Self-assembly and host-guest interaction of metallomacrocycles using fluorescent dipyrazole linker with dimetallic clips

Article abstract of DOI:10.1021/ic100724r

By employing diimine ligands coordinated dimetallic clips ([(bpy) ₂Pd₂(NO₃)₂](NO₃) ₂ or [(phen)₂Pd₂(NO₃) ₂](NO₃)₂, where bp

Full text of DOI:10.1021/ic100724r

Inorg. Chem. 2010, 49, 7783–7792 7783
DOI: 10.1021/ic100724r
Self-Assembly and Host-Guest Interaction of Metallomacrocycles Using
Fluorescent Dipyrazole Linker with Dimetallic Clips
Guo-Hong Ning,† Liao-Yuan Yao,† Li-Xia Liu,†,|| Ting-Zheng Xie,† Yi-Zhi Li,‡ Yu Qin,*,‡ Yuan-Jiang Pan,§ and
Shu-Yan Yu*,†
†Laboratory for Self-Assembly Chemistry, Department of Chemistry, Renmin University of China,
Beijing 100872, China, ‡Department of Chemistry, State Key Laboratory of Coordination Chemistry,
Coordination Chemistry Institute and Key Lab of Analytical Chemistry for Life Science, Ministry of Education,
Nanjing University, Nanjing 210093, People’s Republic of China, and §Department of Chemistry,
Zhejiang University, Hangzhou 310027, People’s Republic of China. ||Present address: Department of
Chemistry and Biochemistry, Auburn University, Auburn, Alabama 36849.
Received April 15, 2010
By employing diimine ligands coordinated dimetallic clips ([(bpy)2Pd2(NO3)2](NO3)2 or [(phen)2Pd2(NO3)2](NO3)2,
where bpy = 2,20-bipyridine, phen = 1,10-phenanthroline) as the corner and anthracene-, naphthalene-, and benzene-
based dipyrazolate dianions as the linker, a series of positively charged metallomacrocycles ([M4L2]4þ or [M8L4]8þ
have been synthesized through a directed self-assembly method in aqueous solution. Every macrocycle has a cavity to
)
1
bind solvent molecules or anions. The structures were characterized by elemental analysis, H and 13C NMR,
electrospray ionization mass spectrometry, and single crystal X-ray diffraction analysis for compound 1 4PF6h (1 =
3
{[(bpy)Pd]4L12}4þ), 3 4PF6h 8CH3CN H2O (3 = {[(bpy)Pd]4L22}4þ), and7 4PF6h 6H2O (7 = {[(bpy)Pd]4L52}4þ). The
3
3
3
3
3
1:1 host-guest complexation for anthracene-based dipyrazolate-bridged macrocycles with aromatic guests was
investigated via UV-vis and fluorescent titration.
Introduction
properties of the metal-assembled systems in magnetism, lumi-
nescence,2 electron transfer,9,10,16 and the exciting applications
In the past two decades, significant progress has made in
the development of supramolecular self-assembly.1,2 A large
number of macrocyclic or cage-like structures have been ob-
tained by rationally designed metal directional self-assembly
approach,1-3 which has attracted a great deal of attention in
recent years not only because of their structure diversity such
as molecular triangles,3,4,6-8 squares and rectangles,3,5-10
pentagons and hexagons,11 bowls and cages,12 cuboctahedra
and dodecahedra,13 helicates, grids, catenanes, nanotubes and
polytubes,14 and so on,15 but also due to the rich physical
(3) (a) Fujita, M.; Tominaga, M.; Hori, A.; Therrien, B. Acc. Chem. Res.
