Syntheses, characterization and crystal structures of novel amine adducts of metal saccharinates, orotates and salicylates

Article abstract of DOI:10.1016/S0022-2860(03)00404-6

Seven novel adducts of ethylenediamine (en), N,N′ -dimethylethylenediamine (dmen) and N, N-dimethylethylenediamine (ndmen) with saccharinate, orotate and salicylate as counter-ions were synthesized and characterized with physico-chemical methods (IR and UV/vis spectroscopy, magnetic susceptibility and thermoanalytical measurements) and X-ray diffraction. Reaction of dmen with tetraaquabis(saccharinato-N)copper(II) dihydrate yielded diaquabis(dmen)copper(II) saccharinate, whereas with the corresponding nickel derivative it afforded bis(dmen)bis(saccharinato-O)nickel(II). In the copper complex the coordinated water and the primary nitrogen end of the donor ligand interact with the saccharinate anion [O1 w?O3 = 2.833 (2), N1?N2 = 2.992(2) ?]. Adjacent molecules are linked by two more hydrogen bonds into a layer structure. In the nickel compound, the dmen ligand also chelates the metal atom, which is bonded to the carbonyl oxygen of the anionic group. The negatively-charged nitrogen atom of the anion is intramolecularly linked to the dmen [N1?N2 = 2.968(2) ?]; hydrogen bonds link the molecules into layers. Under mildly basic conditions, the reaction of orotic acid with cobalt(II) afforded tetraaqua(2,6dioxo-1,2,6-trihydropyrimidine-4-carboxylato-N,O)cobalt(II) hydrate. The complex was oxidatively reacted with en to give a mixed-ligand cobalt(III) adduct which includes both mono- and bisdeprotonated orotate ions. The metal atom in tetraaqua(2,6dioxo-1,2,6-trihydropyrimidine-4-carboxylato-N,O)cobalt(II) hydrate is chelated by the orotato dianion through the carboxyl oxygen and 3-pyrimidyl nitrogen atoms, and its octahedral geometry is completed by four water molecules. The 1-pyrimidyl nitrogen atom engages in hydrogen bonding with the lattice water molecule. The cobalt atom is similarly chelated by the orotato dianion in bis(en)(2,6-dioxo-1,2,6-trihydropyrimidine-4-carboxylato-N,O)cobalt(III) 2,6-dioxo-1,2,3,6-tetrahydropyridimi-dine-4-carboxylate pentahydrate. The copper atom in the five-coordinate aqua(en)orotatocopper(II) monohydrate is chelated by the en ligand, the deprotonated N1 pyrimidine atom and the orotate carboxylate oxygen; the water molecule completes the square-pyramidal coordination. The nickel and copper atoms in bis(en)bis(salicylato-O)nickel(II) and bis(ndmen)bis(salicy-lato-O)copper(II) monomeric octahedral complexes are coordinated by the salicylato monoanion through the carboxylate oxygen in a monodentate fashion and by the en and ndmen molecules through the two amine nitrogen atoms in a bidentate chelating manner. In the copper complex, the carboxylate oxygen atom engages in hydrogen bonding with the lattice water molecule.

Full text of DOI:10.1016/S0022-2860(03)00404-6

Journal of Molecular Structure 657 (2003) 255–270
www.elsevier.com/locate/molstruc
Syntheses, characterization and crystal structures of novel amine
adducts of metal saccharinates, orotates and salicylates
a,
a
a
a
b
*
Hasan Icbudak , Halis Olmez , Okan Z. Yesilel , Figen Arslan , Pance Naumov ,
Gligor Jovanovskib, Abdul Razak Ibrahimc, Anwar Usmanc, Hoong-Kun Func,
Suchada Chantraprommad, Seik Weng Nge
aDepartment of Chemistry, Ondokuz Mayis University, 55139 Kurupelit, Samsun, Turkey
bInstitute of Chemistry, Sv. Kiril i Metodij University, P.O. Box 162, MK-1001 Skopje, Macedonia
cX-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800 Penang, Malaysia
dDepartment of Chemistry, Prince of Songkla University, Hat Yai, 90112 Songkhla, Thailand
eInstitute of Postgraduate Studies, University of Malaya, 50603 Kuala Lumpur, Malaysia
Received 1 May 2003; revised 13 June 2003; accepted 16 June 2003
Abstract
Seven novel adducts of ethylenediamine (en), N; N0-dimethylethylenediamine (dmen) and N; N-dimethylethylenediamine
(ndmen) with saccharinate, orotate and salicylate as counter-ions were synthesized and characterized with physico-chemical
methods (IR and UV/vis spectroscopy, magnetic susceptibility and thermoanalytical measurements) and X-ray diffraction.
Reaction of dmen with tetraaquabis(saccharinato-N)copper(II) dihydrate yielded diaquabis(dmen)copper(II) saccharinate,
whereas with the corresponding nickel derivative it afforded bis(dmen)bis(saccharinato-O)nickel(II). In the copper complex the
coordinated water and the primary nitrogen end of the donor ligand interact with the saccharinate anion [O1w· · ·O3 ¼ 2.833(2),
˚
N1· · ·N2 ¼ 2.992(2) A]. Adjacent molecules are linked by two more hydrogen bonds into a layer structure. In the nickel
compound, the dmen ligand also chelates the metal atom, which is bonded to the carbonyl oxygen of the anionic group. The
˚
negatively-charged nitrogen atom of the anion is intramolecularly linked to the dmen [N1· · ·N2 ¼ 2.968(2) A]; hydrogen bonds
link the molecules into layers. Under mildly basic conditions, the reaction of orotic acid with cobalt(II) afforded tetraaqua(2,6-
dioxo-1,2,6-trihydropyrimidine-4-carboxylato-N,O)cobalt(II) hydrate. The complex was oxidatively reacted with en to give a
mixed-ligand cobalt(III) adduct which includes both mono- and bisdeprotonated orotate ions. The metal atom in tetraaqua(2,6-
dioxo-1,2,6-trihydropyrimidine-4-carboxylato-N,O)cobalt(II) hydrate is chelated by the orotato dianion through the carboxyl
oxygen and 3-pyrimidyl nitrogen atoms, and its octahedral geometry is completed by four water molecules. The 1-pyrimidyl
nitrogen atom engages in hydrogen bonding with the lattice water molecule. The cobalt atom is similarly chelated by the orotato
dianion in bis(en)(2,6-dioxo-1,2,6-trihydropyrimidine-4-carboxylato-N,O)cobalt(III) 2,6-dioxo-1,2,3,6-tetrahydropyridimi-
dine-4-carboxylate pentahydrate. The copper atom in the five-coordinate aqua(en)orotatocopper(II) monohydrate is chelated
by the en ligand, the deprotonated N1 pyrimidine atom and the orotate carboxylate oxygen; the water molecule completes the
square-pyramidal coordination. The nickel and copper atoms in bis(en)bis(salicylato-O)nickel(II) and bis(ndmen)bis(salicy-
lato-O)copper(II) monomeric octahedral complexes are coordinated by the salicylato monoanion through the carboxylate
oxygen in a monodentate fashion and by the en and ndmen molecules through the two amine nitrogen atoms in a bidentate
*
Corresponding author. Tel.: þ362-457-60207159; fax: þ362-457-6080.
E-mail address: icbudak@omu.edu.tr (H. Icbudak).
0022-2860/03/$ - see front matter q 2003 Elsevier B.V. All rights reserved.
doi:10.1016/S0022-2860(03)00404-6

