La. Zasurskaya et al., Crystal structure of calcium [aqua(nitrilotriacetatocobaltate(II)] tetrahydrate, Ca[Co(Nta)(H2O)](2) center dot 4H(2)O, RUSS J C CH, 27(4), 2001, pp. 270-274
Crystals of Ca[Co-II(Nta)](2). 6H(2)O (I), where Nta(3-) is a nitrilotriace
tate ion, were synthesized and studied using X-ray diffraction analysis. Th
ey were found to be monoclinic: a = 6.991(1), b = 10.03 1(1), c = 16.238(3)
Angstrom, beta = 98.50(1)degrees, V= 1126.2(3) Angstrom (3), space group P
2(1)/n, Z = 2, R-1 = 0.0241, wR(2) = 0.0636, GOOF = 1.050 (for 3132 reflect
ions with I > 2 sigma (I)). Structure I is composed of ([Co(Nta)(H2O)](-))(
I infinity), anion chains united by Ca2+ cations into a three-dimensional f
ramework. The coordination polyhedra of Co and Ca atoms are distorted octah
edra. The Co(II) atom environment includes atoms N(1), O(1), O(3), and O(5)
of one Nta(3-) ligand, a carbonyl O(2)' atom of the neighboring anion frag
ment, and an O(w1) atom of the water molecule. The shortest bond is formed
by the Co atom with the bridging O(2)' atom in trans-position relative to a
tom N(1). The Co-O(2)' distance (2.029 Angstrom) is noticeably shorter than
the other bond lengths, Co-O(Nta) (2.069-2.103 Angstrom), Co-O(w1), and Co
-N(1) (2.155 and 2.177 Angstrom, respectively). Cations Ca2+ are located in
the inversion centers and involve in their coordination atoms O(4), O(6),
O(w2), and the oxygen atoms symmetrically bond to them and arranged at 2.27
1(1), 2.420(1), and 2.351(2) A, respectively. The structural formula of the
title compound is {Ca(H2O)(2)[Co(Nta)(H2O)](2)}(3 infinity) . 2H(2)O.