Hydrogen-bonded pillars of alternating chiral complex cations and anions: 1. Synthesis, characterization, X-ray structure and thermal stability of catena-{[Co(H(2)oxado)(3)][Cr(C(2)O(4))(3)].5H(2)O} and of its precursor (H(3)oxado)[Co(H(2)oxado)(3)](SO(4))(2).2H(2)O.
Compound (H(3)oxado)[Co(H(2)oxado)(3)](SO(4))(2).2H(2)O () (H(3)oxado(+) = oxamide dioximemonoximium) reacted metathetically with Ba(6)(H(2)O)(17)[Cr(C(2)O(4))(3)](4).7H(2)O in water to give the one-dimensional complex salt {[Co(H(2)oxado)(3)][Cr(C(2)O(4))(3)].5H(2)O}(infinity) () (H(2)oxado = oxamide dioxime). Compounds and were characterized by elemental analysis, FTIR, UV-Vis and by single crystal X-ray structure determination. The structure of consists of infinite pillars of alternating chiral complex cations and anions linked together along [100] by electrostatic and longitudinal O-HO interactions, with an average intrachain CoCr separation of 4.94 A. Equatorial N-HO bridges cross-link neighboring pillars (which are of opposite chirality) and consolidate a three-dimensional lattice framework which delineates elliptic nanochannels parallel to the a axis, encapsulating highly disordered water molecules. The thermal stability of both compounds was assessed by TGA, and the effective magnetic moment of , checked at room temperature, revealed considerable spin-orbit coupling.
Bélombé
M M
MM
Department of Inorganic Chemistry, Faculty of Science, P.O. Box 812, University of Yaounde I, Yaounde, Cameroon. belombe2000@yahoo.fr
Nenwa
J
J
Mbiangué
Y A
YA
Majoumo-Mbé
F
F
Lönnecke
P
P
Hey-Hawkins
E
E