Novel chains constructed from heterotrinuclear units and 1,2-bis(4-pyridyl)ethane formulated as [M2M′(O2CPh)6](bpa) (M = Co, Zn, M′ = Co, Cd): Their catalytic activity

Article abstract of DOI:10.1016/j.inoche.2009.10.028

Three novel heterometallic complexes containing two bridging ligands bpa and benzoate, formulated as [M₂M′(O₂CC₆H₅]_n(bpa)_n (bpa = 1,2-bis(4-pyridyl)ethane, M₂M′ = Zn₂Co (1), Zn₂Cd (2), and Co₂Cd (3)), have been synthesized. All three compounds show one-dimensional structures containing linear heteronuclear coordination units linked by bridging bpa ligands. Reactivity study of the compounds 1-3 for the transesterification of a variety of esters has shown that they are very efficient and 2 is the best among them.

Full text of DOI:10.1016/j.inoche.2009.10.028

Inorganic Chemistry Communications 13 (2010) 101–104
Contents lists available at ScienceDirect
Inorganic Chemistry Communications
journal homepage: www.elsevier.com/locate/inoche
Novel chains constructed from heterotrinuclear units and
1,2-bis(4-pyridyl)ethane formulated as [M2M0(O2CPh)6](bpa)
(M = Co, Zn, M0 = Co, Cd): Their catalytic activity
Young Min Lee a, Young Joo Song a, Jung In Poong a, Soo Hyun Kim a, Hyo Geun Koo a, Jung Ah Lee a,
b,
b
Cheal Kim a, , Sung-Jin Kim , Youngmee Kim
*
*
a Department of Fine Chemistry, Seoul National University of Technology, Seoul 139-743, Republic of Korea
b Department of Chemistry and Nano Science, Ewha Womans University, Seoul 120-750, Republic of Korea
a r t i c l e i n f o
a b s t r a c t
Article history:
Three novel heterometallic complexes containing two bridging ligands bpa and benzoate, formulated as
[M2M0(O2CC6H5]n(bpa)n (bpa = 1,2-bis(4-pyridyl)ethane, M2M0 = Zn2Co (1), Zn2Cd (2), and Co2Cd (3)),
have been synthesized. All three compounds show one-dimensional structures containing linear hetero-
nuclear coordination units linked by bridging bpa ligands. Reactivity study of the compounds 1–3 for the
transesterification of a variety of esters has shown that they are very efficient and 2 is the best among
them.
Received 4 September 2009
Accepted 27 October 2009
Available online 30 October 2009
Keywords:
Heterometallic complex
One-dimensional chain
1,2-Bis(4-pyridyl)ethane
Transesterification
Ó 2009 Elsevier B.V. All rights reserved.
Coordination polymers through self-assembly have attracted
considerable attention in recent years, not only due to their struc-
tural and topological novelty [1], but also for their potential appli-
cations as functional materials such as ion exchange, gas storage,
molecular sensing, and catalysis [2]. Significantly, the structure of
coordination polymers is highly influenced by many factors such
as the coordination geometry of metal ions, the structure of
organic ligands, the solvent system, pH value, temperature, the
counteranion, and the ratio of ligands to metal ions [3]. In some
cases, a subtle change in any of these factors can lead to new com-
plexes with different structural topologies and different functions
[3]. Among these factors, the incorporation of two or more transi-
tion heterometals in a coordination polymer is a current challenge
for designed synthesis, since the incorporation of two heterometals
can increase the diversity of the coordination polymers [4]. There-
fore, heterometallic coordination polymers are now being increas-
ingly investigated for opportunities to incorporate unusual metal
coordination environments to enhance catalytic, photolumines-
cent, or other properties.
containing coordination polymers, except for only an example that
redox-active ligands such as tetrathiafulvalene (TTF) derivatives
have been applied to the heterometallic trinuclear complexes
formulated as CoII2MII(PhCOO)6(L)2ꢀ2CH3CN (L = 4-[2-(tetrathiaful-
valenyl)ethenyl]pyridine, M = CoII, MnII) which show antiferromag-
netic coupling leading to a magnetic ground state [5]. Therefore, a
further investigation for the understanding of the relationships be-
tween the structures of the coordination polymers containing ben-
zoate and the incorporation of two or more transition metals is
important and necessary to be studied.
