Inorganic-organic hybrid materials based on Co(III) tetra-aza-macrocyclic complexes and Lindqvist type poly-oxo anions: Synthesis, characterization and spectroscopy of [Co~(III)(L)(NO_2)_2] _2[Mo_6O_(19)] and [Co~(III)(L)(NCS) _2]_2[W_6O_(19)]·2CH_3CN (L = Transdiene)

摘要

This article describes the synthesis and characterization of two polyoxometalate based ion-pair compounds [Co~(III)(L)(NO _2)_2]_2[Mo_6O_(19)] (1) and [Co~(III)(L)(NCS)_2]_2[W_6O _(19)]·2CH_3CN (2) (L = 5,7,7,12,14,14-hexamethyl-1,4, 8,11-tetraazacyclotetradeca-4,11-diene). They have been isolated by anionic metathesis of the respective perchlorate and thiocyanate salts with the Lindqvist type isopolyanions. The detailed spectroscopic (IR, UV-visible and ESR) analyses have been performed on compounds 1 and 2 along with their unambiguous crystal structure determination. The polyoxometalate cluster anions not only serve as the counter anions but are also involved in extensive non-covalent interactions with the macrocyclic cationic complexes in their respective crystals. Phase homogeneity of the synthesized compounds in bulk has been established by the X-ray powder diffraction study. Thermal analysis has also been carried out on the title compounds.