Synthesis and crystal structure of two polydimensional molecular architectures from cobalt(II), copper(II) complexes of 2,4-diamino-6-pyridyl-1, 3,5-triazine

Article abstract of DOI:10.14233/ajchem.2014.15424

Two new Co(II) and Cu(II) complexes of 2,4-diamino-6-pyridyl-1,3,5-triazine (ptzda) have been synthesized and structurally characterized. Crystal structure studies reveal that Co atom is six-coordinated by four nitrogen atoms from four dicyanamide anions and the other two nitrogen atoms from 2,4-diamino-6-pyridyl- 1,3,5-triazine and each cobalt atom are connected by two [N(CN) ₂]^- anions to form an infinite double-stranded bridge fashion to give 2D ladder-like motifs. Whereas, Cu atom is five-coordinated by two nitrogen atoms from two dicyanamide anions and the other two nitrogen atoms from 2,4-diamino-6-pyridyl-1,3,5-triazine and each copper atom is connected by one methanol to form an infinite double-stranded bridge fashion to give 1D ladder-like motifs.

Full text of DOI:10.14233/ajchem.2014.15424

Asian Journal of Chemistry; Vol. 26, No. 2 (2014), 419-422
http://dx.doi.org/10.14233/ajchem.2014.15424
Synthesis and Crystal Structure of Two Polydimensional Molecular Architectures from
Cobalt(II), Copper(II) Complexes of 2,4-Diamino-6-pyridyl-1,3,5-triazine
1,*
2
3
3
3
3
3
1,*
JIA-YAN LI , MING-JIN XIE , JING JIANG , QIAO-WEN CHANG , QING-SONG YE , WEI-PING LIU , JIA-LIN CHEN and PING NING
1Oxbridge College, Kunming University of Science and Technology, 650106 Kunming, P.R. China
2Department of Chemistry, Yunnan University, 650031 Kunming, P.R. China
3State Key Lab of Advanced Technologies for PGM, Kunming Institute of Precious Metals, 650106 Kunming, P.R. China
*Corresponding authors: E-mail: ningping58@sina.com
Received: 5 March 2013;
Accepted: 9 May 2013;
Published online: 15 January 2014;
AJC-14557
Two new Co(II) and Cu(II) complexes of 2,4-diamino-6-pyridyl-1,3,5-triazine (ptzda) have been synthesized and structurally characterized.
Crystal structure studies reveal that Co atom is six-coordinated by four nitrogen atoms from four dicyanamide anions and the other two
nitrogen atoms from 2,4-diamino-6-pyridyl-1,3,5-triazine and each cobalt atom are connected by two [N(CN)2]– anions to form an infinite
double-stranded bridge fashion to give 2D ladder-like motifs. Whereas, Cu atom is five-coordinated by two nitrogen atoms from two
dicyanamide anions and the other two nitrogen atoms from 2,4-diamino-6-pyridyl-1,3,5-triazine and each copper atom is connected by
one methanol to form an infinite double-stranded bridge fashion to give 1D ladder-like motifs.
Keywords: 1,3,5-Triazines, Polydimentional molecular architectures, X-Ray crystal structure.
INTRODUCTION
EXPERIMENTAL
The coordination polymer construction of secondary
building units (SBUs) has recently drawn much attention due
to their various topologies of structures and fascinating
properties, such as porosity, nonlinear optical property and
magnetism1-5. Since the secondary building units have trian-
gular, square, tetrahedral, or octahedral building-block geom-
etries which can adopt different spatial configurations and
maintain their structural integrity throughout the self-assembly
process, a variety of multi-dimensional coordination geome-
tries were found in the crystal structure of their complexes,
i.e., one dimension (1D), 2D and 3D. At present, interest in
rational design and synthesis of polynuclear coordination
compounds with predictable functionalities, such as bioacti-
vity6-10, catalytic ability11-13 and magnetic interactions14-19 has
increased tremendously. It was reported that 1,3,5-triazole
and its derivatives, a type of heterocyclic compound, had a
number of biological activity and promising applications in
All the chemicals and solvents used for the synthesis were
of reagent grade and used without further purification.