In our efforts to investigate the control of the self-assembly of
functional supramolecular complexes with intriguing structures
and potential applications in catalysis, we have recently carried
out a systematic study of various metal–organic complexes from
the mixed-ligand systems of multifunctional organic ligand benzo-
ate and bridging ligands such as pyrazine, its derivatives, 4,40-
bipyridine, and 1,2-bis(4-pyridyl)ethane [6]. Importantly, the
assembly process of metal benzoates and bipyridyl ligands has
been, also, highly influenced by solvent system, pH, metal to ligand
ratio, and the coordination geometry of metal ions [6].
There are some reports that the incorporation of two or more
transition heterometals into a coordination polymer can have pro-
found effects on coordination geometry [4]. However, such an ef-
fect is seldom considered in the assembly of metal-benzoate-
As an extension of our previous work, in this study, we have
investigated the complex formation of two heterometal ions with
two bridging ligands bpa and benzoate in order to further prepare
functional supramolecular complexes with intriguing structures
and potential applications especially in catalysis.
* Corresponding authors. Tel.: +82 2 970 6693; fax: +82 2 973 9149 (C. Kim), tel.:
+82 2 3277 2350; fax: +82 2 3277 3419 (S.-J. Kim).
We present, for the first time, three new heterometallic
complexes containing two bridging ligands bpa and benzoate,
E-mail addresses: chealkim@snut.ac.kr (C. Kim), sjkim@ewha.ac.kr (S.-J. Kim).
1387-7003/$ - see front matter Ó 2009 Elsevier B.V. All rights reserved.
doi:10.1016/j.inoche.2009.10.028

102
Y.M. Lee et al. / Inorganic Chemistry Communications 13 (2010) 101–104
formulated as [M2M0(O2CPh)6]n(bpa)n (bpa = 1,2-bis(4-pyridyl)eth-
ane, M2M0 = Zn2Co (1), Zn2Cd (2), and Co2Cd (3)), which show the
catalytic activities for transesterification reactions. They were pre-
pared by a direct diffusion technique where an aqua solution of the
mixture of M(NO3)2, M0(NO3)2 and ammonium benzoate is care-
fully layered by a polar solvent of bpa ligands [7].
The three compounds are isostructural [8], and a centrosym-
metric trinuclear unit is shown in Fig. 1. The hetero-metal trinu-
clear units consist of three metal ions bridged by benzoate
ligands, and they are connected by bpa ligands to form one-dimen-
sional chains for Mn, Cu, and Zn. Importantly, the compounds con-
taining non-redox metals (Zn and Cd) catalyzed efficiently the
transesterification of a variety of esters. This result led us to at-
tempt the transesterification reaction using the compounds 1–3.
Treatment of 4-nitrophenyl acetate and methanol in the presence
of the catalysts 1–3 at 50 °C produced methyl acetate quantita-
tively under the homogeneous neutral conditions within 0.17–
0.63 day (Eq. (1); see entry 1 of Table 1), respectively, while trace
or a small amount of transesterification occurs without each cata-
lyst [6].
O
O
catalysts
HOCH3
CH3COCH3
O2N
OCCH3
O2N
ð1Þ
+
OH +
..
