Thermal decomposition of triethanolamine and monoethanolethylenediamine complexes of some transition metal saccharinates

Article abstract of DOI:10.1016/S0040-6031(01)00685-2

The thermal decomposition behaviour of triethanolamine (TEA) and monoethanolethylenediamine (me-en) complexes of Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Hg(II) saccharinates was studied under non-isothermal conditions by TG, DTA and DTG in dynamic nitrogen atmosphere. The decomposition of the TEA complexes proceeds via three main stages. The first stage involves exothermic removal of two CH₂OH groups, due to degradation of uncoordinated ethanol groups of the TEA molecules, and the second and third stages correspond to formation of metal saccharinates and metals as the end products, respectively. All the me-en complexes show similar decomposition behaviour and, after evolution of two CH₂OH groups, they progressively decompose through saccharinate intermediates and subsequently yield metals or metal oxides as the final residue. Tea complexes showed much higher thermal stability than their me-en analogues. A thermal decomposition mechanism for the metal complexes was suggested.

Full text of DOI:10.1016/S0040-6031(01)00685-2

Thermochimica Acta 383 (2002) 129±135
Thermal decomposition of triethanolamine
and monoethanolethylenediamine complexes
of some transition metal saccharinates
V.T. Yilmaz*, Y. Topcu, A. Karadag
Department of Chemistry, Faculty of Arts and Sciences, Ondokuz Mayis University, 55139 Kurupelit, Samsun, Turkey
Received 17April 2001; received in revised form 29 June 2001; accepted 3 July 2001
Abstract
The thermal decomposition behaviour of triethanolamine (TEA) and monoethanolethylenediamine (me-en) complexes of
Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Hg(II) saccharinates was studied under non-isothermal conditions by TG,
DTA and DTG in dynamic nitrogen atmosphere. The decomposition of the TEA complexes proceeds via three main stages.
The ®rst stage involves exothermic removal of two CH2OH groups, due to degradation of uncoordinated ethanol groups of the
TEA molecules, and the second and third stages correspond to formation of metal saccharinates and metals as the end
products, respectively. All the me-en complexes show similar decomposition behaviour and, after evolution of two CH2OH
groups, they progressively decompose through saccharinate intermediates and subsequently yield metals or metal oxides as the
®nal residue. Tea complexes showed much higher thermal stability than their me-en analogues. A thermal decomposition
mechanism for the metal complexes was suggested. # 2002 Elsevier Science B.V. All rights reserved.
Keywords: Triethanolamine complexes; Monoethanolethylenediamine complexes; Saccharin complexes; Transition metal saccharinates; TG;
DTA
1. Introduction
trace elements in the human body and readily forms
stable compounds in which sac acts as a N-donor
monodentate ligand or a counter-ion, depending on
the presence of other ligands [4±9]. Nowadays it is
generally recognized as safe in the United States [10]
and it has also been suggested that the importance of
sac lies in its potential use as an antidote for metal
poisoning [11].
Naumov et al. [12] studied the thermal decomposi-
tion of alkali metal saccharinates, while the decom-
position behaviours of aqua complexes of the metal(II)
saccharinates were studied by Magri et al. [13] and
Icbudak et al. [14]. A thermally induced intramole-
cular electron transfer process was reported in the
thermal decomposition of the aqua complex of the
Saccharin (o-sulphobenzimide) is not very soluble,
but its alkali metal salts are very soluble and widely
used as non-caloric arti®cial sweeteners and food
additives [1]. Research on the synthesis and structural
analysis of metal±saccharin complexes has been
active in the last two decades, because of their poten-
tial effectiveness in biological systems and the sus-
pected carcinogenic nature of saccharin [2,3].
Saccharin in its deprotonated form (sac) interacts with
* Corresponding author. Tel.: ‡90-362-4576020/ext. 1051;
fax: ‡90-326-457-6081.
E-mail address: vtyilmaz@omu.edu.tr (V.T. Yilmaz).
0040-6031/02/$ ± see front matter # 2002 Elsevier Science B.V. All rights reserved.
