Meaning: Roald Hoffmann, a renowned scientist and Nobel laureate in Chemistry, made the statement, "One day I discovered that one could get the barrier to internal rotation in ethane approximately right using this method. This was the beginning of my work on organic molecules." This quote encapsulates a pivotal moment in Hoffmann's scientific journey and sheds light on his groundbreaking contributions to the field of organic chemistry.

Hoffmann's work on organic molecules revolutionized our understanding of chemical bonding and molecular structure. He is best known for his research on the theoretical principles of chemical reactions, particularly in the context of organic compounds. His statement reflects the moment when he embarked on a new direction in his scientific pursuits, focusing on the complexities of organic molecules and the fundamental principles that govern their behavior.

The "barrier to internal rotation in ethane" refers to the concept of hindered rotation around single bonds in organic molecules. Ethane is a simple hydrocarbon composed of two carbon atoms bonded to each other with single bonds and surrounded by hydrogen atoms. In ethane, the carbon-carbon bond can rotate freely, allowing the molecule to adopt different spatial orientations. However, this rotation is not entirely unhindered, as there is a certain energy barrier that must be overcome for the rotation to occur.

Hoffmann's realization that the barrier to internal rotation in ethane could be approximated using a specific method marked a turning point in his scientific exploration. This breakthrough likely involved the development or application of theoretical and computational models to understand the underlying factors influencing the rotational barrier in ethane. By delving into the intricacies of this seemingly simple molecule, Hoffmann laid the groundwork for his extensive research on organic molecules and their behavior.

Organic molecules are compounds primarily composed of carbon atoms, often bonded to hydrogen, oxygen, nitrogen, and other elements. They form the basis of life and are integral to countless natural and synthetic processes. Understanding the properties and behavior of organic molecules is crucial for fields such as pharmaceuticals, materials science, and biochemistry.

Hoffmann's work on organic molecules not only advanced our fundamental understanding of chemical bonding and reactivity but also had profound implications for practical applications. His contributions provided insights into the structural features and reactivity patterns of organic compounds, paving the way for the development of new drugs, materials, and technologies.

Furthermore, Hoffmann's approach to studying organic molecules exemplifies the interdisciplinary nature of scientific inquiry. His work combined elements of theoretical chemistry, computational modeling, and experimental validation, showcasing the synergy between different scientific disciplines in unraveling the complexities of molecular systems.

In summary, Roald Hoffmann's quote encapsulates a transformative moment in his scientific career, marking the beginning of his pioneering work on organic molecules. His exploration of the barrier to internal rotation in ethane laid the groundwork for groundbreaking discoveries in the field of organic chemistry and continues to inspire and influence scientific research to this day.