256
H. Icbudak et al. / Journal of Molecular Structure 657 (2003) 255–270
chelating manner. In the copper complex, the carboxylate oxygen atom engages in hydrogen bonding with the lattice water
molecule.
q 2003 Elsevier B.V. All rights reserved.
Keywords: Amine complexes; Coordination; Orotate; Saccharinate; Salicylate
1. Introduction
Orotic acid (6-uracilic acid, 1,2,3,6-tetrahydro-2,6-
dioxo-4-pyrimidine carboxylic acid, vitamin B13,
H3Or; Scheme 1) is a key compound in the
biosynthesis of pyrimidine bases of nucleic acids in
living organisms [19]. It also exhibits bacteriostatic
and cytostatic properties. Besides the biological
relevance, the orotic acid and its anions H2Or2,
HOr22 and Or32 are interesting multidentate ligands
as they can coordinate through the two pyrimidine
nitrogen atoms, the two carbonyl oxygens and the
oxygens from the carboxyl group. The equilibrium
composition of the reactant mixture and thus the
solution pH are critical factors which determine the
mode of coordination. Between pH 3 and 9, orotic
acid exists mainly as readily-coordinating monode-
protonated H2Or2 (the carboxylic group has
pK ¼ 2.07). The literature lists many reports on the
coordinating preferences of the orotate moiety in
metal complexes. It was found that in solutions with
neutral or slightly acidic pH, Cu(II), Zn(II), Co(II),
Mn(II), Fe(III), Cr(III), VO(II), Cd(II), Hg(II) and
Ag(I) are coordinated through the carboxylate group,
while Ni(II), Co(II) and Cu(II) are coordinated
through the carboxylate end and the adjacent N1
[20–24]. Bidentate binding through N1 and the
carboxylate group was observed by several crystal
structure determinations [25–29]. In the complexes
[Co(HOr)(OH)(H2O)(NH3)]n and [Ni(HOr)(OH)(H2-
O)2(NH3)]n the orotate anion bridges the metal ions
through the carboxylate and the N1 and O2 atoms,
forming one-dimensional polymeric chains [30]. A
recent reinvestigation of nickel(II) orotate pentahy-
drate [Ni(HOr)(H2O)4]·H2O by modern diffraction,
spectroscopic and theoretical methods revealed novel
structural features [31]. In the present study, we have
synthesized and characterized the analogous pentahy-
drate salt of cobalt(II). In order to investigate the
difference in the coordination type of the orotate with
the same metal in different oxidation states, the metal
was oxidized and stabilized in situ by chelation
with ethylenediamine (en). The resulting crystalline
product included both mono and bisdeprotonated
The increasing scientific attention in the chemistry
of saccharin (o-sulfobenzimide, sac; Scheme 1), an
artificial sweetener, has been turned recently from
model studies of its pathological action to its potentials
for inclusion in functional solid materials. Sulfimide
proton/cation acceptor sites appoint the o-sulfobenzi-
midate counter-anion as a valuable structural tool for
construction of well-habited crystalline solids of
desired structure. Several recent reviews deal with
the structural preferences of the o-sulfobenzimidate
moiety in the solid state [1–3]. Saccharinates readily
form adducts with N-donor aromatic heterocycles,
which in turn provide an insight into their coordination
preferences in presence of ancillary ligands. Recently,
there has been increased interest in the saccharinate
adducts with alkyl or hydroxyalkyl amines, studied
extensively by Yilmaz et al. [4–15] and others [16], as
the conformational flexibility of such readily-coordi-
nating ligands allows for the saccharinate ion to adopt
the thermodynamically-preferred coordination mode.
As the flexible short aliphatic amine backbones can
occasionally result in polymeric triangulo-trimetal
clustered complexes that model the active sites of
some enzymes [17,18], we were challenged to
combine these lower aliphatic diamines with the
polyfunctional rigid saccharinate moiety in mixed-
ligand saccharinates. In the present paper, the
syntheses of three N; N0-dimethylethylenediamine
(dmen) disaccharinate adducts and the X-ray crystal
structures of the copper(II) and nickel(II) adducts are
described.
Scheme 1.

H. Icbudak et al. / Journal of Molecular Structure 657 (2003) 255–270
257
orotate anions in the same structure. Here are
2.1.2. [Co(dmen)2(sac)2], [Ni(dmen)2(sac)2] and
[Cu(dmen)2(H2O)2](sac)2
also presented the results of the syntheses, character-
ization and crystal structure determination of
the ethylenediamine adduct of copper(II) orotate
dihydrate.
Solution of N; N0-dimethylethylenediamine
(dmen) (0.176 g, 2 mmol) in water (30 ml) was
dropped upon stirring to the solution of the metal
saccharinates (1.0 mmol; Co(II): 0.531 g; Ni(II):
0.530 g; Cu(II): 0.535 g) in 50 ml of hot water.
The mixtures were heated to 80 8C in a temperature-
controlled bath with stirring during 4 h. The crystals
that formed upon cooling to room temperature were
separated by filtration, washed with 10 ml-portions
of cold water/acetone and dried in vacuo. Speci-
mens suitable for the diffraction experiment were
selected among the regular large deep blue prisms
of the copper adduct and the irregular magenta
crystals of the nickel complex; the pink cobalt
compound did not furnish crystals of good quality.
The elemental analyses, magnetic susceptibility,
spectral (UV/Vis and IR) and thermal
(TG/DTG/DTA) data of the products detailed else-
where [39] support the compositions [Co(C4H12
N2)2(C7H4NO3S)2], [Ni(C4H12N2)2(C7H4NO3S)2]
and [Cu(C4H12N2)2(H2O)2](C7H4NO3S)2.
Salicylic acid (H2sal; Scheme 1) and metal
salicylates have been used for many years as anti-
inflammatory, antipyretic and analgesic drugs in
medicine [32–35]. In aqueous solutions, the acid
affords hydrogensalicylate (Hsal2) and salicylate
(sal22) ions. The 2-HOC6H4CO22 (Hsal2) anion can
bind to metals as unidentate carboxylate, bidentate
chelating (employing one carboxylate oxygen and
hydroxyl oxygen atoms) or bidentate bridging car-
boxylate ligand. The bisdeprotonated anion
[OC6H4CO2]22 (sal22) regularly chelates through
the hydroxyl and one of the carboxylate oxygen atoms
[36]. The X-ray structures of several mononuclear
metal(II) complexes of salicylate derivatives with N-
donor ligands have been reported [33–37]. It has been
found that the increase of acidity of the alkylcarbox-
ylate ligands or of the basicity of the basic ligands
promotes formation of monomeric complexes [33].
Crystalline coordination polymers, such as
[Mn(Hsal)2(bipyridine)]·H2O, are also known [38].
The present report describes the synthesis, character-
ization and crystal structures of two novel metal
(copper and nickel) salicylate adducts, with en and
N; N-dimethylethylenediamine (ndmen) as secondary
ligands.
2.1.3. [Co(HOr)(H2O)4]·H2O and
[Cu(HOr)(H2O)4]·H2O
Mixture of CoCl2·6H2O (1.19 g, 5 mmol) or
CuCl2·2H2O (0.85 g, 5 mmol) in water (25 ml) and
NaHCO3 (0.42 g, 5 mmol) in water (25 ml) was
dropped with stirring into an aqueous (25 ml)
suspension of orotic acid (0.87 g, 5 mmol) at 80 8C.
The suspension was refluxed and stirred for 24 h at
80 8C in a temperature-controlled bath. After degas-
sing from CO2, the clear solution was cooled to room
temperature. The pinkish-orange crystals from the
cobalt complex and the blue crystals from the copper
complex were filtered off and washed with 10 ml-
portions of cold distilled water and acetone and dried
in vacuo. Yield, Co complex: 1.40 g (82.8%). Found:
C, 20.2; H, 3.9; N, 9.5. Calc. for Co(C5H2N2O4)
(H2O)5: C, 19.8; H, 4.0; N, 9.2%. Yield, Cu complex:
1.22 g (81.4%).
2. Experimental
2.1. Syntheses
2.1.1. [M(sac)2(H2O)4]·2H2O (M ¼ Co, Cu, Ni)
To prepare the starting tetraaquadi(o-sulfobenzi-
midato)copper(II) dihydrate precursor, sodium sac-
charinate (1.025 g, 5 mmol) in water (50 ml) was
added to a warm stirred aqueous (50 ml) solution of
the respective metal sulfates (2.5 mmol, Co(II):
0.703 g; Ni(II): 0.657 g; Cu(II): 0.624 g). The pink
(Co), light blue (Cu) and green (Ni) crystals of the
respective saccharinates [M(sac)2(H2O)4]·2H2O
(M ¼ Co, Cu, Ni) that appeared upon cooling of the
solution were filtered out and washed with cold
distilled water (10 ml) and dried in vacuo.
2.1.4. [Co(HOr)(en)2]·H2Or·5H2O
Solution of ethylenediamine (0.24 g, 4 mmol) in
water (10 ml) was dropped into a stirred solution of
[Co(HOr)(H2O)4]·H2O (0.61 g, 2 mmol) in water
(50 ml). The solution was heated to 60 8C in

