Second sphere coordination complex via hydrogen bonding: Synthesis, spectroscopic studies of [(C6H5)3RP][trans-Co(NH3)2(NO2)4] where R = benzyl, phenyl or ethyl and X-ray crystal structure of [(C6H5)4P][trans-Co(NH3)2(NO2)4]

Article abstract of DOI:10.1016/j.molstruc.2007.11.060

Yellow colored precipitates of [(C₆H₅)₃RP][trans-Co(NH₃)₂(NO₂)₄], where R = benzyl, phenyl or ethyl were obtained by reacting equimolar quantities of K[trans-Co(NH₃)₂(NO₂)₄] and [(C₆H₅)₃RP]Br, where R = benzyl, phenyl or ethyl in aqueous medium at room temperature. The salt [(C₆H₅)₄P][trans-Co(NH₃)₂(NO₂)₄] crystallized from acetone-methanol mixture in monoclinic space group P2₁/n having cell dimensions a = 7.013(1) ?, b = 17.111(1) ?, c = 22.958(3) ?, β = 98.06(1)°, V = 2727.7(6) ?³, Z = 4, R₁ = 0.0485 and wR₂ = 0.1263. X-ray structure determination revealed the presence of discrete ions, [(C₆H₅)₄P]⁺ and [trans-Co(NH₃)₂(NO₂)₄]^-. The constituent ions are held together by hydrogen bonding interactions involving second sphere coordination besides electrostatic forces of interaction.

Full text of DOI:10.1016/j.molstruc.2007.11.060

Available online at www.sciencedirect.com
Journal of Molecular Structure 888 (2008) 107–112
www.elsevier.com/locate/molstruc
Second sphere coordination complex via hydrogen bonding: Synthesis,
spectroscopic studies of [(C6H5)3RP][trans-Co(NH3)2(NO2)4]
where R = benzyl, phenyl or ethyl and X-ray crystal structure
of [(C6H5)4P][trans-Co(NH3)2(NO2)4]
Raj Pal Sharma *, Ajnesh Singh, Paloth Venugopalan *
Panjab University, Chemistry Department, Sector 14, Chandigarh, UT 160014, India
Received 12 October 2007; received in revised form 21 November 2007; accepted 23 November 2007
Available online 15 December 2007
Abstract
Yellow colored precipitates of [(C6H5)3RP][trans-Co(NH3)2(NO2)4], where R = benzyl, phenyl or ethyl were obtained by reacting
equimolar quantities of K[trans-Co(NH3)2(NO2)4] and [(C6H5)3RP]Br, where R = benzyl, phenyl or ethyl in aqueous medium at room
temperature. The salt [(C6H5)4P][trans-Co(NH3)2(NO2)4] crystallized from acetone–methanol mixture in monoclinic space group P21/n
3
˚
˚
˚
˚
having cell dimensions a = 7.013(1) A, b = 17.111(1) A, c = 22.958(3) A, b = 98.06(1)°, V = 2727.7(6) A , Z = 4, R1 = 0.0485 and
wR2 = 0.1263. X-ray structure determination revealed the presence of discrete ions, [(C6H5)4P]+ and [trans-Co(NH3)2(NO2)4]ꢀ. The con-
stituent ions are held together by hydrogen bonding interactions involving second sphere coordination besides electrostatic forces of
interaction.
Ó 2008 Published by Elsevier B.V.
Keywords: Cobalt(III); Coordination chemistry; Inorganic synthesis; Organic cations; Spectroscopy; X-ray crystallography
1. Introduction
design for medicinal use such as anti-viral agent,for exam-
ple [8].
Transition metal ions play crucial roles in chemistry,
biology and medicine [1]. Among the various transition
metals that are involved in biological processes, the cobalt
cation is of major interest. At low concentrations, cobalt is
a biologically essential trace element for humans [2]. How-
ever, cobalt may be toxic at high concentrations, leading to
adverse health effects [3]. Cobalt(III) complexes continue to
receive attention [4] owing to (i) their important role in the
development of inorganic chemistry, (ii) as a metal cofactor
in the form of biologically important molecules such as the
B12 coenzyme and vitamin B12 [5,6], (iii) as catalysts in the
synthesis and hydrolysis of peptides[7] and (iv) in drug
Quaternary phosphonium salts have number of applica-
tions like catalyst [9], bactericides [10], etc. and have been
recognized and developed as new area of chemistry to
attract the large anions [11]. The widespread occurrence
of multiple phenyl embraces in which individual intermo-
lecular phenyl. . .phenyl interaction operates in addition
to significant net attraction [12] is a feature of supramole-
cularity of phenylated molecules. These supramolecular
motifs have been recognized through analysis as the pack-
ing in the molecular crystals [13]. Furthermore, tetraphenyl
phosphonium cation in crystal can form two- and three-
dimensional network as given in the literature [14].
