Carbon 13 Course

Lesson 1 • Energy Levels and Resonance Conditions

Explains Zeeman splitting, the Larmor frequency, and resonance conditions. Links field strength to signal frequency for C-13 nuclei.

Lesson 2 • Relaxation Mechanisms in C-13

Introduces T1 and T2 relaxation and their impact on signal intensity and experiment timing. Explains why C-13 relaxation differs from proton relaxation.

Lesson 3 • Comparing C-13 and Proton NMR

Contrasts sensitivity, spectral width, and coupling patterns between C-13 and H-1 NMR. Prepares students to choose the right experiment for structural questions.

Lesson 4 • Chemical Shift Fundamentals

Defines chemical shift in ppm, the role of electron shielding, and the TMS reference standard. Connects shielding effects to molecular structure.

Lesson 1 • Sample Preparation for C-13

Covers solvent selection, concentration requirements, and tube quality for C-13 experiments. Addresses how sample quality directly affects spectral quality.

Lesson 2 • NMR Spectrometer Components

Describes the magnet, probe, RF electronics, and data system. Provides a functional map of how each component contributes to signal detection.

Lesson 3 • Broadband Decoupling Techniques

Introduces proton-decoupled C-13 acquisition and common decoupling sequences. Explains sensitivity gains and NOE enhancement from decoupling.

Lesson 4 • Acquisition Parameter Optimisation

Guides selection of spectral width, pulse angle, acquisition time, and number of scans. Links each parameter to sensitivity and resolution trade-offs.

Lesson 1 • Baseline Correction and Integration

Teaches baseline roll correction and the limitations of C-13 integration for quantification. Connects baseline quality to accurate peak area measurement.

Lesson 2 • Apodisation and Window Functions

Covers exponential multiplication, Gaussian functions, and their effects on sensitivity and resolution. Teaches selection of window functions for different analytical goals.

Lesson 3 • Phase Correction Methods

Addresses zero-order and first-order phase errors and manual vs. automated correction. Ensures students can produce absorption-mode spectra consistently.

Lesson 4 • Free Induction Decay and Fourier Transform

Explains the FID time-domain signal and the Fourier transform that converts it to a frequency spectrum. Connects FID decay rate to linewidth.

Lesson 1 • Carbonyl and Heteroatom Carbon Shifts

Addresses the distinctive downfield shifts of carbonyl carbons and the influence of adjacent heteroatoms. Differentiates aldehyde, ketone, ester, and amide carbonyls.

Lesson 2 • Olefinic and Aromatic Carbon Shifts

Covers sp2 carbon shift ranges for alkenes and aromatic rings. Explains how substituents shift aromatic carbons through resonance and induction.

Lesson 3 • Using Shift Databases and Prediction Tools

Introduces empirical shift databases and computational prediction tools for C-13 assignment. Teaches critical evaluation of predicted vs. experimental shifts.

Lesson 4 • Stereochemical Effects on Chemical Shift

Examines how stereochemistry, conformational averaging, and ring strain alter C-13 shifts. Connects diastereotopic carbons to distinct resonances.

Lesson 1 • DEPT Pulse Sequence Principles

Explains the DEPT pulse sequence, polarisation transfer, and the role of the theta pulse. Connects pulse angle to the editing outcome for each carbon type.

Lesson 2 • DEPT-Q and DEPTQ Variants

Introduces DEPT-Q and DEPTQ sequences that include quaternary carbon signals. Explains when these variants add value over standard DEPT.

Lesson 3 • Acquiring and Processing DEPT Spectra

Guides acquisition of DEPT-45, DEPT-90, and DEPT-135 sub-experiments. Covers processing steps and linear combination to extract CH, CH2, and CH3 subspectra.

Lesson 4 • Interpreting DEPT in Structure Elucidation

Applies DEPT results to assign carbon types within unknown structures. Integrates DEPT data with chemical shift information for systematic assignment.

Lesson 1 • HMBC Experiment: Long-Range Correlations

Explains HMBC detection of two- and three-bond C-H correlations and its role in connecting molecular fragments. Addresses artefact suppression and ambiguous correlations.

Lesson 2 • Integrating 2D Data for Structure Elucidation

Demonstrates a systematic workflow combining HSQC, HMBC, and COSY data to solve unknown structures. Builds the analytical reasoning skills needed for complex molecules.

Lesson 3 • Principles of 2D NMR Spectroscopy

Introduces the preparation-evolution-mixing-detection framework and how 2D spectra are constructed. Establishes the conceptual basis for all 2D C-13 experiments.

Lesson 4 • HSQC Experiment: One-Bond Correlations

Covers the HSQC pulse sequence, one-bond C-H correlation cross-peaks, and phase-sensitive editing. Enables direct attachment of protons to specific carbons.

Lesson 1 • Relaxation Agents and Sensitivity Enhancement

Introduces paramagnetic relaxation agents that shorten C-13 T1 and reduce experiment time. Evaluates their effect on chemical shifts and spectral quality.

Lesson 2 • Challenges of Quantitative C-13 NMR

Identifies NOE variation, long T1 relaxation, and decoupling artefacts as barriers to quantitative accuracy. Frames the experimental design requirements for reliable results.

Lesson 3 • Internal and External Standards

Compares internal reference compounds and external standard methods for quantification. Addresses standard selection criteria and concentration matching.

Lesson 4 • Validation and Uncertainty Estimation

Applies analytical validation concepts—linearity, precision, accuracy—to quantitative C-13 NMR. Prepares students to document results for quality-assurance purposes.

Lesson 1 • Natural Products and Complex Molecule Analysis

Applies C-13 NMR strategies to natural products with dense functionality and stereochemistry. Demonstrates how overlapping signals and stereochemical complexity are resolved.

Lesson 2 • Critical Evaluation of Spectral Evidence

Trains students to identify artefacts, misassignments, and insufficient evidence in published spectra. Develops the critical judgement needed for peer review and quality control.

Lesson 3 • Polymer and Macromolecule Characterisation

Addresses C-13 NMR of polymers, including tacticity, sequence distribution, and end-group analysis. Covers solution and solid-state approaches for macromolecular systems.

Lesson 4 • Reaction Monitoring and In-Situ NMR

Introduces real-time C-13 NMR for monitoring reaction progress, intermediates, and kinetics. Covers flow-cell and tube-based in-situ experimental designs.