Naphthalene containing amino-ether macrocycle based Cu(ii) templated [2]pseudorotaxanes and OFF/ON fluorescence switching via axle substitution

Abstract

A new naphthalene containing macrocycle, NaphMC, and a new fluorophoric bidentate linear axle derivative of 5,5'-dimethyl-2,2'-bipyridine (L3) along with two other ligands 1,10-phenanthroline (L1) and 5,5'-dimethyl-2,2'-bipyridine (L2) are explored towards the synthesis of Cu(ii) templated [2]pseudorotaxanes. All ternary complexes are well characterized by ESI-MS, UV/Vis, EPR spectroscopy, elemental analysis and emission spectroscopic studies. Single crystal X-ray diffraction studies confirm the geometry around the Cu(ii) center as a distorted trigonal bipyramid via the contribution of [3 + 2] orthogonal motifs of the wheel (NaphMC) and the bidentate chelating ligands L1 and L2 in the cases of pseudorotaxanes, CuPR1 and CuPR2, respectively. Furthermore, the fluorescence "OFF" state of the fluorophoric axle L3 is achieved via threading it to the Cu(ii) complex of NaphMC, whereas fluorescence switching "ON" is demonstrated by the substitution of L3 of CuPR3 with a stronger chelating ligand L1.

NDI-integrated rotaxane/catenane and their interactions with anions

“…Since the invention of mechanically interlocked molecules (MIMs), exploration of their inherent properties has broadened the areas of molecular sensing, 1 switching, 2 shuttling, 3 catalysis, 4 etc. Consequently, numerous templating strategies, like hydrogen bonding, 5 π–π stacking, 6 anion templation, 7 metal–ligand coordination 8 and other assembly strategies, 9 have been established for the synthesis of functional interlocked architectures.…”

From construction to application of a new generation of interlocked molecules composed of heteroditopic wheels

“…This study assists in finding the most favourable combination of macrocycle, selective metal and chelating ligand to form stable [2]pseudorotaxane. 14,15 Furthermore, the crystal structure analysis confirmed that during ternary pseudorotaxane formation, Ni II and Cu II prefer the corresponding hexa ( P1 ) and penta ( P2 , P3 ) orthogonal coordinations, respectively. Such coordination around the metal is satisfied by the tris amine moiety of the wheel, bidentate axle and solvent molecule wherever applicable (Fig.…”

“…13 To explore metal templation based multi-functional MIMs further, Ghosh and co-workers recently developed several new combinations of heteroditopic macrocycles, i.e. amido-triamine ( W2 ), 14 oxy-ether-triamine ( W3 , W4 ) 15 and oxy ether-Phen-ester ( W5 ) 16 wheels. Using anion templation, Beer and co-workers developed different heteroditopic macrocycles depending on isophthalamide/calix[4]diquinone/triazole/oxy-ether ( W6–W7 , W9 ) motifs.…”

Synthesis and Studies of Dibenzofuran Embedded Bis‐(Calix)‐Pentaphyrins

“…[11][12][13][14][15] In recent times, polyaromatic hydrocarbons/heterocycles (PAHs) were used in place of one or more pyrrole rings of porphyrinoids to generate a new type of polyaromatic embedded porphyrinoids with interesting electronic and coordination properties. [16,17] A perusal of literature revealed that the polyaromatic hydrocarbons/heterocycles such as biphenyl, [18] naphthalene, [19] phenanthrene, [20] fluorene [21,22] bipyridine, [23] phenanthroline, [24] dibenzofuran, [25] dibenzothiophene, [26] and phenothiazine [27] are few such polyaromatic hydrocarbons/heterocycles which have been introduced in place of one or more pyrrole rings of porphyrinoid framework and generated a wide range of very novel PAH embedded porphyrinoids. We used few of these PAH units such as dibenzofuran, dibenzothiophene, benzofuran, benzothiophene, fluorene and phenothiazine and synthesized very novel PAH embedded porphyrinoids which showed unique and interesting electronic and coordination properties.…”