PII: S 0 0 4 0 - 6 0 3 1 ( 0 1 ) 0 0 6 8 5 - 2

130
V.T. Yilmaz et al. / Thermochimica Acta 383 -2002) 129±135
Fe(II) saccharinate [15]. Reports on thermal behaviour
of hydrazine, ethylenediamine [16] and 1,10-phenan-
throline [17] complexes of some transition metal
saccharinates have appeared in the literature. As part
of our research on the synthesis, spectral and thermal
analysis of transition metal complexes of sac with
N-donor ligands, we report the thermal decomposition
characteristics of some novel triethanolamine (TEA)
(also named tris(2-hydroxyethyl)amine) and mono-
ethanolethylenediamine (me-en) (alternatively named
N-(2-hydroxyethyl)-ethylenediamine) complexes of
Mn(II), Fe(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II)
and Hg(II) saccharinates.
several fragments [20]. The base peaks appear at m/z
values of 118 and 74 for TEA and me-en, respectively.
The loss of 31 mass units in the transition from 149 to
118 suggests the presence of a CH2OH radical from
TEA. The exotherms in the DTA curves of the metal
complexes are expected to be due to the degradation
of uncoordinated ethanolic groups of the two TEA or
me-en molecules and it would be a good guess to
attribute them to the formation of an ethylene glycol
(OHCH2CH2OH) molecule. Although the calculated
values for the removal of the two CH2OH groups are
consistent with the experimental values, 1H NMR and
IR spectral analyses of the isolated product obtained in
the corresponding temperature range do not con®rm
the proposed assignment for ethylene glycol. Instead,
these results suggest the formation of CH3-O-CO-H
by a rearrangement of the two CH2OH radicals in the
gas phase at high temperatures. Identi®cation of the
volatile product needs more and detailed research.
Therefore, the mass calculations for the corresponding
stage are based on the formation of the CH2OH group.
2. Experimental
2.1. Preparation of the complexes
The TEA, [N(CH2CH2OH)3], and me-en,
(NH2CH2CH2NHCH2CH2OH),complexesofthemetal
saccharinates were prepared by the methods reported
earlier [18,19].
3.1. Triethanolamine -TEA) complexes
2.2. Measurements
Spectral and structural studies of the TEA com-
plexes of the metal saccharinates show that the TEA
ligand behaves as a N,O,O0-donor tridentate ligand in
all the metal complexes, while the sac is present as a
counter-ion [18,21,22]. However, the dimeric Cu(II)
complex crystallizes as a dimethanol solvate and
contains two TEA ligands in a monoanionic form,
acting as a bridge between the two copper atoms and
two sac ligands [18].
Thermoanalytical data for the TEA complexes
of metal saccharinates are given in Table 1, while
Fig. 1 presents the TG, DTG and DTA of the
[Cd(TEA)2](sac)2 complex.
The [Mn(TEA)2](sac)2 complex melts at 188 8C
and begins to decompose after melting. The elimina-
tion of two CH2OH groups during the degradation of
the TEA ligands occurs in the ®rst stage with an
exotherm at 229 8C in the DTA curve and a corre-
sponding peak in the DTG curve. The experimental
mass loss of 9.64% for the stage agrees well with the
calculated value of 8.65%. A sharp colour change
from yellow-brown to orange was observed during the
elimination of the two CH2OH groups. In the second
stage, the rest of the TEA ligand decomposes to form
Simultaneous TG, DTG and DTA curves were
obtained using a Rigaku TG8110 thermal analyser
combined with a TAS100 thermogravimetric analyser.
The experiments were carried out in a dynamic nitro-
gen atmosphere with a ¯ow rate of 80 ml minÀ1 in the
temperature range 20±1100 8C, using platinum cruci-
bles. Sample masses of 5±10 mg and a heating rate of
10 8C minÀ1 were used. Sintered a-alumina was used
as the reference material. A small amount of the
volatile product lost around 200 8C was obtained by
using about 5 g of complex and analysed by 1H NMR
and IR spectroscopy. The solid residues were identi-
®ed by IR spectroscopy.
3. Results and discussion
All the TEA and me-en complexes exhibit an
exotherm in the 150±300 8C range with a mass loss
after or before melting. The mass loss corresponds to
removal of a group with a molar mass of about 60 g.