sional chains (Fig. 2). In the trinuclear unit, two benzoates coordi-
nate to metal ions in a bridging mode (for O11–C11–O12 and O21–
C21–O22 carboxylates) among four possible coordination modes
[6] and the other one coordinates in chelating/bridging mode (for
O31–C31–O32 carboxylate). The central hetero-metal ion [M01] is
lying on an inversion center, and its coordination geometry is dis-
torted octahedral from six benzoate oxygen atoms. Central octahe-
dron in 1 has six Co–O distances ranging from 2.0300(15) to
2.197(2) Å, and those in 2 and 3 have also six Cd–O distances
(2.173(3)–2.333(3) Å for 2 and 2.194(7)–2.286(9) Å for 3). The
coordination geometry of outer metal [M1] ions is distorted trigo-
nal bypyramodal from four oxygen atoms and one nitrogen atoms:
three oxygen atoms from three different benzoates (Zn–O
1.9615(18)–2.1050(18) Å for 1, Zn–O 1.966(3)–2.027(3) Å for 2,
and Co–O 2.077(8)–2.280(11) Å for 3), one nitrogen atom from
bpa (Zn–N 2.036(2) Å for 1, Zn–N 2.032(3) Å for 2, and Co–N
2.149(9) Å for 3), and fifth oxygen atom from the chelating/bridg-
ing benzoate (Zn–O 2.269(2) Å for 1, Zn–O 2.433(4) Å for 2, and
Co–O 2.356(12) Å for 3). A similar coordination arrangement
around the outer M ions was found in comparable CoII2MnII(Ph-
COO)6 complex [5]. Mꢀ ꢀ ꢀM0 distances for 1, 2, and 3 are 3.36(7) Å,
3.302(5) Å, and 3.459(8) Å, respectively. Besides 1, 2, and 3 sys-
tems, other heterometal combinations have been tested (for exam-
ples; Zn/Ni, Zn/Cu, Cd/Ni, Co/Ni, etc.), but only homometal-
containing compounds formed. These results may be due to the
coordination mode of metal ions.
Among them, the compound 2 showed the most efficient reac-
tivity. Importantly, this result is the first example that the mixed-
metal polymers containing benzoate catalyze the transesterifica-
tion reactions, to our best knowledge [4]. In addition, this effi-
cient reactivity is one of best among the catalytic systems
reported previously in Zn- or Cd-containing coordination and
polymeric compounds [2h,6]. Further, we have investigated the
transesterification of various p-substituted phenyl acetates and
benzoates. The substrates with the electron-withdrawing substit-
uents have undergone faster transesterification (entries 1 and 5),
while those with the electron-donating ones have shown
slow reaction (entries 4 and 8). Moreover, vinyl acetate, that is
widely used as a precursor for ester synthesis [9], was also
converted efficiently to the product methyl acetate by the cata-
lysts 1–3 within 0.23–0.63 day (entry 9), suggesting that this
catalytic system can be useful for preparing various esters by
transesterification.
Though we do not know, at this moment, about the exact reac-
tive species and the reaction mechanism for the transesterification
reaction by the catalysts, we can propose the possible reactive spe-
cies by a comparison of the present and previous results [6b]. In
compound 1, Zn-containing complex in solution might be the reac-
tive species, because the reactivity of 1 is similar to that of the
homometal polymer [(Zn3(O2CPh)6)(
l-bpa)(Zn2(O2CPh)4)]n previ-
ously obtained from the reaction of zinc benzoate and bpa [6b].
In the same way, both Zn and Cd complexes for 2 and Cd-contain-
ing complex for 3 might be the reactive species. These complexes
may catalyze the transesterification reactions that probably in-
volve electrophilic activation of the carbon center of the carbonyl
moiety by binding of the metal to the carbonyl oxygen, based on
We have recently shown a systematic investigation on the coor-
dination polymers assembled from metal benzoates and bpa li-
gands [6]. They showed two kinds of structures: parallelogram-
like two-dimensional sheets for Co, Ni, and Cd, and one-dimen-
Fig. 1. A trinuclear unit in heterometallic complexes formulated as [M2M0(O2CPh)6]n(bpa)n. Symmetry operation: i (1 ꢁ x, ꢁy, 1 ꢁ z) for 1, (2 ꢁ x, ꢁy, 1 ꢁ z) for 2, (2 ꢁ x, 2 ꢁ y,
1 ꢁ z) for 3.

Y.M. Lee et al. / Inorganic Chemistry Communications 13 (2010) 101–104
103
Fig. 2. One-dimensional structure containing trinuclear heterometallic units in 1–3.
