Crystal structure of a supramolecular lithium complex of p-tert-butylcalix[4] arene

Crystals of a supramolecular lithium complex with a calix[4] arene derivative, namely tetramethanollithium 5,11,17,23- tetra-tert-butyl- 25,26,27- trihydroxy- 28oxidocalix[4] arene methanol monosolvate, [Li(CH3OH)(4)](C44H55O4) center dot CH3OH or [Li(CH3OH) 4](+) center dot (calix[4] arene(-))] center dot CH3OH (where calix[4] arene(-) represents a mono- metric unit comprises one mono-anionic calixarene molecule, one Li+ cation coordinated to four methanol molecules, and one methanol molecule included in the calixarene cavity. The calixarene molecule maintains a cone conformation by intramolecular hydrogen bonding between one phenoxide (-O-) and three pendent calixarene hydroxy groups (-OH). The coordinated methanol molecules around the metal cation play a significant role in forming the supramolecular assembly. The crystal structure of this assembly is stabilized by three sets of intermolecular interactions: (i) hydrogen bonds involving the -OH and -O- moieties of the calixarene molecules, the -OH groups of the coordinated methanol molecules, and the -OH group of the methanol molecule included in the calixarene cavity; (ii) C-H center dot center dot center dot pi interactions between the calixarene molecules and/or the coordinated methanol molecules; (iii) OH center dot center dot center dot pi interactions between the calixarene molecule and the included methanol molecule.