P-31 NMR Spectroscopy 24-Hour Turnaround

P-31 NMR provides direct, highly sensitive detection of phosphorus atoms in organic and inorganic compounds.

With 100% natural abundance and excellent sensitivity (6.6% of H-1), P-31 NMR is the gold standard for characterizing organophosphorus compounds, phosphine ligands, phosphates, phosphonates, and phosphorus-containing catalysts. Our 24-hour turnaround makes it ideal for reaction monitoring and fast-paced research.

Why P-31 NMR?

Excellent NMR Properties

P-31 is one of the most favorable nuclei for NMR spectroscopy:

  • 100% natural abundance - Only stable isotope of phosphorus
  • Good sensitivity - 6.6% relative to H-1 (66× better than C-13!)
  • Spin 1/2 nucleus - Sharp, well-defined peaks
  • Very wide chemical shift range - ~750 ppm (-500 to +250 ppm)
  • Fast acquisition - Similar to H-1 NMR
  • 24-hour turnaround - Quick results for time-sensitive projects

When to Use P-31 NMR

Order P-31 NMR whenever your molecule contains phosphorus:

  • Organophosphorus compounds (phosphines, phosphonates, phosphates)
  • Phosphine ligands and catalysts (Pd, Pt, Rh, Ru complexes)
  • Phosphate esters and biochemicals (ATP, DNA/RNA building blocks)
  • Flame retardants and additives
  • Pesticides and herbicides
  • Phosphorus-containing pharmaceuticals

What P-31 NMR Reveals

Structural Information

  • Coordination environment - Free ligand vs metal-bound
  • Number of P environments - Each peak = unique P
  • Connectivity - P-P, P-H, P-C coupling patterns
  • Isomers - Positional and stereoisomers
  • Purity - Detect phosphorus-containing impurities

Quantitative & Dynamic Info

  • Integration - Count phosphorus atoms
  • Stability monitoring - Track degradation over time
  • Catalyst speciation - Active species identification
  • Mixture analysis - Quantify components

P-31 Chemical Shift Ranges

P-31 has an extremely wide chemical shift range (~750 ppm total), making it easy to distinguish different phosphorus environments.

Compound Type Chemical Shift Range (ppm) Example
Phosphines (P(III)) -50 to +50 PPh₃ (-6 ppm), PMe₃ (-62 ppm)
Phosphine oxides (P(V)) +10 to +60 Ph₃P=O (+29 ppm)
Phosphonates +15 to +40 (EtO)₂P(O)Me (+32 ppm)
Phosphates (organic) -5 to +5 (RO)₃PO (0 ppm)
Phosphoric acid derivatives 0 to +10 H₃PO₄ (0 ppm, reference)
Phosphonium salts +20 to +35 [PPh₃Me]⁺ (+24 ppm)
Phosphorus ylides +5 to +30 Ph₃P=CH₂ (+16 ppm)
Metal-phosphine complexes -50 to +100 Widely variable (coordination shifts)
Phosphorus halides +150 to +250 POCl₃ (+2.2 ppm), PCl₃ (+220 ppm)
Elemental phosphorus (P₄) -500 to -450 White phosphorus (-488 ppm)

Reference Standard: 85% H₃PO₄ (phosphoric acid) is used as the reference at 0.0 ppm. Most organic phosphates appear near 0 ppm, while phosphines appear upfield (negative) and phosphine oxides/phosphonates appear downfield (positive).

Oxidation State Recognition:

  • P(III) - Phosphines, phosphites: typically -50 to +50 ppm
  • P(V) - Phosphine oxides, phosphonates, phosphates: typically +10 to +60 ppm

Applications of P-31 NMR

Catalysis & Organometallics

  • Phosphine ligands - PPh₃, BINAP, Xantphos, dppe
  • Pd, Pt, Rh, Ru complexes - Catalyst characterization
  • Active species identification - Distinguish catalytic intermediates
  • Ligand exchange dynamics - Variable temperature NMR
  • Coordination chemistry - Metal-phosphine binding
  • Reaction monitoring - Real-time conversion tracking

Example Ligands:

  • PPh₃ (triphenylphosphine) - -6 ppm
  • PCy₃ (tricyclohexylphosphine) - +10 ppm
  • P(t-Bu)₃ - +63 ppm
  • BINAP - variable based on coordination

