PdII and PtII Metal-Directed Self-Assembly of Supramolecular Structures Based on N-Monoalkyl-4,4¢-Bipyridinium Derivatives - Molecular Self-Assembly: Advances and Applications - page 373

Scheme 11.3 Controlling the catenation process by successive addition of

KPF

and 18-crown-6.

6

11.5.3 [3]Catenanes Based on Trans Palladium

Complexes

A slight structural modification at the palladium complex and
ligand allows the synthesis of a new series of [3]catenanes. The
preparation of this type of catenanes from trans -(CH CN) PdCl and

3 2 2

ligand is depicted in Scheme 11.4. The interlocked structures

show a dinuclear Pd

L8

46-membered metallocycle interlocked by
two π-complementary dioxoaryl macrocycles. The catenane was
characterized in solution by means of a NMR study (1D and 2D
experiments). The 1:2 integration ratio between the signals of the
metallomacrocycle and the cyclophane

II

indicates that,
for each metallomacrocyclic component, there are two encircling
cyclophane rings in keeping with the molecular structure of a [3]
catenane. Exchange between the “inside” and “alongside” hydroquinol
rings is fast at room temperature, resulting in an average signal (

BPP34C10

d

= 5.50 ppm) for the aromatic protons of BPP34C10 . The diffusion