Synthesis, thermal and other studies of 2,4'-bipyridine-dichloroacetato complexes of Mn(II), Co(II), Ni(II) and Cu(II)

Article abstract of DOI:10.1023/B:JTAN.0000028033.91256.c6

Four new mixed ligand complexes were prepared by the reaction of title metal dichloroacetates and 2,4'-bipyridine. The general formulae of synthesized compounds are M(2,4'-bpy)₂(CCl₂HCOO) ₂·nH₂0 (where M(II)=Mn,

Full text of DOI:10.1023/B:JTAN.0000028033.91256.c6

Journal of Thermal Analysis and Calorimetry, Vol. 76 (2004) 543–555
SYNTHESIS, THERMAL AND OTHER STUDIES OF
2,4’-BIPYRIDINE–DICHLOROACETATO COMPLEXES
OF Mn(II), Co(II), Ni(II) AND Cu(II)
*
D. Czakis-Sulikowska and A. Czylkowska
Institute of General and Ecological Chemistry, Technical University, ˜ódü, Poland
(Received July 9, 2003; in revised form November 11, 2003)
Abstract
Four new mixed ligand complexes were prepared by the reaction of title metal dichloroacetates and
2 2 2 2
2,4’-bipyridine. The general formulae of synthesized compounds are M(2,4’-bpy) (CCl HCOO) ×nH O
(where M(II)=Mn, Co, Ni, Cu; 2,4’-bpy=2,4’-bipyridine, n=2 or 4). The complexes have been isolated
from aqueous media and characterized by chemical analysis, molar conductance (in MeOH, DMSO and
DMF), magnetic, IR and VIS spectral studies. The nature of metal(II)–ligand coordination is discussed.
The thermal behaviour of obtained complexes was studied by thermal analysis and TG-MS techniques in
air. IR, X-ray powder diffraction and thermoanalytical data were used for the determination of solid in-
termediate products of the thermal decomposition. The principal volatile products of thermal decomposi-
+
+
+
+
+
2
2 2
tion of complexes were proved by mass spectroscopy: H O , CO , HCl , Cl , NO and other.
Keywords: 2,4’-bipyridine-dichloroacetato complexes, IR and VIS spectra, TG-MS data, thermal
decomposition, transition metal(II) complexes
Introduction
Synthesis of metal complexes with carboxylates or mixed ligands compounds con-
taining N-donors (as an example: bipyridines and their derivatives) is extensively
studied due to not only their complicated structures [1–3] but also as their applica-
tion. They exhibit biological activity [4, 5] and catalytic properties [6]. Also their ap-
plication as new materials with potential functions as microporous solids for molecu-
lar adsorption, ion exchange, as materials for gas storage [7, 8] and in nonlinear
optics [9] is interesting.
The reports on mixed 2,4’-bipyridine-carboxylate complexes with transition met-
als(II) are very scarce. In our previous papers we described the compounds of the type:
M(2,4’-bpy) (ox)×2H O (M(II)=Mn, Co, Ni, Cu, Zn), Cd(2,4’-bpy)(ox)×2H O [10, 11]
2
2
2
and M(2,4’-bpy) (CH COO) ×2H O (M(II)=Co, Ni, Cu, Zn, Cd) [12, 13]. Synthesis,
2
3
2
2
characterization, crystal and molecular structures are described for diaquadi(acetato-
*
Author for correspondence: E-mail: dczakisck@sp.p.lodz.pl
1
388–6150/2004/ $ 20.00
Akadémiai Kiadó, Budapest
©
2004 Akadémiai Kiadó, Budapest
Kluwer Academic Publishers, Dordrecht