Table 1
Transesterification of esters by methanol in the presence of compounds 1–3 at 50 °C.a
b
Entry
Substrate
1 (time/days)b
2 (time/days)b
3 (time/days)
1
2
3
4
5
6
7
8
9
4-Nitrophenyl acetate
4-Fluorophenyl acetate
Phenyl acetate
4-Methylphenyl acetate
4-Nitrophenyl benzoate
4-Chlorophenyl benzoate
Phenyl benzoate
4-Methylphenyl benzoate
Vinyl acetate
0.17
8
1.29
1.29
1.67
2
4
4
0.23
0.25
7
1
1
1
1.58
4
4
0.63
31
5
7
13
7
17
21
0.63
c
0.25
a
All esters were completely converted to the corresponding products, methyl acetate and methyl benzoate. Reaction conditions: esters; 0.05 mmol, catalyst; 1.0 mg,
0.88 ꢂ 10ꢁ3 mmol for 1, 1.0 mg, 0.91 ꢂ 10ꢁ3 mmol for 2, 1.0 mg, 0.87 ꢂ 10ꢁ3 mmol for 3, solvent; methanol (1 mL). See Supplementary material for the detailed reaction
conditions.
b
Time necessary for the complete conversion of substrate to product.
The solvent was a mixture of CH3OH/CH2Cl2 (1/1) because of low solubility of substrate in CH3OH.
c
(1998) 474;
our previous results [6]. Detailed mechanistic studies are currently
under investigation.
(c) O.R. Evans, W. Lin, Acc. Chem. Res. 35 (2002) 511;
(d) M.J. Zaworotko, Chem. Commun. (2001) 1;
In summary, we have synthesized three novel heterometallic
complexes containing two bridging ligands bpa and benzoate for-
mulated as [M2M0(O2CPh)6]n(bpa)n (M2M0 = Zn2Co (1), Zn2Cd (2),
and Co2Cd (3)). All three compounds show one-dimensional struc-
tures containing linear heteronuclear coordination units linked by
bridging bpa ligands. These complexes could also carry out the cat-
alytic transesterification of a range of esters with methanol at room
temperature under the mild conditions. This observation is very
significant since it encourages us to construct new polymeric com-
pounds that might be efficiently used as catalysts for a variety of
transformation reactions such as epoxide ring-opening, transeste-
rification, epoxidation, and etc.
(e) P.J. Hagrman, D. Hagrman, J. Zubieta, Angew. Chem., Int. Ed. 38 (1999) 2638;
(f) M.J. Zaworotko, Chem. Soc. Rev. (1994) 283;
(g) S.R. Batten, R. Robson, Angew. Chem., Int. Ed. 37 (1998) 1460;
(h) M. O’Keeffe, M. Eddaoudi, H. Li, T. Reineke, O.M. Yaghi, J. Solid State Chem.
152 (2000) 3;
(i) R. Robson, J. Chem. Soc., Dalton Trans. (2000) 3735;
(j) B. Moulton, M.J. Zaworotko, Chem. Rev. 101 (2001) 1629;
(k) J.L.C. Rowsell, O.M. Yaghi, Micropor. Mesopor. Mater. 73 (2004) 3.
[2] (a) O.M. Yaghi, in: T.J. Pinnavaia, M.F. Thorpe (Eds.), Access in Nanoporous
Materials, Plenum, New York, 1995, p. 111;
(b) M. Zaworotko, R.D. Rogers, Synthesis of new materials by coordination
chemistry self-assembly and template formation, in: ACS Symposium, Anaheim,
1999.;
´
(c) N. Guillou, S. Pastre, C. Livage, G. Ferey, Chem. Commun. (2002) 2358;
(d) B. Chen, M. Eddaoudi, S.T. Hyde, M. O’Keeffe, O.M. Yaghi, Science 291 (2001)
1021;
(e) J.S. Seo, D. Whang, H. Lee, S.I. Jun, J. Oh, Y.J. Jeon, K. Kim, Nature 404 (2000)
982;
(f) S.-K. Yoo, J.Y. Ryu, J.Y. Lee, C. Kim, S.-J. Kim, Y. Kim, Dalton Trans. (2003)
1454;
(g) S.J. Hong, J.Y. Ryu, J.Y. Lee, C. Kim, S.-J. Kim, Y. Kim, Dalton Trans. (2004)
2697;
(h) H. Kwak, S.H. Lee, S.H. Kim, Y.M. Lee, E.Y. Lee, B.K. Park, E.Y. Kim, C. Kim, S.-J.
