S1 One-pot formation of hydrazide macrocycles with modified cavities: An example of pH-sensitive unimolecular cation channels Pengyang Xin,* Si Tan, Yonghui Sun, Qiaojv Ren, Wenpei Dong, Jingjing Guo, Tao Jiang and Chang-Po Chen* Henan Engineering Laboratory of Chemical Pharmaceuticals & Biomedical Materials, Henan Key Laboratory of Organic Functional Molecule and Drug Innovation, Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan 453007, China. *To whom correspondence should be addressed: pyxin27@163.com; changpochen@yahoo.com. Contents 1. General S2 2. Synthetic procedures and characterization data for 1 S2 3. Procedures for proton transport experiments S10 4. Procedures for patch clamp experiments S11 5. References S16 Electronic Supplementary Material (ESI) for ChemComm. This journal is © The Royal Society of Chemistry 2017