This paper reports the synthesis and characterization of
[(C6H5)3RP][trans-Co(NH3)2(NO2)4] where R = benzyl,
phenyl or ethyl so as to study the effect of variation of size
of phosphonium cation on the structure and properties of
anionic cobaltammine, [trans-Co(NH3)2(NO2)4]ꢀ because
*
Corresponding authors. Tel.: +91 172 2544433 (R.P.S.), +91 172
2534443 (P.V.); fax: +91 0172 2545074 (R.P.S. and P.V.).
E-mail addresses: rpsharma@yahoo.co.in (R.P. Sharma), venugopa-
lanp@yahoo.com (P. Venugopalan).
0022-2860/$ - see front matter Ó 2008 Published by Elsevier B.V.
doi:10.1016/j.molstruc.2007.11.060

108
R.P. Sharma et al. / Journal of Molecular Structure 888 (2008) 107–112
of our interest in physico–chemical studies of such salts
[15]. Single crystal X-ray structure determination of one
of these salts, i.e., tetraphenylphosphonium trans-diam-
minetetra nitrocobaltate(III), [(C6H5)4P][trans-Co(NH3)2
(NO2)4] is described. A detailed packing analysis has also
been undertaken for understanding the forces/interactions
responsible for stabilizing the crystal lattice in the solid
state.
88%). The newly synthesized salt decomposes at 180 °C.
The orange colored single crystals suitable for X-ray struc-
ture determination were obtained from acetone–methanol
mixture by slow evaporation at room temperature. Solubil-
ity in water at room temperature (30 °C): 0.01 g/100 ml,
Ksp 2.56 ꢁ 10ꢀ8 and solubility in meth-anol at room temper-
ature (30 °C): 0.38 g/100 ml, Ksp 3.6 ꢁ 10ꢀ5
.
2.5. Synthesis of [(C6H5)3P(C2H5)][trans-Co(NH3)2
(NO2)4]
2. Experimental
2.1. Materials
Potassium trans-diamminetetranitrocobaltate(III) (0.425 g)
was dissolved in 40 ml of hot water by mechanical stirring
for 10–15 min. In another beaker 0.50 g of ethyltriphenyl-
phosphonium bromide was dissolved in minimum amount
of hot water (10 ml). Both the solutions were mixed with
stirring and yellow solid precipitated immediately, which
was washed with ice-cold water and air dried (yield 92%).
Yellow colored crystals of this complex salt have been
grown from acetone–methanol mixture by slow evapora-
tion at room temperature. The newly synthesized salt
decomposes at 183 °C.
Analytical grade reagents were used without any further
purification. K[trans-Co(NH3)2(NO2)4] has been prepared
according to the method described by Schlessinger [16].
2.2. Instruments
C, H, N were estimated microanalytically by automatic
Perkin-Elmer 2400CHN elemental analyzer and Cobalt
was determined by standard method [17]. UV/visible spec-
tra were recorded using HITACHI 330 spectrometer in
acetone as solvent. Infrared spectra of the title complex
salts were recorded using Perkin-Elmer spectrum RX FT-
IR system using Nujol mull or hexachlorobutadiene on
Table 1 lists the data for spectroscopic and physico-
chemical analysis of the title complex salts.
Table 1
1
KBr plates. H NMR, 13C NMR and 31P NMR spectra
Physicochemical and spectroscopic data of [(C6H5)3XP][trans-Co(N-
H3)2(NO2)4] where X = benzyl, phenyl or ethyl
of title complex salts were run in the solvent appropriate
solvents using BRUCKER AC 300F (300 MHz) spectrom-
eter. The chemical shift values are expressed as d value
(ppm) downfield from tetramethylsilane as an internal
standard. The 31P chemical shifts are reported as referenced
to external 85% H3PO4 with shifts occurring downfield
from the reference taken as positive.