Kim, Y. Kim, Eur. J. Inorg. Chem. (2008) 408;
(i) B. Xiao, H. Hou, Y. Fan, J. Mol. Catal. A: Chem. 288 (2008) 42;
(j) O. Kahn, C. Martinez, Science 279 (1998) 44;
(k) O.R. Evans, R. Xiong, Z. Wang, G.K. Wong, W. Lin, Angew. Chem., Int. Ed. 38
(1999) 536;
Acknowledgments
Financial support from Korea Ministry Environment ‘‘ET-Hu-
man resource development Project” and the Korean Science &
Engineering Foundation
0074066) and the SRC program of MOST/KOSEF through the Center
for Intelligent Nano-Bio Materials at Ewha Womans University
(R11-2005-008-00000-0) is gratefully acknowledged.
(R01-2008-000-20704-0 and 2009-
(l) W. Lin, O.R. Evans, R. Xiong, Z. Wang, J. Am. Chem. Soc. 120 (1998) 13272;
´
(m) K. Barthelet, J. Marrot, D. Riou, G. Ferey, Angew. Chem., Int. Ed. 41 (2002)
281;
Appendix A. Supplementary material
(n) B. Chen, N.W. Ockwig, A.R. Millward, D.S. Contreras, O.M. Yaghi, Angew.
Chem., Int. Ed. 44 (2005) 4745;
(o) J.L.C. Rowsell, A.R. Millward, K.S. Park, O.M. Yaghi, J. Am. Chem. Soc. 126
(2004) 5666;
(p) N.L. Rosi, J. Eckert, M. Eddaoudi, D.T. Vodak, J. Kim, M. O’Keeffe, O.M. Yaghi,
Science 300 (2003) 1127.
CCDC 744691, 744692 and 744693 contain the supplementary
crystallographic data for this paper. These data can be obtained
free of charge from The Cambridge Crystallographic Data Centre
via www.ccdc.cam.ac.uk/data_request/cif. Supplementary data
associated with this article can be found, in the online version, at
doi:10.1016/j.inoche.2009.10.028.
[3] (a) D.M. Shin, I.S. Lee, Y.-A. Lee, Y.K. Chung, Inorg. Chem. 42 (2003) 2977;
(b) O.-S. Jung, S.H. Park, K.M. Kim, H.G. Jang, Inorg. Chem. 37 (1998) 5781;
(c) W.-X. Chen, S.-T. Wu, L.-S. Long, R.-B. Huang, L.-S. Zheng, Cryst. Growth Des.
7 (2007) 1171;
(d) Y.-B. Dong, Y.-Y. Jiang, J. Li, J.-P. Ma, F.-L. Liu, B. Tang, R.-Q. Huang, S.R.J.
Batten, Am. Chem. Soc. 129 (2007) 4520;
References
(e) L. Carlucci, G. Ciani, D.M. Proserpio, S. Rizzato, Chem. Eur. J. 5 (1999) 237;
(f) A.J. Blake, N.R. Brooks, N.R. Champness, P.A. Cooke, A.M. Deveson, D. Fenske,
[1] (a) M. Eddaoudi, D.B. Moler, H. Li, B. Chen, T.M. Reineke, M. O’Keeffe, O.M.
Yaghi, Acc. Chem. Res. 34 (2001) 319;
(b) O.M. Yaghi, H. Li, C. Davis, D. Richardson, T.L. Groy, Acc. Chem. Res. 32

104
Y.M. Lee et al. / Inorganic Chemistry Communications 13 (2010) 101–104
P. Hubberstey, M.J. Schroder, J. Chem. Soc., Dalton Trans. (1999) 2103;
(g) V.R. Pedireddi, S. Varughese, Inorg. Chem. 43 (2004) 450.
