@article{RyppaSenge2004,
  author    = {Ryppa, C. and Senge, Mathias O.},
  title     = {Dodecasubstituted porphyrins : an easily accessible type of dendritic porphyrins with tunable properties},
  issn      = {0385-5414},
  year      = {2004},
  abstract  = {Dodecasubstituted dendritic porphyrins with nonplanar macrocycles were synthesized by a convergent approach via Lindsey condensation reactions in good yields},
  language  = {en}
}
@article{SengeHatscherWieheetal.2004,
  author    = {Senge, Mathias O. and Hatscher, S. S. and Wiehe, A. and Dahms, Katja and Kelling, Alexandra},
  title     = {The dithianyl group as a synthon in porphyrin chemistry : condensation reactions and preparation of formylporphyrins under basic conditions},
  issn      = {0002-7863},
  year      = {2004},
  language  = {en}
}
@article{BarkigiaRennerSengeetal.2004,
  author    = {Barkigia, Kathleen M. and Renner, Mark W. and Senge, Mathias O. and Fajer, Jack},
  title     = {Interplay of axial ligation, hydrogen bonding, self-assembly, and conformational landscapes in high-spin Ni(II) porphyrins},
  issn      = {1520-6106},
  year      = {2004},
  abstract  = {The molecular structures of four bis-ligated high-spin Ni(II) complexes of the sterically crowded, nonplanar 2,3,7,8,12,13,17,18-octaethyl-5,10,15,20-tetranitroporphytin (NiOETNP) are reported. The ligands are imidazole (Im), imidazole plus 2-methylimidazole (2-MeIm) in the crystal lattice, 1-methylimidazole (1-MeIm), and 2,1,3- benzoselenadiazole (BSeD). Extensive intermolecular hydrogen bonding is observed in the three imidazole-ligated structures consisting of NH...O and CH...O bonding from the imidazoles to neighboring nitro groups and of NH...N interactions to a nearby 2-MeIm. The different modes of hydrogen bonding, typical of those frequently observed in proteins, mediate the self-assembly of discrete porphyrin dimers as well as more extensive two- and three-dimensional arrays. Only the bis-BSeD complex remains monomeric. The presence or absence of the different types of hydrogen bonds controls the orientations of the axial ligands and also modulates the conformations of the porphyrin skeletons. This interplay of axial ligation, hydrogen bonding, and self-assembly further illustrates the multi conformational landscapes that porphyrins can access as a function of their microenvironment. Such nonplanar deformations have been shown to significantly affect the optical, redox, magnetic, radical, and excited state properties of porphyrin derivatives. That hydrogen bonding can influence ligand interactions with neighboring functional groups as well as macrocycle conformations with their concomitant consequences on physical and chemical properties may thus be particularly relevant to the bioenergetic roles of porphyrin in vivo. These results also raise the question whether point mutations near porphyrins in vivo are structurally, and consequently functionally, innocent},
  language  = {en}
}
@article{SengeBischoff2004,
  author    = {Senge, Mathias O. and Bischoff, Ines},
  title     = {SNAr reactions of beta-substituted porphyrins and the synthesis of meso substituted tetrabenzoporphyrins},
  issn      = {0040-4039},
  year      = {2004},
  abstract  = {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},
  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}
}
@article{SengeRosslervonGersdorffetal.2004,
  author    = {Senge, Mathias O. and Rossler, B. and von Gersdorff, J. and Schafer, A. and Kurreck, H.},
  title     = {The meso-beta-linkage as structural motif in porphyrin-based donor-acceptor compounds},
  issn      = {0040-4039},
  year      = {2004},
  abstract  = {Synthetic strategies for using the beta-linkage as a structural motif in electron transfer mimics have been tested. Exploratory syntheses of directly meso-beta-linked bis- and trisporphyrins and the first representative X-ray structure of a meso-beta-linked bisporphyrins are reported. The structure reveals a unique form of intramolecular- pi-pi stabilization between one porphyrin and a meso-aryl substituent in a second porphyrin unit that accounts for the stability of different atropisomers in trimers. Using beta-formyl porphyrins, dipyrromethanes, and suitable quinone precursor aldehydes, mixed condensations gave convenient access to porphyrin-porphyrin-quinone (P-P-Q) donor acceptor systems consisting of a meso-beta-linked bisporphyrin. a spacer, and a quinone acceptor. (C) 2004 Elsevier Ltd. All rights reserved},
  language  = {en}
}