Crystal structure of a host-guest complex between mephedrone hydro-chloride and a tetra-phospho-nate cavitand

A new supra-molecular complex (I) between the tetra-phospho-nate cavitand Tiiii[C₃H₇,CH₃,C₆H₅] [systematic name: 2,8,14,20-tetra-propyl-5,11,17,23-tetra-methyl-6,10:12,16:18,22:24,4-tetra-kis-(phenyl-phospho-nato-O,O')resorcin[4]arene] and mephedrone hydro-choride {C₁₁H₁₆NO⁺·Cl^-; systematic name: meth-yl[1-(4-methyl-phen-yl)-1-oxopropan-2-yl]aza-nium chloride} has been obtained and characterized both in solution and in the solid state. The complex of general formula (C₁₁H₁₆NO)@Tiiii[C₃H₇,CH₃,C₆H₅]Cl·CH₃OH or C₁₁H₁₆NO⁺·Cl^-·C₆₈H₆₈O₁₂P₄·CH₃OH, crystallizes in the monoclinic space group P2₁/c with one lattice methanol mol-ecule per cavitand, disordered over two positions with occupancy factors of 0.665 (6) and 0.335 (6). The mephedrone guest inter-acts with the P=O groups at the upper rim of the cavitand through two charge-assisted N-H⋯O hydrogen bonds, while the methyl group directly bound to the amino moiety is stabilized inside the π basic cavity via cation⋯π inter-actions. The chloride counter-anion is located between the alkyl legs of the cavitand, forming C-H⋯Cl inter-actions with the aromatic and methyl-enic H atoms of the lower rim. The chloride anion is also responsible for the formation of a supra-molecular chain along the b-axis direction through C-H⋯Cl inter-actions involving the phenyl substituent of one phospho-nate group. C-H⋯O and C-H⋯π inter-actions between the guest and adjacent cavitands contribute to the formation of the crystal structure.