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Cyclophanes, XXVII. [2.2]Indenophane Mono‐ and Dianions: Preparation and Nuclear Magnetic Resonance Spectra
Author(s) -
Frim Ron,
Rabinovitz Mordecai,
Bodwell Graham,
Raulfs FriedrichWilhelm,
Hopf Henning
Publication year - 1989
Publication title -
chemische berichte
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 0009-2940
DOI - 10.1002/cber.19891220422
Subject(s) - chemistry , anisotropy , spectral line , ion , proton , cyclophane , resonance (particle physics) , chemical shift , crystallography , proton nmr , nuclear magnetic resonance , stereochemistry , crystal structure , organic chemistry , atomic physics , physics , quantum mechanics , astronomy
The preparation and chemical and physical properties of negatively charged polycyclic cyclophanes are reported. The throughspace electronic interactions and the through‐space anisotropy effects were deduced from proton and carbon nuclear magnetic resonance data. The systems studied belong to two main groups: a) 4 n π‐polycyclic dianions which are paratropic, e.g. [2.2]benzo‐[ g ]chrysenophane dianion ( 12 2− ), and b) (4 n + 2)π‐polycyclic mono‐ and dianions, which are diatropic. In the dianions both layers are charged, e. g. syn ‐[2.2]indenocyclophane ( 13 2− ) and its anti isomer ( 14 2− ). The monoanions studied are [2.2]benzoindenocyclophane ( 15 1− ), 4,5,17,18‐tetramethyl[2.2]benzoindenocyclophane ( 16 1− ), and 12‐methyl[2.2]benzoindenocyclophane ( 17 1− ). The spectroscopic properties of the layered anions were compared with those of 1,4‐dimethylindenyl anion ( 11 1− ) and with literature data of neutral cyclophanes, viz. 1 – 11 . A differentiation between the anisotropy and charge‐transfer effects has been made and it enables the estimation of the net through‐space interaction.