Interaction of divalent metal ions with D-aldonic acids in the solid phase-II. Structural information

Article abstract of DOI:10.1016/S0277-5387(98)00119-3

Complexes formed between D-glucoheptonate, D-galactonate, D-gulonate and D-ribonate, and several metal ions were obtained in the solid state. Specifically: D-glucoheptonates, Be(C₇H₁₃O₈)₂ · 12H₂O, Mn(

Full text of DOI:10.1016/S0277-5387(98)00119-3

Polyhedron Vol[ 06\ No[ 08\ pp[ 2260Ð2267\ 0887
Þ 0887 Elsevier Science Ltd
Pergamon
All rights reserved[ Printed in Great Britain
9166Ð4276:87 ,08[99¦9[99
\
PII] S9166Ð4276"87#99008Ð2
Interaction of divalent metal ions with !aldonic
D
acids in the solid phase!II[ Structural information0
Alejandro A[ Frutos\a Sandra Signorella\a Luis F[ Sala\aꢀ Graciela M[ Escandar\b
Juan M[ Salas Peregrinc and Virtudes Morenod
aDepartamento de Qu(mica Fisica\ Facultad de Ciencias Bioqu(micas y Farmaceuticas\ Universidad
ꢁ
ꢁ
ꢁ
Nacional de Rosario\ Suipacha 420 "1999# Rosario\ Argentina
bDepartamento de Qu(mica Anal(tica\ Facultad de Ciencias Bioqu(micas y Farmaceuticas\ Universidad
ꢁ
ꢁ
ꢁ
ꢁ
Nacional de Rosario\ Suipacha 420 "1999# Rosario\ Argentina
cDepartamento de Qu(mica Inorganica\ Facultad de Ciencias\ Universidad de Granada\ 07960 Granada
ꢁ
ꢁ
Espana
½
dDepartament de Qu(mica Inorganica\ Universitat de Barcelona\ E!97917 Barcelona\ Espana
ꢁ
ꢁ
½
"Received 2 November 0886^ accepted 05 March 0887#
Abstract*Complexes formed between D!glucoheptonate\ D!galactonate\ D!gulonate and D!ribonate\ and
several metal ions were obtained in the solid state[ Speci_cally] D!glucoheptonates\ Be"C6H02O7#1 = 0:1H1O\
Mn"C6H02O7#1 = 1H1O\ Co"C6H02O7#1 = 1H1O\ Ni"C6H02O7#1 = 1H1O\ Cu"C6H02O7#1 = 1H1O\ Pb"C6H02O7#1^ D!gal!
actonates\ Mn"C5H00O6#1 = 1H1O\ Co"C5H00O6#1 = 2H1O\ Ni"C5H00O6#1 = 2H1O\ Cu"C5H00O6#1\ Pb"C5H00O6#1^ D!
gulonates\ Co"C5H00O6#1 = H1O\ Ni"C5H00O6#1 = 1H1O\ Cu"C5H00O6#1 = 1H1O^ D!ribonates\ Mn"C4H8O5#1\
Co"C4H8O5#1 = 1H1O\ Ni"C4H8O5#1 = 1H1O\ Cu"C4H8O5#1[1H1O and Pb"C4H8O5#1 have been isolated[ These metal
sugar salts were characterized by elemental analysis\ thermogravimetric analysis\ magnetic susceptibility
measurements\ FTÐIR\ di}use re~ectance and EPR spectroscopies[ Þ 0887 Elsevier Science Ltd[ All rights
reserved
Keywords] D!aldonic acids^ metal sugar complexes^ divalent metal ions[
———————————————————————————————————————————————
INTRODUCTION
ing the interaction between carbohydrates and tran!
sition metal ions is related to the use of this type of
ligands as sequestering agents for metal ions present
in biological media ð8\ 09Ł[ The present work comp!
lements previous information a}orded with metal ions
cobalt "II#\ nickel "II# and copper "II#\ and the ligands
I\ II\ III and IV in solution studies ð1\ 3\ 7Ł[ Interactions
of the above!mentioned D!aldonic acids with beryl!