Compounds
A
B
C
Melting
178
180
183
point (°C)
Elemental
analysesa (%)
Co
C
H
9.35 (9.31)
47.6 (47.5)
4.4 (4.3)
9.5 (9.4)
46.7 (46.6)
4.2 (4.0)
10.3(10.1)
35.9 (35.8)
4.5 (4.4)
2.3. Synthesis of [(C6H5)3P(CH2C6H5)][trans-Co(NH3)2
(NO2)4]
N
13.3 (13.2)
13.6 (13.5)
14.8 (14.7)
UV/Visible (nm)
348,431
348,431
348,431
IR (HCB) (cmꢀ1
ma(NH3)
ms(Ar-H)
ms(CH3)
mas(CH2)
ms(C@C)
)
Potassium trans-diamminetetranitrocobaltate(III) (0.364 g)
was dissolved in 40 ml of hot water by mechanical stirring
for 10–15 min. In another beaker 0.50 g of benzyltriphenyl-
phosphonium bromide was dissolved in minimum amount
of hot water (10 ml). Both the solutions were mixed
with stirring and yellow solid precipitated immediately,
which were washed with ice-cold water and air dried
(yield 87%). The newly synthesized salt decomposes at
178 °C.
3341
3028
–
2920
1605
1443
1424
1315
3345
3025
–
3338
3025
2958
–
1605
1444
1424
1315
–
1605
1441
1419
1313
Solvent
mas(Ar-P)
mas(NO2)
ms(NO2)
1H NMR d (ppm) Solvent CDCl3
Solvent CDCl3
7.2–7.8 (m, 15H,
Ar-H), 3.8 (s,
6.8–7.8 (m, 20H, DMSO-d6
Ar-H), 4.6 7.6–7.9 (m,
2.4. Synthesis of [(C6H5)4P][trans-Co(NH3)2(NO2)4]
(d, 2H, ACH2), 20H, Ar-H), 6H, 2NH3), 3.1–
3.8 (s, 6H,
3.7 (s, 6H,
3.2 (m, 2H,
2NH3)
2NH3)
ACH2), 1.2–1.39
(m, 3H, ACH3)
117–135 (Ar-C),
16 (ACH2), 6.5
(ACH3)
One gram of potassium trans-diamminetetranitrocobal-
tate(III) was dissolved in 40 ml of hot water by mechanical
stirring for 10–15 min. In another beaker 1.18 g of tetra-
phenylphosphonium bromide was dissolved in minimum
amount of hot water (10 ml). Both the solutions were mixed
with stirring and yellow solid precipitated immediately,
which was washed with ice-cold water and air dried (yield
13C NMR d (ppm) 129–135 (Ar-C), 117–135
76 (CH2) (Ar-C)
A, trans-[(C6H5)3P(CH2C6H5)][Co(NH3)2(NO2)4]; B, trans-[(C6H5)4P]
[Co(NH3)2(NO2)4]; C, trans-[(C6H5)3P(C2H5)][Co(NH3)2(NO2)4].
a
The values in the parentheses are experimental values.

R.P. Sharma et al. / Journal of Molecular Structure 888 (2008) 107–112
109
Table 3
Table 2
˚
Selected bond lengths [A] and angles [°] of [(C6H5)4P][trans-Co(NH3)2
(NO2)4]
Crystal data and structure refinement parameters of [(C6H5)4P][trans-
Co(NH3)2 (NO2)4]
Co(1)AN(1)
Co(1)AN(2)
Co(1)AN(3)
Co(1)AN(4)
Co(1)AN(5)
Co(1)AN(6)
1.950(3)
1.928(3)
1.958(3)
1.933(4)
1.940(3)
1.932(3)
Empirical formula
Formula weight
Temperature (K)
Diffractometer used
Radiation used,
Wavelength (Ka, A)
Crystal system
Space group
C24 H26 Co N6 O8
616.41
293(2)
Siemens P4
Mo, 0.71073
P
˚
Monoclinic
P21/n
P(1)AC(13)
P(1)AC(1)
P(1)AC(7)
P(1)AC(19)
1.790(3)
1.792(3)
1.797(3)
1.802(3)
Unit cell dimensions
˚
a (A)
7.013(1)
17.111(1)
22.958(3)
98.06(1)
˚
b (A)
˚
c (A)
N(2)ACo(1)AN(6)
N(2)ACo(1)AN(4)
N(6)ACo(1)AN(4)
N(2)ACo(1)AN(5)
N(6)ACo(1)AN(5)
N(4)ACo(1)AN(5)
N(2)ACo(1)AN(1)
N(6)ACo(1)AN(1)
N(4)ACo(1)AN(1)
N(5)ACo(1)AN(1)
N(2)ACo(1)AN(3)
N(6)ACo(1)AN(3)
N(4)ACo(1)AN(3)
N(5)ACo(1)AN(3)
N(1)ACo(1)AN(3)
88.79(17)
91.15(16)
90.17(17)
88.88(16)
177.65(15)
90.22(16)
177.82(15)
91.33(17)
86.68(15)
91.00(16)
93.12(15)
90.04(16)
175.74(15)
89.73(16)
89.06(14)
b (°)
Volume
Z, Calculated density
Absorption coefficient
F(000)
3
˚
2727.7(6) A
4, 1.501 Mg/m3
0.746 mmꢀ1
1272
Crystal size
0.24 ꢁ 0.20 ꢁ 0.17 mm
Max. and min.
