated total reflection unit. QCM was recorded on a CHI400C.