Synthesis, structural characterization and study of {{K(H(2)mna)(2)](+)center dot[K(mu-OH)(2)](-)center dot 4H(2)O}(n) (H(2)mna=2-mercapto-nicotinic acid). A supramolecular architecture of inorganic/metal-organic hybrid self-assembled by strong hydro

摘要

Crystals of a water soluble, potassium(I) complex with the heterocyclic thioamide; 2-mercapto-nicotinic acid (H(2)mna), of formula {[K(H2mna)(2)](+) center dot [K(mu-OH)(2)](-) center dot 4H(2)O}(n) (1) were grown from the filtrate of the reaction between 2-mercapto-nicotinic acid with KOH in a molar ratio 1: 1.5 in water. The complex has been characterized by elemental analysis, TG-DTA, H-1 NMR and FT-IR spectroscopic techniques and X-ray powder diffraction. The single crystal structure of complex (1) has been determined by X-ray diffraction at ambient conditions. The polymeric structure of the complex is microporous, where water molecules are retained. The water molecules can be reversibly removed. The complex is ionic, containing [S-K+-S] linkages and an infinite ribbon of { [K(mu-OH)(2)](-)}(n) as a counter anion. Strong hydrogen bonds and pi-pi interactions stabilize the supramolecular architecture of the inorganic/metal-organic hybrid formed. Heating of (1) at 100 degrees C for 4 h forms the {[K(H2mna)(2)](+) center dot [K(V-OH)(2)](-)}(n) (2), which retains the framework structure although the coordinated water molecules were evacuated. (c) 2005 Elsevier B.V. All rights reserved.