Na[N(CN)2] was purchased fromAldrich Company. Elemental
analyses (C, H, N) were performed on an Elementar Vario EL
III elemental analyzer. X-ray single-crystal diffraction was
determined on Bruker APEX II CCD area detector.
Synthesis of 2,4-diamino-6-pyridyl-1,3,5-triazine
[ptzda]: The ligand ptzda was prepared by some modification
according to the literature23. As illustrated in Scheme-I, a
mixture of one molar proportion of 2-cyanopyridine derivative,
l.25 of dicyandiamide, 0.2 of potassium hydroxide and 6.2 of
methylcellosolve was refluxed for 4 h. After cooling, the
contents of the flask were poured into water and the precipitate
was collected by filtration, dried and recrystallized from
methylcellosolve.Yield: 92.1 %. Anal. calcd. (%) for C8H10N5:
C,54.53; H, 5.72; N, 9.75. Found (%): C, 54.82; H, 5.28; N,
9.89. 1H NMR (500 MHz, CDCl3, δ): 8.70 (J = 2.6,H, pyridyl-
H); 8.20 (J = 7.7, H, pyridyl-H); 7.91 (J = 7.6, H, pyridyl-H);
7.49 (J = 5.5, H, pyridyl-H); 7.09 (2H, NH2); 6.87 (2H, NH2).
Synthesis of complex 1: [Co(ptzda)2(L)]n: CoCl2·6H2O
(35.70 mg, 0.15 mmol) was dissolved in 5 mL of methanol
and allowed to react with methanolic solution (5 mL) of the
ligand ptzda (17.60 mg, 0.1 mmol) in stirring condition. After
a few minutes, an aqueous solution (2 mL) of sodium
many fields such as pharmacy, pesticide, material, etc.20-22
.
1,3,5-Triazole and its derivatives are also good ligands for
transition metal complexes. In this point of view, Co(II) and
Cu(II) complexes of 2,4-diamino-6-pyridyl-1,3,5-triazine
as the ligand were synthesized and characterized. The
complexes were found to have polydimentional molecular
architectures.

420 Li et al.
Asian J. Chem.
observed [I > 2σ(I)]. For complex 2, a total of 8408 indepen-
dent reflections were collected, of which 3110 [R(int) = 0.0393]
were considered as observed [I > 2σ(I)]. The structures were
solved by direct method using the program SHELXS-9724 and
subsequent Fourier difference techniques and refined aniso-
tropically by fullmatrix least-squares on F2 using SHELXL-
9725. Crystal data and structural refinements of two complexes
are shown in Table-1. Crystallographic data of the complexs
1, 2 have been deposited at the Cambridge Crystallogrphic
Data Center, CCDC Nos. 732112 and 732110. Any queries
relating to the data can be e-mailed to deposit@ccdc.cam.ac.uk.
NH
N
NH2
N
KOH
+
reflux
N
CN
N
N
H2N
NHCN
NH2
ptzda
Scheme-I: Synthesis of ligand 2,4-diamino-6-pyridyl-1,3,5-triazines
(ptzda)
dicyanamide (8.90 mg, 0.1 mmol) was added and stirred for
0.5 h. Red single crystals suitable for X-ray analysis were
obtained by slow evaporation at room temperature for three
weeks. Yield: 62 %. Anal. calcd. (%) for C24H16N24Co2: C,
38.00; H, 2.13; N, 44.32. Found. (%): C, 38.09; H, 2.22; N,
44.21.
