A zinc complex based on 4-bromoisophthalic acid and 1,2-Bi(4-pyridyl) ethane: Hydrothermal synthesis, crystal structure, and fluorescent properties

Article abstract of DOI:10.1080/15533174.2011.594838

A novel zinc complex formulated as [Zn(Bript)(bpa)(H₂O)]n (1) (H₂Bript = 4-bromoisophthalic acid, bpa = 1,2-bi(4- pyridyl)ethane) has been synthesized through hydrothermal reaction. It was structurally characterized by elemental analysis and x-ray single-crystal diffraction. The x-ray crystal structure shows that the complex belongs to monoclinic systems, P2₁/n space group, and a = 10.997(6) A, b = 14.578(8) A, c = 12.963(7) A, β = 105.993(6)°. The adjacent Zn atoms are bridged by Bript to form a one-dimensional (1D) chain. Such 1D chains are further connected by hydrogen bonding to generate a three-dimensional (3D) supramolecular network. Fluorescence measurements show that 1 has medium fluorescent emissions at 404 nm and 468 nm upon excitation at 288 nm. Copyright Taylor & Francis Group, LLC.

Full text of DOI:10.1080/15533174.2011.594838

Synthesis and Reactivity in Inorganic, Metal-Organic, and Nano-Metal Chemistry, 41:1268–1273, 2011
Copyright ꢀ Taylor & Francis Group, LLC
C
ISSN: 1553-3174 print / 1553-3182 online
DOI: 10.1080/15533174.2011.594838
A Zinc Complex Based on 4-Bromoisophthalic Acid
and 1,2-Bi(4-pyridyl)ethane: Hydrothermal Synthesis,
Crystal Structure, and Fluorescent Properties
Min-Le Han, Jian-Ge Wang, and Juan-Juan Yao
College of Chemistry and Chemical Engineering, Luoyang Normal University, Luoyang, China
Among the N-donor ligands, exo-bidentate rodlike N,Nꢁ-
donor ligands, such as 4,4ꢁ-bipyridine, can have significant influ-
ence on the assembly systems of multicarboxylate ligands and
metal centers. Its derivatives bpe (1,2-bi(4-pyridyl)ethene), bpp
(1,3-bi(4-pyridyl)propane), and bpa (1,2-bi(4-pyridyl)ethane)
with certain spacers between the two 4-pyridyl rings may also
lead to fascinating architectures with interesting properties. So
they are always employed to construct one-dimensional (1D),
two-dimensional (2D), and three-dimensional (3D) coordina-
tion polymers. In addition, they could act as both hydrogen-bond
acceptors and donors.[21,22]
In this study, we reacted 4-bromoisophthalic acid
(H2Bript) bpa with Zn(II) ion, yielding a new polymer,
[Zn(Bript)(bpa)(H2O)]n (1). Herein, we report its hydrothermal
synthesis, structural characterization, thermal stabilities, and lu-
minescent properties.
A novel zinc complex formulated as [Zn(Bript)(bpa)(H2O)]n
(1) (H2Bript 4-bromoisophthalic acid, bpa 1,2-bi(4-
=
=
pyridyl)ethane) has been synthesized through hydrothermal re-
action. It was structurally characterized by elemental analysis
and x-ray single-crystal diffraction. The x-ray crystal structure
shows that the complex belongs to monoclinic systems, P21/n space
group, and a = 10.997(6) Å, b = 14.578(8) Å, c = 12.963(7) Å,
β = 105.993(6)◦. The adjacent Zn atoms are bridged by Bript to
form a one-dimensional (1D) chain. Such 1D chains are further
connected by hydrogen bonding to generate a three-dimensional
(3D) supramolecular network. Fluorescence measurements show
that 1 has medium fluorescent emissions at 404 nm and 468 nm
upon excitation at 288 nm.
Keywords 1, 2-bi(4-pyridyl)ethane, 4-bromoisophthalic acid, crystal
structure, fluorescent properties
INTRODUCTION
During the past two decades, design and synthesis of
metal–organic hybrid materials have been of great interest be-
cause of their intriguing topologies and potential applications
as functional materials, such as in gas adsorption,[1] lumines-
cence, [2] catalysis,[3] ion exchange,[4] nonlinear optics,[5] and
magnets.[6] One of the current interesting topics is to rationally
design and synthesize coordination polymers and supramolec-
ular assemblies by coordination bonds or noncovalent contacts
such as hydrogen bonding. The key step in building these com-
plexes is to use suitable organic ligands, metal cations, and aux-
iliary ligands. For instance, 1,n-benzenedicarboxylate (n = 2,
3, 4), 1,3,5-benzenetricarboxylate, 1,2,4-benzenetricarboxylate,
1,2,3-benzenetricarboxylate, 1,2,4,5-benzenetetracarboxylate,
and their derivatives are often selected as versatile coordinating
ligands to coordinate with metal ions in a variety of modes.[7–15]
4-Bromoisophthalic acid is a versatile ligand that can coordinate
to transition metals in a variety of modes with donor atoms.[16–20]
EXPERIMENTAL
Materials and Physical Measurements
All chemicals were commercially purchased and used with-
out further purification. Elemental analyses (C, H, and N) were
performed on a Thermo Science Flash 2000 element analyzer.
Thermogravimetric analysis (TGA) was performed on a SII
EXStar6000 TG/DTA6300 analyzer heated from 15 to 895◦C
under nitrogen. The photoluminescent properties were mea-
sured on an F-4500 FL spectrophotometer.
Synthesis of Complex 1
A mixture of 4-bromoisophthalic acid (24.5 mg, 0.1 mmol),
bpa (18.5 mg, 0.1 mmol), Zn(Ac)2•4H2O (24 mg, 0.1 mmol),
and KOH (5.6 mg, 0.1 mmol) was added into water (12 mL)
in a Teflon-lined stainless-steel vessel. The mixture was heated
at 433 K for 3 days, and then slowly cooled down to room
temperature. Colorless block crystals of 1 were obtained. Anal.
(%): Calc. for C20H17BrN2O5Zn: C, 47.04; H, 3.33; N, 5.48.
Found: C, 47.00; H, 3.28; N, 5.40.
Received 6 April 2011; accepted 23 May 2011.
Address correspondence to Min-Le Han, College of Chemistry and
Chemical Engineering, Luoyang Normal University, Luoyang 471000,
China. E-mail: minle han@163.com
1268

