Copper-assisted hemiacetal synthesis: a Cu(II) chain obtained by a one-step in situ reaction of picolinaldehyde

Abstract

[eng] The 1D polymer complex [Cu2(L)2(SCN)2]n (1) has been synthesised in a one-step in situ reaction of picolinaldehyde with sodium thiocyanate. The complex 1 was characterised by FTIR spectroscopy, UV/Vis spectrophotometry and elemental analysis. The crystal structure of complex 1 shows that chains of dimer complexes are formed with tetra- and pentacoordinate copper centres alternately linked by one thiocyanato and two alkoxido bridges. Variable-temperature magnetic measurements showed a strong antiferromagnetic interaction between the copper centres within the dimer mediated by the two alkoxido bridges with a J value of -374 cm-1, which is in agreement with the DFT-calculated value of -284 cm-1. EPR and cyclic voltammetric analyses were also carried out, as well as DFT calculations to evaluate the packing forces and their energies.