Three Rings (disambiguation)

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The Three Rings are fictional artifacts in Tolkien's legendarium.


Three Rings, or variations, may also refer to:

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Heterocyclic compound Cyclic compound that has atoms of at least two different elements as members of its rings

A heterocyclic compound or ring structure is a cyclic compound that has atoms of at least two different elements as members of its ring(s). Heterocyclic chemistry is the branch of organic chemistry dealing with the synthesis, properties, and applications of these heterocycles.

Tricyclic antidepressant Class of medications

Tricyclic antidepressants (TCAs) are a class of medications that are used primarily as antidepressants, which is important for the management of depression. They are second-line drugs next to SSRIs. TCAs were discovered in the early 1950s and were marketed later in the decade. They are named after their chemical structure, which contains three rings of atoms. Tetracyclic antidepressants (TeCAs), which contain four rings of atoms, are a closely related group of antidepressant compounds.

Period may refer to:

A circus is a traveling company of performers that may include acrobats, clowns, trained animals, and other novelty acts.

Trike may refer to:

Dihydroxybenzenes (benzenediols) are organic chemical compounds in which two hydroxyl groups are substituted onto a benzene ring. These aromatic compounds are classed as phenols. There are three isomer: 1,2-dihydroxybenzene is commonly known as catechol, 1,3-dihydroxybenzene is commonly known as resorcinol, and 1,4-dihydroxybenzene is commonly known as hydroquinone.

Ring structure may refer to:

Cyclodecapentaene Chemical compound

Cyclodecapentaene or [10]annulene is an annulene with molecular formula C10H10. This organic compound is a conjugated 10 pi electron cyclic system and according to Huckel's rule it should display aromaticity. It is not aromatic, however, because various types of ring strain destabilize an all-planar geometry. The all-cis isomer (1), a fully convex decagon, would have bond angles of 144°, which creates large amounts of angle strain relative to the ideal 120° for sp2 atomic hybridization. Instead, the all-cis isomer can adopt a planar boat-like conformation (2) to relieve the angle strain. This is still unstable because of the relative higher strain in boat shaped compared to the next planar trans, cis, trans, cis, cis isomer (3). Yet even this isomer is also unstable, suffering from steric repulsion between the two internal hydrogen atoms. The nonplanar trans, cis, cis, cis, cis isomer (4) is the most stable of all the possible isomers.

Spiro compound Organic molecule with two or more rings sharing a common atom

In organic chemistry, spiro compounds are compounds that have at least two molecular rings with only one common atom. The simplest spiro compounds are bicyclic, or have a bicyclic portion as part of the larger ring system, in either case with the two rings connected through the defining single common atom. The one common atom connecting the participating rings distinguishes spiro compounds from other bicyclics: from isolated ring compounds like biphenyl that have no connecting atoms, from fused ring compounds like decalin having two rings linked by two adjacent atoms, and from bridged ring compounds like norbornane with two rings linked by two non-adjacent atoms.

Spiro(s) may refer to:

Cyclic compound Molecule with a ring of bonded atoms

A cyclic compound is a term for a compound in the field of chemistry in which one or more series of atoms in the compound is connected to form a ring. Rings may vary in size from three to many atoms, and include examples where all the atoms are carbon, none of the atoms are carbon, or where both carbon and non-carbon atoms are present. Depending on the ring size, the bond order of the individual links between ring atoms, and their arrangements within the rings, carbocyclic and heterocyclic compounds may be aromatic or non-aromatic; in the latter case, they may vary from being fully saturated to having varying numbers of multiple bonds between the ring atoms. Because of the tremendous diversity allowed, in combination, by the valences of common atoms and their ability to form rings, the number of possible cyclic structures, even of small size numbers in the many billions.

Butriptyline Pharmaceutical drug

Butriptyline, sold under the brand name Evadyne among others, is a tricyclic antidepressant (TCA) that has been used in the United Kingdom and several other European countries for the treatment of depression but appears to no longer be marketed. Along with trimipramine, iprindole, and amoxapine, it has been described as an "atypical" or "second-generation" TCA due to its relatively late introduction and atypical pharmacology. It was very little-used compared to other TCAs, with the number of prescriptions dispensed only in the thousands.

Tricyclic Chemical compounds

Tricyclics are chemical compounds that contain three interconnected rings of atoms.

Dioxin may refer to:

Ketipramine Chemical compound

Ketipramine (G-35,259), also known as ketimipramine or ketoimipramine, is a tricyclic antidepressant (TCA) that was tested in clinical trials for the treatment of depression in the 1960s but was never marketed. It differs from imipramine in terms of chemical structure only by the addition of a ketone group, to the azepine ring, and is approximately equivalent in effectiveness as an antidepressant in comparison.

Dibenzocycloheptene Chemical compound

Preferably called dibenzosuberane is a tricyclic chemical compound featuring two benzene rings bound to a cycloheptene group. It is an occasional motif in synthetic organic chemistry. Various tricyclic antidepressants (TCAs) contain the dibenzocycloheptene moiety in their chemical structures, including amineptine, amitriptyline, amitriptylinoxide, butriptyline, demexiptiline, nortriptyline, noxiptiline, and protriptyline. Cyclobenzaprine, a skeletal muscle relaxant, also contains this functional group.

Yatta may refer to:

Ypthima yatta, the Yatta ringlet or Yatta three-ring, is a butterfly in the family Nymphalidae. It is found in south-central Ethiopia and Kenya.

Three Ring Circus, or variations, may refer to

Two rings, or variations, may refer to: