Substituent effects NMR 6 Hyperconjugative interactions 4 13C NMR 2 13C SCS 2 17O NMR 2 17O chemical shifts 2 19F chemical shift 2 1H chemical shifts 2 2-methylpropenes 2 AS models 2 Allylic couplings 2 Bicyclo[1.1.1]pentanes 2 Bridgehead-substituted bicyclic fluorides 2 Chemical interactions 2 Chemical shifts 2 Conceptual analysis 2 Coupling constants 2 DFT studies 2 DFT-GIAO 2 DFT-NBO 2 DFT-NBO; DFT-GIAO 2 Electronic origins 2 Experiments 2 Fermi contact terms 2 Localized orbitals 2 Nuclear magnetic resonance 2 Orbital contributions 2 PP-RPA qualitative model 2 Propagator approaches 2