NOVEL ZINC COMPLEX
1269
TABLE 1
Crystal data and structure refinement details for compound 1
TABLE 2
Selected bond lengths (Å) and angles for complex 1
Zn(1)–O(5)#1a
Zn(1)–O(1)
1.933(2) Zn(1)–O(2)
2.001(2) Zn(1)–N(1)
1.969(2)
2.016(2)
Empirical formula
C20H17BrN2O5Zn
O(5)#1–Zn(1)–O(2) 109.97(9) O(5)#1–Zn(1)–O(1) 102.78(9)
fw
510.64
Monoclinic
P21/n
10.997(6)
14.578(8)
12.963(7)
105.993(6)
1997.7(19)
4
296(2)
1.698
3.264
1024
O(2)–Zn(1)–O(1)
O(2)–Zn(1)–N(1)
100.36(9) O(5)#1–Zn(1)–N(1) 130.55(10)
106.96(10) O(1)–Zn(1)–N(1) 101.66(10)
Crystal system
Space group
a (Å)
aSymmetry transformations used to generate equivalent atoms: #1:
x – 1/2, –y + 1/2, z + 1/2.
b (Å)
c (Å)
β (◦)
at room temperature. The structures were solved using direct
methods and successive Fourier difference synthesis (SHELXS-
97)[23] and refined using the full-matrix least-squares method
on F2 with anisotropic thermal parameters for all nonhydrogen
atoms (SHELXL-97).[24] An empirical absorption correction
was applied using the SADABS program. The hydrogen atoms
were placed in calculated positions and refined using a riding
on attached atoms with isotropic thermal parameters 1.2 times
those of their carrier atoms. Corrections for Lp factors were ap-
plied and all non-hydrogen atoms were refined with anisotropic
thermal parameters. Crystallographic and experimental details
and the selected bond lengths and bond angles are are summa-
rized in Table 1, Table 2, and Table 3, respectively.
V (Å3)
Z
T (K)
Dcalc (g•cm−3
)
µ(mm−1
F(000)
)
Max./min. transmission
0.7666/0.5804
2.38 to 25.50
11051
θ range (◦)
Reflections collected
Independent reflections (Rint)
Restraint/parameters
3691
0/262
1.045
Goodness-of-fit (GOF) on F2
R1,a wR2 [I > 2σ(I)]
0.0309, 0.0698
0.0458, 0.0749
0.778/–0.381
R1,wR2 (all data)
Largest diff. peak and hole (e •Å−3
RESULTS AND DISCUSSION
)
Crystal Structure Description
ꢀ
ꢀ
ꢀ
ꢀ
2
aR = [ ||F0 | –|Fc||/
|F0 |], RW
=
[|F0 –Fc2 |2/
The asymmetric unit of 1 contains one ZnII center, one Bript
dianion, and one bpa ligand, as well as one coordinated water
molecule. Both of the carboxylate groups of the H2Bript are de-
protonated. Each Bript acts as a bis-monodentate bridge linking
two zinc atoms. The Zn ion is four-coordinated with a distorted
tetrahedral geometry, as shown in Figure 1. The four coordi-
nated atoms come from one nitrogen atoms of bpa ligand, two
carboxylate oxygen atoms of two Bript ligands, and one water
W
W
(|Fw|2) 2]1/2
.
Crystallographic Data Collection and Structure
Determination
Single-crystal diffraction data for
Bruker Smart Apex CCD diffractometer with
graphite-monochromated Mo Kα radiation (λ = 0.71073 Å)
1 were collected
on
a
FIG. 1. Coordination environment of Zn(II) ion in 1. Hydrogen atoms are omitted for clarity. Symmetry codes: A, x – 1/2, –y + 1/2, z + 1/2.

