Phenanthrenium cations

A systematic carbocation concentration dependency study on NMR chemical shifts was performed for the C-l-protonated 477-cyclopenta[fi e/ phenanthrenium cation 7H+ and the C-l-protonated pyrenium cation 2H+ (Fig. 11). Shielding of the PAH arenium ion protons and carbons was observed with decreasing FSO3H PAH ratios without noticeable line-broadening. This was attributed to cation-anion interactions in the low FSO3H PAH domain and possible formation of contact ion... 

A parallel was drawn between stable ion and AMI studies of methylphenanthrenes and solvolytic studies of K-region and non-K-region phenanthrene oxides. The carbocation formed by opening of the 1,2-epoxide closely resembled the 2-methylphenanthrene cation (and 7H ), and the regiochemistry of phenol formation (1-phenanthrol) could be understood. Similarly, phenanthrenium cations derived from the 3-methyl and dimethylated compounds served as models for carbo-cations formed by solvolysis of phenanthrene-3,4-epoxide (formation of 4-phenanthrol following hydride shift). 

Bishomo-square pyramidal cation, 2-bicyclo[3.2.1]octa-3,6-dienyl cation and related cations 302 Cyclobutenyl cations 308 Cyclopentenyl cations 310 Cyclohexenyl cations 311 Benzenium ions and related cations 313 9,l0-Dihydro-10-phenanthrenium ions and related cations 323 Acenaphthenium ions 332 Vinyl cations 334... 

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