Delayed Fluorescence and Phosphorescence of 8-Aza-d-Homogonane in the Gas and Condensed Phases

Abstract

The delayed fluorescence spectrum for 8-aza-D-homogonane in the gas phase consists of a band of E-type delayed fluorescence of M-centers and a band of P-type delayed fluorescence of L-centers being the products of photo- and thermotransformations of a basic steroid. Triplet-triplet energy transfer from the M-centers to the L-centers is established and its efficiency is determined. For 8-aza-D-homogonane in frozen hexane solutions at T=77 K only the phosphorescence of the M- and L-centers is revealed. The phosphorescence of the basic steroid itself (lambda(max)(phos) = 415 nm) as well as that of the M- and L-centers (lambda(max)(phos) = 498 and 532 nm, respectively) is seen in a mixture of frozen tetrahydrofuran and toluene solutions. This is evident of the fact that the basic steroid has the products of its transformations, whose amount grows due to irradiation and heating. The M- and L-centers are stable molecules.

Toward rational design of TADF two-coordinate coinage metal complexes: understanding the relationship between natural transition orbital overlap and photophysical properties

“…Thermally assisted delayed fluorescence (TADF), also known as E-type delayed fluorescence, has been investigated in a wide range of photophysical and photochemical applications. [1][2][3][4][5][6][7][8][9][10][11] The process involves the endothermic intersystem crossing (ISC) from the triplet excited state (T 1 ) to singlet (S 1 ) excited state followed by emission from the S 1 state (Scheme 1). 12 A recent promising application of TADF emitters is to replace heavy-metal (Ir, Pt and Rh etc.)…”

Ultrasound-Assisted Synthesis of Fluorescent Azatetracyclic Derivatives: An Energy-Efficient Approach

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A Review on the Synthesis of Fluorescent Five- and Six-Membered Ring Azaheterocycles

“…The advantages of the azaheterocyclic fluorophores, such as small size, enriched photostability, a wide and tunable spectral range, and, frequently, high brightness, are the reason why these fluorophores are preferred and used in various medical application. Probe structure can be modified to adjust excitation and emission wavelengths, target-binding affinity, chemical reactivity, and subcellular localization [ 13 , 14 , 15 , 16 ].…”