trigonal
/ˈtrɪɡ(ə)n(ə)l
/adjective
1Triangular: square or trigonal double-sided inserts...
- Its morphology is either hexagonal or trigonal.
- The trigonal planar arrangement of the groups around the carbonyl carbon atom enables the carbon atom to be relatively open to attack from above, or below.
- Rhodochrosite crystallizes in the trigonal class of the hexagonal system and occurs in a number of diverse forms.
1.1chiefly Biology Triangular in cross section: large trigonal shells...
- The triangular habit suggested trigonal symmetry and a possible identification as hilairite or a contact-twinned form of gaidonnayite.
- The auricles in early ontogeny are relatively large and distinctly trigonal, with their free margins meeting the hinge line at acute angles.
- At the same time, however, it has been reported that the zeta line is constructed to position a thick filament at the trigonal point of the three thin filaments in the opposite sarcomere.
1.2Of or denoting a crystal system or three-dimensional geometrical arrangement having three equal axes separated by equal angles that are not right angles.These are, in order of decreasing symmetry, the cubic, hexagonal, tetragonal, trigonal, orthorhombic, monoclinic, and triclinic systems....
- Hexagonal crystals (such as aquamarine and emerald) are useful in defining our goals and successes, whilst trigonal crystal systems (ie tourmaline and amethyst) help us to focus on simplicity.
- Simple binuclear and trinuclear complexes form linear and trigonal arrangements but a tetranuclear complex can occur as a tetrahedron or a cubane structure.
Derivatives
trigonally
- The alkene carbon-carbon double bond is made from two sp trigonally hybridized carbons.
- This implies that the triad axes exist in the centers of the rings, and hence they are distorted trigonally as in the hexagonal SrAl2O4.
- The structure of the unit is a trigonally planar one in RTP.
Origin
Late 16th century: from medieval Latin trigonalis, from Latin trigonum (see trigon).