transmission
h Range for data
collection (°)
Scan type
0.934 and 0.819
1.79–25.00
2h ꢀ h
Scan speed
Scan range (x)
Variable, 2.0° to 45.0°/min in x
1.80° plus Ka separation
Background measurement Stationary crystal and stationary counter at
the beginning and end of scan, each for
25.0% of total scan time
C(13)AP(1)AC(1)
C(13)AP(1)AC(7)
C(1)AP(1)AC(7)
C(13)AP(1)AC(19)
C(1)AP(1)AC(19)
C(7)AP(1)AC(19)
110.70(16)
110.50(15)
107.19(15)
107.74(16)
110.89(16)
109.85(16)
Index ranges
ꢀ8 6 h 6 0,ꢀ20 6 k 6 0, ꢀ27 6 l 6 27
Reflections collected
Independent reflections
Refinement method
Data/restraints/
5229
4798 [R(int) = 0.0280]
Full-matrix least-squares on F2
4798/ 0/ 362
parameters
Goodness-of-fit on F2
Weighting scheme
1.014
1/[r2 (F 2oÞ) + (0.0763P)2 +1.56P],
P = (max(F 2o,0)+2 * F 2c Þ/3
13.25:1
rected for Lorentz and polarization factors and an
empirical absorption correction based on w scan method
has also been applied. All other relevant information
about the data collection is presented in Table 2.
Selected bond lengths and bond angles are given in Table
3. The structure was solved by direct methods using
SHELX-97 package [18] and also refined using the same
one.
Data to parameter ratio
Final R indices, 3570
reflections [I > 2r (I)]
R indices (all data)
Extinction coefficient
Largest diff. peak and hole 0.762 and ꢀ0.365 e A
R1 = 0.0485, wR2 = 0.1263
R1 = 0.0743, wR2 = 0.1385
0.0018(5)
ꢀ3
˚
3. Results and discussion
2.6. X-ray crystallography
Novel Phosphonium salts have been prepared with anio-
nic cobaltammines. [(C6H5)3P(CH2C6H5)][trans-Co(N-
H3)2(NO2)4], [(C6H5)4P][trans-Co(NH3)2(NO2)4] and
[(C6H5)3P(C2H5)][trans-Co(NH3)2(NO2)4] salts have been
synthesized and characterized on the basis of elemental
analysis and spectroscopic studies but single crystal X-ray
structure determination of one of them has been carried
out.
The orange colored single crystals of [(C6H5)4P][trans-
Co(NH3)2(NO2)4] suitable for X-ray diffraction studies
were grown from acetone–water mixture by slow evapo-
ration method. A single crystal with dimension 0.24 ꢁ
0.20 ꢁ 0.17 mm was mounted along the largest dimension
and used for data collection. The intensity data were col-
lected on Siemens P4 single crystal diffractometer
˚
equipped with molybdenum sealed tube (k = 0.71073 A)
and highly oriented graphite monochromator. The lattice
parameters and standard deviations were obtained by
least square fit to 40 reflections. The data were collected
by 2h ꢀ h scan mode with variable scan speed ranging
from 2.0° to maximum of 45.0°/min. The data were cor-
3.1. Molar conductance
The conductance measurement studies in methanol at
28 °C were made and a plot between k (molar conductance)
versus square root of concentration is drawn. When the

110
R.P. Sharma et al. / Journal of Molecular Structure 888 (2008) 107–112
concentration in the plot of k (molar conductance) versus
square root of concentration was extrapolated to zero, it
gave the value of ko = 77.66 for [(C6H5)4P][trans-Co(N-
H3)2(NO2)4]. The corresponding value of ko for K[trans-
Co(NH3)2(NO2)4] is measured to be 77.65. It is obvious
that [(C6H5)4P][trans-Co(NH3)2(NO2)4] behaves as 1:1 elec-
trolyte in methanol.