2005, 38, 371–380. (b) Yu, S.-Y.; Li, S.-H.; Huang, H.-P.; Zhang, Z.-X.; Jiao, Q.;
Shen, H.; Hu, X.-X.; Huang, H. Curr. Org. Chem. 2005, 9, 555–563. (c)
€
W€urthner, F.; You, C.-C.; Saha-Moller, C. R. Chem. Soc. Rev. 2004, 33, 133–
146. (d) Seidel, S. R.; Stang, P. J. Acc. Chem. Res. 2002, 35, 972–983. (e) Cotton,
F. A.; Lin, C.; Murillo, C. A. Acc. Chem. Res. 2001, 34, 759–771. (f) Dinolfo,
P. H.; Hupp, J. T. Chem. Mater. 2001, 13, 3113–3125. (g) Leininger, S.; Olenyuk,
B.; Stang, P. J. Chem. Rev. 2000, 100, 853–908. (h) Caulder, D. L.; Raymond,
K. N. Acc. Chem. Res. 1999, 32, 975–982. (i) Navarro, J. A. R.; Lippert, B.
Coord. Chem. Rev. 1999, 185-186, 653–667. (j) Fujita, M. Acc. Chem. Res.
1999, 32, 53–61. (k) Fujita, M. Chem. Soc. Rev. 1998, 27, 417–425. (l) Slone,
ꢀ
*To whom correspondence should be addressed. E-mail: yusy@ruc.edu.
cn (S.-Y.Y.), Qinyu75@nju.edu.cn (Y.Q.).
(1) Lehn, J.-M. Supramolecular Chemistry, Concepts and Perspectives;
VCH: Weinheim, Germany, 1995.
R. V.; Benkstein, K. D.; Belanger, S.; Hupp, J. T.; Guzei, I. A.; Rheingold, A. L.
Coord. Chem. Rev. 1998, 171, 221–243. (m) Stang, P. J. Chem. -Eur. J. 1998, 4,
19–27. (n) Stang, P. J.; Olenyuk, B. Acc. Chem. Res. 1997, 30, 502–518. (o)
Fujita, M.; Ogura, K. Coord. Chem. Rev. 1996, 148, 249–264.
(2) (a) Science 2002, 295, 2395-2421 (Supramolecular Chemistry and Self-
Assembly, Special Issue). (b) Lindoy, L. F.; Atkinson, I. Self-Assembly in
Supramolecular Systems (Monographs in Supramolecular Chemistry); Stod-
dart, J. F., Ed.; The Royal Society of Chemistry: London, 2000. (c) Fujita, M.
Molecular Self-Assembly Organic Versus Inorganic Approach (Structure and
Bonding); Springer: New York, 2000; Vol. 96. (d) Sauvage, J.-P. Transition
Metals in Supramolecular Chemistry, Perspectives in Supramolecular Chem-
istry; Wiley: New York, 1999; Vol. 5. (e) Lehn, J.-M. Templating, Self-Assembly,
and Self-Organization. In Comprehensive Supramolecular Chemistry; Sauvage,
J.-P., Hosseini, M. W., Ed.; Pergamon: New York, 1996. (f) Desvergne, J. P.;
Czarnik, A. W. Chemosensors of Ion and Molecule Recognition. Kluwe
Academic Publisher: The Netherlands, 1996.
(4) (a) Papaefstathiou, G. S.; Hamilton, T. D.; MacGillivray, L. R. Chem.
Commun. 2004, 3, 270–271. (b) Schnebeck, R.-D.; Freisinger, E.; Glahe, F.;
Lippert, B. J. Am. Chem. Soc. 2000, 122, 1381–1390. (c) Schnebeck, R.-D.;
Freisinger, E.; Lippert, B. Chem. Commun. 1999, 8, 675–676. (d) Schnebeck, R.-
D.; Randaccio, L.; Zangrando, E.; Lippert, B. Angew. Chem., Int. Ed. 1998, 37,
119–121.
(5) (a) Angaridis, P.; Berry, J. F.; Cotton, F. A.; Murillo, C. A.; Wang, X.
J. Am. Chem. Soc. 2003, 125, 10327–10334. (b) Bera, J. K.; Angaridis, P.;
Cotton, F. A.; Petrukhina, M. A.; Fanwick, P. E.; Walton, R. A. J. Am. Chem. Soc.
