Nomenclature for Catenanes, Rotaxanes, Molecular Knots, and Assemblies Derived from These Structural Elements

Abstract

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.

Multidisciplinary Investigation of Atypical Inclusion Complexes of β-Cyclodextrin and a Phospholipase-A2 Inhibitor

“…Formation of a complex of β‐cyclodextrin with 6‐ p ‐toluidinylnaphthalene‐2‐sulphonate, was found to require 7 min to reach equilibrium with stirring 13. Formation of a [2]‐pseudorotaxane,14 an inclusion complex of α‐cyclodextrin and decamethylene‐bis‐(trimethylammonium), required 50 min to reach equilibrium, and the complex formed could be separated via HPLC. The slow rate of this complexation reaction ( k f = 0.036 s −1 M −1 ) was attributed to a high activation energy (∼64 kJ/mol −1 ) rather than a high stability constant (1540 mol −1 ).…”

Generation of a Dynamic System of Three‐Dimensional Tetrahedral Polycatenanes

“…1 H NMR analysis of equilibrated DCLs revealed the binding of B to the cage to be best described by a non‐cooperative model,11 yielding a crown ether to cage‐incorporated NDI binding constant of 794±34 L mol −1 . Controlling crown ether and cage concentrations was found to determine the constitution of the library, and allowed the preparation of the fully‐saturated tetrahedral [7]catenane 12…”

An Introduction to the Mechanical Bond

“…248 (iii) Kuroda's macrotricyclic homo [2]catenane of quadruply interlocked cages, 249 (iv) a macrobicyclic [3]catenane, also known as a bis [2]catenane, 250 (v) a branched [6]catenane, 135 (vi) a side-chain poly [2]catenane, 251 (vii) a main-chain poly [2]catenane, which was originally introduced by Geerts,252 (viii) a macrotricyclic hetero [2]catenane, introduced by Becher 253 (ix) a macrobicyclic hetero [4]catenane resulting from a collaboration between Vögtle and Sauvage, 254 (x) covalently bridged [2]catenanes, which originated 106 as precatena nes in Schill's directed syntheses, but later became known [255][256][257] as pretzelanes or [2]pseudocatenanes (xi) a doubly threaded macrobicyclic [2]catenane introduced by Becher 258 under the title of a [3]pseudocatenane, a topology also known [259][260][261] as a 'handcuff' catenane, (xii) a [4]pseudocatenane introduced by Chen,262 (xiii) a macrotricyclic hetero [7]catenane arising from a Nitschke-Sanders collaboration, 263 (xiv) Vögtle's cyclic bis [2]catenane, 264 and (xv) Chiu's cyclic tetrakis [2]catenane. 265 The structures of many beautiful MIMs have also been elucidated in the solid state by X-ray crystallography.…”