1270
M.L. HAN ET AL.
FIG. 2. (a) Perspective view of the 1D chain in 1. (b) 2D view in 1 linked by hydrogen bonding O-H. . .N. Hydrogen bonds are represented as dashed lines.

NOVEL ZINC COMPLEX
1271
(d(O. . .O) = 2.750(3) Å, ∠ (OHO) = 165.2◦), to form a 3D
TABLE 3
Distance (Å) and angles (◦) of hydrogen bonding for complex 1
supramolecular architecture (Figure 3).
D–H. . .Aa
d(D–H) d(H. . .A) d(D. . .A) ∠(DHA)
Thermal Analysis
O(1)–H(2W). . .O(2)#3 0.83
O(1)–H(1W). . .N(2)#4 0.83
1.94
1.87
2.750(3) 165.2
2.699(3) 174.3
To investigate its thermal stabilities, the TGA of 1 was studied
in our laboratory. The experiment was performed on samples
consisting of numerous single crystal of 1 under N2 atmosphere
with a heating rate of 10◦C min−1. The framework of 1 can
be stable up to 340◦C, which make it a potential candidate for
practical applications. Compound 1 lost its coordinated water
molecules and bpa molecules from 340 to 507◦C (obsd. 39.4%,
calcd. 39.6%). Then the compound begins to slowly decompose
at 507◦C, as shown in Figure 4.
aSymmetry transformations used to generate equivalent atoms: #3:
–x + 2, –y, –z + 1; #4: x + 1, y, z + 1.
molecule. The Zn–N bond length is 2.013(10) Å and the Zn–O
ones are in the range of 1.929(8)–2.019(11) Å, respectively.
The adjacent Zn atoms are bridged by Bript to form a 1D
chain, as shown in Figure 2a. Such 1D chains are further
connected by hydrogen bonding, between the coordinated-
Fluorescence Spectrum
Coordination polymers with d10 metal centers and organic
water molecules and the nitrogen of bpa (d(O. . .N) = 2.699(3) ligands are promising candidates for photoactive materials
Å, EMBED Equation.3 (OHN) = 174.3◦) to generate a 2D with potential applications such as chemical sensors and pho-
network (Figure 2b). The 2D networks are further linked by tochemistry.[25] The solid-state photoluminescent property of
hydrogen bonding, between the coordinated water molecules compound 1 has been investigated at room temperature. The
and the carboxylate oxygen groups of the Bript ligands fluorescence and emission peaks are shown in Figure 5. The
FIG. 3. 2D view in 1 linked by hydrogen bonding O-H. . .O. Hydrogen bonds are represented as dashed lines.