2001, 123, 1515–1516. (c) Cotton, F. A.; Daniels, L. M.; Lin, C.; Murillo, C. A.;
Yu, S.-Y. J. Chem. Soc., Dalton Trans. 2001, 121, 502–504. (d) Cotton, F. A.;
Daniels, L. M.; Lin, C.; Murillo, C. A. J. Am. Chem. Soc. 1999, 121, 4538–4539.
r
2010 American Chemical Society
Published on Web 08/06/2010
pubs.acs.org/IC

7784 Inorganic Chemistry, Vol. 49, No. 17, 2010
Ning et al.
Scheme 1. Self-Assembly of [M4L2]4þ-Type Metallomacrocycles
Chart 1
in selective guest inclusion, drug delivery, molecular recognition,
catalysis, and biological mimicry.1,3,6,12,13,17
(6) (a) Fujita, M.; Sasaki, O.; Mitsuhashi, T.; Fujita, T.; Yazaki, J.;
Yamaguchi, K.; Ogura, K. Chem. Commun. 1996, 13, 1535–1536. (b) Fujita,
M.; Yazaki, J.; Ogura, K. J. Am. Chem. Soc. 1990, 112, 5645–5647.
€
(7) (a) Habereder, T.; Warchhold, M.; Noth, H.; Severin, K. Angew.
Chem., Int. Ed. 1999, 38, 3225–3228. (b) Lai, S.-W.; Chan, M. C.-W.; Peng, S.-
M.; Che, C.-M. Angew. Chem., Int. Ed. 1999, 38, 669–671. (c) Thompson, A.;
Rettig, S. J.; Dolphin, D. Chem. Commun. 1999, 7, 631–632. (d) Hall, J.; Loeb,
S. J.; Shimizu, G. K. H.; Yap, G. P. A. Angew. Chem., Int. Ed. 1998, 37, 121–123.
(e) Barbera, J.; Elduque, A.; Gimenez, R.; Oro, L. A.; Serrano, J. L. Angew.
Chem., Int. Ed. 1996, 35, 2832–2835.
(8) (a) Graves, C. R.; Merlau, M. L.; Morris, G. A.; Sun, S.-S.; Nguyen, S. T.;
Hupp, J. T. Inorg. Chem. 2004, 43, 2013–2017. (b) Ferrer, M.; Mounir, M.; Rossell,
O.; Ruiz, E.; Maestro, M. A. Inorg. Chem. 2003, 42, 5890–5899. (c) Schweiger, M.;
Seidel, S. R.; Arif, A. M.; Stang, P. J. Inorg. Chem. 2002, 41, 2556–2559. (d) Sautter,
A.; Schmid, D. G.; Jung, G.; W€urthner, F. J. Am. Chem. Soc. 2001, 123, 5424–5430.
(e) Schnebeck, R.-D.; Freisinger, E.; Lippert, B. Eur. J. Inorg. Chem. 2000, 1193–
1200. (f) Sun, S.-S.; Lees, A. J. J. Am. Chem. Soc. 2000, 122, 8956–8967. (g) Sun, S.-
S.; Lees, A. J. Inorg. Chem. 1999, 38, 4181–4182. (h) Lee, S. B.; Hwang, S.; Chung,
D. S.; Yun, H.; Hong, J.-I. Tetrahedron Lett. 1998, 39, 873–876. (i) Mcquillan, F. S.;
Berridge, T. E.; Chen, H.; Hamor, T. A.; Jones, C. J. Inorg. Chem. 1998, 37, 4959–
4970. (j) Fujita, M.; Ogura, K. Bull. Chem. Soc. Jpn. 1996, 69, 1471–1482.
However, most of the self-assembled metallosupramolecular
systems have been using single metal ions as the corner for co-
ordinating with a variety of monodentate or chelating ligands.
The isolated, structurally characterized metal-metal bonded or
dimetal-interacted based finite molecular architectures play an
€
(9) (a) Wurthner, F.; Sautter, A.; Schmid, D. G.; Weber, P. J. A. Chem.-
Eur. J. 2001, 7, 894–902. (b) Sun, S.-S.; Silva, A. S.; Brinn, I. M.; Lees, A. J.
Inorg. Chem. 2000, 39, 1344–1345. (c) W€urthner, F.; Sautter, A. Chem.