lium "II#\ manganese "II# and lead "II# are given as
additional information[
Solid complexes formed between the metal ions beryl!
lium "II#\ manganese "II#\ cobalt "II#\ nickel "II#\ cop!
per "II# and lead "II#\ and ligands of biological interest\
such as D!glucoheptonic acid "I#\ D!galactonic acid
"II#\ D!gulonic acid "III# and D!ribonic acid "IV# "Fig[
0#\ were isolated[ This work is part of our program on
the coordination chemistry of sugar acids ð0Ð7Ł[ In
previous papers\ studies were carried out on equi!
librium reactions in aqueous solution and in the solid
state for metal complexes of both D!gluconolactone
and D!lactobionic acid ð0\ 1Ł[ The importance of study!
The studies in the solid state were performed by
elemental\ thermogravimetric and susceptibility
analyses\ and by FTÐIR\ di}use re~ectance and EPR
spectroscopies[
These studies represent a contribution to future
crystallographic analyses\ which are complicated by
the di.culties in obtaining X!ray quality crystals of
complexes containing carbohydrates with non!
blocked hydroxyl groups[
0 Presented at the X Physicochemical Argentine Meeting\
April 10 to 14\ 0886\ Tucuman\ Argentina[
ꢁ
ꢀ Author to whom correspondence should be addressed[
Fax] 43!30!249103^ E!mail] inquibirÝsatlink[com[
2260

2261
A[ A[ Frutos et al[
Fig[ 0[ Ligands[
EXPERIMENTAL
percentages in its complexes was determined by com!
plexometric titration with EDTA and zinc nitrate
solutions employing eriochrome black T as an indi!
cator ð01Ł[ The content of beryllium was calculated
Rea`ents
D!glucoheptono!g!lactone\ D!galactono!g!lactone\ from the thermogravimetrical residue[ The metal per!
D!gulono!g!lactone and D!ribono!g!lactone were pur! centage in the other complexes were determined by
chased from Sigma[ Their purities were checked by atomic absorption using a Metrolab 149 AA atomic
elemental analysis\ chromatography and potent! absorption spectrophotometer[ Thermogravimetric
iometric titrations[ The metal carbonates or oxides curves were obtained in an atmosphere of pure air
used were] Co"CO2# = xH1O "Aldrich#\ 1NiCO2 = using a Shimadzu TGA!49 H\ with a heating speed of
2Ni"OH#1 = 3H1O "Aldrich#\ CuCO2 = Cu"OH#1 "Ald! 19>C min−0\ equipped with a Nicolet model 449 IR gas
rich#\ MnCO2 "BDH#\ BeCO2 = 4H1O "BDH# and analyzer and Fisons model Thermolab mass detector[
PbCO2 "Aldrich#[
DSC data were obtained on a Shimadzu DSC!49
di}erential scanning calorimeter\ using a heating
speed of 09>C min−0[ The di}use re~ectance spectra
were obtained with a Cary!4E refractometer provided
with a praying mantis module[ IR spectra were per!
Synthesis of complexes in the solid state
The complexes were prepared following the pro!
cedures described previously ð00Ł[ Brie~y\ the metal
ion was added to a previously re~uxed "0 h# solution
of the lactone\ in order to promote the opening of the
sugar ring a}ording the aldonic acid[ This mixture
was boiled for 1 hrs[ The metalÐlactone ratio was 0]1[
Ethanol was added to the clear solution and a solid
phase was obtained[ The precipitate was separated by
_ltration and recrystallized four times from a mixture
of ethanolÐwater "3]0#[ Finally\ the product was
washed with ethanol\ dried under vacuum over phos!
phorus pentoxide at room temperature and again
dried for 1 hrs[ at 79>C under vacuum over phos!
phorus pentoxide[
formed on
a FTÐIR Nicolet 19 SX7 spec!
