Related Experiment Video
Updated: Aug 22, 2026

Spin Saturation Transfer Difference NMR (SSTD NMR): A New Tool to Obtain Kinetic Parameters of Chemical Exchange Processes
Published on: November 12, 2016
Solvent effects on the spin-spin coupling constants of acetylene revisited: supermolecular and polarizable continuum
Magdalena Pecul1, Kenneth Ruud
1Department of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland.
Abstract:
The solvent shifts of the spin-spin coupling constants of acetylene were calculated using the polarizable continuum model (PCM) for solvents ranging in polarity from cyclohexane to water, using both density functional theory (DFT) and the complete active space self-consistent field (CASSCF) method. The spin-spin coupling constants were also calculated for complexes of acetylene with water, acetonitrile, acetone and benzene using DFT/B3LYP. It is demonstrated that PCM reproduces the substantial experimental solvent shifts of the (1)J(C,C) and (1)J(C,H) couplings with great accuracy. The sign and approximate magnitude are also rendered correctly by the supermolecular method, in spite of the limitation of the models, which included only one or two solvent molecules.
Related Concept Videos
Spin–Spin Coupling: Three-Bond Coupling (Vicinal Coupling)
The extent of coupling depends on the C‑C bond length, the two H‑C‑C angles, any electron-withdrawing substituents, and the dihedral angle between the involved orbitals. The...
Spin–Spin Coupling Constant: Overview
Qualitatively, any spin plus-half nucleus polarizes the spins of its electrons to the minus-half state. Consequently, the paired electron in the hydrogen–carbon bond must have a...
Spin–Spin Coupling: One-Bond Coupling
Spin–Spin Coupling: Two-Bond Coupling (Geminal Coupling)
The central atom need not be NMR-active because its electrons are affected by the electron polarization of the spin-active atoms. However, spin information is transmitted less effectively than in one-bond coupling, and 2J values are usually weaker than 1J values. The energy of...
¹H NMR: Long-Range Coupling
In alkenes, spin information is communicated via σ–π overlap, as seen in allylic (four-bond) and homoallylic (five-bond) couplings. These coupling interactions are stronger when the σ bond is parallel to the alkene π orbitals.
π Electron Effects on Chemical Shift: Overview