Commun. 2000, 6, 445–446. (d) Lahav, M.; Gabai, R.; Shipway, A. N.; Willner,
I. Chem. Commun. 1999, 19, 1937–1938. (e) Campos-Fernandez, C. S.; Clerac,
R.; Dunbar, K. R. Angew. Chem., Int. Ed. 1999, 38, 3477–3479. (f) Woessner,
S. M.; Helms, J. B.; Houlis, J. F.; Sullivan, B. P. Inorg. Chem. 1999, 38, 4380–
4381. (g) Slone, R. V.; Hupp, J. T.; Stern, C.; Albrecht-Schmitt, T. E. Inorg.
Chem. 1996, 35, 4096–4097. (h) Slone, R. V.; Yoon, D. I.; Calhoun, R. M.; Hupp,
J. T. J. Am. Chem. Soc. 1995, 117, 11813–11814. (i) Stang, P. J.; Cao, D. H.;
Saito, S.; Arif, A. M. J. Am. Chem. Soc. 1995, 117, 6273–6283. (j) Stang, P. J.;
Cao, D. H. J. Am. Chem. Soc. 1994, 116, 4981–4982.
(10) (a) Hartmann, H.; Berger, S.; Winter, R.; Fiedler, J.; Kaim, W. Inorg.
Chem. 2000, 39, 4977–4980. (b) Benkstein, K. D.; Hupp, J. T.; Stern, C. L. J. Am.
Chem. Soc. 1998, 120, 12982–12983. (c) Benkstein, K. D.; Hupp, J. T.; Stern,
C. L. Angew. Chem., Int. Ed. 2000, 39, 2891–2893. (d) Woessner, S. M.; Helms,
J. B.; Shen, Y.; Sullivan, B. P. Inorg. Chem. 1998, 37, 5406–5407. (e) Benkstein,
K. D.; Hupp, J. T.; Stern, C. L. Inorg. Chem. 1998, 37, 5404–5405.
(12) (a) Tashiro, S.; Tominaga, M.; Kawano, M.; Therrien, B.; Ozeki, T.;
Fujita, M. J. Am. Chem. Soc. 2005, 127, 4546–4547. (b) Kusukawa, T.; Fujita,
M. J. Am. Chem. Soc. 2002, 124, 13576–13582. (c) Yu, S.-Y.; Kusukawa, T.;
Biradha, K.; Fujita, M. J. Am. Chem. Soc. 2000, 122, 2665–2666. (d) Fujita, M.;
Fujita, N.; Ogura, K.; Yamaguchi, K. Nature 1999, 400, 52–55. (e) Fujita, M.; Yu,
S.-Y.; Kusukawa, T.; Funaki, H.; Ogura, K.; Yamaguchi, K. Angew. Chem., Int.
Ed. 1998, 37, 2082–2085.
(13) (a) Olenyuk, B.; Levin, M. D.; Whiteford, J. A.; Shield, J. E.; Stang,
P. J. J. Am. Chem. Soc. 1999, 121, 10434–10435. (b) Olenyuk, B.; Whiteford,
€
J. A.; Fechtenkotter, A.; Stang, P. J. Nature 1999, 398, 796–799.
(14) (a) Yamaguchi, T.; Tashiro, S.; Tominaga, M.; Kawano, M.; Ozeki,
T.; Fujita, M. J. Am. Chem. Soc. 2004, 126, 10818–10819. (b) Biradha, K.;
Aoyagi, M.; Fujita, M. J. Am. Chem. Soc. 2000, 122, 2397–2398. (c) Aoyagi, M.;
Biradha, K.; Fujita, M. J. Am. Chem. Soc. 1999, 121, 7457–7458. (d) Takeda, N.;
Umemoto, K.; Yamaguchi, K.; Fujita, M. Nature 1999, 398, 794–796.
