triplet state

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trip·let state

a second excited state of a molecule (for example, chlorophyll) produced by absorption of light to produce the singlet state, then loss of some energy (fluorescence) to achieve the longer-lasting triplet state The molecule may remain sufficiently long in the triplet state for a second activating light quantum to be effective in producing a "second triplet" state, at a still-higher level of excitation, hence reactivity. Alternatively, the molecule may lose the triplet state energy directly and return to the ground state.
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Based on the observed photoproducts and reaction kinetics and information available in the relative literatures [21, 25, 26], the photodegradation of TCNM might undergo an n-[PI] * transition to the diradical A, followed by Nesmeyanov rearrangement to B, ring-closure to the oxazirane N-oxide C, and decomposition to CO[Cl.sub.2] and NOCl (Figure 8).
Next, the quantitative cleavage (pyrolysis) of the dimer at the two methylene-methylene bonds at about 680[degrees]C, yields the stable monomeric diradical, p-xylene.
Polymerization is probably of the tetramethylene diradical complex (9) rather than the individual monomers.
The formation of diradical species is thus considered negligible.
Further chapters tackle specific families of organic compounds, such as diradicals and carbenes.
He describes quantum mechanics for organic chemistry, fundamentals of organic chemistry, pericyclic reactions, diradicals and carbenes, organic reactions of anions, solution-phase organic chemistry, and organic reaction dynamics, all of which he punctuates with personal interviews with leading lights in the field.
[C.sub.2] moities refer to two-carbon species such as [C.sub.2][H.sub.2] and to free radicals such as [C.sub.2]H radical or [[C.sub.2][H.sub.2]] diradicals ([C.sub.2]).
[3a] In 1947, Steacie also worked for the appointment of Gerhard Herzberg in the physics division of NRC, and Herzberg was to win the Nobel Prize in Chemistry in 1971 for his photochemical studies, including the generation of carbenes, which can exist as diradicals. This concentration of expertise in free radicals prompted the Faraday Society of Great Britain to organize in 1952 an overseas meeting in Toronto on the subject, [3b,c] with more than 50 participants from Britain.