The mass spectra of the TEA and me-en ligands show

V.T. Yilmaz et al. / Thermochimica Acta 383 -2002) 129±135
131
Table 1
Thermoanalytical results (TG, DTG, DTA) for the TEA complexes of metal saccharinates
a
Complexes
Stage Temperature DTGmax. (8C)
range (8C)
Removed Mass loss in
Solid residue
group
percentage
Found Calculated
[Mn(TEA)2](sac)2
1
2
3
190±248
248±415
415±773
229(À)
2CH2OH
9.64
31.48
49.39
8.65
32.93
50.78
360(‡), 406(‡)
564(‡), 729(‡)
Mn(sac)2
Mn
2Sac
[Co(TEA)2](sac)2
1
2
3
183±271
271±385
385±1000
233(À)
2CH2OH
9.21
31.75
45.33
8.60
32.75
48.28
343(‡), 381(‡)
434(‡), 891(‡)
Co(sac)2
CoO
2Sac-O
[Ni(TEA)2](sac)2
1
2
3
223±256
256±346
346±1000
240(À)
343(‡)
403(‡)
2CH2OH
9.34
31.45
47.97
8.60
32.76
48.29
Ni(sac)2
NiO
2Sac-O
[Cu2(m-TEA)2(sac)2]Á2CH3OH
1
2
3
4
26±120
55(‡), 69(‡)
190(À), 232(À)
334(‡)
2CH3OH
2CH2OH
7.31
13.44
22.44
43.51
7.52
14.57
20.46
42.78
[Cu2(sac)2(TEA)2]
138±262
262±348
348±773
Cu2(sac)2
2Cu
384(‡), 434(‡)
2Sac
[Zn(TEA)2](sac)2
[Cd(TEA)2](sac)2
[Hg(TEA)2](sac)2
1
2
3
188±256
256±374
374±856
224(À)
2CH2OH
9.76
8.52
322(‡), 352(‡), 369(‡)
31.62
50.3750.05
32.46
Zn(sac)2
401(‡), 457(‡)
2Sac
Zn
1
2
3
210±277
219(À)
2CH2OH
8.60
29.84
46.21
8.01
277±442
383(‡), 431(‡)
‡)
30.49
46.89
Cd(sac)2
Cd
442±947685(
2Sac
1
2
3
114±184
184±321
321±440
225(À)
2CH2OH
6.06
28.21
42.64
7.19
27.37
42.20
309(‡)
Hg(sac)2
Hg
335(‡), 376(‡)
2Sac
a Endothermic (‡); exothermic (À).
Mn(II) saccharinate at about 415 8C and this inter-
mediate undergoes endothermic decomposition in the
range 415±773 8C to form metallic Mn.
of the partly degraded TEA ligand and, in the third
stage, Ni(sac)2 decomposes to produce NiO.
The [Cu2(m-TEA)2(sac)2]Á2CH3OH complex exhi-
bits three distinct decomposition stages. In the ®rst
stage, endothermic removal of two methanol solvate
molecules occurs at 55 and 69 8C with a mass loss of
7.31% (calculated 7.52%). The complex melts at
125 8C. The degradation of the triethanolaminate ions
to form methanol occurs in the second stage in the
temperature range 138±262 8C, and results in the
formation of the Cu(sac)2 intermediate at 334 8C. A
35.88% mass loss observed in the stage is in good
agreement with the calculated mass loss of 35.03%.
Over the 348±773 8C range, the DTA curve displays
two endotherms at 384 and 434 8C, attributed to the
complete decomposition of the Cu(sac)2 intermediate
to metallic Cu.
The [Co(TEA)2](sac)2 complex undergoes com-
plete endothermic decomposition in three stages,
after melting at 181 8C. The ®rst stage between
183±271 8C is accompanied by a mass loss of
9.21% (calculated 8.60%) and corresponds to
exothermic removal of two CH2OH radicals. The
decomposition of the remaining part of TEA ligand
and subsequent formation of the Co(sac)2 intermedi-
ate occur in the second stage. In the last stage, in the
temperature range 385±1000 8C, decomposition of
Co(sac)2 to CoO occurs.
In the case of the [Ni(TEA)2](sac)2 complex, the
exothermic formation of two CH2OH groups takes
place between 223±256 8C accompanied by 9.34%
mass loss. The second stage with a mass loss 31.45%
(calculated 32.76%) is attributed to the decomposition
The [Zn(TEA)2](sac)2 complex melts at a relatively
low temperature (90 8C), compared to the other TEA

132
V.T. Yilmaz et al. / Thermochimica Acta 383 -2002) 129±135
Fig. 1. TG, DTG and DTA curves for [Cd(TEA)2](sac)2 heated at 108C minÀ1 in N2.
complexes, being stable up to 181 8C, at which tem-
perature it begins to decompose. The DTA curve shows
a small endotherm at 124 8C, without a mass loss, and
it may be attributed to some kind of changes in the
melted complex. The reason of the effect is not known.
