Trigonal

Trigonal, in the context of geometry and chemistry, describes a shape or structure characterized by three sides, angles, or points. It most commonly refers to the planar or nearly planar arrangement of atoms or groups of atoms around a central atom, where these groups are evenly spaced, resulting in a 120-degree bond angle between them. The term can also apply to crystals and other three-dimensional structures, indicating a symmetry or form based on three-fold rotation. Understanding trigonal geometry is crucial for predicting molecular properties, reactivity, and physical characteristics. In crystallography, it is a crystal system characterized by a three-fold or six-fold axis of symmetry.

Trigonal meaning with examples

• The boron trifluoride (BF3) molecule has a trigonal planar geometry, with the three fluorine atoms equally spaced around the central boron atom, showcasing the trigonal arrangement. This results in a nonpolar molecule, important for chemical reactions.
• Crystals belonging to the trigonal crystal system exhibit a characteristic three-fold symmetry, such as in calcite or quartz. The arrangement of atoms reflects a trigonal basis and symmetry, influencing their physical properties, especially light.
• In a reaction mechanism, a transition state involving a trigonal arrangement of atoms might dictate the pathway. This specific geometry governs the molecular orientation of the participating atoms and influences the rate and outcome.
• The shape of a certain molecule allows the electrons to arrange themselves in a trigonal manner, and hence influence the interactions between the atoms and molecules, shaping how other atoms will react.