trophotometer[ Susceptibility magnetic measurements
were carried out on Manics DSM!7 instrument in
the 79Ð189 K temperature range[ X!band "½8[1 GHz#
EPR spectra were recorded as the _rst derivative of
absorption at 66 and 187 K\ on a Bruker ESP 299E
EPR spectrometer with 099 kHz _eld modulation[ The
microwave frequency was generated with a Bruker
93 ER and measured with a RacalÐDana frequency!
meter[ The magnetic _eld was measured with a Bruker
NMR!probe gaussmeter[
The purity of the obtained complexes was checked
by elemental analysis[
RESULTS AND DISCUSSION
Elemental Analysis
Analysis of the solid complexes
The analytical results for the synthesized complexes
Microanalyses of C and H were performed using are reported in Table 0[ All the complexes present a
a Fisons 0097 CHNS microanalyser[ The nickel "II# 0]1 metalÐligand ratio and were obtained either in

Interaction of divalent metal ions with D!aldonic acids in the solid phase!II[ Structural information 2262
Table 0[ Analytical data and colors for D!aldonic complexes
)C
)H
)M
Complexes
colors
Calc[
Exp[
Calc[
Exp[
Calc[
Exp[
D!glucoheptonates]
Be"C6H02O7#1 = 0:1H1O
Mn"C6H02O7#1 = 1H1O
Co"C6H02O7#1 = 1H1O
Ni"C6H02O7#1 = 1H1O
Cu"C6H02O7#1 = 1H1O
Pb"C6H02O7#1
white
light pink
pink
green
blue
24[89
20[95
29[73
29[74
29[47
14[46
24[51
29[67
29[35
29[73
18[34
14[11
4[70
4[48
4[43
4[26
4[49
2[88
4[72
4[64
4[67
4[77
4[14
3[92
0[81
0[83
09[21
09[70
09[66
00[45
20[40
09[31
09[49
09[18
00[79
20[09
white
D!galactonates]
Mn"C5H00O6#1 = 1H1O
Co"C5H00O6#1 = 2H1O
Ni"C5H00O6#1 = 2H1O
Cu"C5H00O6#1
white
pink
green
blue
18[84
17[53
17[54
20[65
13[01
18[58
17[68
17[32
20[77
13[96
4[33
4[50
4[50
3[78
2[60
4[25
4[69
4[76
4[05
2[48
00[30
00[60
00[57
03[99
23[57
00[19
01[90
00[06
02[54
23[57
Pb"C5H00O6#1
white
D!gulonates]
Co"C5H00O6#1 = H1O
Ni"C5H00O6#1 = 1H1O
Cu"C5H00O6#1 = 1H1O
pink
green
blue
29[74
18[60
18[31
20[17
18[58
18[58
4[07
4[39
4[24
4[16
4[39
3[70
01[50
01[09
01[86
01[39
00[89
01[54
D!ribonates]
Mn"C4H8O5#1
light pink
pink
green
blue
20[07
17[14
17[16
16[84
11[24
29[73
17[64
17[40
16[60
11[18
3[60
4[10
4[11
4[05
2[27
3[69
4[12
4[35
3[56
2[30
03[15
02[75
02[70
03[68
27[44
03[39
02[59
02[17
03[41
27[62
Co"C4H8O5#1 = 1H1O
Ni"C4H8O5#1 = 1H1O
Cu"C4H8O5#1 = 1H1O
Pb"C4H8O5#1
white
anhydrous or solvated form[ It was not possible to ion[ Thermoanalytical data are given in supple!
prepare pure Be"II# D!ribonate because it was con! mentary material[
taminated with the starting material "BeCO2#[ This
fact would be due to low acidity of the ribonic acid
which makes it less reactive towards the carbonate[
Re~ectance spectra
As an example\ Fig[ 2 shows re~ectance spectra
Thermo`ravimetric curves
for di}erent complexes of cobalt "II#\ copper "II# and
nickel "II#[ The bands of the recorded spectra are
As was already reported ð0\ 1\ 5Ł\ the thermo! shown in Table 1 "A and B#[ In this table both the
gravimetric curves of this type of complexes present calculated and experimental frequency ratios accord!
