Home Structure and Conformation of Tetra-meso-, Octa-β-, and Dodecasubstituted 22,24-Dihydroporphyrins (Porphyrin Dications)
Article
Licensed
Unlicensed Requires Authentication

Structure and Conformation of Tetra-meso-, Octa-β-, and Dodecasubstituted 22,24-Dihydroporphyrins (Porphyrin Dications)

  • Mathias O. Senge EMAIL logo and Werner W. Kalisch
Published/Copyright: June 2, 2014
Become an author with De Gruyter Brill

A comparative crystallographic analysis of the conformation of porphyrin diacids with various substituent types reveals considerable differences in the degree of nonplanarity and distortion modes. Diacids of 5,10,15,20-tetraarylporphyrins generally exhibit typical saddledistorted macrocycles with displacements of the Cb positions in the range of 0.7-1.0 Å. Adding peripheral substituents, i.e., using dodecasubstituted porphyrins for the diacid formation yields similar distortion types albeit with larger out-of-plane displacements. As a result of the combined effect of both peripheral (interaction between the Cb and Cm substituents) and core (interaction between the four inner hydrogen atoms) steric strain the maximum Cb displacements reach 1.3-1.5 Å. Quite a different situation is observed for the diacids of 2,3,7,8,12,13,17,18-octaalkylporphyrins. Here, macrocycles with pair-wise displacement of neighboring pyrrole rings and significant NH pyramidalization and those with classic saddle distortion are found. Generally, octa- β-substituted porphyrin diacids show smaller degrees of nonplanarity; Cb displacements ranged from 0.06 to 0.72 Å. On the basis of the overall degree of conformational distortion (⊿24 = average deviation of the 24 macrocycles atoms from the mean plane), the three different types of porphyrin macrocycles studied differ considerably in their degree of conformational flexibility. For several porphyrin crystal structures with different counterions and/or solvate molecules were obtained. Taking into account results from the literature 2,3,7,8,12,13,17,18-octaethyl-22,24-dihydro-5,10,15.,20-tetraphenylporphyrin (13) shows the smallest degree of flexibility (⊿24 = 0.61-0.63 Å; four different X-ray structures), while 22,24-dihydro-5,10,15,20-tetraphenylporphyrin (1) is more flexible (Z⊿24 = 0.42-0.52 Å; four structures). The largest flexibility is observed for 2,3,7,8,12,13,18-octaethyl- 22,24-dihydroporphyrin (7) (⊿24 = 0.02-0.33 Å; four structures).