5
44
CZAKIS-SULIKOWSKA, CZYLKOWSKA: TRANSITION METAL(II) COMPLEXES
O)-bis(2,4’-bipyridine) manganese(II) [2] and mono- and diaquadi(acetato-O)-
bis(2,4’-bipyridine) copper(II) [1]. In these compounds 2,4’-bipyridine coordinated via
N(4’) atom as a monodentate ligand.
In recent years, several studies have been made on the synthesis and characteriza-
tion of the mixed ligand complexes of transition metal ions with 2,2’- or 4,4’-bipyridine
and mono- or trichloroacetates [13–19]. The complexes of formulae: Cd(2,4’-
bpy) (R’COO) ×2H O (R’=CClH –, CBrH –) have been also isolated [12]. We earlier
2 2 2 2 2
determined the conditions of preparation of Mn(II), Co(II), Ni(II) and Cu(II) complexes
with 4,4’-bipyridine and dichloroacetates and studied their thermal decomposition in air
and other properties [17]. The compounds of Mn(II), Co(II), Ni(II) and Cu(II) with
2,4’-bpy and dichloroacetates are unknown. It was thus interest to examine the behav-
iours of 2,4’-bpy and dichloroacetate groups in mixed ligand metal(II) complexes and the
properties of these compounds. This paper reports the results of study of this problem.
Here we describe the synthesis, IR and VIS spectra, magnetic and molar con-
ductivity investigations and thermal decomposition in air of mixed 2,4’-bipyridine-
dichloroacetato complexes of title metals(II).
Experimental
Physical measurements and materials
The thermal decomposition was studied by means of derivatograph Q-1500. The samples
of 100 mg were heated in ceramic crucible in static air atmosphere. a-Al O has used as
2
3
standard material. TG-MS system consisting of derivatograph TG/DTA SETSYS-16/18,
coupled to a mass spectrometer (QMS-422), model ThermoStar Balzers Instruments;
platinium crucible 100 mL; dynamic measurements were carried out in air at flow rate
–1
of 1 L h ; sample of mass in the range ca. 5–8 mg; an ion source temperature of ca.
50°C by using 70 eV electron impact ionization. All thermal investigations were carried
1
–1
between 20–1000°C, at heating rate 10°C min . The other apparatus, experimental con-
ditions and materials were described in previous papers [12, 13, 17]. Preparation and
analyses of complexes of Mn(II), Co(II), Ni(II) and Cu(II) with 2,4’-bpy and
dichloroacetates were performed according to a procedure described in [17], only
2,4’-bpy dissolved in water, containing few drops of 96 v/v% EtOH. The contents of C, H
and N were determined by elemental analysis with V as oxidizing agent; M(II) were
complexometrically determined.
O
2 5
Results and discussion
The empirical formulae of the obtained complexes, analytical results and other char-
acteristic data are collected in Table 1. All complexes were small crystalline solids
and are not isostructural. The obtained compounds are soluble in water (Table 1).
The solubilities of the complexes increase in the order Mn(II)<Cu(II)<Ni(II)<Co(II).
The magnetic moments (in room temperature) of the Co(II), Ni(II) and Cu(II) com-
plexes show that these compounds are paramagnetic. The observed magnetic mo-
J. Therm. Anal. Cal., 76, 2004