258
H. Icbudak et al. / Journal of Molecular Structure 657 (2003) 255–270
a temperature-controlled bath and then refluxed and
stirred for 12 h at 60 8C while bubbling air to oxidize
the metal. The violet-pink crystals that formed after
cooling to room temperature were filtered off and
washed with 10 ml-portions of cold distilled water
and acetone and dried in vacuo. Yield: 0.92 g
(79.3%). Found: C, 29.5; H, 5.3; N, 19.7. Calc. for
Co(C5H2N2O4)(C2H8N2)2(C5H3N2O4)(H2O)5: C,
29.1; H, 5.4; N, 19.4%.
salicylate (1.60 g, 10 mmol) in water (25 ml) at
50 8C. The mixture was stirred at 50 8C in a
temperature-controlled bath for 4 h. The green
crystals that formed upon cooling of the clear solution
to room temperature were filtered off and washed with
10 ml-portions of cold water and acetone, and dried in
vacuo. Yield: 0.95 g. (43.4%).
2.1.9. [Cu(Hsal)2(ndmen)2]·H2O
N; N-dimethylethylenediamine (0.18 g, 2 mmol) in
water (15 ml) was dropped into a stirred solution of
[Cu(Hsal)2(H2O)4]·2H2O (0.45 g, 1 mmol) in water
(25 ml). The solution was heated to 50 8C and stirred
for 2 h in a temperature-controlled bath and then
cooled to room temperature. The blue crystals that
formed were filtered off and washed with 10 ml-
portions of cold water and acetone, and dried in
vacuo. Yield: 0.33 g (43.8%). Found: C, 49.29; H,
6.78; N, 9.92. Calc. for C22H36CuN4O7: C, 49.64; H,
6.76; N, 10.53%.
2.1.5. [Cu(HOr)(H2O)(en)]·H2O
A solution of en (0.24 g, 4 mmol) in water (10 ml)
was dropped into a stirred solution of [Cu(HOr)
(H2O)4]·H2O (0.60 g, 2 mmol) in water (50 ml). The
solution was heated to 60 8C and refluxed with stirring
at that temperature for 12 h. The blue crystals that
formed upon cooling to room temperature were
washed with cold water and acetone and dried in
vacuo. Yield: 0.57 g (90.8%). Found: C, 26.99; H, 4.0;
N 17.67. Calc for Cu(C5H2N2O4)(C2H8N2)(H2O)2: C,
26.77; H, 4.46; N, 17.85%.
2.1.10. Materials and physico-chemical
measurements
2.1.6. [Ni(Hsal)2(H2O)4]·2H2O
NiSO4·6H2O (1.31 g, 5 mmol) in water (25 ml)
was dropped into a stirred solution of sodium
salicylate (1.60 g, 10 mmol) in water (25 ml) at
50 8C. The mixture was stirred at 50 8C in a
temperature-controlled bath during 4 h. The green
crystals formed upon cooling to room temperature
were filtered off and washed with 10 ml-portions of
cold water and acetone, and dried in vacuo. Yield:
0.91 g. (41.4%).
All chemicals used were analytical regent pro-
ducts. Elemental (C, H, N) analyses were carried out
¨
by standard methods (TUBITAK Marmara Research
Center, Turkey). Magnetic susceptibility measure-
ments at room temperatures were performed using a
Sherwood Scientific MXI model Gouy magnetic
balance. UV/vis spectra were obtained from the
aqueous solutions of the complexes with a Unicam
UV2 spectrometer in the 900–190 nm range. IR
spectra were recorded in the 4000–400 cm21 region
with a Mattson 1000 FT IR spectrometer using KBr
pellets. A Rigaku TG8110 thermal analyzer was used
to record simultaneous TG, DTG and DTA curves in a
static air atmosphere (a flow rate of 80 ml min21
dynamic nitrogen atmosphere was employed for
Co(II) and Co(III) complexes only) at a heating rate
of 10 min21 in the temperature range 20 2 1000 8C
using platinum crucibles. Highly sintered a-Al2O3
was used as reference and the DTG sensitivity was
0.05 mg s21. The final decompositions products were
identified by IR comparison with the pure oxides.
2.1.7. [Ni(Hsal)2(en)2]
Ethylenediamine (0.12 g, 2 mmol) in water (15 ml)
was dropped into a stirred solution of [Ni(Hsal)2(H2-
O)4]·2H2O (0.41 g, 1 mmol) in water (25 ml). The
mixture was heated to 50 8C and stirred for 2 h in a
temperature-controlled bath. The yellow crystals that
formed upon cooling to room temperature were
filtered off and washed with 10 ml-portions of cold
water and acetone, and dried in vacuo. Yield: 0.38 g
(82.7%). Found: C, 47.83; H, 6.06; N, 11.94. Calc. for
C18H26N4NiO6: C, 47.66; H, 5.74; N, 12.35%.
2.1.8. [Cu(Hsal)2(H2O)4]·2H2O
CuSO4·5H2O (1.25 g, 5 mmol) in water (25 ml)
was dropped into a stirred solution of sodium
2.1.11. X-ray diffraction
The diffraction measurements for all crystals
were carried out at 290 8C with a Siemens CCD

H. Icbudak et al. / Journal of Molecular Structure 657 (2003) 255–270
259
˚
area-detector diffractometer. The intensities were
corrected for absorption effects [40]. The structures
were solved by direct methods and refined on F2 [41];
the crystallographic details are listed in Table 1.
The structures are illustrated as ORTEP [42] plots in
the figures.
[N· · ·N ¼ 2.992(2) A], the carboximide acceptor thus
bridging the two ligands. Trans-octahedral N4(O w)2-
coordinated copper centers with both o-sulfobenzimi-
date counter-ions in the lattice were also observed in
the p-aminopyridine [44] and N-allylimidazole [45]
adducts; in all cases, the saccharinate contacts the
metal indirectly through the carbonyl group. Analysis
of large number of saccharinates shows that electronic
effects favor the carboximide side of the heterocycle
for coordination over the sulfimide part [2]. In the
tetrakis(isoquinoline) adduct [44], two o-sulfobenzi-
midate carbonyl oxygens contact the metal; only
occasionally, the sulfonyl oxygen can play the role as
in the case of the tetrakis( p-methylpyridine) com-
pound. The molecular parameters of the dmen ligand
are normal if compared with its average Cambridge
Structural Database (CSD) structure (CH3 –
3. Results and discussion
3.1. Saccharinate complexes
3.1.1. General discussion
The reaction of the corresponding tetraaquadisac-
charinatemetal(II) dihydrate with dmen results in
partial substitution of the ligands by the bidentate
amine chelator, yielding compounds characterized by
physicochemical methods as [Co(dmen)2(sac)2],
[Ni(dmen)2(sac)2] and [Cu(dmen)2(H2O)2](sac)2.
While the amine replaces all aqua molecules in the
tetraaquadisaccharinato pro-complexes of cobalt(II)
and nickel(II), under virtually identical reaction
conditions the strongly bonded pair of water mol-
ecules in the Jahn–Teller distorted copper reagent
is retained, the o-sulfobenzimidate ligands being
displaced to the outer sphere instead. The o-sulfo-
benzimidate exchange is feasible due to the inter-
mediate covalency of the metal-N(sac) bonds in the
parent saccharinates [43]. It becomes apparent that the
o-sulfobenzimidate counter-ion has only a secondary
role in the determination of the coordination type; its
eventual participation in the coordination sphere is
primarily directed by the available sites at the metal
center and the chelation requirements of the amine.
1
˚
N ¼ 1.480, N–CH2 ¼ 1.477, C–C ¼ 1.497 A) [46] .
The amine chelates the copper atom at larger angle
(85.3(1)8) than that of the ethanolamine, 80.97(6)8 [5],
but close to the average CSD value of 84.58. The
adjacent molecules are linked by two more hydrogen
bonds between the sulfobenzimide oxygen atoms and
the water/amine donors [N3–H· · ·O3 ¼ 3.062(2);
˚
O1w–H· · ·O2 ¼ 2.844(2) A] into a layer structure
(Fig. 2). The carbonyl stretching mode of the copper
complex at 1623 m21, is red-shifted by the hydrogen
bonding from the typically ‘ionic’ saccharinate value
in copper (II) saccharinates (1638 cm21) closer to the
O-coordinated (ca. 1625 cm21).
In the structure of the neutral solvent-free adduct
bis(dmen)bis(sac-O)nickel(II) (Fig. 3), the nickel
atom is octahedrally surrounded by a pair of
equidistant bidentate dmen ligands. The analytical
data [39] suggested possible isostructurality with the
cobalt(II) analogue. The internal angle of the amine
chelation ring at the metal amounts 83.9(1)8, the bond
distances being normal. The four N–Ni–N angles add
to 3608. The saccharinato ligands bind to the metal at
slightly longer distance. The elongated carbonyl
3.1.2. X-ray structures and spectral data
The metal atom in diaquabis(dmen)copper(II) di(o-
sulfobenzimidate) (Fig. 1) is placed at a center of
symmetry, being octahedrally coordinated by a pair of
equatorial bidentate dmen ligands and contacted by
two apical trans-aqua molecules. The coordination
results in a single electronic band at lmax ¼ 563 nm
˚
group at 1.248(2) A and shortened C7–N1 bond at
˚
1.343(2) A reveal dominance of the 1,2-benzisothia-
2
which is assigned to a 2Eg ! T2 g transition [39]. The
zolyl-3-olato 1,1-dioxide resonant form in the imidate
structure. Strong red-shift of the saccharin carbonyl
equatorial angles around the metal sum up to 3608.
The o-sulfobenzimidate ions contact the metal
indirectly, via hydrogen bonds with the coordinated
water O1w· · ·O ¼ 2.833(2). The negative nitrogen
end simultaneously binds to the amine hydrogen
1
October 2001 version of the CSD. Only unsubstituted dmen
ligands (12 residues in 9 hits) chelated to a single transition metal
were included in the analysis.