Synthesis of complex 2: [Cu(ptzda)2(L)]n: A 5 mL of
methanol solution of CuCl2·6H2O (33.70 mg, 0.15 mmol) was
mixed with the methanolic solution (5 mL) of the ligand
ptzda (17.60 mg, 0.1 mmol) in stirring condition. After a few
minutes, an aqueous solution (2 mL) of sodium dicyanamide
(8.90 mg, 0.1 mmol) was added and stirred for 0.5 h. Red
single crystals suitable for X-ray analysis were obtained by
slow evaporation at room temperature for four weeks. Yield:
52 %. Anal. calcd. (%) for C10H8N9OCu: C, 34.00; H, 2.28; N,
35.69. Found (%): C, 34.19; H, 2.22; N, 36.21.
RESULTS AND DISCUSSION
For complex 1, crystal structures reveal that Co atom is
six-coordinated by four nitrogen atoms from four dicyanamide
anions and the other two nitrogen atoms from ptzda and each
coblat atom is connected by two [N(CN)2]– anions to form an
infinite double-stranded bridge fashion to give 2D ladder-like
motifsis (Fig. 1). A neutral, two-dimensional coordination
network based on coblat clusters is joined by end-end (EE)
[N(CN)2]– anions groups. As shown in Fig. 2, the basic unit
contains coblat metal centres arranged in linear that are bridged
by two end-on (EO) [N(CN)2]– anions ligands. In the unit, the
Co atom is six-coordination with a distorted octahedral geo-
metry, where two nitrogen atom of 2,4-diamino-6-pyridyl-
l,3,5-triazine form the basal plane, while a nitrogen atom of
one EE azide bridge occupies the apical position. The basal
Co-N bond lengths are in the range of 2.104-2.150 Å which is
identical to Cu-[N(CN)2]– anions compounds. The N-Co-N bond
angles are in the range of 86.39(10)-126.1(2)º (Table-2).
Crystallographic data collection and structure deter-
mination: Intensity data for single crystals of complexes were
collected on a BRUKERAPEX II CCD detector with graphite-
monochromatized MoKα radiation (λ = 0.071073 nm). For
complex 1, a total of 9383 independent reflections were
collected, of which 3416 [R(int) = 0.0423] were considered as
TABLE-1
CRYSTAL DATA AND STRUCTURE REFINEMENTS FOR COMPLEXES 1 AND 2
1
2
Empirical formula
C24H16Co2N24
C10H8CuN9O
Formula weight
Temperature (K)
Wavelength(Å)
Crystal system
758.47
298(2)
0.71073
Monoclinic
333.79
298(2)
0.71073
Monoclinic
space group
P2(1)/n
C2/c
A (Å)
7.179(5)
23.205(3)
B (Å)
14.380(10)
9.0844(11)
C (Å)
14.585(10)
12.5312(15)
90
90
α
96.288(9)
91.946(2)
β
90
90.
2640.1(5)
γ
Volume (Å3)
1496.6(17)
Z
2
1.173
764
8
1.669
1344
Absorption coefficient (mm-1)
F(000)
Crystal size (mm)
Theta range for data collection (º)
Limiting indices
Reflections collected/unique
Completeness to theta = 27.94
Refinement method
Data/restraints/parameters
Goodness-of-fit on F2
Final R indices [I > 2σ(I)]
R indices (all data)
Largest diff. peak and hole (e Å-3)
0.20 × 0.20 × 0.20
1.99-27.94
0.21 x 0.16 x 0.10
1.76-28.26
-9 ⇐ h ⇐ 7, -17 ⇐ k ⇐ 18, -11 ⇐ l ⇐ 19
9383 / 3416 [R(int) = 0.0423]
95.00 %
-16 ⇐ h ⇐ 30, -12 ⇐ k ⇐ 12, -16 ⇐l ⇐ 16