CZAKIS-SULIKOWSKA, CZYLKOWSKA: TRANSITION METAL(II) COMPLEXES
545
ment values are in the range expected for the orbital singlet states for pseudo-
octahedral geometry of around these metal(II) ions [20]. The molar conductivities
(
L ) for obtained complexes in DMF, DMSO (except Co(II) in DMSO) and in
M
MeOH (except Mn(II) and Co(II) in MeOH) show behaviour intermediate between
those of non-electrolytes and 1:1 electrolytes. Conductivity data (Table 1) of Mn(II)
and Co(II) complexes in methanol and Co(II) compound in DMSO fall within the
general acceptable range for 1:1 electrolytes [21]. L
DMF»DMSO<MeOH. Higher than anticipated L values (vide IR data) are usually
increase in the sequence:
M
M
due to the displacement of dichloroacetato ligands by solvent molecules. Similar be-
haviours were observed for metal(II) complexes with other bipyridine isomers and
halogenoacetates [14, 15, 17].
Electronic and IR spectra
–1
VIS spectra were obtained in Nujol mulls within the 27 000–12 000 cm . The co-
–1
balt(II) complex exhibit broad band with maximum at 20 400 cm , which corresponds
4
to the transition T (F)® T (P). Two bands have been observed at 26 300 and
4
1
g
1g
–1
3
6 000 cm for Ni(II) complex. The bands are assigned to A ® T (P) and
3
1
2g 1g
3
3
A ® T (F) transitions. These bands are in accordance with a distorted octahedral
2g
1g
geometry around the metal ions [22]. The values ncalcd calculated by the rule of average
–
1
4
environment (RAE) for chromophore MN O are 20 300 cm for T (F)® T (P) and
4
2
4
1g
1g
–1
3
5 600 cm for A ® T (F) transitions, respectively in the cobalt(II) and nickel(II)
3
1
complexes. The comparison of the ncalcd with the experimental n and according to IR
2g 1g
data, indicates that the following chromophores are present in solid-state: CoN O ’O ”
2
2
2
–
and NiN O ’O ” (where O’=atom from (OCO) group, O”=atom from H O). The elec-
2
2
2
2
–1
tronic spectrum of Cu(II) complex shows a broad band in the region ca. 15 600 cm .
This band can be assigned to three transitions lying within one broad envelope
( B ® E , B ® B , B ® A ). The position of this band indicates probably a
1g g 1g 2g 1g 1g
rhombic-octahedral environment around Cu(II) [23].
2
2
2
2
2
2
The IR spectra of all complexes exhibit a strong and broad bands in the water
–
1
stretching region (ca. 3050–3600 cm ). The water bending vibration is observed
–
1
–1
only for Mn(II) (1630 cm ) and for Co(II) (at 1635 cm ) complexes. Selected IR
bands of 2,4’-bpy and of dichloroacetate group, as well as assignments of their fre-
quencies are presented in Table 2.
The IR spectrum of 2,4’-bpy is the sum of characteristic patterns of 2- and 4-
substituted pyridines [24]. Upon coordination with title metals(II), the IR spectrum
of free 2,4’-bpy undergoes a change only in the ring vibration modes of 4-substituted
pyridine (4-sub). A bathochromic shift of the bands attributed to a stretching ring vi-
bration and ring ‘breathing’ frequency for 4-sub pyridine takes place. It is thus possi-
ble to assume that 2,4’-bpy coordinates via the least hindered (4’)N atom [25]. This
conclusion is in good agreement with those reported for other metal(II) complexes
with 2,4’-bpy [2, 10–13, 26].
–
–
The principal IR bands nas(OCO) and n (OCO) of CCl HCOONa and obtained
s 2
complexes are also listed in Table 2. The spectra of region characteristic of
J. Therm. Anal. Cal., 76, 2004

