Synthesis and Properties of Subphthalocyanine–Tetracyanobutadiene–Ferrocene Triads

Abstract

A series of boron subphthalocyanine-tetracyanobutadiene-ferrocene (SubPc-TCBD-Fc) triads was synthesized by subjecting SubPcs with a ferrocenylethynyl substituent at either the axial or peripheral position to a [2 + 2] cycloaddition reaction with tetracyanoethylene followed by retroelectrocyclization. The ferrocenylethynyl unit was introduced at the axial position (at the boron atom) by a simple aluminum chloride-mediated alkynylation reaction, while functionalization at the SubPc periphery was accomplished by a Sonogashira coupling reaction. The conversion of one alkyne unit into a TCBD unit in combination with the location of the resulting TCBD-Fc moiety was found to have a strong influence on the optical and redox properties, which is ascribed to very different ground-state interactions between the individual donor/acceptor systems. The first electrochemical oxidation could thus be anodically shifted by as much as 0.4 V from the strongest donor molecule (with most unperturbed ferrocene character) to the poorest donor molecule (with strongly perturbed ferrocene character). Six redox states could be reached reversibly for the SubPc-TCBD-Fc triads, -3, -2, -1, 0, + 1, + 2, and for one compound the formation of a tetraanion persistent at the time scale of slow scan voltammetry was observed.

Donor−Acceptor‐Functionalized Subphthalocyanines for Dye‐Sensitized Solar Cells

“…Treating the SubPc aryliodide 4 with the terminal alkynes 5 and 6 under Sonogashira conditions provided the target molecules 1 and 2 , respectively (Scheme ). We employed AsPh 3 instead of PPh 3 as ligand as this change has previously shown to be advantageous when subjecting derivatives of SubPc to Sonogashira couplings .…”

“…All reagents and solvents were obtained from commercial suppliers and used as received unless otherwise stated. Compounds 4 and 7 were prepared as described in literature. Dry THF was obtained by distillation from a Na/benzophenone couple.…”

Exploring the Synthesis and Electronic Properties of Axially Substituted Boron Subphthalocyanines with Carbon‐Based Functional Groups

“…1 H NMR (500 MHz, CDCl 3 ): δ = 8.80 (dd, J = 5.9, 3.0 Hz, 6H), 7.84 (dd, J = 5.9, 3.0 Hz, 6H), 7.29-7.24 (m, 2H), 7.24-7.19 (m, 1H), 7.16-7.10 (m, 2H) ppm. 13…”

“…optics [11] and artificial photosynthesis. [12] BsubPcs can be functionalized on the peripheral and/or the axial positions (Figure 1a) and those synthetic variations have been shown to finetune their physical and electrochemical properties [2,4,13] for specific applications.…”

Subphthalocyanine–tetracyanobuta-1,3-diene–aniline conjugates: stereoisomerism and photophysical properties

“…Recently, 1,1,4,4-tetracyanobuta-1,3-diene (TCBD) has been investigated as novel molecular partner for SubPcs. [11][12][13] Up to now, few TCBD-based D-A arrays have been reported, in which the TCBD moiety, a strong electron-withdrawing group, has been linked to electroactive units such as anilines, 14 porphyrins, 15 corannulenes, 16 or phthalocyanines. 17 In most of these systems, photoinduced energy and/or electron transfer has been observed.…”