688(m), 546(w), 452(m). Anal. Calc. for C54H42CdN2O12Zn2 (1154.04), 2: C,
56.20; H, 3.68; N, 2.43. Found: C, 55.95; H, 3.55; N, 2.67%. Preparation of 3:
17.8 mg (0.06 mmol) of Co(NO3)2 hexahydrate, 18.8 mg (0.06 mmol) of
Cd(NO3)2 tetrahydrate and 34.0 mg (0.24 mmol) of ammonium benzoate were
dissolved in 4 mL H2O and carefully layered by 4 mL methanol solution of 1,2-
bis(4-pyridyl)ethane ligand (11.1 mg, 0.06 mmol). Suitable crystals of
compound 3 for X-ray analysis were obtained in four weeks. Compound 3
was stable below 350 °C from thermal gravimetric analysis (TGA). IR (KBr):
[4] (a) W. Clegg, I.R. Little, B.P. Straughan, Inorg. Chem. 27 (1988) 1916;
(b) W. Clegg, I.R. Little, B.P. Straughan, J. Chem. Soc., Dalton Trans. (1986) 1283;
(c) B. Singh, J.R. Long, F.F. de Biani, D. Gatteschi, P. Stavropoulos, J. Am. Chem.
Soc. 119 (1997) 7030;
}
(d) Y. Wang, B. Bredenkotter, B. Rieger, D. Volkmer, Dalton Trans. (2007) 689;
(e) S.R. Caskey, A.J. Matzger, Inorg. Chem. 47 (2008) 7942;
(f) H.-Z. Kou, J. Tao, O. Sato, Dalton Trans. (2008) 3652;
m
(cmꢁ1) = 3064(w), 2950(w), 1599(s), 1558(s), 1399(s), 1165(w), 1135(w),
(g) H.-L. Gao, B. Zhao, X.-Q. Zhao, Y. Song, P. Cheng, D.-Z. Liao, S.-P. Yan, Inorg.
Chem. 47 (2008) 11057;
(h) G. Novitchi, F. Riblet, R. Scopelliti, L. Helm, A. Gulea, A.E. Merbach, Inorg.
Chem. 47 (2008) 10587.
1069(w), 10260(m), 862(m), 835(w), 719(s), 690(m), 546(m), 451(m). Anal.
Calc. for C54H42CdCo2N2O12 (1141.16), 3: C, 56.83; H, 3.72; N, 2.46. Found: C,
56.91; H, 3.54; N, 2.66%.
[8] Crystal data for 1: C54H42CoN2O12Zn2, M = 1100.57, triclinic, a = 10.318(2) Å,
[5] K.S. Gavrilenko, Y.L. Gal, O. Cador, S. Golhen, L. Ouahab, Chem. Commun. (2007)
280.
[6] (a) Y.J. Song, H. Kwak, Y.M. Lee, S.H. Kim, S.H. Lee, B.K. Park, J.Y. Jun, S.M. Yu, C.
Kim, S.-J. Kim, Y. Kim, Polyhedron 28 (2009) 1241;
b = 11.079(2) Å, c = 13.102(3) Å,
V = 1243.5(4) Å3, Z = 1,
(Mo K
4789 unique (Rint = 0.0413) which were used in all calculations, final R = 0.0322
(wR = 0.0809) with reflections having intensities greater than
GOF(F2) = 0.948. Crystal data for 2: C54H42CdN2O12Zn2, M = 1154.04, triclinic,
a = 10.2658(14) Å, b = 11.0981(15) Å, c = 13.2738(18) Å, = 76.787(2)°,
= 64.247(2)°, V = 1256.7(3) Å3, Z = 1, ) = 1.430 mmꢁ1
b = 67.724(2)°, (Mo K ,
a
= 76.00(3)°, b = 67.21(3)°,
c = 64.74(3)°,
l
a
) = 1.352 mmꢁ1, 7035 reflections measured,
2r,
(b) S.H. Kim, B.K. Park, Y.J. Song, S.M. Yu, H.G. Koo, E.Y. Kim, J.I. Poong, J.H. Lee, C.
Kim, S.-J. Kim, Y. Kim, Inorg. Chim. Acta 362 (2009) 4119;
(c) H. Kwak, S.H. Lee, S.H. Kim, Y.M. Lee, B.K. Park, Y.J. Lee, J.Y. Jun, C. Kim, S.-J.
