TY - JOUR A1 - Büchner, Robby A1 - da Cruz, Vinicius Vaz A1 - Grover, Nitika A1 - Charisiadis, Asterios A1 - Fondell, Mattis A1 - Haverkamp, Robert A1 - Senge, Mathias O. A1 - Föhlisch, Alexander T1 - Fundamental electronic changes upon intersystem crossing in large aromatic photosensitizers: free base 5,10,15,20-tetrakis(4-carboxylatophenyl)porphyrin JF - Physical chemistry, chemical physics : a journal of European Chemical Societies N2 - Free base 5,10,15,20-tetrakis(4-carboxylatophenyl)porphyrin stands for the class of powerful porphyrin photosensitizers for singlet oxygen generation and light-harvesting. The atomic level selectivity of dynamic UV pump - N K-edge probe X-ray absorption spectroscopy in combination with time-dependent density functional theory (TD-DFT) gives direct access to the crucial excited molecular states within the unusual relaxation pathway. The efficient intersystem crossing, that is El-Sayed forbidden and not facilitated by a heavy atom is confirmed to be the result of the long singlet excited state lifetime (Q(x) 4.9 ns) and thermal effects. Overall, the interplay of stabilization by conservation of angular momenta and vibronic relaxation drive the de-excitation in these chromophores. Y1 - 2022 U6 - https://doi.org/10.1039/d1cp05420a SN - 1463-9076 SN - 1463-9084 VL - 24 IS - 12 SP - 7505 EP - 7511 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Ou, Z. P. A1 - Tagliatesta, P. A1 - Senge, Mathias O. A1 - Shao, J. G. A1 - Kadish, K. M. T1 - Synthesis and electrochemical investigation of covalently linked porphyrin dimers containing a beta-brominated subunit : Crystal structure of H-2[tripp-tpp(Br-8)]H-2 N2 - Ten meso-tetraphenylporphyrin-type heterodimers containing a partly or completely beta-brominated subunit were synthesized and characterized by UV-visible spectroscopy, cyclic voltammetry and spectroelectrochemistry, showing the presence of low electronic interactions between the two subunits. The investigated compounds are represented as M[(tripp- tpp(Br-4)]M and M[tripp-tpp(Br-8)]M (M = 2H, Zn, Ni, Co and Cu) where tripp-tpp(Br-4) is the tetraanion of 1-[5- (10,15,20-triphenylporphyrinyl)]-4-[10-(2,3,12,13-tetrabromoporphyr inyl)]-benzene and tripptpp(Br-8) is the tetraanion of 1-[5-(10,15,20-triphenylporphyrinyl)]-4-[10-(2,3,7,8,12,13,17,18-octabro moporphyrinyl)] -benzene. One of the synthesized dimers, H-2[tripp-tpp(Br-8)]H-2, was characterized by a single-crystal X-ray investigation. Copyright (C) 2003 Society of Porphyrins & Phthalocyanines Y1 - 2003 SN - 1088-4246 ER - TY - JOUR A1 - Rath, Harapriya A1 - Anand, V. G. A1 - Sankar, J. A1 - Venkatraman, S. A1 - Chandrashekar, T. K. A1 - Joshi, Bhawani S. A1 - Khetrapal, C. L. A1 - Schilde, Uwe A1 - Senge, Mathias O. T1 - Core-Modified Hexaphyrins; Characterization of Two- and Four-Ring Inverted 26 ô Aromatic Macrocycles Y1 - 2003 UR - http://pubs3.acs.org/acs/journals/doilookup?in_doi=10.1021/ol035408q ER - TY - JOUR A1 - Ryppa, C. A1 - Senge, Mathias O. T1 - Dodecasubstituted porphyrins : an easily accessible type of dendritic porphyrins with tunable properties N2 - Dodecasubstituted dendritic porphyrins with nonplanar macrocycles were synthesized by a convergent approach via Lindsey condensation reactions in good yields Y1 - 2004 SN - 0385-5414 ER - TY - JOUR A1 - Ryppa, C. A1 - Senge, Mathias O. A1 - Hatscher, S. S. A1 - Kleinpeter, Erich A1 - Wacker, Philipp A1 - Schilde, Uwe A1 - Wiehe, A. T1 - Synthesis of mono- and disubstituted porphyrins : A- and 5,10-A(2)-type systems N2 - General syntheses have been developed for meso-substituted porphyrins with one or two substituents in the 5,10- positions and no beta substituents. 