Trigonal planar
From Wikipedia, the free encyclopedia
In chemistry, trigonal planar is a molecular geometry with one atom at the center and three atoms at the corners of a triangle all in one plane. In a trigonal planar molecule where all three attached atoms are identical, all bond angles are 120°. Molecules where these atoms differ - such as H2CO - as well as more complex molecules - such as alkenes - will deviate from this ideal geometry due to lowered molecular symmetry. In general the atomic orbitals of a trigonal planar molecule are sp2 hybridized. Examples of molecules with a trigonal planar geometry include boron trifluoride BF3, formaldehyde H2CO, and sulfur trioxide SO3. Some ions with trigonal planar geometry include the nitrate ion NO3-, the carbonate ion CO32-, and the borate ion BO33-.
Pyramidalization is a distortion of this molecular shape towards a tetrahedral molecular geometry. One way to observe this distortion is in pyramidal alkenes.