260
H. Icbudak et al. / Journal of Molecular Structure 657 (2003) 255–270
Table 1
Crystal data
Compound
[Cu(dmen)2(H2O)2](sac)2
[Ni(dmen)2(sac)2]
Colour
Deep blue
C22H36CuN6O8S2
640.23
Lilac
Empirical formula
Formula weight
Space group
C22H32N6NiO6S2
599.37
P21=c
P21=n
Cell dimensions
˚
a (A)
˚
11.8408(5)
7.8447(3)
5.6141(7)
110.802(1)
1355.8(1)
2
8.7752(4)
11.7297(5)
12.9264(6)
94.919(1)
1325.6(1)
2
b (A)
˚
c (A)
b (8)
3
˚
Volume (A )
Z
umax (8 for data collection)
Reflections
collected
29.4
9473
29.4
9322
Independent reflections
Reflections with I . 2sðIÞ
No. parameters refined
R½I . 2sðIÞ; R (all reflections)
wR½I . 2sðIÞꢀ; R (all reflections)
w
3448 (Rint ¼ 0:090)
2964
187
3357 ðRint ¼ 0:098Þ
2854
170
0.048/0.057
0.120/0.125
0.045/0.056
0.110/0.114
2
21
2
21
½s2 þ ð0:0549PÞ ꢀ
½s2 þ ð0:0472PÞ ꢀ
Goodness-of-fit on F2
1.05
20.83 to 0.72
179764
1.00
20.86 to 0.72
179765
23
˚
Diff. hole and peak (eA
CCDC deposition no.
)
Compound
[Co(HOr)(H2O)4]·H2O
[Co(HOr)(en)2]·H2Or·5H2O
Color
Orange
Orange
Empirical formula
Formula weight
Space group
C5H12CoN2O9
303.10
P 2 1
C14H31CoN8O13
578.40
P 2 1
Cell dimensions
˚
a (A)
˚
7.2609(5)
8.3340(6)
10.0864(7)
70.458(1)
80.528(1)
64.666(1)
519.71(6)
2
8.3124(4)
10.5308(6)
13.7098(8)
102.199(1)
93.028(1)
96.387(1)
1162.1(1)
2
b (A)
˚
c (A)
a (8)
b (8)
g (8)
3
˚
Volume (A )
Z
umax (8 for data collection)
Reflections
collected
29.4
3818
29.3
8281
Independent reflections
Reflections with I . 2sðIÞ
No. parameters refined
R½I . 2sðIÞꢀ; R (all reflections)
wR½I . 2sðIÞꢀ; R
2521 ðRint ¼ 0:056Þ
2315
194
5497 ðRint ¼ 0:084Þ
3237
325
0.061/0.066
0.159/0.162
0.084/0.123
0.201/0.215
(all reflections)
2
21
2
21
w
½s2 þ ð0:1101PÞ ꢀ
½s2 þ ð0:0831PÞ ꢀ
Goodness-of-fit on F2
1.02
21.15 to 1.13
179906
0.97
21.60 to 2.32
179907
23
˚
Diff. hole and peak (eA
CCDC deposition no.
)

H. Icbudak et al. / Journal of Molecular Structure 657 (2003) 255–270
261
Table 1 (continued)
Compound
[Co(HOr)(H2O)(en)]·H2O
Color
Blue
Empirical formula
Formula weight
Space group
C7H14CuN4O6
313.76
P 2 1
Cell dimensions
˚
a (A)
˚
7.3609(5)
9.0149(6)
9.4968(6)
67.100(1)
72.923(1)
82.687(1)
554.9(1)
2
b (A)
˚
c (A)
a (8)
b (8)
g (8)
3
˚
Volume (A )
Z
umax (8 for data collection)
Reflections collected
Independent reflections
Reflections with I . 2sðIÞ
No. parameters refined
R½I . 2sðIÞꢀ; R (all reflections)
wR½I . 2sðIÞꢀ; R (all reflections)
w
29.3
4069
2695 ðRint ¼ 0:079Þ
2539
176
0.078/0.083
0.185/0.188
½s2 þ ð0:1000PÞ ꢀ
2
21
Goodness-of-fit on F2
1.12
22.39 to 1.84
179908
23
˚
Diff. hole and peak (eA
CCDC deposition no.
)
Compound
[Cu(Hsal)2(ndmen)2]·H2O
[Ni(Hsal)2(en)2]
Color
Blue
Yellow
Empirical formula
Formula weight
Space group
C22H36CuN4O7
532.09
C2=c
C18H26N4NiO6
453.14
P21=c
Cell dimensions
˚
a (A)
˚
17.0630(8)
9.4689(4)
15.5823(7)
99.475(1)
2483.3(2)
4
10.4537(4)
9.3767(4)
20.3746(9)
94.447(1)
1991.1(1)
4
b (A)
˚
c (A)
b (8)
3
˚
Volume (A )
Z
umax; for data collection (8)
Reflections collected
Independent reflections
29.6
8788
29.5
13617
3143 ðRint ¼ 0:100Þ
2547
161
5003 ðRint ¼ 0:096Þ
3260
267
Reflections with I . 2sðIÞ
No. parameters refined
R½I . 2sðIÞꢀ; R (all reflections)
wR½I . 2sðIÞꢀ; R (all reflections)
w
0.049/0.065
0.117/0.122
0.046/0.074
0.105/0.113
½s2 þ ð0:0635PÞ ꢀ
½s2 þ ð0:0327PÞ ꢀ
2
21
2
21
Goodness-of-fit on F2
0.95
21.45 to 0.65
181779
0.88
21.49 to 0.58
181780
23
˚
Diff. hole and peak (eA
CCDC deposition no.
)
stretching mode in the IR spectrum of the nickel
complex (1618 cm21), below the region of ionic
saccharinates, reveals the pronounced depletion of
electron density along the C–O group due to
the coordination of the ligand. This is considered [1]
a firm spectroscopic evidence of the ionic character of
the metal-saccharinate bonds. The negatively charged
nitrogen atom participates in an intramolecular

262
H. Icbudak et al. / Journal of Molecular Structure 657 (2003) 255–270
Fig. 1. ORTEP plot of bis(N; N0-dimethylethylenediamine)diaquacopper(II) di(o-sulfobenzimidate) at the 75% probability level illustrating the
octahedral geometry of the copper atom. Selected bond distances and angles: Cu1–N2 ¼ 2.040(2), Cu1–N3 ¼ 2.052(2) Cu1–
i
i
˚
O1w ¼ 2.522(2) A; N2–Cu1–N2 ¼ 180.0, N2–Cu1–N3 ¼ 85.3(1), N2–Cu1–N3 ¼ 94.7(1), N2–Cu1–O1w ¼ 87.6(1), N2–Cu1–
O1wi ¼ 92.4(1), N3–Cu1–N3i ¼ 180, N3–Cu1–O1w ¼ 81.0(1), N3–Cu1–O1wi ¼ 99.0(1) O1w–Cu1–O1wi ¼ 1808. Symmetry
transformation: i ¼ 1=2 2 x; 1=2 2 y; 1=2 2 z:
hydrogen bond with the amino group of the amine
˚
[Co(HOr)(H2O)4]·H2O and [Co(HOr)(en)2]·H2Or·5H2
O, respectively) confirmed that [Co(HOr)(H2O)4]·H2O
isanon-electrolyteand[Co(HOr)(en)2]·H2Or·5H2Oisa
1:1 electrolyte in aqueous solutions. [Co(HOr)(H2-
O)4]·H2O exhibits magnetic moment value of 4.31 BM
which corresponds to three unpaired electrons, consist-
ent with a high-spin weak-field octahedral geometry.
The complex [Co(HOr)(en)2]·H2Or·5H2O proved to be
diamagnetic and a strong-field octahedral complex.
The molar conductance value of the copper
complex (LM ¼ 61 V21 cm2 mol21) indicated that
[Cu(HOr)(H2O)(en)]·H2O is an non-electrolyte and
exhibits an experimental magnetic moment value of
1.61 BM, corresponding to one unpaired electron.
ligand [N2–H· · ·N1 ¼ 2.968(2) A]. An additional
intermolecular hydrogen bond between the amine
donor and the saccharinate sulfonyl group [N3–
˚
H· · ·O2 ¼ 3.094(2) A] links the molecules into layers
(Fig. 4). The bands at lmax of 366, 600 and 900 nm
in the electronic spectrum, assigned to the n3 :
3
3
3
3A2g ! T1g(P), n2 : A2g ! T1g(F) and n1 :
3
3A2g ! T2g d–d transitions [39] correspond with
the octahedral coordination.
3.2. Orotate complexes
3.2.1. General discussion
Weakly basic aqueous mixture of orotic acid
afforded with cobalt(II)
a
pentahydrate salt
3.2.2. UV–vis spectra
[Co(HOr)(H2O)4]·H2O. The compound, when
oxidized with air in presence of en, gave a high yield
ofcrystallinebis(en)pentahydrateadduct,forwhichthe
analytical data indicated the formula [Co(HOr)(en)2]·
H2Or·5H2O. The molar conductance values of
the complexes (LM ¼ 81 and 113 V21 cm2 mol21 for
The d–d transition spectra of the complexes in H2O
are compatible with distorted octahedral configur-
ations. The lmax values in the absorption spectrum of
[Co(HOr)(H2O)4]·H2O amount 524 and 582 nm, the
corresponding e values are 18.1 and 15.4 cm21 M21
.
4
4
These bands are assigned to the T1g ! T1g(P) and

