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The synthesis of aliphatically bridged [1](n)rotaxanes and (n)pretzelanes in preparative yields and the dependency of their chiroptical properties on the length (n) of their bridge are reported. A cycloenantiomeric bis(sulphonamide)[2]rotaxane with a sulphonamide group in its axle and its wheel was intramolecularly dialkylated by homologous bifunctional oligomethylene reagents to form chiral [1](n)rotaxanes bearing bridges of different lengths (n) between the axle and the wheel. Intramolecular dialkylation by 1,omega-dibromoalkanes of a topologically chiral bis(sulphonamide)[2]catenane with a sulphonamide group in both of the macrolactam rings leads to pretzel shaped molecules ((n)pretzelanes) with homologous bridges between the two macrocycles. Their yields decrease with decreasing length of the bridge. The shortest bridge isolated so far in reasonable amounts consists of six methylene groups ((6)pretzelane). Remarkably, a covalent connection of axle and wheel in a [2]rotaxane was successful even with much shorter bridges-down to only three methylene groups ([1](3)rotaxane). The structural changes of the [1](n)rotaxanes with decreasing bridge length is expressed by an increasing high-field shift in the 1H NMR spectra. Enantiomeric resolution of the racemates of both series was achieved in seven cases for the [1](n)rotaxanes and two for the (n)pretzelanes by use of chiral HPLC columns. The circular dichrograms of both compound families show a strong dependency on the length of the bridge. However, the shortest bridges displayed some additional unexpected deviations. A new specification of the absolute configuration of supramolecules, such as [n]catenanes, [n]rotaxanes and (n)pretzelanes is introduced together with some nomenclature additions.

New chiral dendrimers with planar-chiral, cycloenantiomeric and topologically chiral cores were prepared in yields of up to 90% starting from a racemic 4-hydroxy[2.2]paracyclophane, a [2]rotaxane with sulfonamide groups in the wheel and axle positions and [2]catenane with a sulfonamide group in both of its macrocycles. The separation of the racemic mix-

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The IUPAC notation system does not provide a nomenclature for interlocked, mechanically linked molecules beyond very simple catenanes and rotaxanes [1]. Whereas simple catenanes and rotaxanes like 1 and 2 can be named explicitly as [2]catenane and [2]rotaxane according to IUPAC, [1] one already brakes new ground with the naming of additionally bridged types of compounds -such as "pretzelanes" 3 [2] which are easily accessible nowadays.Abstract. We introduce a systematic nomenclature for mechanically linked molecules -such as catenanes, rotaxanes, and assemblies derived from these structural elements -which comes up to the increasing complexity of already synthesized interlocked molecules and the ones to be expected in future. Like in the naming of other substance classes (polycycles, ly used by chemists, if they are constructed from easily comprehensible characteristic parts, basing on immediately convincing rules. Like in the former cases mentioned above a new nomenclature seems to be sensible, which contains -analogously to the bicyclo nomenclature of von Baeyer and to the crown compounds, cyclophanes [3], podands [4], and dendrimers [5] -a characteristic part of the name, for example in brackets, so that it indicates the "overall structure" and its most important features, such as e.g. the type, number, and sequence of the mechanical bonds particularly relevant in this case. phanes, crown compounds, podands, dendrimers) we attach importance to the fact, that certain units in the name, e.g. expressions in brackets, quickly convey an idea of the molecular architecture. Furthermore, this modular nomenclature reveals as many analogies to the IUPAC nomenclature as possible.