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POD’’YACHEV et al.
C14a
C16a
C15b
C15a
C13a
C9a
C14b
C8a
C2a
C16b
IA
C1a
C3a
O2a
C9b
O4a
O10b
C10a
C7b
C10b
C4a
O2b
C2b
Cu2
C20a
C20b
C19b
C1b
C3b
C11b
C12b
C17b
C18b
O4b
C6b
C5b
C4b
IB
Cl4
Fig. 1. Geometry and mutual arrangement of independent molecules IA and IB, chloroform solvation molecuyle, and water
molecules in the crystal structure of I. Hydrogen atoms are not shown.
An X-ray diffraction study showed that the crystal
of I contains two crystallographically independent
molecules of the complex, IA and IB, both occupying
special positions: the first molecule, in the center of
symmetry, and the second molecule, on the twofold
axis (Fig. 1). The atomic coordinates in the structure
of I are given in Table 1, and the main geometric pa-
rameters, in Tables 2 4. The Cu1 atom has the square
planar coordination, and the coordination of Cu2 is
somewhat distorted (Table 3). The six-membered
chelate ring in the first molecule (Cu1O2C2C3C4O4)
has a nonplanar twisted boat conformation [the
water molecules occupy a special position on the
twofold axis. Unfortunately, we failed to reveal the
hydrogen atoms of the water molecules; therefore, we
cannot analyze the system of hydrogen bonds in the
crystal of I. We revealed no hydrogen bonds involving
hydroxy groups of sterically hindered phenol moieties.
However, there are a number of short contacts sug-
gesting hydrogen bonding: O10a O103 2.97(1), O2b
O100 [1 + x, y, z] 3.00(1), and O103 O100 3.06(1)
.
A PLATON analysis [3] of the crystal packing of I
reveales the layered packing type. Figure 2 shows
that the layers with the localization of the hydrophilic
area including copper ions, acetylacetonate fragments
of the ligands, and chloroform and water solvation
molecules alternate with lipophilic layers formed by
di-tert-butylphenol moieties. The phenolic hydroxy
groups are arranged in the lipophilic areas, being
blocked by bulky tert-butyl substituents. It should be
noted that the hydroxy groups of IA are located on the
boundary between the hydrophilic and lipophilic areas
and have a short contact with one of the water mole-
cules.
Cu1O2aC2aC3a fragment is planar within 0.001(6)
,
and the deviations of the C4a and O4a atoms from this
plane are 0.080(6) and 0.195(4) , respectively],
and the corresponding chelate ring in the second mol-
ecule is planar. Despite these differences, the lengths
of the Cu O bonds and C C and C O bonds in the
acetylacetonate fragments of molecules IA and IB are
equal within experimental error (Table 2). Molecules
IA and IB somewhat differ in the conformation rela-
tive to the C3 C6 and C6 C7 bonds, i.e., in the turns
of the di-tert-butylphenol moieties relative to the
central part of the complex (Table 4). The dihedral
angles between the planes of the benzene rings and
central chelate rings are 78.8(3) and 73.9(3) , respec-
tively. On the whole, independent molecules IA and
IB have fairly similar conformations (Fig. 1).
The magnetic parameters of the ESR spectra of I in
ethanol solution and in frozen ethanol are very similar
to those of the related complex with the dehydrogen-
ated substituent (Table 5). An increase in g|| and a
decrease in A suggest axial coordination of EtOH at
the free axial position of I. In the solution at 333 K,
gi = 2.129 and Ai = 74.5 Oe. As the temperature is
increased further, gi decreases and Ai grows, in agree-
ment with the progress of desolvation. The solutions
In the crystal of I, we revealed disordered solvent
(chloroform) molecules and two water molecules
(Fig. 1). The chloroform molecule and one of the
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 74 No. 11 2004
Pod''yachev
