@article{BuechnerdaCruzGroveretal.2022,
  author    = {B{\"u}chner, Robby and da Cruz, Vinicius Vaz and Grover, Nitika and Charisiadis, Asterios and Fondell, Mattis and Haverkamp, Robert and Senge, Mathias O. and F{\"o}hlisch, Alexander},
  title     = {Fundamental electronic changes upon intersystem crossing in large aromatic photosensitizers: free base 5,10,15,20-tetrakis(4-carboxylatophenyl)porphyrin},
  series = {Physical chemistry, chemical physics : a journal of European Chemical Societies},
  volume    = {24},
  journal   = {Physical chemistry, chemical physics : a journal of European Chemical Societies},
  number    = {12},
  publisher = {Royal Society of Chemistry},
  address   = {Cambridge},
  issn      = {1463-9076},
  doi       = {10.1039/d1cp05420a},
  pages     = {7505 -- 7511},
  year      = {2022},
  abstract  = {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.},
  language  = {en}
}
@article{SengeFlanaganRyanetal.2016,
  author    = {Senge, Mathias O. and Flanagan, Keith J. and Ryan, Aoife A. and Ryppa, Claudia and Donath, Mandy and Twamley, Brendan},
  title     = {Conformational and structural studies of meso monosubstituted metalloporphyrins-Edge-on molecular interactions of porphyrins in crystals},
  series = {Tetrahedron},
  volume    = {72},
  journal   = {Tetrahedron},
  publisher = {Elsevier},
  address   = {Oxford},
  issn      = {0040-4020},
  doi       = {10.1016/j.tet.2015.11.008},
  pages     = {105 -- 115},
  year      = {2016},
  abstract  = {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.},
  language  = {en}
}
@article{SengeDahmsHoldtetal.2015,
  author    = {Senge, Mathias O. and Dahms, Katja and Holdt, Hans-J{\"u}rgen and Kelling, Alexandra},
  title     = {Porphyrin substituent regiochemistry, conformation and packing - the case of 5,10-diphenylporphyrin},
  series = {Zeitschrift f{\"u}r Naturforschung : B, Chemical sciences},
  volume    = {70},
  journal   = {Zeitschrift f{\"u}r Naturforschung : B, Chemical sciences},
  number    = {2},
  publisher = {De Gruyter},
  address   = {T{\"u}bingen},
  issn      = {0932-0776},
  doi       = {10.1515/znb-2014-0217},
  pages     = {119 -- 123},
  year      = {2015},
  abstract  = {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.},
  language  = {en}
}
@article{SengeRyppaFazekasetal.2011,
  author    = {Senge, Mathias O. and Ryppa, Claudia and Fazekas, Marijana and Zawadzka, Monika and Dahms, Katja},
  title     = {5,10-A2B2-Type meso-Substituted PorphyrinsuA Unique Class of Porphyrins with a Realigned Dipole Moment},
  series = {Chemistry - a European journal},
  volume    = {17},
  journal   = {Chemistry - a European journal},
  number    = {48},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {0947-6539},
  doi       = {10.1002/chem.201101934},
  pages     = {13562 -- 13573},
  year      = {2011},
  abstract  = {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.},
  language  = {en}
}
@article{WackerDahmsSengeetal.2007,
  author    = {Wacker, Philipp and Dahms, Katja and Senge, Mathias O. and Kleinpeter, Erich},
  title     = {Conformational Landscape of meso-(1,3-Dithian-2-yl)porphyrins},
  doi       = {10.1021/Jo0708700},
  year      = {2007},
  abstract  = {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.},
  language  = {en}
}
@article{SengeShakerPinteaetal.2010,
  author    = {Senge, Mathias O. and Shaker, Yasser M. and Pintea, Monica and Ryppa, Claudia and Hatscher, Sabine S. and Ryan, Aoife and Sergeeva, Yulia},
  title     = {Synthesis of meso-substituted ABCD-Type porphyrins by functionalization reactions},
  issn      = {1434-193X},
  doi       = {10.1002/ejoc.200901113},
  year      = {2010},
  abstract  = {Considerable progress has been made in recent years in the search for synthetic methods leading to functionalized porphyrins, especially for modification of either the beta- or meso positions. For the latter, total synthesis based on condensation methods or partial synthesis through functionalization of preformed porphyrin have emerged as possible methods. The increasing number of possible technical and medicinal applications for unsymmetrically meso-substituted porphyrins requires straightforward methods for the preparation of the so-called ABCD-porphyrins, i.e., porphyrins with up to four different meso substituents. Here, we describe new