H. Icbudak et al. / Journal of Molecular Structure 657 (2003) 255–270
263
Fig. 2. The molecular packing in the structure of bis(N; N0-dimethylethylenediamine)diaquacopper(II) di(o-sulfobenzimidate) viewed along the
b-axis (the hydrogen bonds are not shown).
Fig. 3. ORTEP plot of bis(N; N0-dimethylethylenediamine)bis(o-sulfobenzimidato-O)nickel(II) at the 75% probability level illustrating the
˚
octahedral geometry of the nickel atom. Selected bond distances and angles: Ni1–N2 ¼ 2.105(1), Ni1–N3 ¼ 2.102(2), Ni1–O1 ¼ 2.133(1) A;
N2–Ni1–N2i ¼ 180.0, N2–Ni1–N3 ¼ 83.9(1), N2–Ni1–N3i ¼ 96.1(1), N2–Ni1–O1 ¼ 94.0(1), N2–Ni1–O1i ¼ 86.0(1), N3–Ni1–
N3i ¼ 180.0,
N3–Ni1–O1 ¼ 85.7(1),
N3–Ni1–O1ii ¼ 94.3(1),
O1-Ni1-O1ii ¼ 180.08.
Symmetry
transformation:
i ¼ 1=2 2 x; 1=2 2 y; 1=2 2 z; ii ¼ 2x; 2y; 2z:

264
H. Icbudak et al. / Journal of Molecular Structure 657 (2003) 255–270
doublet at 3220/3130 cm21 accompanied by two
bands probably resulted by Fermi resonance
(2983, 2812 cm21). In the spectrum of [Co(HOr)
(H2O)4]·H2O, the expected N3–H band was heavily
overlapped with the OH stretchings and could not be
discerned with confidence among the peaks at 3326,
3212 and 3126 cm21 on the broad absorption in the
3650–2600 cm21 region. Deformation of the N3–H
group (contribution of ca. 60% to the respective
mode) in the latter complex gives rise to a band at
1392 cm21, close to the 1388 cm21 band in the
spectrum of [Ni(HOr)(H2O)4]·H2O [13]. A doublet of
d
N1/N3–H bands at 1425 and 1381 cm21 appears in the
spectrum of [Co(HOr)(en)2]·H2Or·5H2O, consistent
with the presence of H2Or2 ligands. In
[Co(HOr)(en)2]·H2Or·5H2O, the water stretching
gives bands at 3482 and 3433 cm21. The spectral
data suggest notably stronger hydrogen bonding
in the structure of cobalt(II) orotate than in the
amine adduct.
Stretchings of the carbonyl groups of polycrys-
talline H3Or give rise to three strong and
overlapped bands, at 1729 (66%nCyO(carboxylic)
17%nC5yO4,in-phase), 1719 (56%nC5yO4 þ 19%
nCyO(carboxylic), and
1700 cm21
þ
)
out-of-phase
Fig. 4. The molecular packing in the structure of bis(N; N0-
dimethylethylenediamine)bis(o-sulfobenzimidato-O)nickel(II)
viewed along the b-axis (the hydrogen bonds are not shown).
(73%nC4yO3 þ 11%nring) [47]. In the infrared spec-
trum of nickel orotate [31], a complex band at
1612 cm21 appears. Three carbonyl bands were
observed in the Raman spectrum, at 1661
(88%nCyO(carboxylic)), 1618 (58%nC4yO3 þ 10%
4
4T1g ! A2 g d–d transitions. The MLCT band is cen-
tered at 310 nm. The complex [Co(HOr)(en)2]·H2Or·
5H2O has a band around 488 nm (1 ¼ 160 cm21 M21
)
nring,in-phase
)
and 1572 cm21 (58%nring þ 11%
which is assignable to the 1A1g ! T1 g transition and
suggests a distorted octahedral stereochemistry. The
MLCT band appears around 294 nm. The absorption
spectra indicate that the cobalt(III) complex forms a
stronger crystal field than the cobalt(II) compound.
The d–d transition spectrum of [Cu(HOr)
(H2O)(en)]·H2O is compatible with distorted square-
pyramidal configuration. The maximal absorption is
1
n
C4yO3,out-of-phase) and assigned from the theoretical
calculations. The bisdeprotonation of the acid
therefore leads to red-shift of all three bands; the
two orotic acid bands which were mainly C5yO4
stretchings become mainly coupled C4yO3 stretch-
ings in the spectrum of the orotate ion. In the IR
spectrum of [Co(HOr)(H2O)4]·H2O, the carbonyl
stretchings are overlapped with the water bending
and give a broadened very strong absorption at
1632 cm21. Additional sharp and much weaker
band at 1727 cm21 in the carbonyl stretching
region might be due to the stretching of the
carboxylate group or a second-order vibration; its
definite assignment remains unclear at the present.
Two more shoulders (1650, 1638 cm21) in the
spectrum of nickel orotate were assigned as water
bendings [31] and also appear on the carbonyl
at 601 nm and the respective
1 value is
68.0 cm21 M21. This band is assigned to the a1 !
b1 d–d transition. The band observed at around
307 nm (1 ¼ 1829 cm21 M21) is attributed to MLCT.
3.2.3. IR spectra
In the spectrum of [Co(HOr)(en)2]·H2Or·5H2O, the
N1/N3–H stretching bands at 3154/3137 cm21 of
orotic acid [47] were clearly observable as strong

H. Icbudak et al. / Journal of Molecular Structure 657 (2003) 255–270
265
stretching band of cobalt(II) orotate. In the
spectrum of [Co(HOr)(en)2]·H2Or·5H2O, two
equally strong nCyO bands at 1697 and
1628 cm21 correspond to the stretching of the
carbonyl groups in the mono- and bisdeprotonated
orotate ligands. The frequency order of the
stretchings of the endo-carbonyl groups is H3Or .
H2Or2 . HOr22. From the IR spectra, it can be
assumed that in both complexes the orotate
residues HOr22 are coordinated as bidentate ligands
to the metal through the carboxylic oxygen and N1
from the pyrimidine ring.
confirmed by the low temperature of thermal
dehydration.
The decomposition of the copper complex takes
place in three stages in the interval 20–1000 8C. The
thermal dehydration occurs in two successive steps by
giving endothermic peaks at 105 and 150 8C. The
weight loss (exp. 10.98%, theor. 10.42%) in the range
60–160 8C correspond to loss of one lattice water and
one coordinated water molecule. The anhydrous
complex is stable up to 275 8C. The following steps
are related to decomposition of the en and orotato
ligands. The decomposition starts at 275 8C and
continues up to 900 8C, when CuO is formed. The
overall weight loss (78.88%, theor. 81.61%) agrees
with the proposed structure. The final decomposition
product was identified with IR spectroscopy.
In the spectrum of the copper complex, the
crystal and coordinated water stretchings appear at
3588 and 3338 cm21, respectively. The IR spec-
trum shows weak absorption bands at 3287 and
3258 cm21. These bands represent the asymmetrical
and symmetrical NH stretching modes, respectively.
The bands are shifted to longer wavelengths as
compared with the typical values of primary
amines (3500 and 3400 cm21). The very broad
and strong band at 1655 cm21 is prescribed to
overlapped CyO and CC stretchings, and bending
water and amine modes. The medium-intense band
at 1481 cm21 is assigned to the C–N stretching of
the uracilate ring. The red-shift of the band from
the typical C–N stretching frequencies indicates
increase of the bond order upon deprotonation.
3.2.4. Thermal analyses
Thermal decomposition of [Co(HOr)(H2O)4]·H2O
and [Co(HOr)(en)2]·H2Or·5H2O proceeds in two
stages. The first stage is related to dehydration. The
thermal dehydration stage of the complex occurs in
three steps in the temperature range 44–154 8C,
accompanied by endothermic effects (DTGmax: 96,
116 and 133 8C). In the second stage, the anhydrous
cobalt(II) complex decomposes in several consecutive
steps in the temperature range 272–645 8C to give
metallic cobalt. The three-step dehydration of the
cobalt(III) complex occurs in the temperature range
33–123 8C (DTGmax: 42, 61 and 88 8C). The
anhydrous residue is stable up to 250 8C and
subsequently decomposes to metallic cobalt at
700 8C. The cobalt(II) complex contains both crystal-
lization and coordination water, while the cobalt(III)
complex includes only uncoordinated water. The
weak bonding of the lattice water molecules is
Fig. 5. ORTEP plot of [(H2O)4·Co(C5H2N2O4)]·H2O at the 90%
probability level; hydrogen atoms are drawn as spheres of arbitrary
radii. Selected bond distances and angles: Co1–O1 ¼ 2.057(2),
Co1–O1w ¼ 2.048(2), Co1–O2w ¼ 2.111(2), Co1–O4w ¼
˚
2.148(2), Co1–O3w ¼ 2.151(2), Co1–N2 ¼ 2.094(2) A; O1–
Co1–O1w ¼ 172.7(1), O1–Co1–O2w ¼ 96.0(1), O1–Co1–
O3w ¼ 91.0(1), O1–Co1–O4w ¼ 89.8(1), O1–Co1–N2 ¼
78.9(1), O1w–Co1–O2w ¼ 91.3(1), O1w–Co1–O3w ¼ 89.2(1),
O1w–Co1–O4w ¼ 90.8(1), O1w–Co1–N2 ¼ 93.9(1), O2w–
Co1–O3w ¼ 87.4(1), O2w–Co1–O4w ¼ 85.8(1), O2w–Co1–
N1 ¼ 174.7(1), O3w–Co1–N2 ¼ 91.2(1), O3w–Co1–O4w ¼
173.3(1), O4w–Co1–N2 ¼ 95.5(1)8.

