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R. Kubiak et al. / Polyhedron 26 (2007) 4179–4186
In particular, it was shown that 4-picoline (4-Mepy)
with a two dimensional CCD area detector. Graphite
monochromatized Mo Ka radiation (k = 0.71073 A) and
the x-scan technique (Dx = 1ꢁ) were used for data collec-
tion. Data collection and reduction along with absorption
correction were performed using the CRYSALIS software
package [20].
The structures were solved by direct methods using
SHELXS-97, revealing positions of almost all the non-
hydrogen atoms. The remaining atoms were located from
subsequent difference Fourier syntheses. The structures
were refined using SHELXL-97 [21] with anisotropic thermal
displacement parameters. Hydrogen atoms were located
from the difference Fourier maps, but in the final refine-
ment the positions of all hydrogen atoms were con-
strained. Details of the data collection parameters,
crystallographic data and final agreement parameters are
collected in Table 1. Selected geometrical parameters are
listed in Table 2.
˚
formed isostructural complexes with iron and cobalt pht-
halocyanines, in which the central M is biaxially ligated
by 4-Mepy, and the compounds crystallized with the com-
position [MPc(4-Mepy)2] Æ 2(4-Mepy) [18]. For these rea-
sons, we expected that the beryllium, magnesium and
zinc phthalocyanines, when recrystallized in 4-Mepy, will
show significant individuality in features of the eventually
formed crystalline complexes, in particular for the coordi-
nation geometry of the central metal. Additionally, all of
the new metallophthalocyanine complexes are potentially
interesting colorants and materials for modern industry
[19].
2. Experimental
2.1. Synthesis
Firstly, it should be stressed here that an attempt was
made to perform the reactions of BePc as well as MgPc
and ZnPc with 4-Mepy in water-free conditions.
2.3. Thermal measurements
The BePc sample used in the synthesis was obtained as
described elsewhere [3]. The magnesium phthalocyanine
(90% dye content) and zinc phthalocyanine (97% dye con-
tent) as well as 4-picoline (bp 145 ꢁC) were purchased from
Sigma–Aldrich Co. Before use, the magnesium and zinc
phthalocyanines were zone refined. The transformative
recrystallization processes of the BePc, MgPc and ZnPc
samples with 4-picoline were performed as follows. A sam-
ple of one of the selected M(II)Pc’s was pressed into a pel-
let, about 0.5 g in mass. The pellet was inserted in a glass
ampoule and covered with c.a. 8 mL 4-picoline. The sample
was then degassed and sealed off. Next, the suspension was
thermally processed over the several days to ensure the
completeness of the transformative process as well as effec-
tive crystallization. Next the crystalline product was imme-
diately filtered after opening the ampoule. The best single
crystals of the respective compounds, [BePc(4-Mepy)]-
(4-Mepy) – (I), MgPc(4-Mepy)2 – (II) and ZnPc(4-Mepy) –
(III), were obtained by prolonged heating of the suspension
of the beryllium phthalocyanine at 80 ꢁC, the magnesium
phthalocyanine at 120 ꢁC and the zinc phthalocyanine at
160 ꢁC. Routinely the crystalline products (I, II and III)
were checked by X-ray powder diffraction and energy dis-
persive spectroscopy for their uniformity and composition.
Elemental Anal. Calc. for C44H30N10Be (I): Be, 1.27; C,
74.67; N, 19.79, H, 4.27. Found: Be, 1.25; C, 74.72; N,
19.73; H, 4.30%. Elemental Anal. Calc. for C44H30N10Mg
(II): Mg, 3.36; C, 73.09; N, 19.37; H, 4.18. Found: Mg,
3.30; C, 73.27; N, 19.29; H, 4.09%. Elemental Anal. Calc.
for C38H23N9Zn (III): Zn, 9.74; C, 68.02; N, 18.79; H,
3.46. Found: Zn, 9.60; C, 68.12; N, 18.87; H, 3.40%.
The thermogravimetric measurements (TG) and differ-
ential thermal analyses (DTA) were carried out on a Lin-
seis L-81 thermobalance with Pt crucibles. The initial
sample masses were about 15 mg. Powder Al2O3 was
used as a reference. The measurements of the sample
were performed under static air and recorded at the heat-
ing rate of 5 ꢁC minꢁ1. Upper temperature limits were
introduced to prevent eventual contamination of the appa-
ratus, as indicated by our previous experiences. The
observed weight loss is ꢀ26.5%, 25.5% and 13.9% for
compounds I, II and III, respectively. The respective val-
ues calculated for these compounds are 26.30%, 25.74%
and 13.87%.
2.4. X-ray powder diffraction measurement
The rest of the sample left after thermogravimetric anal-
yses was measured on a STOE powder diffractometer
equipped with a linear PSD detector [22] using Cu Ka1
˚
radiation (k = 1.54060 A) at room temperature.
3. Results and discussion
3.1. Synthesis: equilibrium in solution
The procedure described in Section 2.1 gave for each
complex (I, II and III) well developed crystals suitable
for X-ray analysis, showing the typical red-violet colour
for the phthalocyanines. However, we want here to add
some observation registered during the thermal processing
of the ampoule with the beryllium phthalocyanine in 4-pic-
oline suspension. Namely, it occurs that by heating the
ampoule resting in the oven, the liquid seen over the sedi-
mented solid species is practically non-transparent, as
could be expected, but it was so only till up ca. 100 ꢁC.
With further temperature increase, being however still
2.2. X-ray single crystal diffraction
Single crystals of I, II and III were used for data collec-
tion on a four-circle KUMA KM4 diffractometer equipped
Kubiak
