Diatomic molecules attached to complexed iron or cobalt centres are important in many biological processes. In natural systems, metallotetrapyrrole units carry respiratory gases or provide sensing and catalytic functions. Conceiving synthetic model systems strongly helps to determine the pertinent chemical foundations for such processes, with recent work highlighting the importance of the prosthetic groups' conformational flexibility as an intricate variable affecting their functional properties. Here, we present simple model systems to investigate, at the single molecule level, the interaction of carbon monoxide with saddle-shaped iron– and cobalt–porphyrin conformers, which have been stabilized as two-dimensional arrays on well-defined surfaces. Using scanning tunnelling microscopy we identified a novel bonding scheme expressed in tilted monocarbonyl and cis-dicarbonyl configurations at the functional metal-macrocycle unit. Modelling with density functional theory revealed that the weakly bonded diatomic carbonyl adduct can effectively bridge specific pyrrole groups with the metal atom as a result of the pronounced saddle-shape conformation of the porphyrin cage.
Subscribe to Journal
Get full journal access for 1 year
only $13.33 per issue
All prices are NET prices.
VAT will be added later in the checkout.
Rent or Buy article
Get time limited or full article access on ReadCube.
All prices are NET prices.
Spiro, T. G. & Kozlowski, P. M. Is the CO Adduct of myoglobin bent, and does it matter? Acc. Chem. Res. 34, 137–144 (2001).
Collman, J. P., Boulatov, R., Sunderland, C. J. & Fu., L. Functional analogues of cytochrome c oxidase, myoglobin, and hemoglobin. Chem. Rev. 104, 561–588 (2004).
Ghosh, A. Metalloporphyrin–NO bonding: building bridges with organometallic chemistry. Acc. Chem. Res. 38, 943–954 (2005).
Hoard, J. L. Stereochemistry of hemes and other metalloporphyrins. Science 174, 1295–1302 (1971).
Kratky, C. et al. The saddle conformation of hydroporphinoid nickel(II) complexes: structure, origin, and stereochemical consequences. Helv. Chim. Act. 68, 1312–1327 (1985).
Barkigia, K. M., Chantranupong, L., Smith, K. M. & Fajer, J. Structural and theoretical models of photosynthetic chromophores. Implications for redox, light absorption properties and vectorial electron flow. J. Am. Chem. Soc. 110, 7566–7567 (1988).
Barkigia, K. M. et al. Nonplanar porphyrins. X-ray structures of (2,3,7,8,12,13,17,18-octaethyl- and -octamethyl-5,10,15,20-tetraphenyl-porphinato)zinc(II). J. Am. Chem. Soc. 112, 8851–8857 (1990).
Sparks, L. D. et al. Metal dependence of the nonplanar distortion of octaalkyltetraphenylporphyrins. J. Am. Chem. Soc. 115, 581–592 (1993).
Shelnutt, J. A. et al. Nonplanar porphyrins and their significance in proteins. Chem. Soc. Rev. 27, 31–41 (1998).
Senge, M. O. Exercises in molecular gymnastics—bending, stretching and twisting. Chem. Commun. 243–256 (2006).
Weber-Bargioni, A. et al. Visualizing the frontier orbitals of a conformationally adapted metalloporphyrin. ChemPhysChem 9, 89–94 (2008).
Auwärter, W. et al. Site-specific electronic and geometric interface structure of Co-tetraphenyl-porphyrin layers on Ag(111). Phys. Rev. B 81, 245403 (2010).
Springer, B. A., Sligar, S. G., Olson, J. S. & Phillips, G. N. Jr. Mechanisms of ligand recognition in myoglobin. Chem. Rev. 94, 699–714 (1994).
Aono, S. Biochemical and biophysical properties of the CO-sensing transcriptional activator CooA. Acc. Chem. Res. 36, 825–831 (2003).
Kim, H. P., Ryter, S. W. & Choi, A. M. K. CO as a cellular signaling molecule. Annu. Rev. Pharmacol. Toxicol. 46, 411–449 (2006).
Kachalova, G. S., Popov, A. N. & Bartunik, H. D. A steric mechanism for inhibition of CO binding to heme proteins. Science 284, 473–476 (1999).
Sigfridsson, E. & Ryde, U. On the significance of hydrogen bonds for the discrimination between CO and O2 by myoglobin. J. Biol. Inorg. Chem. 4, 99–110 (1999).
Leu, B. M. et al. Quantitative vibrational dynamics of iron in carbonyl porphyrins. Biophys. J. 92, 3764–3783 (2007).