reports in literature [21]. The antisymmetric stretching
modes of NH3 and NO2 appeared at around 3345 and
1424 cmꢀ1, respectively. The symmetric stretching mode
of NO2 appears at 1315 cmꢀ1. For [(C6H5)3PCH2C6H5]+,
[(C6H5)4P]+ and [(C6H5)3PC2H5]+ cations assignments
were done on the basis of well established literature values
[22,23] and are given in Table 1.
1H NMR and 13C NMR spectra of all the salts
[(C6H5)3P(CH2C6H5)][trans-Co(NH3)2(NO2)4], [(C6H5)4P]
[trans-Co(NH3)2(NO2)4] and [(C6H5)3P(C2H5)][trans-Co
(NH3)2(NO2)4] were run in the appropriate solvents at
25 °C temperature and characteristic assignments [24,25]
are given in Table 1. The chemical shift values are
expressed as d value (ppm) down field from tetramethylsil-
ane as a internal standard.
3.2. Spectroscopy
1
The two electronic transitions A1g ? 1T1g and
1A1g ? 1T2g at around 470 and 340 nm, respectively pro-
ducing the familiar orange–yellow color for number of
classical coordination compounds containing cobalt(III)
[19]. But a special absorption band [20] due to nitro group
is reported to appear in the region from 350 to 330 nm. The
second absorption found in cobalt(III) complexes is
strongly masked [20] because the band in the range
330–350 nm is extremely bathochromic. Thus the absorp-
tion curves are usually observed which are quite different
from [Co(NH3)6]3+, [Co(en)3]3+ and [Co(NH3)5Cl]2+. In
the titled complex salt dissolved in acetone only shoulder
at 431 nm is observed which may be assigned to one of
the d–d transitions typical for low spin Co(III) d6 octahe-
dral complexes. A strong absorption 348 nm (which masks
one of the d–d transition) in all three complex salts, is
assigned to the presence of two nitro groups in cis-position
as reported in the literature [20].
The 31P metal nuclide has a spin 1/2. Its employment as
a probe of structural features in R3P+-RXꢀ compounds
[26], where R = alkyl or aryl group and X = halogen
through NMR spectroscopy, has been quite useful. 31P
NMR spectra were recorded and found to be 27.1 for
[(C6H5)3P(CH2C6H5)][trans-Co(NH3)2(NO2)4] in CDCl3,
28.4 for [(C6H5)4P][trans-Co(NH3)2 (N O2)4] in DMSO-d6
and 23.8 for [(C6H5)3P(C2H5)][trans-Co(NH3)2(NO2)4] in
CDCl3. These values are consistent with 31P NMR results
for (C6H5)3(C6H5CH2)P+, (C6H5)4P+ and (C6H5)3(C2H5)
P+ cations [27] which show chemical shifts in the range
25.5–18.8, 20.8–25.1 and 23.5–17.8, respectively.
These results show conclusively that [(C6H5)3P(CH2
C6H5)][trans-Co(NH3)2(NO2)4], [(C6H5)4P][trans-Co (NH3)2
(NO2)4] and [(C6H5)3P(C2H5)][trans-Co(NH3)2(NO2)4]
have ionic phosphonium salt structure.
Infrared spectra of the newly synthesized complex salts
have been recorded in the region 4000–400 cmꢀ1 and tenta-
tive assignments have been made on the basis of earlier
Fig. 1. ORTEP III view and atom numbering scheme for [(C6H5)4P][trans-Co(NH3)2(NO2)4].

R.P. Sharma et al. / Journal of Molecular Structure 888 (2008) 107–112
111
Table 4
4. Crystal structure
˚
Hydrogen bonding parameters of (A, °) [(C6 H5)4 P][trans-Co(NH3)2
(NO2)4]
The structure of [(C6H5)4P][trans-Co(NH3)2(NO2)4] has
been unambiguously established by single crystal X-ray
crystallography. The crystals suitable for X-ray structure
determination have been grown from acetone–methanol
mixture by slow evaporation at room temperature. ORTEP
III diagram of title complex salts and numbering scheme
employed is shown in Fig. 1.