(15) (a) Duriska, M. B.; Neville, S. M.; Moubaraki, B.; Cashion, J. D.;
Halder, G. J.; Chapman, K. W.; Balde, C.; Letard, J.-F.; Murray, K. S.;
Kepert, C. J.; Batten, S. R. Angew. Chem., Int. Ed. 2009, 48, 2549–2552. (b)
Lu, Z.; Knobler, C. B.; Furukawa, H.; Wang, B.; Liu, G.; Yaghi, O. M. J. Am.
Chem. Soc. 2009, 131, 12532–12533. (c) Ghosh, K.; Hu, J.; White, H. S.; Stang,
P. J. J. Am. Chem. Soc. 2009, 131, 6695–6697. (d) Oppel, I. M.; Foecker, K.
Angew. Chem., Int. Ed. 2008, 47, 402–405.
(11) (a) Matsumoto, N.; Motoda, Y.; Matsuo, T.; Nakashima, T.; Re, N.;
Dahan, F.; Tuchagues, J.-P. Inorg. Chem. 1999, 38, 1165–1173. (b) Mamula,
O.; von Zelewsky, A.; Bernardinelli, G. Angew. Chem., Int. Ed. 1998, 37, 289–
293. (c) Stang, P. J.; Persky, N. E.; Manna, J. J. Am. Chem. Soc. 1997, 119, 4777–
4778. (d) Hasenknopf, B.; Lehn, J.-M.; Baum, G.; Kneisel, B. O.; Fenske, D.
Angew. Chem., Int. Ed. 1996, 35, 1838–1840.

Article
Inorganic Chemistry, Vol. 49, No. 17, 2010 7785
Scheme 2. Synthesis of Flexible Dipyrazolate Linkers
important role in both inorganic and organometallic chemistry,
which have been rarely reported.18 In the past years, we have
been interested in developing the emerging supramolecular self-
assembly via metal-metal bonding or bonding interaction.19
In our previous work, we have developed the solution self-
assembly method and structural characterization of a series of
metallomacrocyclic complexes with dipalladium (II, II) and
diplatinum (II, II) centers and multipyrazolate anion linkers via
spontaneous deprotonation in aqueous solution.20-22
Herein, we designed the flexible dipyrazolyl ligands
with luminescent spacers. With anthracene-based dipyra-
zolate dianion as the linker and [(bpy)2Pd2(NO3)2](NO3)2
or [(phen)2Pd2(NO3)2](NO3)2 dimetallic clips as the cor-
ner, we synthesized and characterized a series of metallo-
macrocyclic complexes with interior cavities via self-
assembly in aqueous solution (as shown in Scheme 1).
Host-guest properties for luminescent metal macrocyclic
host and aromatic guests (depicted in Chart 1) were
studied though UV-vis and fluorescent titrations.
Results and Discussion
Self-Assembly and Characterization of the [M4L2]4þ-Type
Metallomacrocycles. [(bpy)2Pd2(NO3)2](NO3)2 or [(phen)2-
Pd2(NO3)2](NO3)2 was treated with a solution containing
0.5 equivalent of H2Ln (n labeled by 1, 2, 3, 4, 5, 6) (as shown
in Scheme 2) in water at room temperature over 2 h,
followed by adding acetone into the solution. The resulting
mixture was heated at 60 ꢀC for 12 h to produce [M4L2]-
(NO3)4 in quantitative yield with spontaneous deprotona-
tion of dipyrazole ligands. The 1Hand13C NMR analyses of
the product indicated the formation of a single highly sym-
metrical species, and integration of the signals is indicative
of 2:1 ratio of metal complex ((bpy)Pd2þ or (phen)Pd2þ
fragment to the dipyrazolate dianion.
)
The formation of the [M4L2]4þ-type metallomacrocyclic
structure is further supported by electrospray ionization mass
spectrometry (ESI-MS). For the hexafluorophosphate com-
plex, the ESI-MS experiment was performed in acetonitrile
solution. As shown in Figure 1a, the signals at m/z = 1310.2,
(16) (a) Iengo, E.; Milani, B.; Zangrando, E.; Geremia, S.; Alessio, E.
