Article
Inorganic Chemistry, Vol. 48, No. 13, 2009 6281
as bulk compound to best understand the structure and also
an analysis of the magnetic network for 1, to try to justify the
magnetic properties. The 3D-nets formed in 1 are of some
importance, as they show topologies not previously reported.
Especially the magnetic net, as this is a highly symmetric
network built from nodes with geometries easily obtainable
from various “secondary building units” and molecular
building blocks. The present case seems to be the first
assigned example of this net in chemistry.
Table 1. Relevant Crystal Data for 1
empirical formula
formula weight
cryst system
C
444.19
monoclinic
C2/m
11.708(2)
12.641(3)
9.482(2)
90
90.03(3)
90
1403.3(5)
4
2.102
896
5579
1486
0.0448, 0.0944
0.0520, 0.0973
1.114
6
H
14Co
2 16
N O
space group
˚
a (A)
˚
b (A)
˚
c (A)
R (deg)
β (deg)
γ (deg)
3
˚
V (A )
Z
Experimental Section
-1
Fcalcd(g.cm
F(000)
)
Starting Materials. Co(II) chloride hexahydrate, HMTA, and
sodium azide (Aldrich) were used as obtained. Aqueous hydra-
zoic acid is obtained with a modified Kipp’s generator
no. reflections coll.
no. reflections unique
R
R
1
, wR
, wR
2
(obs. refls)
(all data)
by decomposition of NaN
sequent transfer of HN into H O with aid of an inert-gas
3 2 4 2
in H SO /H O (1:3, v:v) and sub-
1
2
3
2
GOF
17,18
stream.
Caution! Hydrazoic acid and Azide compounds are potentially
explosive. Only a small amount of material should be prepared,
and it should be handled with care.
a
˚
Table 2. Selected Bond Lengths (A) and Bond Angles (deg) for 1
Co1-N11A
Co1-O1
Co2-N23D
Co2-N2G
N11-N12
N21-N22
N32-N31E
2.093(3)
2.159(4)
2.059(3)
2.370(3)
1.206(6)
1.172(4)
1.188(3)
Co1-N21C
Co1-N1
Co2-N31D
Co2-N2F
N12-N13
N22-N23
N2-Co2B
2.123(3)
2.201(4)
2.148(3)
2.370(3)
1.130(7)
1.187(4)
2.370(3)
Spectral and Magnetic Measurements. Infrared spectra (4000-
-1
4
3
00 cm ) were recorded from KBr pellets on a Perkin-Elmer
80-B spectrophotometer. Magnetic susceptibility measurements
under several magnetic fields in the temperature range 2-300 K
and magnetization measurements in the field range of 0-5 T
were performed with a Quantum Design MPMS-XL SQUID
magnetometer at the Magnetochemistry Service of the University
of Barcelona. All measurements were performed on powdered
polycrystalline samples. Pascal’s constants were used to estimate
the diamagnetic corrections, which were subtracted from the
experimental susceptibilities to give the corrected molar magnetic
susceptibilities.
N11A-Co1-N11
N11-Co1-N21
N11A-Co1-O1
N11-Co1-N1
O1-Co1-N1
N23-Co2-N2G
N12-N11-Co1
N13-N12-N11
N21-N22-N23
N32-N31-Co2
77.0(2)
N11A-Co1-N21
N21-Co1-N21C
N21-Co1-O1
167.47(12)
98.3(2)
91.97(13)
87.82(9)
100.83(9)
168.9(2)
91.59(11)
128.50(9)
180.0
85.80(11)
86.94(11)
90.46(12)
92.08(11)
103.0(2)
134.1(3)
123.4(3)
178.1(5)
N21-Co1-N1
N23D-Co2-N31D
N31-Co2-N2G
Co1A-N11-Co1
N22-N21-Co1
N22-N23-Co2
N31-N32-N31E
2 3 4 2 n
Synthesis. [Co (N ) (HMTA)(H O)] (1). Sodium azide (0.293 g,
4
.5 mmol) CoCl 6H O (0.480 g, 2.02 mmol) and HMTA (0.280 g,
2
177.9(4)
129.2(2)
3
2
2
.00 mmol) were dissolved in minimum amount of aqueous hydra-
zoic acid (21 mL) to obtain a clear red solution upon heating to
0 °C. Transparent red crystals of 1 were separated by slow cooling
of the solution to 4 °C within 2 days. (yield approximately 0.375 g,
3.7%) Anal., Found: C, 16.0; H, 3.0; Co, 26.4; N, 50.7. Calcd for
C H Co N O (444.19): C, 16.2; H, 3.2; Co, 26.5; N, 50.5. IR
a
Symmetry codes: (A) -x + 1, -y + 1, -z; (B) x, y, z - 1; (C) x,
y + 1, z; (D) -x + 3/2, -y + 3/2, -z + 1; (E) -x + 1, y, -z + 1;
7
-
(
F) x, y, z + 1; (G) -x + 3/2, -y + 3/2, -z.