8408 / 3110 [R(int) = 0.0393]
98.10%
Full-matrix least-squares on F2
3416/0/226
Full-matrix least-squares on F2
3110/0/190
1.002
1.051
R1 = 0.0423, wR2 = 0.0938
R1 = 0.0750, wR2 = 0.1090
0.289 ~ -0.370
R1 = 0.1158, wR2 = 0.3593
R1 = 0.1536, wR2 = 0.3813
3.977 ~ -1.223

Vol. 26, No. 2 (2014)
Synthesis and Crystal Structure of Two Polydimensional Molecular Architectures 421
TABLE-2
BOND LENGTHS [Å] AND ANGLES [º] FOR COMPLEX 1
Co(1)-N(7)
N(1)-C(5)
N(5)-H(5A)
N(6)-C(8)
N(6)-H(6A)
N(7)-C(9)
2.104(3)
1.343(4)
0.8600
1.327(4)
0.8600
N(7)-Co(1)-N(9)
C(5)-N(1)-C(1)
C(11) -N(10)-C(12)
N(1)-C(1)-C(2)
C(3)-C(2)-C(1)
N(7)-C(9)-N(8)
95.18(12)
118.2(3)
118.4(3)
122.3(3)
118.6(3)
172.2(4)
1.135(4)
As for complex 2, Cu atom is five-coordinated by two
nitrogen atoms from two dicyanamide anions and the other
two nitrogen atoms from ptzda and each copper atom is
connected by one methanol to form an infinite double-stranded
bridge fashion to give 1D ladder-like motifs (Fig. 3). The
clusters act as rod-shaped SBUs and are joined into a 1D
network by the EE azide groups in the bc plane (Fig. 4). Each
rod-shaped unit is directly connected to four neighboring rods
through four EE azide bridges. In the solid state, the 1D net-
work extend to three-dimension architecture by two hydrogen
bonds of N7- H7A···N4 (symmetry: -x + 1, -y + 1, -z + 1),
N(6)-H(6B)···O(1) (Tables 3 and 4).
Fig. 1. A view of the molecule structure of 1 with the atomic labeling
scheme
(A)
Fig. 3. A view of the molecule structure of 2 with the atomic labeling
scheme
TABLE-3
BOND LENGTHS [Å] AND ANGLES [º] FOR COMPLEX 2
Cu(1)-N(7)
Cu(1)-Cl
N(1)-C(1)
N(6)-H(6A)
C(3)-C(4)
C(10)-N(8)#1
1.982(5)
2.3449(14)
1.340(6)
0.8600
1.377(9)
1.305(7)
N(7)-Cu(1)-N(1)
N(7)-Cu(1)-Cl
C(1)-N(1)-C(5)
C(1)-N(1)-Cu(1)
C(6)-N(2)-C(8)
C(7)-N(5)-H(5A)
89.87(17)
89.98(15)
118.1(4)
127.1(3)
114.0(4)
120.0
#1 x,-y, z+1/2 #2 x, -y, z-1/2.
TABLE-4
HYDROGEN BONDS COMPLEX 2 [Å AND º]
D-H···A d(D-H) d(H···A) d(D···A) <(DHA)
N(7)-H(7A)···N(4)#3
N(6)-H(6B)···O(1)
0.86
0.86
2.20
2.54
3.052(12)
3.221(9)
173.9
136.7
(B)
Symmetry transformations used to generate equivalent atoms: #1 x, -y,
z + 1/2 #2 x, -y, z-1/2 #3 -x+1, -y+1, -z+1.
Fig. 2. A and B view showing the weak pairing of 1 molecules within the
unit cell

422 Li et al.
Asian J. Chem.
ACKNOWLEDGEMENTS
The authors are grateful to the National Science Founda-
tion of P. R. China (Grant No. 21161010 and 21161022) and
Yunnan Provincial Science Foundation (Grant No.2005C009Z)
for financial support.
REFERENCES
1. O.M. Yaghi, H. Li, C. Davis, D. Richardson and T.L. Groy, Acc. Chem.
Res., 31, 474 (1998).
2. M. Eddaoudi, D.B. Moler, H. Li, B. Chen, T.M. Reineke, M. O'Keeffe
and O.M. Yaghi, Acc. Chem. Res., 34, 319 (2001).
3. O.M. Yaghi, M. O'Keeffe, N.W. Ockwig, H.K. Chae, M. Eddaoudi and
J. Kim, Nature, 423, 705 (2003).
(A)
4. N.W. Ockwig, O. Delgado-Friedrichs, M. O'Keeffe and O.M. Yaghi,
Acc. Chem. Res., 38, 176 (2005).