Madura, P. & Scheidt, W. R. Stereochemistry of low-spin cobalt porphyrins. 8. α,β,γ,δ-Tetraphenylporphinatocobalt(II). Inorg. Chem. 15, 3182–3184 (1976).
Auwärter, W. et al. Controlled metalation of self-assembled porphyrin nanoarrays in two dimensions. ChemPhysChem 8, 250–254 (2007).
Meyer, G., Neu, B. & Rieder, K. H. Controlled lateral manipulaiton of single molecules with the scanning tunneling microscope. Appl. Phys. A 60, 343–345 (1995).
Lee, H. J. & Ho, W. Single-bond formation and characterization with a scanning tunneling microscope. Science 286, 1719–1722 (1999).
Auwärter, W. et al. Molecular nanoscience and engineering on surfaces. Int. J. Nanotechnol. 5, 1171–1193 (2008).
Brand, H. & Arnold, J. Recent developments in the chemistry of early transition metal porphyrin compounds. Coord. Chem. Rev. 140, 137–168 (1995).
Smith, P. D., James, B. R. & Dolphin, D. H. Structural aspects and coordination chemistry of metal porphyrin complexes with emphasis on axial ligand binding to carbon donors and mono- and diatomic nitrogen and oxygen donors. Coord. Chem. Rev. 39, 31–75 (1981).
Wahl, P. et al. Kondo effect of molecular complexes at surfaces: ligand control of the local spin coupling. Phys. Rev. Lett. 95, 166601 (2005).
Flechtner, K., Kretschmann, A., Steinrück, H. P. & Gottfried, J. M. NO-induced reversible switching of the electronic interaction between a porphyrin-coordinated cobalt ion and a silver surface. J. Am. Chem. Soc. 129, 12110–12111 (2007).
Barth, J. V. Fresh perspectives for surface coordination chemistry. Surf. Sci. 603, 1533–1541 (2009).
Kresse, G. & Joubert, D. From ultrasoft pseudopotentials to the projector augmented-wave method. Phys. Rev. B 59, 1758–1775 (1999).
Mercurio, G. et al. Structure and energetics of azobenzene on Ag(111): benchmarking semiempirical dispersion correction approaches. Phys. Rev. Lett. 104, 036102 (2010).
Vladimirova, M. et al. Substrate-induced supramolecular ordering of functional molecules: theoretical modelling and STM investigation of the PEBA/Ag(111) system. Acta Mater. 52, 1589–1596 (2004).
Rohlfing, M., Temirov, R. & Tautz, F. S. Adsorption structure and scanning tunneling data of a prototype organic–inorganic interface: PTCDA on Ag(111). Phys. Rev. B 76, 115421 (2007).
Klappenberger, F. et al. Conformational adaptation in supramolecular assembly on surfaces. ChemPhysChem 8, 1782–1786 (2007).
Franke, K. J. et al. Reducing the molecule–substrate coupling in C60-based nanostructures by molecular interactions. Phys. Rev. Lett. 100, 036807 (2008).
This work was supported by the European Research Council Advanced Grant MolArt (no. 247299), the Deutsche Forschungsgemeinschaft Cluster of Excellence Munich Center for Advanced Photonics, Canadian National Science and Engineering Research Council (NSERC) and Canada Foundation for Innovation (CFI). W.A., A.W.-B. and J.R. thank the Technische Universität München Institute for Advanced Studies, the German Academic Exchange Service and the Deutsche Forschungsgesellschaft for scholarships, respectively. M.–L.B. acknowledges computational time at the Leibniz Rechenzentrum Garching. N.L. thanks Spanish Ministerio de Ciencia e Innovación for financial support (grant no. FIS2009-1271-C04-01).
The authors declare no competing financial interests.
About this article
Cite this article
Seufert, K., Bocquet, M., Auwärter, W. et al. Cis-dicarbonyl binding at cobalt and iron porphyrins with saddle-shape conformation. Nature Chem 3, 114–119 (2011) doi:10.1038/nchem.956
Bifunctional Behavior of a Porphyrin in Hydrogen-Bonded Donor–Acceptor Molecular Chains on a Gold Surface
The Journal of Physical Chemistry C (2019)
One-Dimensional Double Wires and Two-Dimensional Mobile Grids: Cobalt/Bipyridine Coordination Networks at the Solid/Liquid Interface
The Journal of Physical Chemistry Letters (2019)
The Journal of Physical Chemistry C (2018)
Sparse-coding denoising applied to reversible conformational switching of a porphyrin self-assembled monolayer induced by scanning tunnelling microscopy
Journal of Microscopy (2018)