MS36-P09 Giant Organometallic Molecular Containers Alexander Virovets (Institute of Inorganic Chemistry, Dept. of Chemistry and Pharmacy, University of Regensburg, Regensburg, Germany) Eugenia Peresypkina (Institute of Inorganic Chemistry, Dept. of Chemistry and Pharmacy, University of Regensburg, Regensburg, Germany) Manfred Scheer (Institute of Inorganic Chemistry, Dept. of Chemistry and Pharmacy, University of Regensburg, Regensburg, Germany)email: avvirovets@yahoo.comOne of the most outstanding and challenging areas in the modern coordination chemistry is the rational design of giant supramolecules built up from metal atoms connected to each other via polytopic organic or organometallic ligands resulting into large hollow cages. During last decade we have been investigating the chemistry of pentaphosphaferrocenes, [CpRFe(η5-P5)] (CpR = η5-C5R5, R = Me (Cp*), Me4Et (Cpx), CH2Ph (CpBn), PhC4H9 (CpBIG)). Being stable in inert atmosphere, these organometallic compounds proved to be very attractive as versatile building blocks for the rational design of giant supramolecules with an inorganic core built up from Cu+ and Ag+ cations coordinated to the phosphorus atoms of the cyclo-P5 ligands [1-3] (Fig. 1). Varying the nature of R, counterions and synthetic conditions, we obtained, in astonishingly high yields, hollow or multishell supramolecules of 2.1 – 4.6 nm in diameter alongside with the first coordination polymers with such supramolecules as nodes (Fig. 1c,f). Special crystallization techniques allow obtaining the single crystals suitable for the X-ray diffraction study using laboratory diffractometers or synchrotron radiation, which is accompanied by NMR studies in solid state and solution.
The central cavity of the hollow supramolecules (reaching 0.60 – 1.35 nm) can include various guest molecules (Fig. 1). Host supramolecule can often be adjusted to the size, shape and charge of the guest molecule. Thus, we succeeded in encapsulation of metastable molecules of white phosphorus (P4) and yellow arsenic (As4), various metallocenes (e.g., Cp2Fe, Cp2Ni, CpVC7H7) and triple-decker complexes (e.g. [(CpCr)25-As5)] and [(CpMo)23-P3)(η-PS)]), as well as cage molecules (C60, adamantane, o-carborane, P4S3, P4Se3) (Fig. 1a-e). The anionic and cationic species also can be encapsulated, like, e.g., the cobaltocenium cation into the negatively charged supramolecule in [CoCp2]+3{[CoCp2]+@[{Cp*FeP5}8Cu24.25Br28.25(CH3CN)6]4} [2] (Fig. 1a).
The analysis of the host-guest interactions allowed us to reveal their novel types, namely, P5···P5 and C5···P5 π-π-stacking between the cyclo-P5 ligands of the supramolecular host and Cp*FeP5 or Cp-containing guest molecules. Usually the guest molecules are disordered, statically or dynamically depending on their nature. Thus, the way of disorder of ferrocene molecule in the central cavity of supramolecular host in [FeCp2]@[{Cp*FeP5}8Cu19.5Br19.5] proved to be temperature-dependent in a range between 5 and 243 K (Fig. 1e).
This work was supported by the SELFPHOS grant ERC-2013-AdG-339072. Parts of these investigations were carried out at PETRA III synchrotron source at DESY, a member of the Helmholtz Association (HGF).
References:

[1] Heindl, C. et al (2017) Angew. Chem. Int. Ed. 56, 13237-13243.

[2] Peresypkina, E. et al (2018) Chem.-A Eur. J. 2018, 24, 2503 – 2508.

[3] Heindl, C. et al (2015) J. Am. Chem. Soc. 137, 10938–10941
Keywords: self-assembly, host-guest compounds, pentaphosphaferrocene