5
46
CZAKIS-SULIKOWSKA, CZYLKOWSKA: TRANSITION METAL(II) COMPLEXES
J. Therm. Anal. Cal., 76, 2004

CZAKIS-SULIKOWSKA, CZYLKOWSKA: TRANSITION METAL(II) COMPLEXES
547
J. Therm. Anal. Cal., 76, 2004

5
48
CZAKIS-SULIKOWSKA, CZYLKOWSKA: TRANSITION METAL(II) COMPLEXES
–
n (OCO) and n (OCO) vibrations are analogous for cobalt(II) and nickel(II) com-
–
as
s
–
–
plexes. The magnitudes of the separation Dn between the n (OCO) and n (OCO) in
as
s
these compounds are higher than in sodium salt. On the basis of the Nakamoto crite-
rion [27] and other papers [5, 12–15, 28–30], the carboxylate groups in Co(II) and
Ni(II) are monodentate. Probably non-completely equivalent bonds between Co(II)
–
and Ni(II) and dichloroacetate ligands are formed (nas(OCO) is splitted) [29]. The
–
n (OCO) of the Mn(II) and Cu(II) complexes are clearly splitted into three (Mn) and
s
–
two (Cu); bands n (OCO) of Mn(II) compound is splitted into poorly resolved dou-
as
–
blet. In case of Mn(II) complex the Dn values are 253 and 274 cm and are higher
1
than for sodium salt. The carboxylate groups here appear as unidentate
(
(
non-equivalent) groups. In addition, Dn for Mn(II) complex has also value
–
235 cm ) lower than for the sodium salt. This fact, as well as splitting n (OCO) into
1
–
s
three bands suggests, that in Mn(II) complex the dichloroacetate act also as bidentate
asymmetrical bridging group; probably strong intermolecular hydrogen bonds
–
1
exist [1]. The Dn for Cu(II) have values 247 and 270 cm . The separation of these
modes shows the presence of coordinated monodentate dichloroacetate group. The
–
bands n (OCO) is splitted into two, and Dn are higher than for sodium salt, probably
that non-equivalent bonds between Cu(II) and carboxylate groups exists [28–30].
s
Thermal decomposition
The obtained complexes are stable at room temperature. The solid intermediate prod-
ucts of decomposition were determined from TG curve and were confirmed by re-
cording the IR spectra of sinters. IR spectra for sinters (prepared during the heating of
sample of complex up to definite temperature from TG) occur the bands of 2,4’-bpy
–
and carboxylate group or only bands of 2,4’-bpy. In the sinters presence of anions Cl
was investigated. The final solid products of decomposition were calculated from TG
curve and verified by X-ray diffraction patterns registration. The thermal decomposi-
tion data of the obtained complexes are collected in Table 3.
The thermoanalytical curves of Mn(II) and Ni(II) complexes are presented, as an
example in Fig. 1. All the complexes decompose progressively. Hydrated compounds are
stable up to the temperature 60–70°C. During heating the Ni(II) and Cu(II) complexes lose
water molecules in one step. Co(2,4’-bpy) (CCl HCOO) ×4H O dehydrates in two steps.
2 2 2 2
First it eliminates 3 mol of water (60–120°C) and at 120–170°C all water is lost.
Mn(2,4’-bpy) (CCl HCOO) ×2H O – at first 1 mol of water (60–120°C) is eliminated,
2
2
2
2
while by 170–238°C it loses all water producing Mn(2,4’-bpy) (CCl HCOO)Cl. The
2
2
dehydration processes are accompanied by small endothermic effects. The decomposition
of the anhydrous compounds to corresponding oxides is the multi-stage process. The
decomposition of dichloroacetates and subsequent detachment of 2,4’-bpy was observed.
At first stage partial decomposition of dichloro- acetates takes place to give intermediate
products: Mn(2,4’-bpy)
(170–220°C), Cu(2,4’-bpy) - (CCl HCOO) Cl (170–200°C). The IR spectra of all the
-(CCl HCOO)Cl (170–238°C), Co(2,4’-bpy) (CCl HCOO)Cl
2 2 2 2
2
2
0.5 1.5
sinters (prepared during heating of complexes up to temperature 238° (Mn), 220° (Co) and
00°C (Cu)) indicated the presence of bands characteristic of 2,4’-bpy and carboxylate
2
J. Therm. Anal. Cal., 74, 2003

CZAKIS-SULIKOWSKA, CZYLKOWSKA: TRANSITION METAL(II) COMPLEXES
549
J. Therm. Anal. Cal., 76, 2004

5
50
CZAKIS-SULIKOWSKA, CZYLKOWSKA: TRANSITION METAL(II) COMPLEXES
J. Therm. Anal. Cal., 76, 2004

CZAKIS-SULIKOWSKA, CZYLKOWSKA: TRANSITION METAL(II) COMPLEXES
551
Fig. 1 TG/DTG and DTA curves of a – Mn(2,4’-bpy)
b – Ni(2,4’-bpy) (CCl HCOO) ×2H O; mass sample 100 mg
2 2 2 2
(CCl HCOO) ×2H O;
2
2
2
2
groups. Also in these sinters presence of chlorine ions were identicated. Above these
temperatures remaining molecules of dichloroacetate decompose and release of 2,4’-bpy
begins. During these processes, only the intermediate compounds M(2,4’-bpy)Cl2
(M(II)=Mn, Co) were detected from thermal curves (in sinters obtained at 360°C for
Mn(II) and 380°C for Co(II)), chlorine ions and absorption bands only for 2,4’-bpy were
evident. The Mn(2,4’-bpy)Cl transformed exothermically (DTA peaks at 562 and 660°C)
2
to Mn O , probably via Mn O . Above 800°C, only diffraction lines characteristic of
3
4
2
3
Mn O were detected. Between 380–780°C, Co(2,4’-bpy)Cl was transformed to pure
3
4
2
Co O . The X-ray diffraction pattern of Co(2,4’-bpy) (CCl HCOO) ×4H O heated up to
2
3
4
2
2
2
780°C is similar to that of the original Co O . Above 930°C Co O decompose to CoO
3 4 3 4
very slowly. DTA curve exhibited several exo- and endoeffects. Process of decomposition
of the intermediate compound Cu(2,4’-bpy) (CCl HCOO) Cl is very complicated. TG
2
2
0.5 1.5
curve shows bending at ca. 340°C. However, in the sinters of Cu(2,4’-bpy)2-
CCl HCOO) ×2H O heated up to 340°C indicate only very weak IR bands for 2,4’-bpy.
(
2
2
2
On increase of the temperature molecules of organic ligands decomposed and volatile
compounds of copper are formed, only ca. 3.5% CuO is as the final product (theor. 11.9%).
(The volatile products also occur during thermal decomposition of Cu(CCl HCOO) [32]).
2 2
The DTA curve presents several exoeffects. A strong broad exothermic effect is observed
in the temperature range ca. 720–800°C with center at about 760°C. The endothermic
effects associated with volatilization of volatile compounds of copper and other
decomposition processes are masked by these exoeffect. Clearly endo peak is
demonstrated on the DTA curve only at 460°C.
The anhydrous complex Ni(2,4’-bpy) (CCl HCOO) decomposes in different way.
2 2 2
During heating it was transformed to NiO, with intermediate formation (Ni(2,4’-bpy) Cl
2
2
J. Therm. Anal. Cal., 76, 2004