two steps] dehydration "between 099Ð199>C# and pyr! ing to the DQ:B values are presented ð03Ł[ The band
olytic processes "above 199>C#[ Figure 1 shows two of the spectra of cobalt "II# complexes were these
typical thermal decompositions for both hydrated and expected for the electronic transition of a d6 metal
anhydrous complexes\ respectively[ Thermoanalytical ion in an octahedral arrangement ð04Ł"a#ð05Ł"b#[ The
data are in good agreement with the elemental analy! spectra of the nickel "II# complexes also show three
sis[ The temperature of water loss and the sharp peak absorption bands and the relationship between the
on the DSC diagram may indicate that these molecules _rst two bands "0[6# suggests octahedral geometries
are coordinated to the metal[ The pyrolitic process for these complexes ð04Ł"b#ð05Ł"a#[ In all cases\ the
took place in two\ three or four steps[ The pyrolitic second bands were found to split into two signals[
products identi_ed by IR spectra were] water\ carbon This fact can be attributed either to interactions with
monoxide and carbon dioxide[ The pyrolitic residues the nearest electronic level 0Eg or to spinÐorbit coup!
at 399Ð799>C were determined to be oxides or mixture ling[ The copper "II# complexes showed spectra with
of carbonates and oxides of the corresponding metal a single wide band with maxima in the range 688Ð

2263
A[ A[ Frutos et al[
Fig[ 1[ Thermogravimetric curves for "a# Cu "II# D!galactonate "initial mass] 4[862 mg#^ "b# Co "II# D!gulonate "initial mass]
4[982 mg#[

Interaction of divalent metal ions with D!aldonic acids in the solid phase!II[ Structural information 2264
Fig[ 2[ Re~ectance spectra for "a# Cu "II# D!gulonate^ "b# Co "II# D!galactonate^ "c# Ni "II# D!glucoheptonate[
703 nm[ The frequencies of these maxima are coinci! quencies of stretching carboxyl groups\ respectively
dent with the value of the crystal _eld splitting and
correspond to the electronic transitions 1T1g31Eg[
According to these results tetragonal distortion of
octahedral arrangements was proposed for these com!
plexes ð04Ł"c#ð05Ł"c#[
ð06Ł[ The di}erence in frequency between these two
bands allowed us to infer the coordination mode of
the metal center towards the carboxylate groups[ Most
of the complexes under study showed values which
were equal to\ or higher than\ 199 cm−0\ always related
to a monodentate coordination ð07Ł[ Lead "II# D!gluco!
heptonate and cobalt "II#\ nickel "II# and copper "II#
D!galactonate presented values in the range 059Ð
199 cm−0\ which were in agreement with an additional
hydrogen!bonded coordination between the carbonyl
oxygen and protons of the carbonate chain ð07Ł[ Lead
"II# D!ribonate complex spectrum showed a splitting
of the signals corresponding to symmetric and anti!
symmetric stretching\ suggesting that the metal ion is
not located in a symmetric environment[ In the spec!
tral region of 0399Ð0099 cm−0\ shifting and broad!
ening for the CH1\ OH and COH bending modes were
observed in the presence of the metal ions\ and were
attributed to the metalÐOH interaction in the com!
plexation[ Both the sugar CÐO stretching vibrations
"0099Ð839 cm−0# and the deformation modes of the
lactone ring skeletal "899Ð499 cm−0# showed major
changes upon metal ion chelation[ Selected infrared
absorption frequencies for complexes and aldo!
IR spectra
The IR spectra of the solid complexes were carried
out between 3999Ð399 cm−0 and the interpretation
was based on a comparison with both the cor!
responding sugar acids and structurally related com!
pounds[
The wide bands at 2499Ð2099 cm−0 in the spectra
of the free ligands were assigned to strongly hydrogen!