DAH. . .A
(DAH)
(H. . .A)
<DHA
(D. . .A)
N5AH5A. . .O5
N5AH5B. . . O1
N5AH5C. . .O7
N6AH6A. . .O8
N6AH6B. . .O2
N6AH6C. . .O4
N6AH6C. . .O1i
N5AH5A. . .O3ii
C17AH17A. . .O7iii
C22AH22A. . .O7iii
C9AH9A. . .O2iv
0.890
0.890
0.890
0.890
0.890
0.890
0.890
0.890
0.930
0.930
0.930
2.203
2.172
2.320
2.149
2.230
2.398
2.492
2.546
2.543
2.415
2.440
118.43
124.54
106.10
123.91
118.69
115.83
149.65
130.62
131.28
157.36
150.01
2.741 (5)
2.776 (5)
2.706 (5)
2.747 (6)
2.770 (5)
2.899 (6)
3.291 (6)
3.197 (5)
3.233(5)
3.293 (7)
3.278(5)
[(C6H5)4P][trans-Co(NH3)2(NO2)4] crystallizes in mono-
clinic system (space group P21/n) with four molecules in
the unit cell. There is one discrete anion [trans-Co(N-
H3)2(NO2)4]ꢀ and cation [P(Ph)4]+ in the asymmetric unit.
The cobalt(III) metal center has distorted octahedral dispo-
sition of coordinating moieties around it and the two NH3
groups are trans to each other (N1ACoAN2 = 177.6o).
The selected bond angles and bond lengths are listed in
Table 3. The bond lengths and bond angles for the
[(C6H5)4P][trans-Co(NH3)2(NO2)4](V) are comparable with
K[trans-Co(NH3)2(NO2)4](I), NH4[trans-Co(NH3)2(NO2)4]
(II), [Co(en)2(NO2)2][trans-Co(NH3)2(NO2)4](III) and [(C2
H5)3NCH2C6H5][trans-Co(NH3)2(NO2)4](IV) [20,28–30]. In
the [(C6H5)4P][trans-Co(NH3)2(NO2)4], the average CAP
bond distances and bond angles \CAPAC for the
[(C6H5)4P]+ ion are 1.795(3)and 109.47(16), respectively,
which are comparable with other complex salts having same
cation as (Ph)4P[Pt(Cl3)(C4H8O2)] [31], (Ph)4PClO4 [32].
The orientation of the four-phenyl groups around the
phosphorus atom is such that the possible tetrahedral sym-
metry is not achieved in the lattice. Most probably, this is
due to the steric requirements of the close packing for max-
imal electrostatic interaction between [trans-Co(N-
H3)2(NO2)4]ꢀ and [P(Ph)4]+. It is interesting to note that
the spatial juxtaposition of the nitro groups that are coor-
dinated to Co is in such a way that six of their oxygen
atoms take part in the intramolecular hydrogen bond with
the hydrogen atom of the coordinated ammonia molecules
(first six entries in Table 4). Thus, every NH3 group gener-
ates three five membered rings of hydrogen bonds in which
the cobalt atom is a common member and they adopt the
stable envelope confirmation. These multiple hydrogen
bonds would certainly contribute to the observed confirma-
tion of [trans-Co(NH3)2(NO2)4][P(Ph)4].
Sym. Op.: (i) [x ꢀ 1, y, z], (ii) [ꢀx,ꢀy ꢀ 1,ꢀz], (iii) [ꢀx + 1,ꢀy,ꢀz] and (iv)
[ꢀx,ꢀy,ꢀz].
˚
hydrogen bond (N5AH5A. . ..O3 = 2.546 A) as shown in
Fig. 2. These dimer units are further stabilized through
two CAH. . .O interactions involving the O7 and H17 A
and H22 A hydrogen atom of aromatic ring [P(Ph)4] . In
˚
+
˚
addition, there is one more CAH. . .O hydrogen bond
˚
˚
involving O2 and H9 A [C9AH9A. . .O2 = 2.440 A]. Thus,
a composite interplay of NAH. . .O and CAH. . .O hydro-
gen bond stabilizes the crystal lattice [trans-Co(N-
H3)2(NO2)4]ꢀ and [P(Ph)4]+.