5
52
CZAKIS-SULIKOWSKA, CZYLKOWSKA: TRANSITION METAL(II) COMPLEXES
(140–260°C), Ni(2,4’-bpy)Cl (260–340°C) and NiCl (340–480°C). The IR bands of
2 2
2,4’-bpy are observed only in products obtained during heating of Ni(2,4’-
bpy) (CCl HCOO) ×2H O up to 260 and 340 C; the characteristic modes for carboxylate
o
2
2
2
2
groups were not noted. A horizontal mass level in the TG curve begins at 660°C,
corresponding to pure NiO (verified by X-ray diffraction pattern). DTA curve exhibits
several exo- and endoeffects.
Mass spectrometric thermal analysis
A coupled TG-MS system was used to analyse of volatile species which are forming
during the dynamic thermal decomposition of M(2,4’-bpy) (CCl HCOO) ×nH O in
air atmosphere. MS data for all obtained complexes detected several signal intensi-
2
2
2
2
1
12
14
16
35
ties. The registered mass spectra of lines based on: H, C, N, O and Cl were
Fig. 2 TG curve and ion current detected by the MS in air for
Ni(2,4’-bpy)
3
2
2
(CCl
–44 with sensitivities of: E-09, E-12, E-09 A, respectively; b – m/z: 1–30;
–70; 3–76 with sensitivities of: E-10, E-12, E-13 A, respectively
2 2 2
HCOO) ×2H O mass sample 8.02 mg: a – m/z: 1–18; 2–36;
J. Therm. Anal. Cal., 76, 2004

CZAKIS-SULIKOWSKA, CZYLKOWSKA: TRANSITION METAL(II) COMPLEXES
553
Fig. 3 TG curve and ion current detected by the MS in air for
Co(2,4’-bpy)
2 2 2 2
(CCl HCOO) ×4H O mass sample 5.60 mg, m/z: 1–18; 2 – 30; 3 –
4
4 with sensitivities of: E-09, E-10, E-09 A, respectively
only examined. Generally, MS data are very similar. Many MS signals are observed
by ca. 160, 250, 430°C for Mn(II), 220, 350°C for Co(II), 150–200, 390°C for Ni(II)
and ca. 190, 270°C in case of Cu(II) complex. The corresponding MS peaks for coor-
dination (or crystalline) water appeared at 117° (Mn), 120° (Co), 139° (Ni)
and 125°C (Cu). These MS peaks coincide with the mass decrease appeared on TG.
When the temperature of the sample raised, maximum rates of H
decomposition of organic ligands at 321–367° for (Mn), 538 in (Co), 226, 411° for
O forming during
2
+
(
Ni) and 290° (Cu) are observed. The ion intensities of CO have centers at 194, 381,
2
4
Cu(II) complex. The first maxima of CO coincide with begin of decomposition of
59° (Mn), 227, 538, 588° (Co), 197, 416° (Ni) and 192, 271, 428, 529°C in case of
+
2
dichloroacetato ligands; further peaks with the total decomposition of ligands and the
burning of organic residues. MS measurement presents also volatile species contain-
+
+
ing halogen Cl , HCl , with centres in temperature range: 192–227°C (and addition-
2
+
ally at 307°C for Mn(II) complex). Profiles for m/z=30 (NO ) and m/z=76 (N O )
+
2
3
were clearly shown by MS, during heating of all complexes at range ca. 210°,
40–473° (additionally 381, 502° (Mn), 594° (Co) and 530°C (Cu)). MS data pre-
4
sented also several ion signals from fragmentation which were not analysed. TG cou-
pled with MS data for some ion current are shown in Figs 2 and 3.
Conclusions
The composition and several properties of Mn(II), Co(II), Ni(II) and Cu(II) com-
plexes with dichloroacetates and isomers of bipyridine depend on the position of the
nitrogen atoms in bipyridine. In case of 2,4’-bpy compounds, molar ratio of metal(II)
to N-donors is 1:2, whereas with 4-bpy is 1:3 (only complex of Ni(II) with formula
J. Therm. Anal. Cal., 76, 2004