Angew. Chem., Int. Ed. 2000, 39, 1096–1099. (b) Drain, C. M.; Nifiatis, F.;
Vasenko, A.; Batteas, J. D. Angew. Chem., Int. Ed. 1998, 37, 2344–2347. (c)
Funatsu, K.; Imamura, T.; Ichimura, A.; Sasaki, Y. Inorg. Chem. 1998, 37, 1798–
1804. (d) Slone, R. V.; Hupp, J. T. Inorg. Chem. 1997, 36, 5422–5423. (e) Drain,
C. M.; Lehn, J.-M. J. Chem. Soc., Chem. Commun. 1994, 19, 2313–2315.
(17) (a) Yu, S.-Y.; Huang, H.; Liu, H.-B.; Chen, Z.-N.; Zhang, R.; Fujita,
M. Angew. Chem., Int. Ed. 2003, 42, 686–690. (b) Li, S.-H.; Huang, H.-P.; Yu,
S.-Y.; Li, Y.-Z.; Huang, H.; Sei, Y.; Yamaguchi, K. Dalton Trans. 2005, 2346–
2348. (c) Liu, L.-X.; Huang, H.-P.; Li, X.; Sun, Q.-F.; Sun, C.-R.; Li, Y.-Z.; Yu, S.-
Y. Dalton Trans. 2008, 1544–1545. (d) Ning, G.-H.; Xie, T.-Z.; Pan, Y.-J.; Li, Y.-
Z.; Yu, S.-Y. Dalton Trans. 2010, 3203–3211.
(18) Cotton, F. A., Murillo, C. A., Walton, R. A. Multiple Bonds between
Metal Atoms, 3rd ed.; Springer Science and Business Media: New York, 2005.
(19) (a) Yu, S.-Y.; Sun, Q.-F.; Lee, T. K.-M.; Cheng, E. C.-C.; Li, Y.-Z.;
Yam, V. W.-W. Angew. Chem., Int. Ed. 2008, 24, 4551–4554. (b) Sun, Q.-F.;
Lee, T. K.-M.; Li, P.-Z.; Yao, L.-Y.; Huang, J.-J.; Huang, J.; Yu, S.-Y.; Li, Y.-Z.;
Cheng., E. C. -C.; Yam, V. W.-W. Chem. Commun. 2008, 43, 5514–5516. (c) Yu,
S.-Y.; Zhang, Z.-X.; Cheng, E. C.-C.; Li, Y.-Z.; Yam, V. W.-W.; Huang, H.-P.;
Zhang, R. J. Am. Chem. Soc. 2005, 127, 17944–17995. (d) Cotton, F. A.; Lei, P.;
Lin, C.; Murillo, C. A.; Wang, X.-P.; Yu, S.-Y.; Zhang, Z.-X. J. Am. Chem. Soc.
2004, 126, 1518–1525.
-
2þ
,
825.5, and 583.1, which are assignable to [1 2PF6
[1 PF6
]
3
-
]
660.1, and 458.8 are assignable to [3 2PF6
3þ, and [1]4þ, respectively. In Figure 1b, 1062.1,
3
- 3þ
- 2þ, [3 PF6
]
]
,
3
3
and [3]4þ, respectively.
Self-Assembly and Characterization of [M8L4]8þ-Type
Metallomacrocycle. Unlike other flexible dipyrazolate
ligands, the treatment of H2L1 with [(phen)2Pd2(NO3)2]-
(NO3)2 in a 1:2 ratio in water and acetone quantitatively
gave the metallomacrocycles complex {[(phen)Pd]8L1 }-
4
(NO3)8 instead of [M4L2]4þ, which resulted in a huge
metallomacrocyle with a big cavity, as shown in Scheme 3.
The assignment of [M8L4]8þ-type metallomacrocycle
9 8PF6h is proved by ESI-MS studies, as shown in Figure 2.
3
The multiple-charged molecular ions of 9 8PF6h at m/z =
3
(20) Yu, S.-Y.; Jiao, Q.; Li, S. H.; Huang, H. P.; Li, Y. Z.; Pan, Y. J.;
Yamaguchi, K. Org. Lett. 2007, 9, 1379–1382.