8
6
14
2
16
atoms of the HMTA ligand were inserted in calculated positions.
Full-matrix least-squares refinement on F with anisotropic
thermal motion parameters for all the non-hydrogen atoms and
-
1
2
(
1
9
(
KBr, cm ): 3408 vw, 3351 vw, 3007 vw, 2961 vw, 2084 vs (νas
451 w, 1359 w, 1297 w, 1233 m, 1228 w, 1061 w, 1005 m, 973 m,
15 w, 844 w, 797 m, 774 w, 692 m, 662 w, 614 w, 511 w, 425 w
v=very, s=strong, m=medium, w=weak).
3
N ),
2
0
isotropic for the remaining atoms were employed. Selected
bond parameters are summarized in Table 2.
From the synthetic point of view, it should be emphasized that a
compound of formula [Co(N ) (HMTA)(H O) ] has been ob-
Network Analysis. Abbreviations (three-letter codes) for 3D
nets were taken from the web-based Reticular Chemistry Struc-
ture Resource, where crystallographic coordinates and other
3
2
2
2 n
9
1
tained under controlled hydrothermal synthesis. This compound
is a 1D infinite polymeric chain in which the HMTA acts as
bidentate bridging ligand, and the azido is only a terminal ligand.
Structure Determination. A suitable single crystal of 1 (ap-
proximately size: 0.26ꢀ0.18ꢀ0.12 mm) was selected for X-ray
diffraction. Intensity data were collected with a Bruker AXS
KAPPA APEX II diffractometer using graphite monochromated
Mo-KR radiation. Data were collected at 100 K using ω-scans.
Cell parameters were retrieved and refined using Bruker SMART
and SAINT software programs. Absorption correction was
applied using SADABS. The structure was solved by direct
methods by using the SHELXS-86 program and was refined with
SHELXL-93 incorporated in the SHELXTL/PC sofware pack-
age. Relevant structural data are given in Table 1. Hydrogen
2
1
useful details for 3D-nets can be obtained. More unusual and
exotic nets with confirmed occurrence in known structures are
listed in the TTO collection obtainable with the TOPOS pro-
2
2,23
gram, also used to established the topologies of the nets in 1.
The six- and three-connected net in 1 has been given the loh1
symbol in the TTO collection. Mathematically derived nets can
(20) (a) Blessing, R. H. Acta Crystallogr. 1995, A51, 33. SADABS; Bruker
AXS: Madison, WI, 1998. (b) Sheldrick, G. M. SHELXS-86, Program for the
Solution of Crystal Structure; University of Goettingen: Goettingen, Germany,
1
986. (c) Sheldrick, G. M. SHELXL-93, Program for the Refinement of Crystal
Structure; University of Goettingen: Goettingen, Germany, 1993. (d) SHELXTL
5.03 (PC-Version), Program library for the Solution and Molecular Graphics;
Siemens Analytical Instruments Division: Madison, WI, 1995.
(21) O’Keeffe, M.; Yaghi, O. M.; Ramsden, S. Reticular Chemistry
(
17) Bitschnau, B.; Egger, A.; Escuer, A.; Mautner, F. A.; Sodin, B.;
Vicente, R. Inorg. Chem. 2006, 45, 868, and references therein.
18) Energetic Materials; Fair, H. D., Walker, R. F., Eds.; Plenum Press:
New York, 1977; Vol. I, pp 25-31.
19) Chakraborty, J.; Samanta, B.; Rosair, G.; Gramlich, V.; Salah El
Fallah, M.; Ribas, J.; Mitra, S. Polyhedron 2006, 25, 3006.
Structure Resource; Australian National University Supercomputer Facil-
ity: http://rcsr.anu.edu.au/, February 2009
(22) Blatov, V. A.; Shevchenko, A. P.; Serezhkin, V. N. J. Appl. Crystal-
logr. 2000, 33, 1193.
(23) TOPOS website: http://www.topos.ssu.samara.ru/, Ac. Pavlov St. 1,
(
(
443011 Samara, Russia, February 2009.