5
54
CZAKIS-SULIKOWSKA, CZYLKOWSKA: TRANSITION METAL(II) COMPLEXES
Ni(4-bpy) (CCl HCOO) was obtained) [17]. Many complexes of these types are hy-
2
2
2
drated and stable in air. The 2,4’- and 4-bpy are bonded to the title metal(II) ions. Due
to spherical position of nitrogen atoms 2,4’-bpy coordinated with metal(II) via the
least hindered (4’)N atom [1], when 4-bpy is mainly bonded as bridging ligand [3].
Carboxylate groups [1] in mixed complexes with 2,4’-bpy (Mn(II), Co(II), Ni(II),
Cu(II)) and 4-bpy (Ni(II), Cu(II)) are bonded as monodentate; in other complexes in
different way (monodentate and bidentate bridging) [17].
Thermal decomposition of our new synthetized hydrated compounds begins with the
release of a water above 60–70°C. After dehydration pyrolysis of the dichloroacetates takes
place. The intermediate products of the types M(2,4’-bpy) (CCl HCOO)2–nCl (where n=0, 1
2 2 n
or 1.5), M(2,4’-bpy)Cl (M(II)=Mn, Co, Ni) and Ni(2,4’-bpy) Cl are formed. The
2
2
2
fragmentary thermal decomposition of halogenoacetates was observed in other mixed ligand
complexes containing bipyridine isomers (2-bpy, 4-bpy) and halogenoacetates [13–15, 17].
Next, the 2,4’-bpy is released and conversion into pure Mn O (via Mn O ), CoO (via Co O )
3
4
2
3
3
4
and NiO takes place. In the case of Cu(II) complex during decomposition of organic ligands,
the volatile products copper are formed and only trace of CuO was observed. The principal
volatile species produced during pyrolysis of metal(II) complexes with 4-bpy [17] and
2,4’-bpy are similar, only major maxima of ion current are shifted.
Generally, the process and products of thermal decomposition of the new syn-
thesized complexes of Mn(II), Co(II), Ni(II) and Cu(II) with 2,4’-bpy and dichloro-
acetates is near to correspond for previously studied complexes with 4-bpy [17, 18].
Only differences were observed in the temperature ranges of decomposition and cer-
tain differences in composition of intermediate compounds as well as in the tempera-
ture of elimination of maximum rate of volatile thermal decomposition products.
The anhydrous complexes Ni(2,4’-bpy)
2
(CCl
2
HCOO)
bpy) (CCl HCOO) [17] are new examples of complexes with ligand isomerism.
2
and Ni(4-
2
2
2
*
* *
This work was supported by KBN, project no. 4 TO9B 103 22. We thank Ph. D. R. Mrozek for the
magnetic measurements.
References
1
R. KruszyÕski, A. Adamczewska, J. RadwaÕska-Doczekalska and T. J. Bartczak, J. Coord. Chem.,
5 (2002) 1209.
5
2
3
4
T. J. Bartczak, D. Czakis-Sulikowska and J. KaÓuüna, ibid., 46 (1998) 193.
R. Carballo, A. Castiñeiras, B. Covelo and E. M. Vázquez-López, Polyhedron, 20 (2001) 899.
E. Andogová, K. Györyová and F. N. Nour El-Dien, J. Therm. Anal. Cal., 69 (2002) 243 and
references cited therein.
5
6
7
S. C. Mojumdar, E. Jóna and M. Melnik, ibid., 61 (2000) 915, ibid., 60 (2000) 571.
L. Alvila and T. A. Pakkanen, J. Mol. Cat., 84 (1993) 145 and references cited therein.
W. Moriand and T. Ohmura, XIIIth Winter School on Coordination Chemistry, Karpacz,
Poland 9–13 December 2002, p. 44.
th
8
S. Kitagawa, X Winter School on Coordination Chemistry, Karpacz, Poland 8–12
December 1997, p. 19.
J. Therm. Anal. Cal., 76, 2004

