ISSN 10703284, Russian Journal of Coordination Chemistry, 2015, Vol. 41, No. 11, pp. 765–771. © Pleiades Publishing, Ltd., 2015.
Original Russian Text © E.E. Netreba, 2015, published in Koordinatsionnaya Khimiya, 2015, Vol. 41, No. 11, pp. 693–699.
Coordination compounds with ligands of the bicy
clobisureas are poorly studied to the moment. One of
these ligands is 4,4,10,10tetramethyl1,3,7,9tetra
This bicyclospirobisurea is a precursor of urea and
has a series of valuable biological properties: a low tox
= 3000 mg/(kg of weight of white
mice) , membranotropicity , and the ability to
penetrate through and be accumulated in the cyto
plasm of leucosis cells of the mice and human L1210
and CEMT4 lines, respectively . Spirocarbone Sk
also favors an increase in the amount of protein and a
decrease in starchiness in oats . The efficiency of
spirocarbone as a stimulator of callus formation in
Forsythia europaea  and root formation in Snow
belle was proved. The efficiency of using spirocarbone
as a stimulator of growth and development in sheep
breeding was shown . Therefore, the synthesis and
study of coordination compounds of this bicyclospiro
bisurea (hard Lewis base) will clarify more completely
the chemical nature of the interaction of Sk with vari
ous metal atoms.
We have previously synthesized and characterized
the binuclear complexes of spirocarbone with rare
earth metals in the oxidation state 3+ (Table 1) in
which the metal to ligand ratio is 1 : 1. An analysis of
the synthesis procedures of the earlier mentioned
complexes showed that the specified molar ratio of the
(ligand), resulted in the formation
of binuclear 16membered chelates in which ligand Sk
performed the bidentatebridging function.
Continuing these studies, in this work we
describe the synthesis and structure of the new
mononuclear biligand complex of spirocarbone and
cerium(III) nitrate, bis(4,4,10,10tetramethyl
). The molar
ratio of the reactants
(ligand) was specified
in the synthesis.
Cerium nitrate hexahydrare
(reagent grade), Sk obtained by known procedures
[18, 19], and acetone (special purity grade) were used.
Synthesis of compound
A weighed sample of
cerium(III) nitrate was dissolved in acetone, spirocar
bone was added in a molar ratio of 1 : 3, and the mix
ture was magnetically stirred for 10 min. The obtained
solution was filtered, corked up, and left to stay for
several days to form crystals. The formed white crystals
were filtered off, washed with acetone, and dried in air.
The yield was ~64% (based on the salt).
Synthesis and Crystal Structure of the New Complex Bis(4,4,10,10
E. E. Netreba
Krym Federal University, ul. Yaltinskaya 4, Simferopol, Crimea, Russia
Received April 3, 2015
—A mononuclear biligand complex of cerium(III) nitrate with bicyclic bisurea (4,4,10,10tetrame
thyl1,3,7,9tetraazospiro[5.5]undecane2,8dione or spirocarbone (Sk)),
), is synthesized. Its structure is determined by Xray diffraction analysis (CIF file CCDC 985759). The
crystals are monoclinic: space group
= 24.1857(10) Å,
= 3456.7(3) Å
= 1.619 g/cm
= 4. The structure is molecular. The cerium(III) cat
ion is coordinated by two oxygen atoms of two molecules of the organic ligand, two O(H
O) atoms, and six
O atoms of three bidentate nitrate anions. The coordination number of the cerium(III) atom is ten, and the
coordination polyhedron is an irregular tenvertex polyhedron. The crystal is a nonmerohedral twin, whose
components are turned by 180° along the
axis, and the relative weights of the components are 0.82 : 0.18.