Hyperconjugative interactions Coupling constants Nuclear magnetic resonance Paramagnetism Spin-spin coupling constants Substituent effects Sulfur compounds 1H chemical shifts 1JCH and 2JCH coupling constants 2 fluorophenol 2-fluorophenol 2-methylpropenes 3,4JCH 3JCH couplings ¹J_CH and ²J_CH coupling constants AS models Acetonitriles Allylic couplings Anomeric effect Bond angle Carbonyl group Carbonyl groups Chemical bonds Chemistry, Physical Chloroacetamide Cholesterol levels Conceptual analysis Coupling constant Cyclohexanes DFT studies