5. A. Escuer, F.A. Mautner, M.A.S. Goher, M.A.M. Abu-Youssef and R.
Vicente, Chem. Commun., 605 (2005).
6. H. Beinert, R.H. Holm and E. Munck, Science, 277, 653 (1997).
7. P. Horcajada, C. Serre, M. Vallet-Regí, M. Sebban, F. Taulelle and G.
Férey, Angew. Chem. Int. Ed., 45, 5974 (2006).
8. J.E. Sheats, R.S. Czernuszewicz, G.C. Dismukes, A.L. Rheingold, V.
Petrouleas, J. Stubbe, W.H. Armstrong, R.H. Beer and S.J. Lippard, J.
Am. Chem. Soc., 109, 1435 (1987).
9. G.N. George, I.J. Pickering, Y.E. Yu, R.C. Prince, S.A. Bursakov, O.Y.
Gavel, I. Moura and J.J.G. Moura, J. Am. Chem. Soc., 122, 8321 (2000).
10. H. Dobbek, L. Gremer, R. Kiefersauer, R. Huber and O. Meyer, Proc.
Nat. Acad. Sci. USA, 99, 15971 (2002).
11. U. Riaz, O.J. Curnow and M.D. Curtis, J. Am. Chem. Soc., 116, 4357
(1994).
12. M. Hidai, S. Kuwata and Y. Mizobe, Acc. Chem. Res., 33, 46 (2000).
13. R.D. Adams and B. Captain, Angew. Chem. Int. Ed., 47, 252 (2008).
14. D. Gatteschi, Adv. Mater., 6, 635 (1994).
15. O. Kahn, Molecular Magnetism, VCH, New York (1993).
16. J.S. Miller and A.J. Epstein, Angew. Chem. Int. Ed., 33, 385 (1994).
17. L.F. Ma, Y.Y. Wang, L.Y. Wang, J.Q. Liu, Y.P. Wu, J.G. Wang, Q.Z. Shi
and S.M. Peng, Eur. J. Inorg. Chem., 5, 693 (2008).
(B)
Fig. 4. A and B view showing the weak pairing of 2 molecules within the
unit cell
18. L.F. Ma, L.Y. Wang, X.K. Huo, Y.Y. Wang, Y.T. Fan, J.G. Wang and
S.H. Chen, Cryst. Growth. Des., 8, 620 (2008).
Conclusion
19. D. Gatteschi and R. Sessoli, Angew. Chem. Int. Ed., 42, 268 (2003).
20. A.K. Gadad, C.S. Mahajanshetti, S. Nimbalkar and A. Raichurkar, Eur.
J. Med. Chem., 35, 853 (2000).
21. A. Andreani, D. Bonazzi, M. Rambaldi, G. Fabbri and K.D. Rainsford,
Eur. J. Med. Chem., 17, 271 (1982).
22. A.K. Gadad, M.N. Noolvi and R.V. Karpoormath, Bioorg. Med. Chem.,
12, 5651 (2004).
23. F.H. Case and E. Koft, J. Am. Chem. Soc., 81, 905 (1959).
24. G.W. Sheldrick, SHELXS-97, Program for Crystal Structure Solution,
University of Go¨ttingen, Germany (1997).
The Co(II) and Cu(II) complexes of 2,4-diamino-6-
pyridyl-1,3,5-triazine were synthesized by the chemical
reaction of MCl2·6H2O (M = Co or Cu) with 2,4-diamino-6-
pyridyl-l,3,5-triazine and sodium dicyanamide in methanol.
The complexes exhibit polydimentional molecular architec-
tures in which the dicyanamide anion acts as the bridged ligand,
featuring special formations probably endowed with some
application.
25. G.W. Sheldrick, SHELXS-97, Program for Crystal Structure Refine-
ment, University of Go¨ttingen, Germany (1997).