Rational Design of a Coordination Cage with a Trigonal‐Bipyramidal Shape Constructed from 33 Building Units

Abstract

According to plan: C2‐ and C3‐symmetric ligands are essential to the rational design of a low‐symmetry coordination cage with the outer shape of a trigonal bipyramid (view along the C3 axis shown; green: Pd, red: ligand, blue: 5,5‐diethylbarbiturate). The characterization of an intermediate gives insight to the mechanism of formation.

Sn<sup>IV</sup> and Zr<sup>IV</sup> Compounds of a <i>C</i><sub>3</sub>-Symmetric Ligand with Amine [ONN] and [ONNO] Coordination Sites

“…They have been used for the construction of various supramolecular architectures [7] [8] [9] [10] [11]. Nonetheless, condensation reactions are reversible and during our work with these hydrazone derived ligands, we observed their decomposition especially under extreme conditions.…”

Rational Design of a Double‐Walled Tetrahedron Containing Two Different C3‐Symmetric Ligands

“…This design principle can be used for the construction of even more complex coordination compounds with additional ligands, such as octahedral or trigonal-bipyramidal cages. [7,8] However, we are just starting to understand the reactions that take place when the ligands and metal centers do not match exactly, and a prediction of the products is not usually possible. Herein, we report the rational design of the first double-walled tetrahedron containing a ligand-metal pair that is not perfectly matched.…”

“…The overall charge of 4À is compensated by four triethylammonium ions, one of which is located inside the cage. It is disordered with an additional water molecule that is fixed to the NH group by a hydrogen bond (d(N À H···O) = 1.57 (8) ). Owing to the large degree of disorder outside the cage (about 24 650 3 or 34 % of the overall cell volume is occupied by countercations and solvent molecules), only the central N atoms of the countercations could be found in the Fourier difference synthesis.…”

Gezielte Synthese eines doppelwandigen Tetraeders, aufgebaut aus zwei unterschiedlichen C3‐symmetrischen Liganden

“…Das Baukastenprinzip kann sogar auf kompliziertere Systeme angewendet werden: So führt der zusätzliche Einbau von zweifach verbrückenden Liganden zur Bildung von Koordinationskäfigen mit der äußeren Gestalt eines Oktaeders oder einer trigonalen Bipyramide. [7,8] : 0.97 [9] ). Dieser kleinere Radius würde dazu führen, dass die Tetraederflächen einander zu nahe kommen, was sterisch ungünstig ist.…”