In-situ characterisable nitrosyl-iron complexes with controllable reactivity in multiphasic reaction media

Nitrosyl-iron species are formed on the reaction of gaseous nitric oxide (NO) with solutions of ferrous starting materials. For the development of multiphasic reaction environments they exhibit ideal preconditions: (1) the product species are detectable and characterisable with a multitude of methods, among them spectroscopic methods that permit in-situ analyses, (2) there is practically no restriction regarding the liquid phase, in particular water can be used as a solvent, (3) significant characteristics such as the complexes' thermodynamic stability or their kinetic and mechanistic parameters vary, dependent on the spectator ligands' type, on an unusually large scale, (4) the typical starting materials are inexpensive; accordingly, costly investigations with technically interesting reactands can be modelled properly. These facts apply to the intensely coloured, "brown-ring-type" nitrosyl-iron species of the S=3/2-{FeNO}7 class which are characterised by an octahedral iron centre with a mostly weakly bound NO ligand in a special electronic situation (triplet-NO(minus) fragment, antiferromagnetically coupled to a high-spin ferric centre). In order to make the advantagesof the substance class usable for chemical engeneering, the rather unknown structure-property relationships are to be established. As the project's major goal, rules shall be derived on the basis of structure analyses and computations, in order to control the thermodynamic and kinetic characteristics as needed for the engeneering part of the study. The substances, both provided by recent preliminary work and newly developped as part of the proposal, shall be investigated by cooperating groups with respect to intrinsic kinetics, and to their reaction in fluid-fluid and in gas-fluid streams. Modelling and simulation are used to fit the experimental data.



Ludwig-Maximilians-Universität München
Fakultät für Chemie und Pharmazie

Project leader
Prof. Dr. Peter Klüfers


Project manager
Dr. Martin Oßberger
Bianca Aas, M.Sc.