266
H. Icbudak et al. / Journal of Molecular Structure 657 (2003) 255–270
Fig. 6. ORTEP plot of [(C2H8N2)2Co(C5H2N2O4)][C5H2N2O4]·5H2O at the 90% probability level; hydrogen atoms are drawn as spheres of
arbitrary radii. Selected bond distances and angles: Co1–O1 ¼ 1.914(4), Co1–N2 ¼ 1.974(4), Co1–N3 ¼ 1.954(4), Co1–N4 ¼ 1.944(4),
˚
Co1–N5 ¼ 1.954(4), Co1–N6 ¼ 1.961(4) A; O1–Co1–N2 ¼ 83.6(2), O1–Co1–N3 ¼ 90.3(2), O1–Co1–N4 ¼ 176.1(2), O1–Co1–
N5 ¼ 88.8(2), O1–Co1–N6 ¼ 90.1(2), N2–Co1–N3 ¼ 92.0(2), N2–Co1–N4 ¼ 97.0(2), N2–Co1–N5 ¼ 171.6(2), N2–Co1–N6 ¼
90.1(2), N3–Co1–N4 ¼ 85.9(2), N3–Co1–N5 ¼ 91.6(2), N3–Co1–N6 ¼ 177.9(2), N4–Co1–N5 ¼ 90.8(2), N4–Co1–N6 ¼ 93.7(2),
N5–Co1–N6 ¼ 86.3(2)8.
3.2.5. X-ray crystal structures
the constraints used to locate the hydrogen atoms
˚
The crystal structures of the complexes are
presented in Figs. 5–7. The bisdeprotonated orotic
acid ligand in the crystal of tetraaquaorotatocobalt(II)
monohydrate, [Co(HOr)(H2O)4]·H2O (Fig. 5) acts as a
bidentate N; O-chelator. Three water molecules and
the deprotonated orotate nitrogen make up the
equatorial plane of the cobalt coordination octa-
hedron. An additional aqua molecule and the carboxyl
oxygen from the orotate bind to the metal axially at
shorter distances. The orotate intraligand bond lengths
are comparable with those in the similar nickel
complex [31]. Deprotonation brings to electron
accumulation and strong shortening of C2–C3, N2–
(O–H ¼ 0.85 ^ 0.01 A, equal Co· · ·H distances for
the coordinated water), we were able to observe
hydrogen bonding of O5w with both the pyrimidine
˚
hydrogen N1–H (2.763(3) A) and the coordinated
˚
oxygen atom (2.702(3) A). The uncoordinated water
is also bonded to the coordinated water O2w from
˚
C5 and N2–C2 (1.351(4), 1.359(3) and 1.362(3) A);
˚
the C3–C4 (1.435(3) A) is lengthened more than in
˚
the nickel compound (1.419(2) A). The endo carbonyl
groups C5–O4 and C4–O3 are similar in length
˚
(1.243(3) and 1.252(3) A) and also with the nickel
˚
compound (1.254(2) and 1.246(2) A). The carbox-
ylate group is asymmetric due to the coordination and
participation in the hydrogen bonding (C1–
˚
O2 ¼ 1.245(3), C1–O1 ¼ 1.256(3) A).
In a recent reinvestigation of nickel orotate,
Wysokinski et al. [31] reported that the lattice water
is bonded to the proton of the coordinated water
Fig. 7. ORTEP plot of [Cu(H2O)(C2H8N2)(C5H2N2O4)]·H2O at the
90% probability level: hydrogen atoms are drown as spheres of
arbitrary radii: Selected bond distances and angles: Cu1–
O1 ¼ 1.990(2), Cu1–N2 ¼ 1.986(3), Cu1–N3 ¼ 2.009(3), Cu1–
˚
molecule, O5w· · ·H–O2w ¼ 2.643(2) A, in addition
of the hydrogen bond between the uncoordinated
water molecule O5w and the pyrimidine proton N1H
of the neighbor unit. In our study of the cobalt
complex, the lattice water showed some disorder with
smeared thermal ellipsoids (Fig. 5). Under
˚
N4 ¼ 2.012(3), Cu1–O1W ¼ 2.367(3) A; O1–Cu1–N2 ¼81.9(1),
O1–Cu1–N3 ¼ 166.8(1), O1–Cu1–N4 ¼ 93.3(1), O1–Cu1–
O1W ¼ 93.3(1), N2–Cu1–N3 ¼ 99.5(1), N2–Cu1–N4 ¼
173.7(1), N2–Cu1–O1W ¼ 90.4(1), N3–Cu1–N4 ¼ 84.3(1),
N3–Cu1–O1W ¼ 99.8(1), N4–Cu1–O1W ¼ 93.9(1)8.

H. Icbudak et al. / Journal of Molecular Structure 657 (2003) 255–270
267
the
3.052(4) A). The difference probably results from
neighbor
˚
unit
(O5w–H5w1· · ·O2w ¼
and C5–O4 are close to each other (1.242(4) and
˚
1.233(4) A, respectively). Larger discrepancy
˚
the different metal-O2w distances, 2.111(2) A in the
˚
between the carboxylate C1–O1 (1.270(4) A) and
˚
cobalt and 2.066(1) A in the nickel complex. Each of
˚
C1–O2 (1.240(4) A) distances is influenced by the
the three coordinated water molecules uses its protons
to form a pair of hydrogen bonds: O1w, O3w and O4w
bond to carbonyl oxygen atoms and O2w bonds to
coordinated water molecules. A strong intramolecular
coordination as well as participation in hydrogen
bonding. Both (coordinated and uncoordinated) water
molecules participate in hydrogen bonding of
OW· · ·O, OW· · ·OW and OW· · ·N type (ranging
˚
hydrogen bond (2.660(3) A) connects O1w and O4.
˚
from 2.751 to 2.943 A), whereas the en NH2 groups
are included in the hydrogen bonds of N· · ·O type
˚
(ranging from 2.819 to 3.176 A).
In the structure of the ethylenediamine adduct of
cobalt(III) orotate (Fig. 6), [Co(HOr)(en)2]·H2Or·5H2-
O, two amine ligands and the bisdeprotonated
orotate act as bidentate ligands, sufficing the metal
coordination sphere. The metal-ligand bonds ranging
3.3. Salicylate complexes
˚
1.914(4)–1.974(4) A are all shorter than those in
3.3.1. General discussion
the cobalt(II) complex. The refinement confirmed
the other analytical results that a second orotate was
re-protonated during the oxidation and included as a
counter anion. The bite angle of the orotate to the
metal is similar with those of the amine ligands.
Ethylenediamine chelators are twisted, with N3–C6–
C7–N4 ¼ 51.28 and N5–C8–C9–N6 ¼ 46.88, with
normal intraligand distances. Orotate moieties are
planar, with slightly more rotated carboxylate group
in the coordinated one (ca. 78 compared with 48). The
carboxylate functionality of the ionic orotate is
The molar conductance values of the complexes
(LM ¼ 81 and 71 V21 cm2 mol21 for [Ni(Hsal)2
(en)2] and [Cu(Hsal)2(ndmen)2]·H2O, respectively)
indicate that the complexes are not electrolytes in
water. The nickel and copper complexes exhibit a
experimental magnetic moment value of 2.81 and
1.53 BM corresponding to three and one unpaired
electron, respectively, consistent with a weak field
octahedral geometry.
3.3.2. UV/vis spectra
˚
symmetric (C–O ¼ 1.250(7) and 1.251(7) A), while
For the yellow complex [Ni(Hsal)2(en)2] no d–d
bands were resolved in ethanol, suggesting an
octahedral structure. The band at 561 nm is assigned
to ligand-to-metal charge transfer. The electronic
spectrum of [Cu(Hsal)2(ndmen)2]·H2O in water
exhibits a very broad d–d absorption transition
centered at 577 nm (e ¼ 123 cm21M21). This band
that of the ligated orotate is distorted by the
˚
coordination (C–O ¼ 1.278(6) and 1.223(6) A).
Both endocyclic carbonyl groups in the ionic orotate
are shortened from the respective values in the ligand
(C13–O7 ¼ 1.218(7), C14–O8 ¼ 1.235(6), C4–
˚
O3 ¼ C5–O4 ¼ 1.243(6) A). The differences in the
2
2
ring bonds were precluded by the large e.s.d values.
Five molecules of water in the lattice participate in
the hydrogen bonding network.
is assigned to the Eg ! T2 g d–d transition. The
spectrum also exhibits
a
band at 400 nm
(1 ¼ 139 cm21M21) assigned to ligand-to-metal
charge transfer. A similar band between 400 and
450 nm previously reported for the mononuclear
copper(II) salicylate compounds was ascribed to a
ligand-to-metal charge transfer transition [34].
Similarly to the previously discussed ethylenedia-
mine adduct of Co(III) orotate, the ethylenediamine as
well as the dideprotonated orotic acid ligand in the
structure of monoaquaethylenediamineorotoatocop-
per(II) monohydrate, [Cu(HOr)(H2O)(en)]·H2O, act
as a bidentate ligands. In addition to the two en
nitrogens and to the orotate nitrogen and oxygen atom
which form the square plane, the distorted square
pyramidal coordination of copper atom is completed
by the water oxygen atom. An additional uncoordi-
nated water molecule is present in the structure. The
C–O distances in the endo carbonyl groups C4–O3
3.3.3. IR Spectra
The bands due to the antisymmetric and sym-
metric carbonyl stretches n(COO) of the solid
salicylic acid are positioned at 1637 and
1448 cm21, respectively. The bands are shifted to
lower frequencies, 1590 and 1399 cm21 in the
spectrum of [Ni(Hsal)2(en)2] and to 1594 and

