Synthesis and Characterisation of a New Cu(O(2)CNAllyl(2))(2) Carbamato Complex and an Unusual Polymeric Cu-I Complex [(Cu4Cl4)-Cl-I(NHAllyl(2))(4)]n: New Insights into Metal Carbamato Chemistry

Transition-metal N,N-dialkylcarbamato complexes represent an interesting class of compounds that can be conveniently used as precursors for the controlled formation of inorganic compounds, typically oxides. They can also be used as convenient precursors for chemical grafting of metal oxides on oxide surfaces as well as for the synthesis of inorganic-organic hybrid materials. In this last case, the presence of double bonds on the complex would enable its covalent embedding into a polymer matrix through reaction with suitable monomers. To this aim, we addressed the synthesis of an allyl-functionalised copper carbarnato complex. During the synthesis of the N,N-diallylcarbamato complex Cu(O2CN-Allyl(2))(2) (Cut), the formation of the crystalline and unusual polymeric Cu-I complex [(Cu4Cl4)-Cl-I(NHAllyl(2))(4)](n) (Cu2) was observed. The new compound was characterised by X-ray single crystal diffraction and FTIR, H-1 and C-13 NMR spectroscopic analysis. In an attempt to investigate the redox mechanism and the equilibria leading to the formation of the observed unusual Cu-I polymeric complex, gas chromatography coupled with mass spectrometry (GC-MS) experiments were carried out, which allowed us to identify 3,4-dimethylpyrrole as the oxidation product of the reaction, leading to the reduction of Cu-II to Cu-I.