Related Experiment Video
Updated: Jul 19, 2026

Origami Inspired Self-assembly of Patterned and Reconfigurable Particles
Published on: February 4, 2013
Tetrameric fluorophosphazene, (NPF(2))(4), planar or puckered?
A J Elias1, B Twamley, R Haist
1Contribution from the Department of Chemistry, University of Idaho, Moscow, Idaho, 83844-2343, USA.
The eight-membered heterocycle N(4)P(4)F(8) is not planar, contrary to previous findings. This study reveals a puckered ring structure, especially below a phase transition temperature of -74°C.
Area of Science:
- Inorganic chemistry
- Solid-state chemistry
- Crystallography
Background:
- Previous structural determination of N(4)P(4)F(8) suggested a planar eight-membered heterocycle.
- Understanding the precise molecular geometry of inorganic ring systems is crucial for predicting their properties and reactivity.
Purpose of the Study:
- To redetermine the crystal structure of N(4)P(4)F(8) using multiple experimental techniques.
- To clarify the structural behavior of the N(4)P(4) ring system, particularly concerning its planarity and phase transitions.
Main Methods:
- Single-crystal X-ray diffraction
- Gas electron diffraction (GED)
- Differential scanning calorimetry (DSC)
- Computational structure optimizations (HF/6-31G, B3LYP/6-31G)
Main Results:
- The eight-membered N(4)P(4)F(8) heterocycle is definitively not planar.
- Above the phase transition temperature (-74°C), the ring is disordered and puckered, appearing pseudoplanar.
- Below the phase transition, the ring adopts a saddle (K form) conformation, similar to N(4)P(4)Cl(8).
- The low-temperature unit cell is derived from the high-temperature phase by doubling the c-axis and reducing symmetry.
Conclusions:
- The experimental and computational data conclusively refute the previous report of a planar N(4)P(4)F(8) structure.
- The study provides a detailed understanding of the puckered, non-planar structure of N(4)P(4)F(8) and its conformational changes across a phase transition.
More Related Videos
07:283D Printing and In Situ Surface Modification via Type I Photoinitiated Reversible Addition-Fragmentation Chain Transfer Polymerization
Published on: February 18, 2022
08:21Forming Micro-and Nano-Plastics from Agricultural Plastic Films for Employment in Fundamental Research Studies
Published on: July 27, 2022
Related Concept Videos
VSEPR Theory and the Basic Shapes
Coordination Number and Geometry
Newman Projections
The organic molecules rotate across the single bonds leading to numerous temporary three-dimensional structures of varying energy known as conformers.
Fischer Projections
Crystallographic Point Groups
Quadric Surfaces