268
H. Icbudak et al. / Journal of Molecular Structure 657 (2003) 255–270
Fig. 8. ORTEP plot of bis(N,N-dimethylethylenediamine)bis(salicylato-O)copper(II) hydrate at the 75% probability level; hydrogen atoms are
˚
drawn as spheres of arbitrary radii. Selected bond distances and angles: Cu1–O1 ¼ 2.639(1), Cu1–N1 ¼ 1.990(2), Cu1–N2 ¼ 2.114(2) A;
O1–Cu1–O1i ¼ 180.0, O1–Cu1–N1 ¼ 91.4(1), O1–Cu1–N1i ¼ 88.6(1), O1–Cu1–N2 ¼ 96.7(1), O1–Cu1–N2i ¼ 83.3(1), N1–Cu1–
N1i ¼ 180.0, N1–Cu1–N2 ¼ 85.0(1), N1–Cu1–N2i ¼ 95.0(1), N2–Cu1–N2i ¼ 180.08. Symmetry transformation: i ¼ 1 2 x; 1 2 y; 1 2 z:
1389 cm21 in that of [Cu(Hsal)2(ndmen)2]·H2O. The
band positions and their separations indicate that
carboxylate groups are monodentate [34]. The n(OH)
bands of the Ni(II) and Cu(II) complexes were
observed at 3365 and 3324 cm21, respectively. The
phenolic d(OH) peak at 1305 cm21 of the salicylic
acid remained at nearly the same position in both
complexes, suggesting that the phenol group retains
the proton. The n(NiN) and n(CuN) vibrations can be
stages (DTGmax ¼ 215 and 441 8C, respectively), two
moles of ndmen and two moles of Hsal ligands are
decomposed, resulting in CuO.
3.3.5. X-ray crystal structures
The metal atom in [Cu(Hsal)2(ndmen)2]·H2O is
trans-octahedrally coordinated by a pair of bidentate
ndmen ligands and two monodentate salicylate ions
(Fig.8).TheheavyJahn–Tellerdistortionresultsintwo
tentatively assigned as bands at 459 and 449 cm21
respectively.
,
3.3.4. Thermal analysis
Thermal decomposition of [Ni(Hsal)2(en)2] and
[Cu(Hsal)2(ndmen)2]·H2O proceed in two and three
stages, respectively. In the first decomposition stage
of [Ni(Hsal)2(en)2], two moles of ethylenediamine
and two moles of CO2 are released (exp. weight loss is
46.10%, close to calculated 45.92%) in the tempera-
ture range 244–307 8C, giving endothermic effect
(DTGmax: 268 8C). In the second stage, a strong
exothermic peak on the DTA curve (DTGmax: 386 8C)
is associated with burning of the organic residue,
leading to NiO. The first decomposition stage of
[Cu(Hsal)2(ndmen)2]·H2O is related to dehydration in
the range 56–102 8C and accompanied by endother-
mic effect (DTGmax: 84 8C). The anhydrous Cu(II)
complex is thermally stable up to 155 8C and starts to
decompose with melting at 172 8C (DTA curve). In
the endothermic second and the exothermic third
Fig. 9. ORTEP plot of bis(N,N-dimethylethylenediamine)bis(sali-
cylato-O)copper(II) hydrate illustrating the hydrogen-bonded chain
˚
propagating along the c-axis; O· · ·O ¼ 2.788(2) A.

H. Icbudak et al. / Journal of Molecular Structure 657 (2003) 255–270
269
bond angles at C8 and C9 amount 108.7(2) and
109.9(2)8, respectively; the amine bites the metal at an
angle of 85.0(1)8. The ndmen ligands are twisted, with
N1–C8–C9–N2 ¼ 52.9(2)8. The salicylate ligands
are nearly orthogonal to the equatorial coordination
plane of the amine. The carboxylate groups are only
slightly distorted (C1–O1 ¼ 1.262(2), C1–
˚
O2 ¼ 1.268(2) A, O1–C1–O2 ¼ 123.9(2)8). A strong
˚
intramolecular bond of 2.519 A connects the hydroxyl
proton with the carboxylate oxygen O2. The uncoordi-
nated water molecule joins the adjacent neutral
bisaminebissalicylatocopper(II) units through hydro-
gen bond with the coordinated oxygen O1 into infinite
hydrogen-bondedchainsthatpropagatealongthecaxis
˚
(O1w–H· · ·O1 ¼ 2.788(2) A, Fig. 9). The amine pro-
tons are involved in hydrogen bonding with the water
˚
(N1–H1a· · ·Ow ¼ 2.972(2) A) and the carboxyl oxy-
˚
gen O2 (N1–H1b· · ·O2 ¼ 2.901(2) A).
The en adduct of nickel(II) salicylate salt,
[Ni(Hsal)2(en)2], has a trans-octahedrally coordinated
metal atom (Fig. 10). The amine ligands are
non-planar with dihedral angle N1–C1–C2–
N2 ¼ 56.5(3) and 53.7(3)8 in the two crystallographi-
cally independent units a and b. The respective angles
at C1 and C2 are 108.3(2) and 108.8(2)8 in a, and
109.8(2) and 198.7(2)8 in b; the ligand chelates the
metal at an angles of 82.8(1) and 83.5(1)8. The
intraligand distances (a=b : C1–N1 ¼ 1.472(3)/
Fig. 10. ORTEP plot of one of the two symmetry independent
molecules of (C2H8N2)2Ni(C7H5O3)2 at the 75% probability level;
hydrogen atoms are drawn as spheres of arbitrary radii. Selected
bond distances and angles for molecule a: Ni1a–O1a ¼ 2.088(2),
1.468(3),
C2–N2 ¼ 1.478(3)/1.479(3),
C1–
˚
C2 ¼ 1.504(3)/1.512(4) A) are typical for the en
adducts and similar with those of the ndmen ligand
in the copper(II) complex. The carboxylate groups are
nearly symmetric (a=b : C3–O1 ¼ 1.252(3)/1.257(3),
˚
Ni1a–N1a ¼ 2.092(2), Ni1a–N2a ¼ 2.111(2) A; O1a–Ni1a–
O1a ¼ 180.0, O1a–Ni1a–N1a ¼ 86.4(1), O1a–Ni1a–N1a i ¼
93.6(1), O1a–Ni1a–N2a ¼ 90.6(1), O1a–Ni1a–N2a i ¼ 89.4(1),
N1a–Ni1a–N1a i ¼ 180.0, N1a–Ni1a–N2a ¼ 82.8(1), N1a–
Ni1a–N2a i ¼ 97.3(1), N2a–Ni1a–N2a i ¼ 180.08. Selected bond
˚
C3–O2 ¼ 1.269(3)/1.261(3) A). The phenyl protons
are
strongly
hydrogen
bonded
(O3a–
distances and angles for molecule b: Ni1b–O1b ¼ 2.078(1), Ni1b–
˚
˚
ii
˚
H· · ·O2a ¼ 2.552 A, O3b–H· · ·O2b ¼ 2.533 A) to
the uncoordinated carboxylate oxygen atoms in both
salicylate ligands. The neutral bis(sal)bis(en)nicke-
l(II) entities are held together by weak van der Waals
forces.
N1b ¼ 2.076(2), Ni1b–N2b ¼ 2.107(2) A; O1b–Ni1b–O1b
¼
180.0, O1b–Ni1b–N1b ¼ 88.2(1), O1b–Ni1b–N1b ii ¼ 91.8(1),
O1b–Ni1b–N2b ¼ 91.2(1), O1b–Ni1b–N2b ii ¼ 88.8(1), N1b–
Ni1b–N1b ii ¼ 180.0, N1b–Ni1b–N2b ¼ 96.6(1), N1b–Ni1b–
N2b ii ¼ 83.5(1), N2b–Ni1b–N2b ii ¼ 180.08.
elongated bonds with the disubstituted amine nitrogen
˚
N2 andtwo verylong Cu–O1 contacts of ca. 2.6 A with
Acknowledgements
thecarboxylateoxygenatomofthesalicylate.TheC–C
bondsintheamineligandsarestretchedbythechelation
˚
to1.500(3) AandtheC–Nbondsarenearlyequal(C9–
We thank to Ondokuz Mayis University Research
Found in Turkey, the National Science Council for
R&D, Malaysia (IRPA 305/PFIZIK/610961) and
the University of Malaya (F0758/2001A) and
˚
N2 ¼ 1.481(2), C8–N1 ¼ 1.484(3) A). The smaller

