Cation-induced supramolecular organization of Co(II) and Ru(II) tetra-15-crown-5-phtalocyaninates in organic solvents | 2017 ИФХЭ РАН

Yulia G. Gorbunova. Yulia Yu. Enakieva, Lyudmila I. Demina and Aslan Yu. Tsivadze

The cation-induced supramolecular aggregation of tetra-15-crown-5-phthalocyaninates of cobalt (II) (R4Pc)Co (1) and ruthenium (II) (R4Pc)Ru(CO)(CH3OH) (2) (R=15-crown-5) was studied by means of UV-Vis electronic absorption and FT-IR spectroscopies. Influence of receptor’s and substrate’s nature to the supramolecular assemblies architecture is shown. It is established, that interaction of complex (1) with potassium salts yield supramolecular cofacial dimer of the composition 2(R4Pc)Co x 4KX (X= SCN-, Cl-, C1O4-, СН3СОО-). The reaction of sodium tiocyanate with (R4Pc)Co occurs in two steps. The first step is incapsulation of sodium cations to the crown-ethers fragments with formation of a complex of the composition Co(R4Pc) x 4NaX. During the second stage the formation of the coordinate bond between the tiocyanate anions at the sodium cations located in the crown ether cavity and cobalt ions in phthalocyanine is observed. As the results the framework type of supramolecular aggregates is formed. It is observed only in the case of sodim tiocyanate and is not manifested in the presence of other anions. The reaction of complex (1) with NaCl, NaClO4, and NaCH3COO is stoped after formation of Co(R4Pc)x4NaX complexes.

It is established, that reactions of the complex (R4Pc)Ru(CO)(CH3OH) with K+, Rb+, Cs+ thiocyanates yield supramolecular aggregates of the n.(R4PcRu(CO)(CH3OH))x2n.MNCS in the form of framework. The axial CO and CH3OH ligands prevent the formation of cofacial supramolecular aggregates.

A specific feature of sodium thiocyanate-induced aggregation is the participation of the Ru(II) central ion in formation of supramolecular assemblies. This can occur if the axially coordinated methanol molecule is replaced by the thiocyanate ion. The use of the acetate or perchlorate ion instead of thiocyanate ion as the anion of the substrate modifies the architecture of the resulting supramolecular aggregate.

Thus, the complexes investigated can be recommended for ion-selective sensors for alkali metals cations and tiocyanate-ion determination.

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