Nikolai Hippchen

The symmetrical 7,16-diaza-6,8,15,17-tetrakis(triisopropylsilylethynyl)heptacene was obtained by a Pd-catalyzed reaction of a 2,3-diamino-1,4-diethynylanthracene with a 2,3-dibromo-1,4-diethynyl anthracene. Positioning the TIPS-ethynyl groups adjacent to the central ring suppresses dimerization via [4+4] cycloadditions...

Four substituted nonacenes were prepared and characterized by UV-vis and EPR spectroscopy and X-ray crystallography. The compounds are the most stable and soluble nonacenes to date - due to six...

This work presents the 2 generation of cata-annulated azaacene bisimides with increased electron affinities (up to -4.38 eV) compared to their consaguine conventional azaacenes. These compounds were synthesized via Buchwald-Hartwig...

We present the reduction of two azaacenes (a benzo-[3,4]cyclobuta[1,2-]phenazine and a benzo[3,4]cyclobuta[1,2-]naphtho[2,3-]phenazine derivative), featuring a single cyclobutadiene unit, to their radical anions and dianions. The reduced species were produced using...

Cyclopentannulation was explored as a strategy to access large, stable azaarenes. Buchwald-Hartwig coupling of previously reported di- and tetrabrominated cyclopentannulated N,N'-dihydrotetraazapentacenes furnished stable azaarenes with up to 13 six-membered rings...

Brominated pentannulated dihydrotetraazapentacenes were prepared by gold- or palladium-catalyzed 5-endo-dig cyclization of TIPS-ethynylated dihydrotetraazaacenes (TIPS = triisopropylsilyl). Post-functionalization was demonstrated by Sonogashira alkynylation and Rosenmund-von Braun cyanation. Calculations predict these...

Sixfold TIPS-ethynylation combined with fourfold bromination of the armchair edges furnishes a long-lived, soluble heptacene; π-extension via Stille coupling accesses a persistent tetrabenzononacene. Both types of acenes were stabilized best...

The synthesis of novel (N-)acene-based cyclooligomers is reported. Glaser-Hay coupling of the bisethynylated monomers results in cyclodimers and cyclotrimers that are separable by column and gel-permeation chromatographies. For the diazatetracene,...

The syntheses, properties and application of the air-stable electron acceptors, diindenopyrazines 4 a-g are reported demonstrating the introduction of functional aryl groups in the 6- and 12-positions. The targets are...

Engineering the energetics of perovskite photovoltaic devices through deliberate introduction of dipoles to control the built-in potential of the devices offers an opportunity to enhance their performance without the need...