1272
M.L. HAN ET AL.
REFERENCES
1. Kitagawa, S.; Kitaura, R.; Noro, S. Functional porous coordination poly-
mers. Angew. Chem. Int. Ed. 2004, 43, 2334–2375.
2. Yang, X.P.; Jones, R.A.; Wong, W.K.; Lynch, V.; Oyec, M.M.; Holmes, A.L.
Design and synthesis of a near infra-red luminescent hexanuclear Zn-Nd
prism. Chem. Commun. 2006, 1836–1838.
3. Baca, S.G.; Reetz, M.T.; Goddard, R.; Filippova, I.G.; Simonov, Y.A.;
Gdaniec, M.; Gerbeleu, N. Coordination polymers constructed from o-
phthalic acid and diamines: syntheses and crystal structures of the phthalate-
imidazole complexes {[Cu(Pht)(Im)2]1.5H2O}n and [Co(Pht)(Im)2]n and
their application in oxidation catalysis. Polyhedron 2006, 25, 1215–
1222.
4. Mi, L.W.; Hou, H.W.; Song, Z.Y.; Han, H.Y.; Xu, H.; Fan, Y.T.; Ng,
S.W. Rational construction of porous polymeric cadmium ferrocene-1,1ꢁ-
disulfonates for transition metal ion exchange and sorption. Cryst. Growth
Des. 2007, 7, 2553–2561.
5. Zou, J.P.; Peng, Q.; Wen, Z.H.; Zeng, G.S.; Xing, Q.J.; Guo, G.C. Two novel
metal-organic frameworks (MOFs) with (3,6)-connected net topologies:
Syntheses, Crystal structures, third-order nonlinear optical and luminescent
properties. Cryst. Growth Des. 2010, 10, 2613–2619.
6. Li, D.S.;Wang, Y.Y.; Luan, X.J.; Liu, P.; Zhou, C.H.; Ma, H.R.; Shi, Q.Z.
1-D Open-channeled 3-D supramolecular self-assembled frameworks en-
capsulating unprecedented cyclic(H2O)8 clusters or solvent molecules. Eur.
J. Inorg. Chem. 2005, 2678–2684.
FIG. 4. TGA plot of complex 1.
7. Xu, L.; Yan, S.H.; Choi, E.Y.; Lee, J.Y.; Kwon, Y.U. Product control by
halide ions of ionic liquids in the ionothermal syntheses of Ni–(H)BTC
metal–organic frameworks. Chem. Commun. 2009, 3431–3433.
8. Che, G.B.; Liu, C.B.; Liu, B.; Wang, Q.W.; Xu, Z.L. Syntheses, structures
and photoluminescence of a series of metal-organic complexes with 1,3,5-
benzenetricarboxylate and pyrazino[2,3-f] [1,10]-phenanthroline ligands.
CrystEngComm. 2008, 10, 184–191.
9. Pan, L.; Parker, B.; Huang, X.Y.; Oison, D.H.; Lee, J.Y.; Li, J. Zn(tbip)
(H2tbip = 5-tert-butyl isophthalic acid): A highly stable guest-free micro-
porous metal organic framework with unique gas separation capability. J.
Am. Chem. Soc. 2006, 128, 4180–4181.
10. Du, M.; Jiang, X.J.; Zhao, X.J. Molecular tectonics of mixed-ligand
metal−organic frameworks: Positional Isomeric effect, metal-directed as-
sembly, and structural diversification. Inorg. Chem. 2007, 46, 3984–3995.
11. Xiao, D.R.; Wang, E.B.; An, H.Y.; Li, Y.G.; Xu, L. Syntheses and struc-
tures of three unprecedented metal−ciprofloxacin complexes with helical
character. Cryst. Growth Des. 2007, 7, 506–512.
12. Manna, S.C.; Zangrando, E.; Ribas, J.; Chaudhuri, N.R. Supramolecular
isomerism in coordination polymers of isophthalato-bridged MnII com-
plexes using 4,4ꢁ-Dipyridyl N,Nꢁ-dioxide. Eur. J. Inorg. Chem. 2008, 1400–
1405.
13. Ma, C.B.; Chen, C.N.; Liu, Q.T.; Liao, D.Z.; Li, L.C. Synthesis and charac-
terization of a ladder-like coordination polymer composed of trimanganese
clusters formed and linked by isophthalato ligands. Eur. J. Inorg. Chem.
2008, 1865–1870.
14. Ma, L.F.; Meng, Q.L.; Wang, L.Y.; Liu, B.; Liang, F.P. Multi-
dimensional transition-metal coordination polymers with 5-nitro-1,2,3-
benzenetricarboxylic acid exhibiting ferro-/antiferromagnetic interactions.
Dalton Trans. 2010, 39, 8210–8218.
FIG. 5. Fluorescence and emission spectra of 1 in the solid state at room
temperature.
measurement of photoluminescence spectra of 1 shows a flu-
orescence emission at 404 nm and 468 nm upon excitation at
288 nm.
15. Ma, L.F.; Wang, L.Y.; Du, M.; Batten, S.R. Unprecedented 4- and 6-
connected 2D coordination networks based on 44-subnet tectons, showing
unusual supramolecular motifs of rotaxane and helix. Inorg. Chem. 2010,
49, 365–367.
CONCLUSIONS
In summary, a new zinc complex has been synthesized and
characterized. Complex 1 contains 1D infinite chains, and these
1D chains are further linked by hydrogen bonding to form a 16. Huang, Y.; Yan, B.; Shao, M. Hydrothermal synthesis, crystal structure and
photoluminescence of two 1D Zn(II) coordination polymers. J. Mol. Struct.
2009, 919, 185–188.
17. Su, Z.; Xu, J.; Fan, J.; Liu, D.J.; Chu, Q.; Chen, M.S.; Chen, S.S.; Liu, G.X.;
3D supramolecular network. Fluorescence measurement show
that 1 has medium fluorescent emission. Further syntheses and
studies of structures and properties of coordination frameworks
Wang, X.F.; Sun, W. Synthesis, crystal structure, and photoluminescence
with the H2Bript ligand and other metal ions are under way in
our laboratory.
of coordination polymers with mixed ligands and diverse topologies. Cryst.
Growth Des. 2009, 9, 2801–2811.

