Tuning the electrochemical potential of perfunctionalized dodecaborate clusters through vertex differentiation

Abstract

We report a new class of redox-active vertex-differentiated dodecaborate clusters featuring pentafluoroaryl groups. These [B12(OR)11NO2] clusters share several unique photophysical properties with their [B12(OR)12] analogues, while exhibiting significantly higher (+0.5 V) redox potentials. This work describes the synthesis, characterization, and isolation of [B12(O-CH2C6F5)11NO2] clusters in all 3 oxidation states (dianion, radical, and neutral). Reactivity to post-functionalization with thiol species via SNAr on the pentafluoroaryl groups is also demonstrated.

Tunable Dopants with Intrinsic Counterion Separation Reveal the Effects of Electron Affinity on Dopant Intercalation and Free Carrier Production in Sequentially Doped Conjugated Polymer Films

“…In this work, we take advantage of DDB clusters that have similar size and shape and whose redox potentials can be controllably tuned via their substituents. [36,52,53] The clusters have an icosahedral dodecaborane core with a substituent on each boron atom in the form B 12 (OCH 2 R) 12 , where R is a functionalized aryl group (see Figure 1a for core structure and Figure 1c for R-group substituents). The redox potential of the cluster varies roughly linearly with the Hammett parameter of the chosen R-group, [54] providing a straightforward way to produce clusters with any desired redox potential, as shown in Figure 1b; see the Supporting Information for more details of how the redox potentials were measured.…”

A Super-Oxidized Radical Cationic Icosahedral Boron Cluster

“…(A) Structures of polyhedral closo -boron clusters as predicted by the Wade–Mingos electron-counting rules. , (B) Examples of redox-active, perfunctionalized closo -dodecaborate clusters ([B 12 (OH) 12 ] 2– , [B 12 (CH 3 ) 12 ] 2– , and [B 12 Cl 12 ] − ). (C) Established redox chemistry for alkoxy and benzyloxy-substituted B 12 clusters, ,,,,, and this work, which introduces a third, reversible redox event for the B 12 (O-3-methylbutyl) 12 ( 1 ) derivative.…”

Synthesis, Electronic Properties and Reactivity of [B12X11(NO2)]2− (X=F–I) Dianions

“…Starting from the parent closo ‐dodecaborate [B 12 H 12 ] 2− the ammonio‐substituted perhalogenated clusters [B 12 X 11 (NH 3 )] − (X=F–I) were obtained in two steps by known procedures [13a,e, 16] . Subsequently, the ammonio group was oxidized with H 2 O 2 following a procedure used before for the synthesis of [B 12 (OH) 11 (NO 2 )] 2− [15, 17] . For this purpose, the potassium salts of [B 12 X 11 (NH 3 )] − were dissolved in an aqueous solution of hydrogen peroxide (30 %).…”

“…[13a,e, 16] Subsequently,t he ammonio group was oxidized with H 2 O 2 following ap rocedure used before for the synthesis of [B 12 (OH) 11 (NO 2 )] 2À . [15,17] For this purpose, the potassium salts of [B 12 X 11 (NH 3 )] À were dissolved in an aqueous solution of hydrogen peroxide (30 %). Subsequently,p otassium hydroxide was added to adjust the pH value to 8-10 (Caution:As trong gas evolutionc an occur due to decomposition of H 2 O 2 .T he use of a burst shield to protect from possible explosion is recommended.).…”

“…[13] Introduction of an NR 3 + group reduces the total charge from À2t oÀ1, which leads to better solubility in organic solvents and allowed the synthesis of new ionic liquids. [13d] While the functional groups Y = NH 2 , OH and OR reduce the electronic stabilityo ft he dianion, a nitro group (Y = NO 2 )i se xpected to increase the electronic stability of [B 12 X 11 (NO 2 )] 2À compared to [B 12 X 12 ] 2À .T he closo-borate anions[ B n H n-1 (NO 2 )] 2À (n = 6, 9, 10) [14] and [B 12 (OR) 11 (NO 2 )] 2À [15] with one nitro group have been reported, but no halogenated derivatives are known. Herein, we report the synthesis of [B 12 X 11 (NO 2 )] 2À (X = FÀI).…”