N,N,N′,N′,N′,N″,N‴,N‴-Octamethyl-[bi-2,4,6-cycloheptatrien-1-yl]- 3,3′-dicarboxamidinium-Salze: Struktur der meso-Verbindung in Lösung und im Kristall [1] / N,N,N′,N′,N′,N″,N‴,N‴-Octamethyl-[bi-2,4,6-cycloheptatriene-1-yl]- 3,3′-dicarboxamidinium Salts: Structure of the meso-Compound in Solution and in Solid State [1]

Abstract

3,3′-Bicycloheptatrienylamidinium salts 3 have been prepared by oxidative dimerization of 8 ,8 -bis(dimethylamino)heptafulvene (1). An X-ray structure analysis of the meso-octamethyl[bi-2,4,6-cycloheptatrienyl]3,3'-dicarboxamidinium-bis(triiodide) (3b) has been carried out. The dication 3 is centrosymmetric (Ci-symmetry) with boat shaped cycloheptatriene rings. The amidinium groups are twisted out of the plane of the C3(C3′)-C2(C2′) double bonds. The structure of the dication in the solid state is discussed in comparison with the structure in solution by aid of 1H NMR techniques. The N-methyls within one amidinium group show temperature dependent 1H NMR spectra and are chemically nonequivalent (anisochronous).