NOVEL ZINC COMPLEX
1273
18. Liu, G.X.; Huang, R.Y.; Xu, H.; Kong, X.J.; Huang, L.F.; Zhu, K.; Ren, X.M.
Controlled assembly of zero-, one- and two-dimensional metal-organic
frameworks involving in situ ligand synthesis under different reaction pH.
Polyhedron 2008, 27, 2327–2336.
19. Ma, L.F.; Meng, Q.L.; Wang, L.Y.; Liang, F.P. Hydrothermal preparation,
crystal structures, and properties of new Mn(II) metal-organic frameworks
ular structures in one, two and three dimensions. Acta Cryst. 2001, B57,
201–212.
22. Ma, L.F.; Wang, L.Y.; Wang, Y.Y.; Du, M.; Wang, J.G. Synthesis, structures
and properties of Mn(II) coordination frameworks based on R-isophthalate
(R = CH3 or –C(CH3)3) and various dipyridyl-type co-ligands. Crys-
tEngComm. 2009, 11, 109–117.
with 4-bromoisophthalic acid and N-donor ligands. Synth. React. Inorg. 23. Sheldrick, G.M. SHELXS 97, Program for the Solution of Crystal Structure;
Metal-Org. Nano-Metal Chem. 2010, 40, 855–860.
University of Go¨ttingen: Go¨ttingen, Germany, 1997.
20. Ma, L.F.; Li, X.Q.; Meng, Q.L.; Wang, L.Y.; Du, M.; Hou, H.W. Sig-
nificant positional isomeric effect on structural assemblies of Zn(II) and
24. Sheldrick, G.M. SHELXL 97, Program for the Crystal Structure Refinement;
University of Go¨ttingen: Go¨ttingen, Germany, 1997.
Cd(II) coordination polymers based on bromoisophthalic acids and various 25. Santis, G.D.; Fabbrizzi, L.; Licchelli, M.; Poggi, A.; Taglietti, A. Molecular
dipyridyl-type coligands. Cryst. Growth Des. 2011, 11, 175–184.
21. Burchell, C.J.; Glidewell, C.; Lough, A.J.; Ferguson, G. Salts of 3,5-
dinitrobenzoic acid with organic diamines: Hydrogen-bonded supramolec-
recognition of carboxylate ions based on the metal–ligand interaction and
signaled through fluorescence quenching. Angew. Chem, Int. Ed. Engl.
1996, 35, 202–204.

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