Tris(pyridylmethylamino)cyclotriguaiacylene Cavitands: An Investigation of the Solution and Solid‐State Behaviour of Metallo‐Supramolecular Cages and Cavitand‐Based Coordination Polymers

Abstract

The synthesis of the three isomeric tris(pyridylmethylamino)cyclotriguaiacylene cavitands is reported, along with the crystal structures of the 2- and 4-pyridyl derivatives. The generality of a previously described [Ag(2){tris(3-pyridylmethylamino)cyclotriguaiacylene}(2)](2+) dimeric capsule motif and the [Ag(4){tris(4-pyridylmethylamino)cyclotriguaiacylene}(4)](4+) tetrahedron with several silver salts was confirmed in the solid state and the corresponding solution species were investigated by NMR spectroscopy. Host-guest interactions in these systems have been probed and these interactions are demonstrated to alter and influence the self-assembly outcome of the reaction. Notably, introduction of larger glutaronitrile guest molecules to the [Ag(4)L(4)](4+) tetrahedron system prevents formation of the tetrahedral structure, resulting instead in the formation of a 4.8(2) coordination network in the solid state. In the absence of templating acetonitrile guests in the [Ag(2)(3)(2)](2+) capsule system, formation of a cage-based one-dimensional coordination polymer is observed.

Silver and Copper Complexes with closo-Polyhedral Borane, Carborane and Metallacarborane Anions: Synthesis and X-ray Structure

“…The centrosymmetric capsule forms through the head-to-head coordination of two ligands to two silver atoms. The silver cation is coordinated by a terminal acetonitrile ligand at an Ag-N distance of 2.321) Å, and three pyridyl groups at Ag-N distances of 2.327, 2.350), and 2.292 Å in a distorted tetrahedral geometry ( Figure 117) [108]. with tris(4-pyridylmethylamino)cyclotriguaiacylene (tris(4-pyamino)CTG) from acetonitrile-2,2,2-trifluoroethanol in the presence of glutaronitrile [108].…”

“…This results in 2D-network structure incorporating roughly rectangular channels. These channels are largely occupied by the globular metallacarbaborane anions and glutaronitrile molecules (Figure 118) [108]. Ag[3,3-Co(1,2-C2B9H11)2] with tris(4-pyridylmethylamino)cyclotriguaiacylene (tris(4-pyamino)CTG) from acetonitrile-2,2,2-trifluoroethanol in the presence of glutaronitrile [108].…”

“…These channels are largely occupied by the globular metallacarbaborane anions and glutaronitrile molecules (Figure 118) [108]. Ag[3,3-Co(1,2-C2B9H11)2] with tris(4-pyridylmethylamino)cyclotriguaiacylene (tris(4-pyamino)CTG) from acetonitrile-2,2,2-trifluoroethanol in the presence of glutaronitrile [108]. The silver cation has a tetrahedral geometry coordinated by three pyridyl moieties from three different molecules of tris(4-pyamino)CTG (Ag-N bond lengths of 2.343(6)-2.369(6) Å) and a monodentate capping glutaronitrile molecule (Ag-N bond length of 2.25(1) Å).…”

Self-assembled Cages and Capsules Using Cyclotriveratrylene-type Scaffolds

“…Rather than an Ag 4 L 4 tetrahedron, this hostguest interaction induces the formation of a 2D coordination polymer. 38 The templation effect of large guests on the self-assembly of these host-type ligands with metals has also been observed for the assembly of the same ligand with Cd(OAc) 2 , where in the absence of a guest discrete species are found, but the addition of bulky orthocarborane promotes formation of a coordination polymer with ortho-carborane bound at each ligand. 4+ assembly is a meso isomer containing both ligand enantiomers, and the ligands only coordinate through two of the three quinoyl groups.…”

“…Here a layer of capsule motifs is created by a combination of hostguest binding of anthracene by the (CTC)¢3(phen) hydrogen-bonded complex along with ππ stacking interactions (Figure 11). 52 A variety of coordination polymers that involve CTV, 53 CTC, 43 or CTV-type tripodal ligands 38,40,5457 have been reported. This is of particular interest because the use of molecular hosts as building units for MOFtype materials allows a hierarchy of potential hostguest interactions through embedded molecular-recognition sites alongside framework cavities and channels.…”