132177-65-2Relevant academic research and scientific papers
Conformationally controlled intramolecular charge transfer complexes
Kost, Daniel,Peor, Na'Ama,Sod-Moriah, Gali,Sharabi, Yifat,Durocher, David T.,Raban, Morton
, p. 6938 - 6943 (2007/10/03)
Trans-1-acceptor-2-donor-substituted cyclohexanes (1), as well as their 4- (or 5-)methyl-substituted homologues (2), have been prepared and are shown to form intramolecular charge-transfer (donor-acceptor) complexes. These weak complexes are turned on and off by the chair-chair interconversion of the cyclohexane ring. The CT absorptions have been measured and the equilibrium constants for the ring reversal have been determined by UV/vis spectroscopy at 298 K, as well as by NMR spectroscopy at two temperatures: at 183 K, by direct comparison of signals due to the two chair conformations, and at 300 K, by comparison of calculated and measured widths of the α-proton signals. The Gibbs free energies assigned to the donor-acceptor interactions range between 0 and -1 kcal mol-1. A crystal structure of one of the complexes (1b) confirms the intramolecular donor-acceptor alignment and interaction. The regioisomers of the methyl-substituted complexes were characterized by NOE interaction between the methyl and an α-proton cis to it.
Conformationally Controlled Intramolecular Charge Transfer Complexes
Raban, Morton,Durocher, David T.
, p. 5125 - 5128 (2007/10/02)
The formation of intramolecular charge transfer complexes between an electron-poor 3,5-dinitrobenzoyl fragment and electron-rich 4-substituted phenoxy fragments can be controlled by restricting the conformation of substituted cyclohexanes containing these