The exotherm at 224 8C is due to the release of two
CH2OH groups with a mass loss of 9.76% (calculated
8.52%). The partly decomposed TEA yields zinc
saccharinate at 374 8C and decomposes to give metal-
lic zinc at 856 8C. A continuous weight loss occurs up
to 1000 8C, due to the evaporation of the melted zinc.
The [Cd(TEA)2](sac)2 and [Hg(TEA)2](sac)2 com-
plexes show similar decomposition characteristics.
The ®rst stage corresponds to the loss of two CH2OH
groups and the second stage results in the formation of
the metal saccharinates. The last endothermic stage is
related to decomposition of the sac ions to produce the
metals. However, in the case of the Hg(II) complex,
the metallic Hg evaporates at higher temperatures
without leaving any residue.
N-donor ligand and its ethanol group is not involved
in coordination. The sac ions coordinate the metal
(through the deprotonated N) as a monodentate ligand.
Consequently, the metal ions are octahedrally coordi-
nated by these ligands. Table 2 lists the thermoana-
lytical data for the me-en complexes of the metal
saccharinates and the TG, DTG and DTA curves of
the [Cd(sac)2(me-en)2] complex are shown in Fig. 2.
The [Mn(sac)2(me-en)2] complex has a very high
thermal stability. Its decomposition begins at about
315 8C after melting at 154 8C, and proceeds in three
stages. The mass loss between 163 and 263 8C corre-
sponds to the release of two CH2OH groups. This
process is due to the partial decomposition of the me-
en ligand and is represented by an endotherm at
237 8C on the DTA curve and a corresponding peak
on the DTG curve. The decomposition of the me-en
ligand is completed at 308 8C to give the manganese
saccharinate, which also follow a complicated decom-
position process to produce metallic Mn at ca. 860 8C.
The TG, DTG and DTA curves for the dimeric
[Co2(sac)2(me-en)2]Á2H2O complex reveal that the
decomposition process proceeds via four main stages.
The ®rst stage is attributed to dehydration of the
complex at 93 8C, with a mass loss of 4.33% (calcu-
lated 4.97%). The complex melts at 162 8C. The
degradation of the ligand me-en takes place in the
3.2. Monoethanolethylenediamine -me-en)
complexes
The me-en complexes of the metal saccharinates
contain both the me-en molecules and the sac ions as
ligands [19]. The me-en ligand acts as a bidentate

V.T. Yilmaz et al. / Thermochimica Acta 383 -2002) 129±135
133
Table 2
Thermoanalytical results (TG, DTG, DTA) for the me-en complexes of metal saccharinates
a
Complexes
Stage
Temperature
DTGmax. (8C)
Removed
group
Mass loss in percentage
Solid residue
range (8C)
Found
Calculated
[Mn(sac)2(me-en)2]
1
2
3
163±260
237(‡)
2CH2OH
2Sac
9.65
23.06
57.45
9.88
23.32
58.08
263±338
338±857348(
308(‡), 321(‡)
‡), 374(‡),
426(‡), 710(‡)
Mn(sac)2
Mn
[Co2(sac)2(me-en)2]Á2H2O
1
2
3
4
25±144
93(‡)
2H2O
2CH2OH
4.33
8.71
4.97[Co
8.56
2(sac)2(me-en)2]
2Co(sac)2
170±286
286±354
3540±(80737
263(‡)
338(‡), 350(‡)
‡), 704(‡)
20.15
50.95
19.92
2Sac
50.31
2Co
[Ni(sac)2(me-en)2]
[Cu(sac)2(me-en)2]
1
2
3
151±204
169(‡)
304(‡)
‡)
CH2OH
5.12
27.85
57.26
4.95
28.09
57.74
226±320
Ni(sac)2
Ni
320±927664(
2Sac
1
2
3
190±258
2589±(34727
347±850
242(‡)
2CH2OH
95.879.7
22.58
‡)
23.00
Cu
Cu(sac)2
363(‡), 379(‡),
565(À)
2Sac
56.837057
[Zn(sac)2(me-en)2]
[Cd(sac)2(me-en)2]
[Hg(sac)2(me-en)2]
1
2
3
162±261
261±362
362±977
258(‡)
2CH2OH
9.93
22.19
56.99
9.72
22.94
57.13
349(‡)
Zn(sac)2
Zn
412(‡), 740(‡)
2Sac
1
2
3
227±300
300±371
371±805
258(‡)
2CH2OH
9.26
21.36
53.09
9.05
21.36
53.21
324(‡)
Cd(sac)2
Cd
424(‡), 705(‡)
2Sac
1
2
3
157±212
212±289
289±396
158(‡), 169(À)
218(‡), 267(À)
357(‡)
2CH2OH
8.21
18.66
47.92
8.02
18.93
47.14
Hg(sac)2
Hg
2Sac
a Endothermic (‡); exothermic (À).