In addition to the intramolecular hydrogen bonds, O1
and O3 atoms of nitrate groups are also involved in intra-
molecular hydrogen bonding with the hydrogen atom of
coordinated NH3 molecule. It is noteworthy that these
intermolecular hydrogen bonds are considerably weak in
˚
nature (minimum d(H. . .A) = 2.492 A, Table 4), than the
intramolecular hydrogen bond in which these amino
˚
hydrogen also take part (minimum d(H. . .A) = 2.149 A).
What is interesting in the packing is that the large tetra-
phenylphosphonium ions, six of them, with tetrahedrally
oriented aromatic rings generate a columnar cavity which
is sufficient to accommodate a pair of [trans-Co(N-
H3)2(NO2)4][P(Ph)4]. This pair is generated as a centrosym-
metric dimer that is formed with a weak NAH. . ..O
Fig. 2. Packing diagram of the title complex salt showing NAH. . .O
hydrogen bond interactions.

112
R.P. Sharma et al. / Journal of Molecular Structure 888 (2008) 107–112
(e) C.A. Jimenez, J.B. Belmar, J. Alderete, F.S. Delgado, M.L.
5. Conclusions
Rodrigues, O. Pena, M. Julve, C.R. Perez, Dalton Trans. (2007) 135.
[5] S. Balachandran, R.A. Vishwakarma, S.M. Monaghan, A. Prelle,
P.N. Stamford, F.J. Leeper, A.R. Battersby, J. Chem. Soc. Perkin
Trans. 1 (1994) 487.
[6] L. Debussche, M. Couder, D. Thibaut, B. Cameron, J. Crouzet, F.J.
Blanche, Bacteriology 22 (1992) 7445.
[7] R.J. Brown, D.A. Buckinghum, C.R. Clark, P.A. Sutton, Adv. Inorg.
Chem. 49 (1999) 307.
[8] M.D. Hall, T.W. Failes, N. Yamamoto, T.W. Hambley, Dalton
Trans. (2007) 3980.
[9] Y.S. Cho, S.H. Kang, J.S. Han, B.R. Yoo, N. Jung, J. Am. Chem.
Soc. 123 (2001) 5584.
[10] Y. Chen, X. Wang, B. Li, Patent No. US6261538, 2001.
[11] (a) R. Haiges, J.A. Boatz, A. Vij, M. Gerken, S. Schneider, T.
Schoesten, K.O. Christe, Angew. Chem. Int. Ed. 42 (2003) 5847;
The elemental analyses and spectroscopic studies
showed that the reaction of [(C6H5)3RP]Br, where
X = benzyl, phenyl or ethyl with K[trans-Co(NH3)2(NO2)4]
in aqueous medium at room temperature leads to the for-
mation of salts [(C6H5)3RP][trans-Co(NH3)2(NO2)4], where
R = benzyl, phenyl or ethyl. The single crystal X-ray struc-
ture determination of [(C6H5)4P][trans-Co(NH3)2(NO2)4]
confirmed the independent existence of discrete ions i.e.,
[(C6H5)4P]+ and [trans-Co(NH3)2(NO2)4]ꢀ, which are held
together by electrostatic forces of attraction and hydro-
gen-bonding interactions NAH. . .O involving second
sphere coordination.
(b) R. Lescoue¨zec, G. Marinescu, M.C. Munoz, D. Luneau, M.
˜
Andruh, F. Lloret, J. Julve, J.A. Mata, R. Llusar, J. Cano, New J.
Chem. 25 (2001) 1224;
(c) S. Lorenzo, D.C. Craig, M.L. Scudder, I.G. Dance, Polyhedron 18
(1999) 3181.
Acknowledgement
We thank the CSIR, New Delhi, India for their financial
support (Grant No. 01(1768)/02/EMR-II Dated
15.01.2002).
[12] M. Sceudder, I. Dance, J. Chem. Soc. Dalton Trans. (1998) 3167.
[13] (a) J.D. Dunitz, Pure Appl. Chem. 63 (1991) 177;
(b) G.R. Desraju, The crystal as a supramolecular entity, in: J.M.
Lehn (Ed.), Perspective in Supramolecular Chemistry, John Wiley
Chichester, 1996.