Received: 1999-5-4
Published Online: 2014-6-2
Published in Print: 1999-7-1

© 1946 – 2014: Verlag der Zeitschrift für Naturforschung

Articles in the same Issue

  1. Titelei
  2. The Structural Chemistry of GoId(I) Quinoline-2-thiolate and Iodide Complexes of Polytertiary Phosphines
  3. EPR-Einkristall-Untersuchungen an (n-Bu4N)2[Cu(dmit)2] im antiferromagnetisch gekoppelten Wirtsgitter (n-Bu4N)2[(dmit)Cu(tto)Cu(dmit)]: Ein Beitrag zur Aufklärung der sogenannten „paramagnetischen Verunreinigung“ im Wirtsgitter / A Single Crystal EPR Investigation on (n-Bu4N)2[Cu(dmit)2] in the Antiferromagnetically Coupled Host Lattice (n-Bu4N)2[(dmit)Cu(tto)Cu(dmit)]: A Contribution to the Nature of the So-called “Paramagnetic Impurities”
  4. Reaktionen von [(η5-C5R5)2WH2] mit Boranen / Reactions of [(η5-C5R5)2WH2] with Boranes
  5. [Ni(NH3 )6]S04 : Kristallstruktur und Infrarotspektren / [Ni(NH3)6]SO4: Crystal Structure and Infrared Spectra
  6. Zur Reaktion von 2,4-Dioxo-4-ferrocenyl-butansäureethylester mit primären aromatischen Aminen / On the Reaction of Ethyl 2,4-Dioxo-4-ferrocenyl-butanoate with Primary Aromatic Amines
  7. Complexes of N-Aryltriphenylphosphinimines with Mercury(II) Halides
  8. Condensed [Ru4Sn6] Units in the Stannides LnRu4Sn6 (Ln = La, Pr, Nd, Sm, Gd) - Synthesis, Structure, and Chemical Bonding
  9. Neutronen- und Röntgenbeugungsuntersuchungen an Pulvern und Einkristallen von Strukturverwandten des Berliner Blaus: CsMnIICrIII(CN)6 · D2O , NMe4MnII(Cr0,06,Mn0,94)III(CN)6 · 8 H2O , NMe4MnIICoIII(CN)6 · 8 H20 , Mn3II[MnIII(CN)6]2 · 15 H2O und Cd3[FeIII(CN)6]2 · 15 H2O / Neutron and X-Ray Diffraction Studies on Powders and Single Crystals of Compounds Structurally Related to Prussian Blue: CsMnIICrIII(CN)6 · D2O, NMe4MnII(Cr0,06Mn0,94)III(CN)6 · 8 H2O, NMe4MnIICoIII(CN)6 · 8 H2O, Mn3II[MnIII(CN)6]2 · 15 H2O and Cd3[FeIII(CN)6]2 · 15 H2O
  10. Über das Octastannandiid R*6Sn8[Na(THF)2 ]2 und zur möglichen Existenz des Octastannans R*6Sn8 [1] / On an Octastannanediide R*6Sn8[Na(THF)2]2 and the Possible Existence of an Octastannane R*6Sn8 [1]
  11. Ligandenaustauschreaktionen von NiCl2 (PPh3)2 mit O(S)⌒N⌒S-Liganden / Ligand Exchange Reactions of NiCl2(PPh3)2 with O(S )⌒ N ⌒ S Ligands
  12. Bis(n-pentanethiolato)mercury(II), Hg(SC5H11)2 - Preparation, Characterization, Crystal and Molecular Structure; Reactivity towards Organic Thiols
  13. K[B6PO10(OH)4]: Ein Borophosphat mit gestreckten Bändern aus Tetraeder-Vierer-Ringen und offen-zyklischen Verzweigungen über planare B2O3(OH)2-Gruppen / K[B6PO10(OH)4]: A Borophosphate Containing Rods of Tetrahedral Vierer-Rings with Additional Open-Loop Branchings via Planar B2O3(OH)2 Groups
  14. Mixed-Sandwich η57 Vanadium Complexes. The Molecular Structure of (η5-2-Methyl-indenyl)-(η7-cycloheptatrienyl)-vanadium
  15. Antimony as a Donor Atom in Silver Coordination Chemistry: Synthesis, IR Spectra and Structure of the Silver(I) Cyanoximate Complexes with Triphenylstibine and Triphenylphosphine Model Compounds
  16. Reaktionen von Isochinolinium-Salzen mit Hydroxylamin-Derivaten, 3. Mitteilung. Mechanismus der Aminoxid-Bildung / Reactions of Isoquinolinium Salts with Hydroxylamine Derivatives, 3rd Communication. Mechanism of Amine Oxide Generation
  17. Alkyl Heteroaromatics as Building Blocks in Organic Synthesis: The Reactivity of Alkyl Azoles toward Electrophilic Reagents
  18. Electronic Structure of 2,6-Bis{.N-(2-hydroxyphenyl)immoinethyl}-4-methylphenol
  19. Two New Aromatic Constituents from Stocksia brahuica
  20. Structure and Conformation of Tetra-meso-, Octa-β-, and Dodecasubstituted 22,24-Dihydroporphyrins (Porphyrin Dications)
  21. Organoactinide Chemistry: Polysilylated Actinidocenes of Thorium, Uranium, and Neptunium
Downloaded on 10.9.2025 from https://www.degruyterbrill.com/document/doi/10.1515/znb-1999-0719/html
Scroll to top button