second stage in the range 170±286 8C to release two
molecules of CH2OH radicals. The decomposition of
the me-en ligand is complete at 354 8C to give the
corresponding saccharinate. In the last stage, the
decomposition of the sac ions occurs to yield Co as
the end product.
The ®rst step in the decomposition of [Ni(sac)2(me-
en)2] corresponds to the removal of one of the two
CH2OH groups at 169 8C due to the partial degrada-
tion of the me-en ligand. The experimental mass loss
(5.12%) for this stage is in good agreement with the
calculated mass loss (4.95%). The remaining part of
the ligand decomposes at 304 8C and the decomposi-
tion proceeds with a continuous mass loss between
320±27 8C. The ®nal decomposition product is metal-
lic nickel.
correlated with the evolution of two CH2OH groups at
242 8C, accompanied by a 9.87% mass loss (calcu-
lated 9.75%). The decomposition of residue of the
me-en ligand results in the production of the sacchar-
inate intermediate at 279 8C and the decomposition
of the intermediate occurs in subsequent stages in the
temperature range 347±50 8C to metallic copper, with
three DTG maxima at 363, 379 and 565 8C.
The [Zn(sac)2(me-en)2] complex exhibits three
stages of decomposition. In the ®rst stage, removal
of two CH2OH groups takes place in the temperature
range 162±261 8C with a mass loss of 9.93% (calcu-
lated 9.72%). The following two stages between 261
and 362 8C are attributed to decomposition of the
remaining part of the me-en ligand. Decomposition
of the zinc saccharinate residue is observed in the
last stage between 362 and 977 8C to give metallic
zinc.
The [Cu(sac)2(me-en)2] complex melts at 180 8C
and decomposes in three stages. The ®rst stage may be

134
V.T. Yilmaz et al. / Thermochimica Acta 383 -2002) 129±135
Fig. 2. TG, DTG and DTA curves for [Cd(sac)2(me-en)2] heated at 10 8C minÀ1 in N2.
The [Cd(sac)2(me-en)2] complex shows a small
and me-en complexes conclusively prove that the
main feature is the evolution of two CH2OH groups
in the ®rst stage of decomposition, and the formation
of the metal saccharinates as intermediates, which
decompose to the respective metals. Our efforts to
isolate the intermediates were unsuccessful in most
cases due to the overlapping decomposition stage.
Hence, we tried to assign the possible intermediates
from the TG mass losses, which are reasonably con-
sistent with the calculated values. In some cases, IR
spectrometer was used for the identi®cation of the
solid intermediates. The presence of the carbonyl and
sulfonyl absorption bands in the IR spectra of the
intermediates obtained after removal of the amine
ligands suggests that the intermediates consist mainly
of the corresponding metal saccharinates.
The thermal behaviour of the solid metal complexes
indicates that their stability sequence is Ni > Cd >
Mn > Zn > Co > Cu >Hg for the TEA complexes
and Cu > Co > Cd > Mn > Zn > Hg >Ni for the
me-en complexes. This does not conform to the
Irving±Williams series, which re¯ect the stability of
divalent metal complexes in solution [23]. For a given
metal, the TEA complexes usually show much higher
thermal stability than their me-en analogues. The
thermal stabilities of the metal complexes are usually
determined by the metal±ligand strength, but in the
endothermic effect at 147 8C, probably due to a rever-
sible phase transition in the solid state. The complex is
stable up to 227 8C and then begins to decompose with
melting. The me-en ligand undergoes endothermic
decomposition ®rst at 258 by losing two CH2OH
groups and then at 324 8C to give Cd(sac)2. The total
experimental mass loss (30.62%) for these stages is in
good agreement with the calculated mass loss
(30.41%). The last stage in the temperature range
300±805 8C is due to decomposition of Cd(sac)2 to
produce metallic cadmium.