[14] T. Nakashima, J. Mishiro, M. Ito, G. Kura, Y. Ikuta, N. Matsumoto,
K. Nakajima, M. Kojima, Inorg. Chem. 42 (2003) 2323.
[15] (a) D.S. Gill, V. Pathania, B.K. Vermani, R.P. Sharma, Z. Phys.
Chem. 217 (2003) 739;
(b) D.S. Gill, B.K. Vermani, R.P. Sharma, J. Mol. Liquids 124 (2006)
58.
[16] G. Schlessinger, Inorg. Synth. 9 (1968) 110.
[17] A.I. Vogel, A text book of quantitative inorganic analysis, third ed.,
Longmans, London, 1961.
[18] SHELX-97 G.M.Sheldrick, Programme for solution and refinement
of crystal structure determination, University of Go¨ttingen, Ger-
many, 1997.
[19] P. Hendry, A. Ludi, Adv. Inorg. Chem. 35 (1990) 117.
[20] Y. Komiyama, Bull. Chem. Soc. Jpn. 30 (1957) 13.
[21] I. Nakagawa, T. Shimanouchi, Spectrochim. Acta 23A (1967) 2099.
[22] L.M. Bellamy, The Infra-red Spectra of Complex Molecules, second
ed., Chapman & Hall, London, 1980.
[23] B. Smith, Infrared Spectral Interpretation, CRC Press, New York,
1999.
[24] R.M. Sieverstein, F.X. Webster, Spectroscopic Identification of
Organic Compounds, sixth ed., J. Wiley and Sons, Inc., 1998.
[25] H. Karaman, R.J. Barton, B.E. Robertson, D.G. Lee, J. Org. Chem.
49 (1984) 4509.
Appendix A. Supplementary data
Crystallographic data for the structural analysis of the
title compound has been deposited at the Cambridge Crys-
tallographic Data Center, 12 Union Road, Cambridge CB2
1EZ, UK, and are available free of charge from the Direc-
tor on request quoting the deposition number CCDC
237637 (Fax: +44 1223 336033, email: deposit@ccdc.ca-
m.ac.uk). Supplementary data associated with this article
can be found, in the online version, at doi:10.1016/
j.molstruc.2007.11.060.
References
[1] (a) C. Deraeve, M. Pitie, H. Mazarguil, B. Meunier, New J. Chem. 31
(2007) 193;
(b) A. Gorzsas, I. Andersson, L. Pettersson, Eur. J. Chem. (2006)
3559;
(c) L. Casella, Eur. J. Chem. (2006) 3545.
[2] (a) D.L. Nelson, M.M. Cox, Lehninger Principles of Biochemistry,
fourth ed., Worth Publications, New York, 2004;
(b) A. Sigel, H. Sigel, Probing of Proteins by Metal Ions and their
Low Molecular Weight Complexes, Marcel Dekker, New York, 2001.
[3] (a) D. Lison, M. De Boeck, V. Verougstraete, M. Kirsch-Volders,
Occup. Environ. Med. 58 (2001) 619;
[26] T.A. Albright, W.J. Freeman, E.E. Schweizer, J. Am. Chem. Soc. 97
(1975) 2946.
[27] T.A. Albright, W.J. Freeman, E.E. Schweizer, J. Am. Chem. Soc. 97
(1975) 2942.
(b) D.G. Barceloux, J. Toxicol. Clin. Toxicol. 3 (1999) 201.
[4] (a) S.E. Harnong, E. Larsen, Inorg. Chem. 46 (2007) 5166;
(b) T. Aridomi, T. Kawamoto, T. Konno, Inorg. Chem. 42 (2007) 1343;
(c) R.E. Cowley, R.P. Bontchev, J. Sorrell, O. Sarracino, Y. Feng, H.
Wang, J.M. Smith, J. Am. Chem. Soc. 129 (2007) 2424;
(d) S.G. Telfer, J.D. Wuest, Chem. Com. (2007) 3166;
[28] I. Bernal, Inorg. Chim. Acta 96 (1985) 99.
[29] I. Bernal, Inorg. Chim. Acta 101 (1985) 175.
[30] R.P. Sharma, R. Sharma, R. Bala, B.K. Vermani, D.S. Gill, P.
Venugopalan, J. Coord. Chem. 58 (2005) 309.
[31] M. Colapietro, L. Zambonelli, Acta Cryst. B27 (1971) 734.
[32] S.R. Batten, A.R. Harris, K.S. Murray, Acta Cryst. C56 (2000) 1394.