5-Substituted porphyrins with only one meso substituent are easily prepared by an acid-catalyzed condensation of dipyrromethane, pyrrole-2-carbaldehyde. and an appropriate aldehyde using a "[2+1+1]" approach. Similarly, 5,10-disubstituted porphyrins are accessible by simple condensation of unsubstituted tripyrrane with pyrrole and various aldehydes using a "[3+1]" approach. The yields for these reactions are low to moderate and additional formation of either di- or mono-substituted porphyrins due to scrambling of the intermediates is observed. However, the reactions can be performed quite easily and the desired target compounds are easily removed due to large differences in solubility. A complementary and more selective synthesis involves the use of organolithium reagents for SNAr reactions. Reaction of in situ generated porphyrin (porphine) with 1.1-8 equivalents of RLi gave the monosubstituted porphyrins, while reaction with 3-6 equivalents of RLi gave the 5,10-disubstituted porphyrins in yields ranging from 43 to 90%. These hitherto almost inaccessible compounds complete the series of different homologues of A-, 5,15-A(2)-, 5,10-A(2)-, A(3)-, and A(4)-type porphyrin's and allow an investigation of the gradual influence of type, number, and regiochemical arrangement of substituents on the properties of meso-substituted porphyrins. They also present important starting materials for the synthesis of ABCD porphyrins and are potential synthons for supramolecular materials requiring specific substituent orientations Y1 - 2005 SN - 0947-6539 ER - TY - JOUR A1 - Senge, Mathias O. A1 - Bischoff, Ines T1 - SNAr reactions of beta-substituted porphyrins and the synthesis of meso substituted tetrabenzoporphyrins N2 - Reaction of 2,3.7,8,12,13,17,18-octaethylporphyrin with LiR reagents containing functional groups readily yields meso substituted derivatives suitable for further transformations with residues such as -p-C6H5Br, -p-C6H5-C=CH - p-C6H5-NH2 or -(CH2)(3)-CH=CH2. Similar reactions of tetrabenzoporphyrin with alkyllithium reagents afforded the first entry into meso mono- and dialkylsubstituted tetrabenzoporphyrins while reaction of bicyclo[2.2.2]oct-type masked isoindole precursors with LiR followed by in situ retro-Diels-Alder reaction also afforded the 5-phenyl and 5,10- diphenyltetrabenzoporphyrins in high purity. (C) 2004 Elsevier Ltd. All rights reserved Y1 - 2004 SN - 0040-4039 ER - 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 - Flanagan, Keith J. A1 - Ryan, Aoife A. A1 - Ryppa, Claudia A1 - Donath, Mandy A1 - Twamley, Brendan T1 - Conformational and structural studies of meso monosubstituted metalloporphyrins-Edge-on molecular interactions of porphyrins in crystals JF - Tetrahedron N2 - A series of meso monosubstituted metalloporphyrins were synthesized to assess the structural chemistry of porphyrins with only one substituent. The structures of four nickel(II) and zinc(II) complexes with either alkyl or aryl residues indicate primarily planar macrocycles. This gives rise to a different type of pi-interactions in the crystal and the formation of dimeric, trimeric or tetrameric porphyrin units that function as building blocks for the overall crystal structure. Notably, some structures exhibit a unique edge-on packing of porphyrins, while the molecules of (5-n-butylporphyrinato)nickel(II) forms an unusual bilayer type structure where rows of two porphyrin macrocycles are separated by the alkyl residues arranged in a head-to-head fashion. This adds to the canon of intermolecular porphyrin packing arrangements and is of relevance for the preparation of ordered nanoscopic porphyrin devices. (C) 2015 Elsevier Ltd. All rights reserved. KW - Porphyrins KW - Conformational analysis KW - Tetrapyrroles KW - Crystal structure KW - Crystal packing Y1 - 2016 U6 - https://doi.org/10.1016/j.tet.2015.11.008 SN - 0040-4020 VL - 72 SP - 105 EP - 115 PB - Elsevier CY - Oxford 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 - TY - JOUR A1 - Senge, Mathias O. A1 - Richter, J. T1 - Synthetic, transformations of porphyrins : Advances 2002-2004 N2 - Contemporary methods for the modification of porphyrins are presented. In association with the Third International Conference on Porphyrins and Phthalocyanines (ICPP-3) a survey of current method developments and reactivity studies is made. The review focuses on synthetic transformations of porphyrins currently in use for various applications and on functional group transformations. A brief survey of important developments covers selectively the literature from late 2001 to early 2004. Copyright (c) 2004 Society of Porphyrins C Phthalocyanines Y1 - 2004 SN - 1088-4246 ER -