Spiro molecules

These latter two techniques are important both for spiro molecules in which the rings containing the common atom are of different constitution and for ring assembly compounds. Additionally, note that in many instances the other distinct types of nomenclature that had been introduced earlier [Cartesian (in Chapter 1) and cylindrical (in Chapter 3)] may be interconverted in much the same way as the different types of coordinate systems in geometry may be interconverted. 

Spiro-DAMP (27) was slightly more potent at Mg muscarinic receptors than at Mg receptors. It was proposed that the geometry of the spiro-molecule might reflect the receptor-bound conformation of 4-DAMP (26) this conformation differs from that observed in the crystal structure of 4-DAMP. 

Chemical and electro-oxidation of this spiro molecule were studied using electrochemical methods and UV-visible absorption spectroscopy [11,36]. The hep-tamer segments were oxidized sequentially by using FeCls to produce the mono radical cation, the bis-(radical cation), the radical cation/dication and the bis-(dication) respectively (Scheme 14.13). 

Comparison of the experimental data of the spiro molecule (36 in Scheme 14.10) with those obtained for the heptamer oligomer (34 in Scheme 14.9) indicates evidence of some interaction between the neutral and the radical cation of orthogonally positioned heptamer. However, no significant electronic interaction was found between these segments when they were both in the same electronic state (neutral, radical cation or dication states). Only some weak magnetic coupling between the oxidized segments was noted. 

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