CZAKIS-SULIKOWSKA, CZYLKOWSKA: TRANSITION METAL(II) COMPLEXES
555
9
V. Bolzani, A. Juris, M. Venturi, S. Campagna and S. Serroni, Chem. Rev., 96 (1996) 775.
10 D. Czakis-Sulikowska, A. Malinowska and M. Markiewicz, J. Therm. Anal. Cal., 60 (2000) 151.
11 D. Czakis-Sulikowska, J. RadwaÕska-Doczekalska and M. Markiewicz, ibid., 60 (2000) 145.
12 D. Czakis-Sulikowska, J. RadwaÕska-Doczekalska, M. Markiewicz, N. Pustelnik and B. Kuünik,
Polish J. Chem., 71 (1997) 513.
1
3 J. RadwaÕska-Doczekalska, D. Czakis-Sulikowska and M. Markiewicz, J. Therm. Anal. Cal.,
4
8 (1997) 865.
1
1
1
4 D. Czakis-Sulikowska, A. Czylkowska and A. Malinowska, ibid., 65 (2001) 505.
5 D. Czakis-Sulikowska, A. Czylkowska and J. RadwaÕska-Doczekalska, ibid., 63 (2001) 387.
6 S. Sen, S. Mitra, P. Kundu, M. K. Saha, C. Krüger and J. Bruckmann, Polyhedron,
1
6 (1997) 2475.
1
1
1
7 D. Czakis-Sulikowska and A. Czylkowska, J. Therm. Anal. Cal., 71 (2003) 394
and paper in press.
8 D. Czakis-Sulikowska and A. Czylkowska, Krajowe Seminarium im. Prof. St. Bertsznajdera,
PÓock 2002, p. 267.
9 A. Czylkowska, R. Czylkowski and D. Czakis-Sulikowska, XLV Zjazd Naukowy Polskiego
Towarzystwa Chemicznego, Cracow, September 2002, p. 282.
0 S. F. A. Kettle, Physical Inorganic Chemistry, Spectrum Academic Publications, Oxford 1996.
1 W. I. Geary, Coord. Chem. Rev., 7 (1971) 81.
2
2
2
2
2
2
2
2 A. B. P. Lever, Inorganic Electronic Spectroscopy, Elsevier, Amsterdam 1984.
3 B. J. Hathaway, J. Chem. Soc. Dalton Trans., (1972) 1196.
4 C. K. Pearce, D. K. Grosse and Hessel, Chem. Eng. Data, 15 (1970) 567.
5 P. Castan, F. Duhan, S. Wimmer and F. L. Wimmer, J. Chem. Soc. Dalton Trans., (1990) 2971.
6 R. KruszyÕski, T. J. Bartczak, A. Adamczewska, D. Czakis-Sulikowska and J. KaÓuüna,
Act. Cryst. Sec. E, (2001) 183.
2
7 K. Nakamoto, Infrared and Raman Spectra of Inorganic and Coordination Compounds,
John Wiley and Sons, New York 1997.
2
2
8 S. C. Mojumdar, M. Melnik and M. Valko, Polish J. Chem., 73 (1999) 457.
9 W. Brzyska and W. Oüga, J. Therm. Anal. Cal., 60 (2000) 123;
ibid., 61 (2000) 135 and references therein.
3
3
3
3
0. W. Brzyska, Z. Rz·czyÕska and A. Kula, Monatsh. Chem., 120 (1989) 211.
1 J. S. Strukl and J. L. Walter, Spectrochim. Acta, 2717 (1971) 223.
2 D. C. K. Lin and J. B. Westmore, Canad. J. Chem., 51 (1973) 573.
3 E. Spinner, J. Chem. Soc., (1964) 4217.
J. Therm. Anal. Cal., 76, 2004