TY  - JOUR
A1  - Senge, Mathias O.
A1  - Dahms, Katja
A1  - Holdt, Hans-Jürgen
A1  - Kelling, Alexandra
T1  - Porphyrin substituent regiochemistry, conformation and packing - the case of 5,10-diphenylporphyrin
JF  - Zeitschrift für Naturforschung : B, Chemical sciences
N2  - 5,10-Disubstituted porphyrins are more recent additions to the family of meso-substituted porphyrins. A crystallographic comparison of 5,10-diphenylporphyrin with the regioisomeric 5,15-disubstituted system reveals striking differences in their conformation. In the free base porphyrins the former uses mainly out-of-plane distortion to alleviate steric strain while in-plane core elongation predominates in the latter. In contrast, the structure of the Cu(II) complex is planar and forms strong p-p aggregates with very small lateral shifts. Macroscopically, the packing is similar to that of porphyrin sponges of the 5,10,15,20-tetraphenylporphyrin type.
KW  - conformational analysis
KW  - crystal structure
KW  - porphyrins
KW  - tetrapyrroles
Y1  - 2015
U6  - https://doi.org/10.1515/znb-2014-0217
SN  - 0932-0776
SN  - 1865-7117
VL  - 70
IS  - 2
SP  - 119
EP  - 123
PB  - De Gruyter
CY  - Tübingen
ER  - 
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  - 
TY  - JOUR
A1  - Wacker, Philipp
A1  - Dahms, Katja
A1  - Senge, Mathias O.
A1  - Kleinpeter, Erich
T1  - Conformational Landscape of meso-(1,3-Dithian-2-yl)porphyrins
N2  - An investigation of the conformational landscape of 1,3-dithian-2-yl bearing porphyrins and the rotational behavior of the dithianyl substituents in meso position was carried out by variable-temperature (VT) NMR spectroscopy. Additionally, theoretical results for alternative conformations and energy barriers were obtained by molecular modeling. The study revealed different NH trans tautomers with regard to the orientation of the dithianyl ligands for the free base porphyrins 1-3. Relatively ruffled porphyrin core conformations were established for the transition states of the dithianyl rotation, resulting in a lower rotational energy barrier for the nickel(II) complex 4 compared to that of the free base systems. The data obtained and the first depiction of a rotational transition state for the rotation of bulky meso-alkyl substituents illustrate the close structural interplay between meso-alkyl substituents and the macrocycle conformation in porphyrins.
Y1  - 2007
UR  - http://pubs.acs.org/doi/full/10.1021/jo0708700
U6  - https://doi.org/10.1021/Jo0708700
ER  - 
TY  - JOUR
A1  - Senge, Mathias O.
A1  - Hatscher, S. S.
A1  - Wiehe, A.
A1  - Dahms, Katja
A1  - Kelling, Alexandra
T1  - The dithianyl group as a synthon in porphyrin chemistry : condensation reactions and preparation of formylporphyrins under basic conditions
Y1  - 2004
SN  - 0002-7863
ER  -