Related Experiment Video
Updated: May 18, 2026

Dissection and Flat-mounting of the Threespine Stickleback Branchial Skeleton
Published on: May 7, 2016
The correct physical basis of protobranching stabilization
1Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA. lbart@umich.edu
Abstract:
The source of the extra stability of branched hydrocarbons over unbranched (hereafter referred to as protobraching stabilization) has been explained in several different self-consistent ways. Gronert, basing his arguments on well-established properties of organic molecules, namely that geminal atoms strongly repel each other, formulated a model which accounted for this "protobranching" stability simply and very well. However, careful quantum computations were found to yield correct protobranching energies only if they properly took electron correlation into account. Such a source of stability would not have been needed in Gronert's model. The present article analyzes what is correct and what is uncertain about Gronert's atomic repulsion model, and concludes that the computations of Wiberg, Bader, Grimme, Schleyer, and their colleagues overturn Gronert's model and that bond-bond electron correlation energies provide the correct explanation of protobranching.
Related Concept Videos
Diversity of Protists III
Buoyancy and Stability for Submerged and Floating Bodies
The Thoracic Cage: Sternum
The sternum is the elongated bony structure on the anterior side of the thoracic cage. It consists of three parts: the manubrium, the body, and the xiphoid process.
Overview of the Axial Skeleton
The axial skeleton of the adult...
Applications of Stress
The...
Stability of structures