Synthetic Chemistry

  • Wittig reagents - Phosphonium ylides
  • Horner-Wadsworth-Emmons - Phosphonate esters
  • Mitsunobu reactions - DEAD/DIAD/Ph₃P complexes
  • Appel reactions - Ph₃P/CCl₄ system
  • Staudinger ligation - Azide reduction

Biochemistry & Pharmaceuticals

  • Nucleotides - ATP, GTP, ADP (multiple P signals)
  • DNA/RNA building blocks - Phosphoramidites
  • Phospholipids - Membrane components
  • Prodrugs - Phosphate ester masking groups
  • Antiviral agents - Nucleoside phosphonates

Materials & Additives

  • Flame retardants - Organophosphorus compounds
  • Plasticizers - Phosphate esters
  • Antioxidants - Phosphites (e.g., Irgafos)
  • Polymer additives - Stabilizers

Agrochemicals

  • Organophosphate pesticides - Insecticides
  • Herbicides - Glyphosate, glufosinate
  • Nerve agent degradation - Environmental monitoring

P-31 Coupling Patterns

Common Coupling Interactions

P-H Coupling (¹JPH):

  • Direct P-H bonds: 180-700 Hz
  • Example: PH₃ shows a large 1:2:1 triplet (~700 Hz)
  • Useful for identifying P-H containing compounds

P-C Coupling (¹JPC):

  • Typical range: 10-200 Hz
  • Often not resolved in routine P-31 spectra
  • Visible in high-resolution or ³¹P{¹H} decoupled spectra

P-P Coupling (¹JPP):

  • Direct P-P bonds: 200-500 Hz
  • Example: Diphosphines show P-P coupling
  • Indicates phosphorus-phosphorus connectivity

P-F Coupling (¹JPF):

  • Very large: 700-1400 Hz
  • Common in phosphorus fluorides (PF₃, PF₅)

P-Metal Coupling:

  • Pt-P: ¹JPtP = 2000-4500 Hz (huge satellite peaks!)
  • Rh-P: ¹JRhP = 100-200 Hz (doublet)
  • Provides direct evidence of metal coordination

Decoupling Options

We run ³¹P{¹H} (proton-decoupled P-31 NMR) to simplify spectra:

  • Removes P-H coupling → cleaner, simpler spectra
  • Improves signal-to-noise ratio
  • Easier integration and interpretation
  • Standard for routine P-31 analysis

Sample Requirements

Sample Amount

  • Minimum: 5-10 mg
  • Recommended: 20-50 mg for best results

Solvent

  • Common solvents: CDCl₃, DMSO-d₆, THF-d₈, D₂O, CD₂Cl₂
  • Reference: External 85% H₃PO₄ (0.0 ppm)
  • Sensitivity notes: Air-sensitive phosphines should be prepared under inert atmosphere

Concentration

  • 10-30 mM typical
  • Lower concentrations acceptable for sensitive compounds

Turnaround Time & Pricing

Fast 24-Hour Turnaround

Standard Turnaround: 24 hours (same as H-1 NMR)

Why so fast? P-31 has excellent sensitivity and fast acquisition times, making it ideal for quick characterization and reaction monitoring.

For pricing information, please visit our Pricing page or contact us.

What You'll Receive

Standard Deliverables

  • P-31 NMR spectrum (proton-decoupled)
  • Peak picking
  • Integration values
  • Coupling constants (upon request)
  • Raw data files (Bruker format)
  • PDF report

Optional Add-Ons

  • Proton-coupled P-31 - See P-H coupling
  • Variable temperature - Study fluxional processes
  • Quantitative P-31 - Precise ratios

Need P-31 NMR Analysis?

Submit your phosphorus-containing compounds for expert P-31 NMR spectroscopy

⚡ 24-Hour Turnaround Available ⚡

Submit a Sample Request a Quote

Phone: (858) 793-6057 | Email: NuMegaLab@NuMegaLabs.com

H-1 NMR

Proton NMR analysis

C-13 NMR

Carbon skeleton

F-19 NMR

Fluorine analysis

Other Nuclei

Multinuclear NMR