270
H. Icbudak et al. / Journal of Molecular Structure 657 (2003) 255–270
[25] M. Sabat, D. Zglinska, B. Jezowska-Trzebiatowska, Acta
Crystallogr. B36 (1980) 1187.
the Ministry of Education and Science of the Republic
of Macedonia for supporting this work.
[26] I. Mutikainen, P. Lumme, Acta Crystallogr. B36 (1980) 2233.
[27] T. Solin, K. Matsumoto, K. Fuwa, Bull. Chem. Soc. Jpn 54
(1981) 3731.
References
[28] T.S. Khodashova, M.A. Porai-Koshits, N.K. Davidenko, N.N.
Vlasova, Koord. Khim. 10 (1984) 262.
[1] P. Naumov, G. Jovanovski, Curr. Org. Chem. 5 (2001) 1059.
[2] P. Naumov, G. Jovanovski, Struct. Chem. 11 (2000) 19.
[3] G. Jovanovski, Croat. Chem. Acta, 73 (2000) 843.
[4] Y. Topcu, O. Andac, V.T. Yilmaz, W.T.A. Harrison, Acta
Crystallogr. E57 (2001) 82.
[29] A. Karipides, B. Thomas, Acta Crystallogr. C42 (1986) 1705.
[30] I. Mutikainen, Finn. Chem. Lett. (1985) 193.
[31] R. Wysokinski, B. Morzyl-Ociepa, T. Glowiak, D. Michalska,
J. Mol. Struct. 606 (2002) 241.
[32] H. Necefoglu, H. Icbudak, D.A. Kose, A. Uyanik, in: M.
Melnik, A. Sirota (Eds.), Challenges for Coordination
Chemistry in the New Century, vol. 5, 2001, pp. 427,
(Bratislava) Slovak Technical University Press.
[33] F. Jian, Z. Wang, C. Wei, Z. Bai, X. You, Acta Crystallogr.
C55 (1999) 1228.
[5] V.T. Yilmaz, O. Andac, Y. Topcu, W.T.A. Harrison, Acta
Crystallogr. C57 (2001) 271.
[6] H. Icbudak, T.K. Yazicilar, V.T. Yilmaz, Thermochim. Acta
335 (1999) 93.
[7] V.T. Yilmaz, Y. Topcu, A. Karadag, Thermochim. Acta 383
(2002) 129.
[34] A.L. Abuhijleh, C. Woods, Inorg. Chem. Commun.
(2001) 119.
4
[8] Y. Topcu, O. Nadac, V.T. Yilmaz, W.T.A. Harrison, J. Mol.
Struct. 610 (2002) 99.
[35] J.D. Ranford, P.J. Sadler, D.A. Tocher, J. Chem. Soc. Dalton
Trans. (1993) 3393.
[9] Y. Topcu, O. Andac, V.T. Yilmaz, W.T.A. Harrison, Cryst.
Res. Technol. 37 (2002) 509.
[36] N.J. Brownless, D.A. Edwards, M.F. Mahon, Inorg. Chim.
Acta 287 (1999) 89.
[10] V.T. Yilmaz, A. Karadag, C. Thoene, J. Coord. Chem., 55
(2002) 609.
[37] N. Petrovcic, B. Kozlevcar, L. Golic, I. Leban, P. Segedin,
Acta Crystallogr. C55 (1999) 176.
[11] Y. Topcu, O. Andac, V.T. Yilmaz, W.T.A. Harrison, J. Coord.
Chem. 55 (2002) 805.
[38] M. Devereux, M. Curran, M. McCann, M.T. Casey, V.
McKee, Polyhedron 15 (1996) 2029.
¨
[39] O.Z. Yesilel, H. Ic¸budak, H. Olmez, P. Naumov, Synth. React.
[12] O. Andac, Y. Topcu, V.T. Yilmaz, W.T.A. Harrison, Acta
Crystallogr. C58 (2002) 14.
[13] V.T. Yilmaz, Y. Topcu, F. Yilmaz, C. Thoene, Polyhedron 20
(2001) 3209.
¨
[14] Y. Topcu, V.T. Yilmaz, C. Thone, Acta Crystallogr. 57
Inorg. Met.-Org. Chem 33 (2003) 77.
[40] SADABS, G.M. Sheldrick, Program for empirical absorption
¨
correction of area detector data, University of Gottingen,
(2001) 600.
Germany, 1996.
[15] O. Andac, Y. Topcu, V.T. Yilmaz, K. Guven, Acta Crystal-
logr. C57 (2001) 1381.
[41] SHELX97, G.M. Sheldrick, Programs for crystal structure
¨
analysis (Release 97-2), University of Gottingen, Germany,
[16] C.A. Johns, K.M.A. Malik, Polyhedron 21 (2002) 395.
[17] D.A. Handley, P.B. Hitchcock, G. Jeffery, Leigh, Inorg. Chim.
Acta 314 (2001) 1.
1997.
[42] ORTEP-II, C.K. Johnson, Report ORNL-5138, Oak Ridge
National Laboratory, Oak Ridge, Tennessee, USA, 1976.
[18] D.A. Handley, P.B. Hitchcock, T.H. Lee, G. Jeffery, Leigh,
Inorg. Chim. Acta 314 (2001) 14.
ˇ
¨
[43] E. Kleinpeter, D. Strohl, G. Jovanovski, B. Soptrajanov, J. Mol.
Struct. 246 (1991) 185.
[19] D.D. Genchev, Dokl. Bolg. Akad. Nauk 23 (1970) 435.
[20] G. Maistralis, A. Koutsodimou, N. Katsaros, Transit. Met.
Chem., 25 (2000) 166.
[44] P. Naumov, G. Jovanovski, M.G.B. Drew, S.W. Ng, Inorg.
Chim. Acta 314 (2001) 154.
[45] P. Naumov, G. Jovanovski, M. Ristova, I. Abdul Razak, S.
C¸ akir, S. Chantrapromma, H.-K. Fun, S.W. Ng, Z. Anorg.
Allg. Chem. 628 (2002) 2930.
[21] F. Nepveu, N. Gaultier, N. Korber, J. Jaud, P. Castan, J. Chem.
Soc. Dalton Trans. 24 (1995) 4005.
[22] E.R. Tucci, B.E. Doody, N.C. Li, J. Phys. Chem., 65
(1961) 1570.
[46] F.H. Allen, O. Kennard, R. Taylor, Acc. Chem. Res. 16
(1983) 146.
[23] E.R. Tucci, C.H. Ke, N.C. Li, J. Inorg. Nucl. Chem. 29 (1967)
1657.
[47] A. Hernanz, F. Billes, I. Bratu, R. Navarro, Biopolymers 57
(2000) 187.
[24] A.K. Singh, R.P. Singh, Indian J. Chem. 17A (1979) 469.