Optically induced electron transfer in an N,N,N′,N′‐tetraanisyl‐o‐phenylenediamine radical cation

Abstract

Upon electrochemical and spectroelectrochemical investigation the radical cation of tetraanisyl-ophenylenediamine turned out to be an almost delocalized system at the borderline between class II and III with an extremely low reorganization energy.

Trends in Electron-Vibration and Electronic Interactions in Bis(dimethylamino) Mixed-Valence Systems: A Joint Experimental and Theoretical Investigation

“…6 Additionally, although the IVCT band in 1 + -3 + narrows upon increasing the length of the conjugated bridge, the trend for the I + -III + series turns out to be quite different as the IVCT band first narrows on going from I + to II + and then broadens when going from II + to III + . 13 Finally, as the π-conjugation path lengthens in I + -III + , the IVCT bands become more symmetric, a trend that also contrasts with 1 + -3 + . These results indicate that the replacement of the methyl terminal groups with p-anisyl groups has a significant effect on the nature of the electron-vibrational coupling.…”

“…With such compounds, a number of aspectssincluding the influence of the bridge (e.g., the role of the bridge length, topology, and energetics) on the extent of electronic communication between the organic redox sitesshave been well-characterized. 6,13,[19][20][21][22][23][24][25][26][27][28][29] In this contribution, we describe the electronic and electronvibration couplings in the series of bis-dimethylamino species shown in Figure 1: N,N,N′,N′-tetramethyl-p-phenylenediamine (1), N,N,N′,N′-tetramethyl-benzidine (2), and N,N,N′,N′-tetramethyltolane-4,4′-diamine (3). The vis-NIR spectroscopy results show that 1 + -3 + exhibit a well-separated IVCT band with a finely resolved vibrational structure, a feature that allows for a detailed study of the electron-vibrational interaction.…”

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] In such systems, the inherent ET properties and patterns of charge (de)localization strongly depend on the interplay and strengths of electronic and vibrational interactions [i.e., transfer integrals (electronic coupling) and intermolecular reorganization energies, respectively]. A characteristic feature of MV compounds is the presence of an absorption band in the visible or near-infrared (NIR).…”

Electronic Communication Across Diamagnetic Metal Bridges: A Homoleptic Gallium(III) Complex of a Redox-Active Diarylamido-Based Ligand and Its Oxidized Derivatives

“…5-8 Electronic communication between donor ends of such molecules can vary dramatically by changing: i) the groups, X, along the diarylamine donor; 5c,h-j ii) the type of bridge; 7a,8 9 . iii) the bridge length; or iv) the geometric disposition of donors about the bridge, 5i,5j,9 including the dihedral angle between bridging phenylene groups (that also affect the dihedral of orbitals containing the nitrogen lone pair). 10 In cases such as A and B in Fig 1, electronic communication can occur via tunneling, superexchange, or a “hopping” mechanism whereby the bridge becomes an active participant.…”

Charge Delocalization in a Homologous Series of α,α′-Bis(dianisylamino)-Substituted Thiophene Monocations

“…[36][37]50 Indeed, these absorptions fall into the spectral range in which intervalence absorptions of bis(triarylamine) radical cations are commonly observed. 16,20,[34][35][51][52][53][54][55][56][57][58][59][60][61] An important difference to the intervalence absorptions of coordination compounds 40,[62][63][64][65] are the comparatively large extinction coefficients of these bands, but this is a (favorable) peculiarity of organic mixed-valence compounds which has been noted many times before. Table 2.…”