bonded OH groups[ The interaction between the
hydroxyl groups of the aldonolactones and the metals
produces broadening\ but not shifting\ of the sugar
OH stretching vibrations[ The carbonyl stretching
bond in the spectra of the studied lactones appeared
at 0699Ð0799 cm−0[ In the spectra of the complexes\
this band disappeared and two new bands were
detected at about 0599 and 0399 cm−0[ The latter were
assigned to the antisymmetric and symmetric fre! nolactones are given in supplementary material[

2265
A[ A[ Frutos et al[
Table 1[ Electronic absorption spectral data in the solid phase
"A#
Complex
n0
n1
n2
Do "cm−0
6465
#
Bꢀ "cm−0
562
893
*
#
Co"II# D!glucoheptonate
Ni"II# D!glucoheptonate
Cu"II# D!glucoheptonate
Co"II# D!galactonate
Ni"II# D!galactonate
Cu"II# D!galactonate
Co"II# D!gulonate
Ni"II# D!gulonate
Cu"II# D!gulonate
Co"II# D!ribonate
Ni"II# D!ribonate
Cu"II# D!ribonate
3T1g33T0g
"7012 cm−0
2T1g32A1g
"7661 cm−0
1T1g31Eg
3A1g33T0g
"04588 cm−0
2T0g32A1g
"03770 cm−0
*
3T0g"P#33T0g
#
#
#
#
"07651 cm−0
#
2T0g"P#32A1g
7661
"14270 cm−0
*
#
01174
6738
"01174 cm−0
#
3T1g33T0g
3A1g33T0g
"04687 cm−0
2T0g32A1g
"04095 cm−0
*
3T0g"P#3 3T0g
"07238 cm−0
576
789
*
"6838 cm−0
2T1g32A1g
"7623 cm−0
1T1g31Eg
#
#
#
#
2T0g"P#3 2A1g
7623
#
"13641 cm−0
*
#
01327
6174
"01327 cm−0
#
3T1g33T0g
3A1g33T0g
"04226 cm−0
2T0g32A1g
"03814 cm−0
*
3T0g"P#3 3T0g
"07828 cm−0
564
783
*
"7941 cm−0
2T1g32A1g
"7762 cm−0
1T1g31Eg
#
#
#
#
2T0g"P#32A1g
7762
#
"14334 cm−0
*
#
01405
6202
"01405 cm−0
#
3T1g33T0g
3A1g33T0g
"04273 cm−0
2T0g32A1g
"03814 cm−0
*
3T0g"P#33T0g
"07581 cm−0
#
547
814
*
"7960 cm−0
2T1g32A1g
"7525 cm−0
1T1g31Eg
#
#
#
2T0g"P#32A1g
7525
#
"14334 cm−0
*
#
01235
"01235 cm−0
#
ꢀCalculated according to Ref[ ð02Ł[
"B#
Complex
Dq:B
n0:n1
n2:n0
n2:n1
Co"II# D!glucoheptonate
Ni"II# D!glucoheptonate
Co"II# D!galactonate
Ni"II# D!galactonate
Co"II# D!gulonate
Ni"II# D!gulonate
Co"II# D!ribonate
Ni"II# D!ribonate
0[0
0[9
0[0
0[9
0[0
0[9
0[0
9[8
0[822 "1[027#
0[585 "0[537#
0[876 "1[027#
0[629 "0[537#
0[894 "1[027#
0[571 "0[537#
0[895 "1[027#
0[617 "0[556#
1[209 "1[303#
1[782 "1[741#
1[297 "1[303#
1[723 "1[741#
1[241 "1[303#
1[757 "1[741#
1[205 "1[303#
1[835 "2[999#
0[084 "0[018#
0[695 "0[620#
0[050 "0[018#
0[528 "0[620#
0[124 "0[018#
0[694 "0[620#
0[104 "0[018#
0[694 "0[799#
" #According to Ref[ ð03Ł[
Ma`netic susceptibility measurements
for both cobalt "II# and copper "II# D!ribonates present
a signi_cant deviation of the linearity at values lower
Table 2 shows the magnetic data for the studied than 069 and 049 K respectively[
complexes[ In all cases the CurieÐWeiss law was veri!
_ed] xM ꢂ C:"T−u#\ where xM is the corrected molar
susceptibility\ C is the Curie Constant\ T is the absol! EPR measurements
ute temperature and u is the Weiss Constant[ Copper
"II# and nickel "II# D!galactonates\ and manganese "II#
Cu"II# D!aldonic acids complexes[ The polycrystal!
