Interpenetration
in π‑Rich Mixed-Ligand
Coordination Polymers
- Publication date
- Publisher
Abstract
Structural and chemical influences
on interpenetration have been
investigated through the preparation and structural analysis of a
series of seven chiral coordination polymers using a phenylalanine-substituted
naphthalenediimide ligand (H<sub>2</sub>PheNDI). The reaction
of H<sub>2</sub>PheNDI with Mn<sup>II</sup> or Cd<sup>II</sup> and
a range of linear dipyridyl-based coligands forms a series of coordination
polymers which vary greatly in terms of their topologies and interpenetration
while largely retaining a common metallomacrocyclic motif. The metallomacrocyclic
motif is found in a tube-like 1D coordination polymer <i>poly</i>-[Cd(bipy)(OH<sub>2</sub>)(PheNDI)] (<b>2</b>) and a closely related 2D polythreaded network <i>poly</i>-{[Cd<sub>2</sub>(bipy)<sub>2</sub>(PheNDI)<sub>2</sub>][Cd(bipy)(DMF)<sub>1.5</sub>(NO<sub>3</sub>)<sub>2</sub>(OH<sub>2</sub>)<sub>0.5</sub>]} (<b>3</b>) which are synthesized as pure phases under slightly different conditions.
The longer 1,2-di(4-pyridyl)ethylene (dpe) ligand gives rise
to a 2D coordination polymer <i>poly</i>-[Cd<sub>4</sub>(DMF)(dpe)<sub>4</sub>(OH<sub>2</sub>)<sub>2</sub>(PheNDI)<sub>4</sub>] (<b>5</b>) in which the metallomacrocycles
are connected only “sideways” rather than as a tube.
This difference allows for 2-fold 2D → 2D interpenetration,
between two crystallographically distinct sheets, whereby the dpe
passes through the metallomacrocycle, assisted by face-to-face aromatic
interactions. The use of a larger dipyridyl ligand, <i>N</i>,<i>N</i>′-bis(4-pyridyl)naphthalenediimide
(4pyNDI), yielded 3D coordination polymers with distorted pcu topologies
of the form <i>poly</i>-[M<sub>2</sub>(PheNDI)<sub>2</sub>(4PyNDI)<sub>2</sub>] (M = Cd, <b>6</b>; Mn, <b>7</b>) which contain neither the metallomacrocyclic motif nor
interpenetration
