TY  - JOUR
A1  - Senge, Mathias O.
A1  - Ryppa, Claudia
A1  - Fazekas, Marijana
A1  - Zawadzka, Monika
A1  - Dahms, Katja
T1  - 5,10-A2B2-Type meso-Substituted PorphyrinsuA Unique Class of Porphyrins with a Realigned Dipole Moment
JF  - Chemistry - a European journal
N2  - Current applications in porphyrin chemistry require the use of unsymmetrically substituted porphyrins. Many current industrial interests in optics and biomedicine require systems with either pushpull (electron-donating and -withdrawing groups) or amphiphilic systems (hydrophobic and hydrophilic groups). In this context we present the class of 5,10-A2B2-type porphyrins for which two different substituents are positioned in diagonally opposite meso positions. Thus, the intramolecular dipole moment in these tetrapyrroles is positioned along a beta-beta vector passing through two pyrrole rings. This is opposite to the situation of the frequently used 5,15-A2BC porphyrins for which the dipole moment is oriented along a mesomeso axis. We have elaborated syntheses of the 5,10-A2B2 porphyrins by using transition-metal-catalyzed transformations of 5,10-A2 porphyrins or direct substitutions reactions thereof; this gives the target molecules in 2277% overall yields. The compounds exhibit interesting structural, spectroscopic, and optical features and can serve as building blocks for new porphyrin arrays and applications.
KW  - macrocycles
KW  - nitrogen heterocycles
KW  - nonlinear optics
KW  - porphyrinoids
KW  - tetrapyrroles
Y1  - 2011
U6  - https://doi.org/10.1002/chem.201101934
SN  - 0947-6539
VL  - 17
IS  - 48
SP  - 13562
EP  - 13573
PB  - Wiley-VCH
CY  - Weinheim
ER  -