D!glucoheptonate showed ferromagnetic interactions line samples exhibit rhombic EPR spectra with EPR
while the rest of the isolated compounds displayed an parameters "` factors and hyper_ne splitting constants
antiferromagnetic coupling[ The values of the e}ective A# summarized in Table 3[ The spectra recorded at
magnetic moment "me}# for all the complexes studied 66 K are very similar to those at room temperature\
suggest that the metal ions are in an octahedral high indicating no signi_cant change in the coordination
spin environment[ The plots of xM vs[ T "not shown# geometry "Fig[ 3#[

Interaction of divalent metal ions with D!aldonic acids in the solid phase!II[ Structural information 2266
Table 2[ Magnetic moments for complexes
The EPR spectral patterns and parameters observed
for the Cu"II# D!gluconate\ Cu"II# D!lactobionate ð0Ł\
Cu"II# D!gulonate and Cu"II# D!glucoheptonate were
typical for molecules of pseudo!axial symmetry\ hav!
ing `z × `x ¼ `y × 1^ generally showing a hyper_ne
structure due to the nuclear spin "I ꢂ 2:1# at the `>
region and were indicative for a predominantly dx1Ð
dy1 ground state with small mixing of a dz1 con!
tribution ð08\ 19Ł[ The rhombic signal was probably
a consequence of the bulkiness of the carbohydrate
moiety as well as its tendency to form intermolecular
hydrogen bonds ð10Ł[ For Cu"II# D!galactonate a
rhombic signal centered at ¼2024 G was observed[ In
this case the coordination sphere of the copper center
was less distorted than for the other complexes and
the di}erent anisotropic components of ` were not
resolved[
Temperature
"K#
u
me}
Complex
"K#
"BM#
Mn "II# D!glucoheptonate
Co "II# D!glucoheptonate
Ni "II# D!glucoheptonate
Cu "II# D!glucoheptonate
Mn "II# D!galactonate
Co "II# D!galactonate
Ni "II# D!galactonate
Cu "II# D!galactonate
Co "II# D!gulonate
Ni "II# D!gulonate
Cu "II# D!gulonate
Mn "II# D!ribonate
Co "II# D!ribonate
82Ð189
008Ð189
68Ð189
9[74
−7[84
−1[46
−07[3
−7[37
−09[20
9[36
5[97
3[85
2[13
0[88
4[59
4[03
2[16
0[64
3[81
2[26
1[93
4[70
4[11
2[23
0[84
74Ð189
039Ð189
099Ð189
70Ð179
89Ð189
88Ð189
1[07
−01[14
−8[72
−03[9
−9[22
−00[8
−3[87
−13[47
89Ð189
029Ð189
090Ð189
069Ð189
011Ð189
049Ð189
Ni "II# D!ribonate
Cu "II# D!ribonate
CONCLUSION
All isolated complexes presented a 0]1 metalÐligand
stoichiometry\ with di}erent hydration degrees[ Both
the presence or absence of water in the compounds
was con_rmed by thermogravimetric analyses[ The
water molecules would be coordinated to the metal
center[ The infrared spectra suggest that the car!
boxylic groups of sugars are involved in the chelation[
The structural data obtained from magnetic measure!
ments would indicate that the metal ions in manganese
"II#\ cobalt "II#\ nickel "II# and copper "II# complexes
are in an octahedral environment[ For cobalt "II#\
nickel "II# and copper "II# complexes was con_rmed
an octahedral geometry by di}use re~ectance spectra[
In the case of the copper "II# complexes\ the EPR
measurements con_rm also octahedral environment[
The molecular ~exibility of the studied sugar acids
would enable on octahedral coordination mode[
Table 3[ Room temperature "or 66 K# EPR parameters for
copper "II# complexes
Compound
`z "`>#
A> "G# `x\ `y "`_#
Cu "II# D!gluconate
Cu "II# D!lactobionate
Cu "II# D!gulonate
1[25
1[23
1[23
1[23
024
032
032
032
1[94\ 1[91
1[94
1[94
Cu "II# D!glucoheptonate
1[94
Acknowled`ements*We are grateful for _nancial support
from the Universidad Nacional de Rosario "UNR#\ Argen!
tine and from the Agreement between Consejo Nacional de
Investigaciones Cient(_cas y Tecnicas "CONICET\ Argen!
ꢁ
tine# and the Universidad de Granada\ Spain[
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