The [Hg(sac)2(me-en)2] complex decomposes in
three stages. The endothermic removal of two CH2OH
groups takes place in the temperature range 157±
212 8C, after melting at 157 8C. The decomposition
of the partly degraded ligand is completed at 289 8C to
produce the corresponding saccharinate intermediate,
which decomposes between 289 and 396 8C to form
metallic Hg, which evaporates at higher temperatures.
4. Conclusions
The solid metal complexes studied are stable at the
room temperature and decompose progressively dur-
ing heating. The thermoanalytical results of the TEA

V.T. Yilmaz et al. / Thermochimica Acta 383 -2002) 129±135
135
[2] I.C. Munro, C.A. Modie, D. Krewski, H.C. Grice, Toxicol.
Appl. Pharmacol. 32 (1957) 513.
case of the TEA and me-en complexes, the metal±
ligand strength seems to be insigni®cant to determine
the thermal stability. The results of the present work
show that the thermal stabilities of the metal com-
plexes with the TEA and me-en ligands are largely due
to the reactivity of the free ethanolic groups, which
initiate the decomposition of the metal complexes.
The general decomposition scheme of the metal
complexes can be summarized in the following
mechanisms.
[3] M.J. Allen, E. Bayland, C.E. Dukes, E.S. Horning, J.G.
Watson, Br. J. Cancer 11 (1957) 212.
[4] B. Kamenar, G. Jovanovski, Cryst. Struct. Commun. 11
(1982) 257.
[5] Z. Haider, K.M.A. Malik, K.J. Ahmed, H. Hess, H. Riffel,
M.B. Hursthouse, Inorg. Chim. Acta 72 (1983) 21.
[6] Z. Haider, K.M.A. Malik, K.J. Ahmed, Inorg. Synth. 23
(1985) 47.
[7] F.A. Cotton, G.E. Lewis, C.A. Murillo, W. Schwotzer, G.
Valle, Inorg. Chem. 23 (1984) 4038.
[8] F.A. Cotton, E. Libby, C.A. Murillo, G. Valle, Inorg. Synth.
27(1990) 306.
The TEA complexes:
‰Mꢀtea† Šꢀsac†
!
‰MꢀLÆ Šꢀsac†
[9] Y. Zhang, Spectrosc. Lett. 31 (1998) 1609.
[10] J. Anderson, B. Deskins, The Nutrition Bible, William
Morrow and Company, 1995.
2
2
2
2
À2CH2OH
‰MꢀLÆ Šꢀsac† ! Mꢀsac†
2
2
2
À2LÃ
[11] E.W. Ainscough, E.N. Baker, A.M. Brodie, Inorg. Chim. Acta
172 (1990) 185.
Mꢀsac† ! Mꢀor MO†
2
À2sac
[12] P. Naumov, G. Jovanovski, S. Abbrent, L.E. Tergenius,
Thermochim. Acta 359 (2000) 123.
The me-en complexes:
[13] D. Magri, G. Dascenzo, S.N. Cesaro, E. Chiacchieri,
Thermochim. Acta 36 (1980) 279.
‰Mꢀsac†2ꢀme-en† Š
!
‰Mꢀsac†2ꢀLÆ Š
2
2
[14] H. Icbudak, V.T. Yilmaz, H. Olmez, J. Thermal. Anal. 53
(1998) 843.
À2CH2OH
‰Mꢀsac†2ꢀLÆ Š ! Mꢀsac†
2
2
[15] V.T. Yilmaz, Synth. React. Inorg. Met. Org. Chem. 29 (1999)
62.
À2LÃ
Mꢀsac† ! M
Here, LÃ indicates partly degraded amine ligand.
[16] H. Icbudak, T.K. Yazicilar, V.T. Yilmaz, Thermochim. Acta
335 (1999) 93.
2
À2sac
[17] V.T. Yilmaz, F. Yilmaz, Y. Topcu, O. Andac, K. Guven,
J. Mol. Struct. 560 (2001) 9.
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Acknowledgements
[19] V.T. Yilmaz, A. Karadag, C. Thoene, J. Coord. Chem., in press.
[20] W.G. Mallard, P.J. Linstrom (Eds.), NIST Chemistry
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National Institute of Standards and Technology, Gaithersburg,
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The authors thank Ondokuz Mayis University for
the ®nancial support given to the project.
È
[21] Y. Topcu, O. Andac, V.T. Yilmaz, W.T.A. Harrison, Acta
Crystallogr. E57(2001) m82.
È
[22] O. Andac, Y. Topcu, V.T. Yilmaz, K. Guven, Acta Crystal-
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