Synthesis and valence orbital structures of azacycl[3.3.3]azines in a systematic series

Systematic series of azacycl[3.3.3]azines of varying nitrogen content: Nitrogen‐15 magnetic resonance spectra

“…The term cyclazine denotes a fused conjugated ring system held planar by three covalent bonds to an internal nitrogen atom [3,4] [S] to orange (2) [7], lavendar (3) , blue (5and 7) [7, 10-121, and brown ( 6 ) [6]. The wavelength of the lowest energy transition, So-S1, moves correspondingly from 443 nm (1, CH,CN) [5] to 531 (2, CH,CN) [7], 608 (3, CH,CN) [7], 632(5, EtOH) [lo], and 1290 ( 6 , cyclohexane) [13, 141. This band shows maximal absorption at 637 nm (CH,CN) for the only 1,4-diazine-c0ntaining member of the series 1,3,4,6,8-pentaazacyc1[3.3.3]azine (4), which is described as blue [7] or violet [15]. The difference of -100 nm between the long-wavelength maxima of 4 and its osition isomer, 1,3,4,6,7-pentaazacycl[ 3.3.31azine &), with all the peripheral nitrogens in alternating positions is noteworthy.…”

“…The term cyclazine denotes a fused conjugated ring system held planar by three covalent bonds to an internal nitrogen atom [3,4], as in 1-5, also 6 and 7 . 1,3,4,6,7,9-Hexaazacyc1 [S] to orange (2) [7], lavendar (3) [7-91, blue (5and 7) [7, 10-121, and brown ( 6 ) [6]. The wavelength of the lowest energy transition,…”

Enhancing Light‐Absorption and Luminescent Properties of Non‐Emissive 1,3,4,6,9b‐Pentaazaphenalene through Perturbation of Forbidden Electronic Transition by Boron Complexation

“…In this research, as a new potential π‐conjugated element‐block, azaphenalene (AP) has been focused because of its unique electronic properties originating from the triangular structure . Leupin and Wirz thoroughly investigated electronic properties of the series of AP derivatives, and they revealed that APs have a symmetry‐forbidden transition from the first singlet (S 1 ) excited state to the ground (S 0 ) state .…”

“…In this research, as a new potential π-conjugated elementblock, azaphenalene (AP) has been focused [10][11][12][13] because of its unique electronic properties originating from the triangular structure. [11][12][13][14][15][16] Leupin and Wirz thoroughly investigated electronic properties of the series of AP derivatives, and they revealed that APs have a symmetry-forbidden transition from the first singlet (S 1 ) excited state to the ground (S 0 ) state. [14] As a consequence, the slow radiative process was observed due to the symmetry-forbidden nature of the S 0 À S 1 transition, and indeed poor luminescent properties are commonly obtained from the AP derivatives.…”

Theoretical investigation on carbon-centered tri-s-tetrazine and its 10 derivatives

“…Among all the s-triazine-based compounds, Pauling and Sturdivant [11] suggested a common nucleus, three coplanar fused s-triazine rings. In the past decade, the tri-s-triazines were studied in detail, both experimentally [12][13][14][15][16] and theoretically [17][18][19][20][21]. In this work, we study a framework consisting of three fused s-tetrazines, i.e., tri-stetrazines (C 4 N 9 H 3 ) (Fig.…”