Kim, Y. Kim, Polyhedron 28 (2009) 553;
(d) H. Kwak, S.H. Lee, S.H. Kim, Y.M. Lee, B.K. Park, E.Y. Lee, Y.J. Lee, C. Kim, S.-J.
Kim, Y. Kim, Polyhedron 27 (2008) 3484–3492.
a
c
l
a
7099 reflections measured, 4832 unique (Rint = 0.1195) which were used in all
calculations, final R = 0.0420 (wR = 0.0776) with reflections having intensities
greater than
M = 1141.16, triclinic, a = 10.457(2) Å, b = 10.969(2) Å, c = 13.194(3) Å,
2r, ,
GOF(F2) = 0.803. Crystal data for 3: C54H42CdCo2N2O12
[7] Preparation of 1: 18.2 mg (0.06 mmol) of Zn(NO3)2 hexahydrate, 17.8 mg
(0.06 mmol) of Co(NO3)2 hexahydrate and 34.0 mg (0.24 mmol) of ammonium
benzoate were dissolved in 4 mL H2O and carefully layered by 4 mL acetone
solution of 1,2-bis(4-pyridyl)ethane ligand (22.3 mg, 0.12 mmol). Suitable
a
K
= 73.124(4)°, b = 67.707(3)°,
c l(Mo
= 63.577(3)°, V = 1240.4(4) Å3, Z = 1,
a
) = 1.151 mmꢁ1
,
6579 reflections measured, 4602 unique (Rint = 0.0264)
which were used in all calculations, final R = 0.0805 (wR = 0.2489) with
crystals of compound
Compound was stable below 345 °C from thermal gravimetric analysis
(TGA). IR (KBr):
(cmꢁ1) = 3437(brm), 3064(m), 2950(w), 1607(s), 1567(s),
1
for X-ray analysis were obtained in
a
week.
reflections having intensities greater than
2r,
GOF(F2) = 1.052. Structural
1
information was deposited at the Cambridge Crystallographic Data Center
(CCDC reference numbers 744691 for 1, 744692 for 2 and 744693 for 3). The X-
ray diffraction data for all three compounds were collected on a Bruker SMART
m
1399(s), 1228(m), 1175(w), 1069(m), 1028(m), 939(w), 864(m), 839(m),
820(m), 718(s), 679(s), 548(m), 468(m). Anal. Calc. for C54H42CoN2O12Zn2
(1100.57), 1: C, 58.92; H, 3.85; N, 2.55. Found: C, 58.73; H, 3.80; N, 2.81%.
Preparation of 2: 18.2 mg (0.06 mmol) of Zn(NO3)2 hexahydrate, 18.8 mg
(0.06 mmol) of Cd(NO3)2 tetrahydrate and 34.0 mg (0.24 mmol) of ammonium
benzoate were dissolved in 4 mL H2O and carefully layered by 4 mL acetonitrile
solution of 1,2-bis(4-pyridyl)ethane ligand (11.1 mg, 0.06 mmol). Suitable
crystals of compound 2 for X-ray analysis were obtained in three weeks.
Compound 2 was stable below 260 °C from thermal gravimetric analysis (TGA).
APX diffractometer equipped with
a monochromater in the Mo Ka
(k = 0.71073 Å) incident beam. Each crystal was mounted on a glass fiber. The
CCD data were integrated and scaled using the Bruker-SAINT software package,
and the structure was solved and refined using SHEXTL V6.12. All hydrogen
atoms were placed in the calculated positions. The crystallographic data for
compounds 1–3 are listed in Table S1. The selected bond distances and angles
are listed in Table S2.
[9] (a) G.W. Nyce, J.A. Lamboy, E.F. Connor, R.M. Waymouth, J.L. Hedrick, Org. Lett.
4 (2002) 3587;
IR (KBr):
1398(s), 1229(w), 1175(w), 1070(w), 1028(w), 839(w), 858(w), 819(w), 719(s),
m
(cmꢁ1) = 3436(brm), 3064(w), 2929(m), 2362(m), 1604(s), 1565(s),
(b) D. Tashiro, Y. Kawasaki, S. Sakaguchi, Y.J. Ishii, J. Org. Chem. 62 (1997) 8141.