strategies for the synthesis of ABCD-type porphyrins based on porphyrin reactions with organolithium reagents and the use of Pd-catalyzed coupling reactions. With the whole repertoire of contemporary functionalization methods, a comprehensive analysis and comparison of the various strategies for A-, AB-, A(2)B-, ABC-, A(2)BC- and ABCD-type porphyrins is given. In addition, we report on the synthesis of new functionalized derivatives for some of these porphyrin classes. In practical terms and taking an applied-science- oriented approach, the synthesis of unsymmetrically meso-substituted porphyrins is best accomplished by a combination of well-developed condensation methods with subsequent functionalization. by organolithium compounds or transition-metal- catalyzed coupling protocols. The methods described are suitable for the preparation of porphyrins for many divergent applications ranging over amphiphilic porphyrins for photodynamic therapy, push-pull systems for optical applications and chiral systems useful in catalysis to donor-acceptor systems suitable for electron-transfer studies.},
  language  = {en}
}
@article{OuTagliatestaSengeetal.2003,
  author    = {Ou, Z. P. and Tagliatesta, P. and Senge, Mathias O. and Shao, J. G. and Kadish, K. M.},
  title     = {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},
  issn      = {1088-4246},
  year      = {2003},
  abstract  = {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},
  language  = {en}
}
@article{RathAnandSankaretal.2003,
  author    = {Rath, Harapriya and Anand, V. G. and Sankar, J. and Venkatraman, S. and Chandrashekar, T. K. and Joshi, Bhawani S. and Khetrapal, C. L. and Schilde, Uwe and Senge, Mathias O.},
  title     = {Core-Modified Hexaphyrins; Characterization of Two- and Four-Ring Inverted 26 {\^o} Aromatic Macrocycles},
  year      = {2003},
  language  = {en}
}
@article{SengeRichter2004,
  author    = {Senge, Mathias O. and Richter, J.},
  title     = {Synthetic, transformations of porphyrins : Advances 2002-2004},
  issn      = {1088-4246},
  year      = {2004},
  abstract  = {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},
  language  = {en}
}
@article{VenkatramanKumarSankaretal.2004,
  author    = {Venkatraman, S. and Kumar, R. and Sankar, J. and Chandrashekar, T. K. and Sendhil, K. and Vijayan, C. and Kelling, Alexandra and Senge, Mathias O.},
  title     = {Oxasmaragdyrin-ferrocene and oxacorrole-ferrocene conjugates : Synthesis, structure, and nonlinear optical properties},
  issn      = {0947-6539},
  year      = {2004},
  abstract  = {Ferrocenyl macrocyclic conjugates involving 22pi oxasmaragdyrins and 18pi oxacorroles have been synthesized and characterized. The direct covalent linkage of the ferrocenyl moiety to the meso position of the macrocycle is achieved by simple oxidative coupling of appropriate precursors with trifluoroacetic acid as catalyst. The electronic coupling between the ferrocenyl moiety and the macrocyclic pi system is apparent from: a) the red shifts (293-718 cm(-1)) of the Soret and Q-bands in the electronic absorption spectra of ferrocenyl conjugates; b) the shift of oxidation potentials (50 130 mV) of both the ferrocene and the corrole rings to the positive potentials; and c) considerable shortening of the C-C bond which connects the ferrocene and the meso-carbon atom of the macrocycle. The single-crystal X-ray structure of oxasmaragdyrin-ferrocene conjugate 9 reveals the planarity of the 22pi skeleton with very small deviations of the meso-carbon atoms. The meso-ferrocenyl substituent has a small dihedral angle of 38degrees, making way for mixing of the molecular orbitals of the ferrocene and the macrocycle. However, the other two meso substituents are almost perpendicular to the mean plane, defined by the three meso carbon atoms. Classical C-(HO)-O-... and nonclassical C- H(...)pi interactions lead to a two-dimensional supramolecular network. Ferrocene-smaragdyrin conjugate 9 bonds to a chloride ion in the protonated form and a rhodium(i) ion in the free base form. Nonlinear optical measurements reveal a larger nonlinear refractive index (-5.83 x 10(-8) cm(2) W-1) and figure of merit (2.28 x 10(-8) cm(3)W(-1)) for the rhodium smaragdyrin-ferrocene conjugate 19 than for the others, suggesting its possible application in optical devices},
  language  = {en}
}