Nitro­sonium complexation by the tetra­phospho­nate cavitand 5,11,17,23-tetra­methyl-6,10:12,16:18,22:24,4-tetra­kis­(phenyl­phospho­nato-κ(2) O,O)resorcin(4)arene

The crystal structure of a new supra­molecular complex between the tetra­phos­pho­nate cavitand 5,11,17,23-tetra­methyl-6,10:12,16:18,22:24,4-tetra­kis(phenyl­phospho­nato-κ(2) O,O′)resorcin(4)arene and the nitrosyl cation NO(+), as the BF(4) (−) salt, is reported. The complex, of general formula [(C(56)H(44)P(4)O(12))(NO)]BF(4)·CH(2)Cl(2) or NO@Tiiii[H, CH(3), C(6)H(5)] BF(4)·CH(2)Cl(2), crystallizes in the space group P-1. The nitrosyl cation is disordered over two equivalent positions, with occupancies of 0.503 (2) and 0.497 (2), and inter­acts with two adjacent P=O groups at the upper rim of the cavitand through dipole–charge inter­actions. In the lattice, the cavitands are connected through a series of C—H⋯π inter­actions involving the methyl and methyl­enic H atoms and the aromatic rings of the macrocycle. The structure is further stabilized by the presence of C—H⋯F inter­actions between the hydrogen atoms of the cavitands and the F atoms of the tetra­fluorido­borate anion. As a result of the disorder, the lattice di­chloro­methane mol­ecules could not be modelled in terms of atomic sites, and were treated using the PLATON SQUEEZE procedure [Spek (2015 ▸). Acta Cryst. C71, 9–18]. The complexation process has also been studied in solution through NMR titrations.