Controlling the assembly of cyclotriveratrylene-derived coordination cages

Abstract

A review of the emerging field of cyclotriveratrylene-derived coordination cages is presented. Ligand-functionalised cyclotriveratrylene (CTV) derivatives self-assemble with a range of metal cations to afford coordination cages, polymers and topologically non-trivial constructs, such as [2]catenanes and a self-entangled cube. Increased control over their self-assembly allows for the controlled and predictable formation of well-defined coordination cages for application in host-guest and recognition chemistry, with surfactant binding and single-crystal-to-single-crystal (SCTSC) uptake of small-molecule guests being observed.

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

“…CTV and its analogues have also demonstrated an affinity for globular, electron-poor guests, such as fullerenes and carboranes, which form "ball-in-socket" superstructures. Therefore, study of interactions of cyclotriveratrylene and its analogues with weakly-coordinating carboranes and metallacarboranes is very exciting [78].…”

“…CTV and its analogues have also demonstrated an affinity for globular, electron-poor guests, such as fullerenes and carboranes, which form "ball-in-socket" superstructures. Therefore, study of interactions of cyclotriveratrylene and its analogues with weakly-coordinating carboranes and metallacarboranes is very exciting [78]. Cyclotriveratrylene (CTV) and its analogues (Scheme 3) represent a class of shape-persistent C 3 -symmetric molecular hosts derived from the tribenzo[a,d,g]cyclononatriene scaffold.…”

Tris-N-alkylpyridinium-functionalised cyclotriguaiacylene hosts as axles in branched [4]pseudorotaxane formation

“…Tris-(isonicotinoyl)cyclotriguaiacylene has been previously reported as a ligand for crystalline coordination polymers 20,21 and cagespecies. 18 N-alkylation was achieved through the reaction of tris-(isonicotinoyl)cyclotriguaiacylene with an excess of the appropriate alkyl bromide in the presence of KI, to give cationic cavitand molecules with three N-ethyl-pyridinium -butyl-pyridinium (L3 3+ ) and N-octyl-pyridinium (L4 3+ ) moieties in good yields, Scheme 1. Finkelstein conditions were used, employing sub-stoichiometric KI as the nucleophilic catalyst, which rendered the desired N-alkylpyridinium compounds as a mixture of bromide and iodide salts.…”

“…16 The hydroxyl groups are easily functionalised, and there is a rich chemistry of tritopic CTG extended-arm CTG derivatives that have found great utility in host-guest chemistry and in the construction of both organic and metal-organic cages and assemblies. [16][17][18] There are few examples of molecular hosts being used as structured branched axles for pseudorotaxane or rotaxane formation, the best known are the tetra [2]rotaxanes reported by Böhmer and co-workers which are capsule-like heterodimers with urea-axle functionalisation on one calix [4]arene. 19 …”

Chiral Self-Sorting in Truxene-Based Metallacages

“…Coordination-driven self-assembly methodology has been extensively used during the last few decades to construct bi-or tri-dimensional discrete architecture [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17]. Beyond the challenge of producing more and more sophisticated compounds, special attention has been given to functional architectures that are responsive to an external stimulus such as light [18][19][20][21][22], redox [23][24][25][26][27][28][29][30][31], or the addition of a chemical [32] in order to target original properties [33][34][35][36][37][38][39][40][41].…”