Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Aromatic Hydrocarbon Cations: Structural Overview01:18

Aromatic Hydrocarbon Cations: Structural Overview

4.3K
Cycloheptatriene is a neutral monocyclic unsaturated hydrocarbon that consists of an odd number of carbon atoms and an intervening sp3 carbon in the ring. The three double bonds in the ring correspond to 6 π electrons, which is a Huckel number, and therefore satisfies the criteria of 4n + 2 π electrons. However, the intervening sp3 carbon disrupts the continuous overlap of p orbitals. As a result, cycloheptatriene is not aromatic.
Removing one hydrogen from the intervening CH2 group...
4.3K
Valence Bond Theory02:42

Valence Bond Theory

11.7K
Coordination compounds and complexes exhibit different colors, geometries, and magnetic behavior, depending on the metal atom/ion and ligands from which they are composed. In an attempt to explain the bonding and structure of coordination complexes, Linus Pauling proposed the valence bond theory, or VBT, using the concepts of hybridization and the overlapping of the atomic orbitals. According to VBT, the central metal atom or ion (Lewis acid) hybridizes to provide empty orbitals of suitable...
11.7K
Coordination Number and Geometry02:57

Coordination Number and Geometry

19.8K
For transition metal complexes, the coordination number determines the geometry around the central metal ion. Table 1 compares coordination numbers to molecular geometry. The most common structures of the complexes in coordination compounds are octahedral, tetrahedral, and square planar.
19.8K
Five-Membered Heterocyclic Aromatic Compounds: Overview01:13

Five-Membered Heterocyclic Aromatic Compounds: Overview

6.0K
Heterocyclic aromatic compounds are cyclic compounds that are aromatic and have one or more heteroatoms—atoms other than carbon, in the ring. Depending upon the number of atoms present in the ring, they can be either five or six-membered. Examples of five-membered heterocyclic aromatic compounds include pyrrole, furan, thiophene, and imidazole. Pyrrole consists of one nitrogen atom having one lone pair of electrons. Furan and thiophene have one oxygen and one sulfur heteroatom,...
6.0K
Crystal Field Theory - Tetrahedral and Square Planar Complexes02:46

Crystal Field Theory - Tetrahedral and Square Planar Complexes

49.7K
Tetrahedral Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
49.7K
Predicting Molecular Geometry02:27

Predicting Molecular Geometry

47.0K
VSEPR Theory for Determination of Electron Pair Geometries
47.0K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Nanoscale Magnetic Arrays through Block Copolymer Templating of Polyoxometalates.

Nano letters·2024
Same author

Intramolecular C-N bond activation by a transient boryl anion.

Chemical communications (Cambridge, England)·2023
Same author

One- and two-electron reductions of a bulky BODIPY compound.

Dalton transactions (Cambridge, England : 2003)·2023
Same author

Macrocyclic pentamers functionalised around their periphery as potential building blocks.

RSC advances·2022
Same author

Towards more effective beryllium chelation: an investigation of second-sphere hydrogen bonding.

RSC advances·2022
Same author

Geometric Frustration and Long-Range Ordering Induced by Surface Pressure Oscillation in a Langmuir-Blodgett Monolayer of Magnetic Soft Spheres.

Langmuir : the ACS journal of surfaces and colloids·2021

Related Experiment Video

Updated: Mar 30, 2026

Construction and Systematical Symmetric Studies of a Series of Supramolecular Clusters with Binary or Ternary Ammonium Triphenylacetates
06:35

Construction and Systematical Symmetric Studies of a Series of Supramolecular Clusters with Binary or Ternary Ammonium Triphenylacetates

Published on: February 15, 2016

8.6K

Tetrapyrrole Complexes with Unusual Geometries: a Main Group Element Perspective.

Penelope J Brothers1

  • 1Research School of Chemistry, Australian National University, Acton 2002, Australia.

Accounts of Chemical Research
|March 28, 2026
PubMed
Summary

Roald Hoffmann

Area of Science:

  • Coordination Chemistry
  • Bioinorganic Chemistry
  • Main Group Chemistry
  • Porphyrin Chemistry

Background:

  • The 1970s and 1980s saw significant expansion in bioinorganic chemistry, utilizing molecular coordination chemistry to model metalloenzymes and metal cofactors.
  • Synthetic porphyrin ligands became crucial for studying high-valent metal-oxo/nitrido species, metal-metal multiple bonds, and organometallic chemistry.
  • Historically, porphyrin chemistry focused on d-block elements (e.g., iron, cobalt), with limited exploration of s- and p-block elements.

Purpose of the Study:

  • To review the concept of metalloporphyrins with unusual geometries, as introduced by Hoffmann and Tatsumi in 1981.
  • To explore how main group elements coordinated within tetrapyrrole complexes have expanded upon these initial ideas.
  • To highlight the unique chemistry arising from the "misfit" between main group elements and the porphyrin ligand environment.

More Related Videos

Line Shape Analysis of Dynamic NMR Spectra for Characterizing Coordination Sphere Rearrangements at a Chiral Rhenium Polyhydride Complex
10:52

Line Shape Analysis of Dynamic NMR Spectra for Characterizing Coordination Sphere Rearrangements at a Chiral Rhenium Polyhydride Complex

Published on: July 27, 2022

3.5K
The Synthesis, Characterization and Reactivity of a Series of Ruthenium N-triphosPh Complexes
10:51

The Synthesis, Characterization and Reactivity of a Series of Ruthenium N-triphosPh Complexes

Published on: April 10, 2015

12.9K

Related Experiment Videos

Last Updated: Mar 30, 2026

Construction and Systematical Symmetric Studies of a Series of Supramolecular Clusters with Binary or Ternary Ammonium Triphenylacetates
06:35

Construction and Systematical Symmetric Studies of a Series of Supramolecular Clusters with Binary or Ternary Ammonium Triphenylacetates

Published on: February 15, 2016

8.6K
Line Shape Analysis of Dynamic NMR Spectra for Characterizing Coordination Sphere Rearrangements at a Chiral Rhenium Polyhydride Complex
10:52

Line Shape Analysis of Dynamic NMR Spectra for Characterizing Coordination Sphere Rearrangements at a Chiral Rhenium Polyhydride Complex

Published on: July 27, 2022

3.5K
The Synthesis, Characterization and Reactivity of a Series of Ruthenium N-triphosPh Complexes
10:51

The Synthesis, Characterization and Reactivity of a Series of Ruthenium N-triphosPh Complexes

Published on: April 10, 2015

12.9K

Main Methods:

  • Review of historical and contemporary research on metalloporphyrins and tetrapyrrole complexes.
  • Discussion of extended Hückel calculations used to understand bonding and geometries.
  • Analysis of the interplay between element properties (size, electronegativity) and the tetrapyrrole scaffold.

Main Results:

  • Main group elements (Li to Bi, C, B, P, Si, Ge) form diverse porphyrin complexes, often with unusual geometries and out-of-plane coordination.
  • Main group elements challenge the traditional "metalloporphyrin" definition, exhibiting rich chemistry despite their differing properties from transition metals.
  • Examples include diboron porphyrinoids acting as binucleating ligands and silicon/germanium porphyrins/phthalocyanines showcasing ligand-element redox interplay.

Conclusions:

  • The study of main group tetrapyrrole complexes has significantly extended the understanding of unusual geometries in coordination chemistry.
  • The "misfit" between main group elements and porphyrins drives novel chemical reactivity and structural diversity.
  • The concepts explored in main group tetrapyrrole chemistry offer transferable insights to broader areas of the chemical sciences.