The first chiral bipyridyl-type metalloligands based on aluminum derivatives of cinchonine (CN-H) were synthesized and characterized by single-crystal X-ray diffraction studies. These bischelate complexes, (CN)(2)AlX [X = Cl (1a), Me (1b)] were found to be effective building blocks for the preparation of novel helical nanotubular architectures as well as chiral bimetallic coordination polymers, as demonstrated by the rational synthesis of a helical structure formed by 1a and ZnCl(2). The applied methodology stands as an exemplary strategy for the rational synthesis of chiral metal-organic frameworks through self-organization driven by nonbonding interactions or coordination, which could potentially find applications in enantioselective separations and catalysis.

Dedicated to Professor Stanisław Pasynkiewicz on the occasion of his 80th birthdayA particularly demanding task in the area of hybrid organicinorganic materials has been the engineering of well-defined void nanospaces [1] capable of selectively binding a guest molecule to perform a specific function of the system, such as catalysis, [2] storage, [3] or separation.[4] The most common and effective approach to design and prepare metal-organic frameworks (MOFs) or porous coordination polymers (PCPs) of desired topology and functionality is based on coordination-driven self-assembly, and both the correct choice of metal centers and the engineering of the ligands features, such as size, flexibility, and directionality of binding centers, play a decisive role. [5] An additional level of tailorability in the design of these hybrid materials can be achieved by implementation of metalloligands. [5c, 6] Alternatively, soft noncovalent synthesis from simple molecular metal complex-based building blocks could provide a convenient and economic way to construct noncovalent porous materials (NPMs) with a unique guest-responsive framework, [1f, 7] and this approach is one of the major challenges in chemistry. Molecular metal complexes are potentially very attractive as building units for microporous architectures, as relatively weak intermolecular bonding interactions in these supramolecular structures allow the microcavities to conform to the shape or functionality of the guest molecules. However, construction of robust NPMs based on this alternative strategy is still in its infancy and examples of such materials are very rare, [8] which stems from the inherent propensity of molecular crystals to form architectures of maximal density.[9]Recently, we have been focusing on rational design strategies to replace common bipyridines as N-ditopic organic linkers [10] by metal complexes with pyridyl units, namely cinchonine-based metalloligands. Initially we synthesized bischelate aluminum complexes, XAl(CN) 2 (where CN = deprotonated cinchonine), as novel chiral N,N-metalloligands I (Scheme 1), and demonstrated their excellent capability as metallotectons for noncovalent-interaction-driven selfassembly into novel microporous chiral architectures prone to enantioselective sorption, as well as their coordinationdriven self-organization for constructing coordination polymers of helical topology.[11] Herein, we extend this strategy to dinuclear aluminum-cinchone complexes as novel molecular building blocks II to produce flexible homochiral NPMs. We show that the resulting NPMs can compete with classical MOFs as highly selective adsorbents exhibiting unique properties, such as temperature-triggered adsorption as well as very high affinities for H 2 , CO 2 , and CH 4 .A dimethylaluminum derivative of cinchonine, [Me 2 Al(m-CN)] 2 (1), was prepared in high yield by the addition of 1 equiv of AlMe 3 to a slurry of cinchonine (CN-H) in THF (Scheme 2; for experimental details see the Supporting Information). We note that the synthesis and...

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