Electronic and structural properties of N → B-ladder boranes with high electron affinity

Grandl, Markus; Sun, Yu; Pammer, Frank

doi:10.1039/c7qo00876g

Cited by 21 publications

(16 citation statements)

References 128 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The lower optical gap of P4PyBBN originates from a differing electronic structure associated with the 9BBN moiety. We have observed similar effects in other 9BBN-containing N → B ladders − and have further corroborated this observation through DFT calculations discussed in a subsequent section of this paper (see also section 2.2 of the Supporting Information).…”

Section: Results and Discussionsupporting

confidence: 84%

“…The Pammer group has an ongoing interest in the study of N → B ladder boranes that are accessible by hydroboration, − and other synthetic strategies . In our previous works we showed that hydroboration of suitable substrates allows the highly selective introduction of boryl groups and yields N → B ladder boranes whose electron affinity can be varied over a broad range through the substituents on boron. − Furthermore, hydroboration is a mild preparative method that provides near-quantitative yields and has been employed in macromolecular chemistry to prepare boron-containing polymers via polyhydroboration , and introduces boryl groups into polythiophenes and dendrimers . The synthetic method should therefore also be suitable for the preparation of N → B ladder polymers.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

N → B Ladder Polymers Prepared by Postfunctionalization: Tuning of Electron Affinity and Evaluation as Acceptors in All-Polymer Solar Cells

Grandl¹,

Schepper

Maity

et al. 2019

Macromolecules

Self Cite

View full text Add to dashboard Cite

A poly(biphenylene−pyrazinylene) (PPz, E g opt = 3.10 eV) and a head-to-tail regioregular polypyridine (rr-P4Py, E g opt = 3.25 eV) equipped with 1-alkenyl side chains have been prepared and postfunctionalized by hydroboration with different hydroboranes (9H-BBN, (C 6 F 5) 2 B-H (BPF-H), Cl 2 B-H) to give the corresponding ladder polymers featuring intramolecular coordinative N → B bonds. Characterization of the optical and electrochemical properties of the postfunctionalized polymers shows that the borylation strongly increases their electron affinity and lowers the optical gaps. Electron affinities between −3.75 eV (PPzBBN, E g opt = 2.16 eV) and −4.35 eV (PPzBPF, E g opt = 2.07 eV) can be reached for hydroborated PPz, while rr-P4Py-derivatives reach LUMO levels of −3.45 eV (P4PyBBN, E g opt = 2.88 eV), −3.85 eV (P4PyBPF, E g opt = 2.95 eV), and −4.15 eV (P4PyBCl 2 , E g opt = 2.95 eV). The potential of this class of compounds as electron acceptors is demonstrated by the investigation of the semiconducting properties of PPzBBN and PPzBPF, which showed ambipolar charge transport with hole and electron mobilities in order of 2 × 10 −5 cm 2 V −1 s −1. The polymers were tested as acceptors in all-polymer solar cells, which yielded functioning devices, with open-circuit voltages that directly reflect the electron affinity of the employed acceptor.

show abstract

Section: Results and Discussionsupporting

confidence: 84%

Section: Introductionmentioning

confidence: 99%

N → B Ladder Polymers Prepared by Postfunctionalization: Tuning of Electron Affinity and Evaluation as Acceptors in All-Polymer Solar Cells

Grandl¹,

Schepper

Maity

et al. 2019

Macromolecules

Self Cite

View full text Add to dashboard Cite

show abstract

“…B←N has been extensively reported to greatly lower the energies of the LUMO/HOMO of π-conjugated molecules and π-conjugated polymers. − In this work, the N–B←N bridge with proper substitutes leads to greatly lowered LUMO energy, nearly unchanged HOMO energy as well as decreased band gap. This is attributed to the increased quinoid structure of the thiophene/thiazole rings with the N–B←N bridge in BNTzT.…”

Section: Resultsmentioning

confidence: 88%

N–B ← N Bridged Bithiophene: A Building Block with Reduced Band Gap to Design n-Type Conjugated Polymers

et al. 2021

View full text Add to dashboard Cite

The development of conjugated polymers with excellent performance of optoelectronic device depends to a large extent on the molecular design of electron-accepting (A) building blocks. Previously reported A building blocks based on a bithiophene skeleton always show lower lowest unoccupied molecular orbital (LUMO) and highest occupied molecular orbital (HOMO) energies compared to those of bithiophene itself. Herein, we report a new A building block (BNTzT), in which the thiophene−thiazole skeleton is bridged by a N−B←N moiety. Compared to bithiophene, BNTzT exhibits a LUMO level, which is 0.85 eV lower, and a nearly unchanged HOMO level, leading to a reduced band gap. This is due to the electron-withdrawing property and the increased quinodial character of the bithiophene skeleton resulting from the incorporation of the N−B←N moiety. The LUMO energy of the homopolymer of BNTzT is estimated to be −3.68 eV, the band gap as narrow as 1.71 eV, and a nearinfrared fluorescence peaked at 700 nm. Owing to their interesting optoelectronic properties, conjugated polymers constructed from the BNTzT unit can function as electron acceptors in all-polymer solar cells (all-PSCs). This work not only provides a novel A building block for conjugated polymers but also demonstrates a new strategy for designing narrow-band-gap polymers by introducing an N−B←N moiety into a conjugated skeleton.

show abstract

“…Not only transition metals, but also non-transition metals have been used for the preparation of 1,5-naphthyridine complexes. The hydroboration of 1,5-naphthyridine-based precursor 263 ( Scheme 106 ) with 9 H -9-borabicyclo[3.3.1]nonane (9H-BBN) afforded π-conjugated N→B-ladder borane 264 [ 123 ].…”

Section: Reactivity Of 15-naphthyridinesmentioning

confidence: 99%

“…Aluminium chelates of 1,5-naphthyridine derivatives have been studied as exciton-blocking material for organic photovoltaics with prolonged lifetime [ 125 , 143 ]. Also π-conjugated naphthyridine N→B-ladder boranes are materials of interest for use in organic n-type applications in organic electronics [ 123 ].…”

Section: Applications Of 15-naphthyridinesmentioning

confidence: 99%

Synthetic Strategies, Reactivity and Applications of 1,5-Naphthyridines

et al. 2020

View full text Add to dashboard Cite

This review covers the synthesis and reactivity of 1,5-naphthyridine derivatives published in the last 18 years. These heterocycles present a significant importance in the field of medicinal chemistry because many of them exhibit a great variety of biological activities. First, the published strategies related to the synthesis of 1,5-naphthyridines are presented followed by the reactivity of these compounds with electrophilic or nucleophilic reagents, in oxidations, reductions, cross-coupling reactions, modification of side chains or formation of metal complexes. Finally, some properties and applications of these heterocycles studied during this period are examined.

show abstract

Electronic and structural properties of N → B-ladder boranes with high electron affinity

Abstract: A series of electronically and structurally diverse N → B-ladder boranes has been prepared by hydroboration.

Cited by 21 publications

References 128 publications

N → B Ladder Polymers Prepared by Postfunctionalization: Tuning of Electron Affinity and Evaluation as Acceptors in All-Polymer Solar Cells

N → B Ladder Polymers Prepared by Postfunctionalization: Tuning of Electron Affinity and Evaluation as Acceptors in All-Polymer Solar Cells

N–B ← N Bridged Bithiophene: A Building Block with Reduced Band Gap to Design n-Type Conjugated Polymers

Synthetic Strategies, Reactivity and Applications of 1,5-Naphthyridines

Contact Info

Product

Resources

About