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A novel [2]pseudorotaxane of cucurbit[6]uril(CB[6]) and 1-butyl-3-methyl-imidazolium bromide ([C4mim]Br) was synthesized by directly mixing the host and the guest molecules in non-aqueous system. Structural characterizations of the [2]pseudorotaxane were carried out by 1D, 2D NMR and X-ray crystallography techniques both in solution and in crystal structure. The crystal structure demonstrated that CB[6] and [C4mim]Br formed a complex with the ratio 1:1, in which one guest [C4mim]Br was included inside the CB[6], while two other [C4mim]Br molecules were free and surrounded the [2]pseudorotaxane as solvent molecules, which could stabilize the crystal structure through hydrogen bonds. Moreover, parallel solvent channels consisting by free [C4mim]Br molecules occupied the pores among the frame of the pseudorotaxanes and formed zigzag lines in the crystal structure. [C4mim]Br can serve as not only the guest reactant but also the solvent in the formation of [2]pseudorotaxane formation.

A pseudorotaxane of cucurbit[6]uril (CB[6]) with guest molecule N,N′-hexamethylenebis (pyrazinyl perchlorate) (BPHP) was synthesized and characterized by 1H NMR spectra, IR, single crystal X-ray diffraction analysis and thermogravimetric analysis. The structure of the pseudorotaxane (CB[6]·BPHP) is stabilized by host-guest hydrogen bonds. Self-assembly of the pseudorotaxane produces infinite one-dimensional and two-dimensional networks with intermolecular hydrogen bonds. In the molecular packing of the CB[6]·BPHP, ClO4−(H2O)2 water clusters serve as bridges to associate these pseudorotaxanes and form three-dimensional networked pseudopolyrotaxane.

A novel series of morpholinium salts, N-alkyl-N-methylmorpholinium salts (Mor1,nX, n=10, 12, 14, 16, X=BF4−) and Bronsted acidic N-hexadecyl morpholinium salts (Mor16X, X=BF4−, CH3SO3− and p-CH3C6H4SO3−) were synthesized. And their mesomorphic properties were characterized by differential scanning calorimetry and polarized optical microscopy. The single crystal X-ray diffraction and the detailed temperature dependent small angle X-ray diffraction were used to investigate the molecular structure of Mor1,16BF4. These results suggested that the favor the formation and stabilization of mesogenic compounds. And hydrogen bonds between the BF4− and morpholinium cations contributed to the conformational change of phase transition of Mor1,16BF4.