(21) (a) Yu, S.-Y.; Huang, H. P.; Li, S. H.; Jiao, Q.; Li, Y. Z.; Wu, B.; Sei,
Y.; Yamguchi, K.; Pan, Y. J.; Ma, H. W. Inorg. Chem. 2005, 44, 9471–9488.
(b) Li, S. H.; Huang, H. P.; Yu, S.-Y.; Li, X.-P. Chin. J. Chem. 2006, 24, 1225–
1229.
1058.1, 857.8, 714.4, and 607.1 are ascribed to [9 3PF6h]5þ
,
3
[9 2PF6h]6þ, [9 1PF6h]7þ, and [9]8þ, respectively.
3
3
Ring numbers of cyclic assemblies are often controlled
by changing reaction conditions (concentration, tempera-
ture, etc.) or by adding a template molecule that selectively
binds to and stabilizes one particular assembly. In this
(22) Sun, Q. F.; Liu, L. X.; Huang, H. P.; Yu, S.-Y.; Yam, W. W. V. Inorg.
Chem. 2008, 47, 2142–2145.

7786 Inorganic Chemistry, Vol. 49, No. 17, 2010
Ning et al.
-
Scheme 3. Self-Assembly and Top View of Macrocycle 9 8NO3
3
Calculated with CAChe 6.1.1 Program (see ref 30)a
Figure 1. ESI-MS spectra of (a) 1 4PF6h and (b) 3 4PF6h in acetoni-
3
3
trile. The inset shows the isotopic distribution of the species (a) [1 PF6h]3þ
3
and [1]4þ and (b) [3 2PF6h]2þ, [3 PF6h]3þ, and [3]4þ
.
3
3
work, to control the size of the metallomacrocyle, we used
the dimetallic clips with a rigid phen ring, which could
produce more hindrance than the bpy ligand.
Crystal Structure of Assembly [M4L2]4þ-Type Metallo-
macrocycles. The ORTEP diagram of 1 4PF6h is shown
3
in Figure 3. Complex 1 4PF6h crystallizes in the ortho-
rhombic space group Fddd. The crystal structure analysis
3
for 1 4PF6h reveals the Pd4 bowl-shaped macrocyclic
3
structure with two (μ-pyrazolato-N,N0)2 doubly bridged
[(bpy)Pd]2 dimetal corners. The two anthracene rings
form a dihedral angle of 90 o, and each one forms a dihedral
angle of about 60.9 and 71.8ꢀ with pz planes in the dipyrazole
˚
bridged ligand. The Pd1 Pd2 separation of 3.157 A sug-
3 3 3
gests the presence of weak metal-metal interaction. The
dihedral angles between the two pz (N3A-N4A and N1A-
N2A; N4--N3 and N1-N2) planes at each corner are 89.25
and 70.50ꢀ, which are smaller than the dihedral angles
between the Pd1A-N3A-N4A-Pd2A and Pd1-N3-
N4-Pd2 planes (116.38 and 115.05ꢀ). The cavity of the
Pd4 bowl-shaped macrocycle is small, because it is twisted by
the two vertical anthracene planes. The distances of Pd1-
a (a) Ball-and-stick model and (b) Space-and-stack model. (yellow: Pd;
gray: C; white: H; and blue: N).
in Figure 4b, one CH3CN binds between the two bpy rings
by C-H π interactions between the H54A atom and X
3 3 3
(1D) (the centroid of one bpy ring), which is separated by
˚
˚
Pd1A and Pd2-Pd2A are 11.95 and 13.32 A, respectively.
2.565 A (C54A-H54A π) with the C-H X angle
3 3 3
3 3 3
The ORTEP diagram of 3 4PF6h 8CH3CN H2O is
158.11ꢀ. Furthermore, two acetonitrile molecules are en-
3
3
3
capsulated through C-H π interactions22 within the
shown in Figure 4. Complex 3 4PF6h crystallizes in the
monoclinic space group C2/c with one cocrystallized water
3
3 3 3
aromatic ring built cavity, and the distances from C-H of
the CH3CN tothethreecentroids(X (1A), X(1B), X (1C) in
molecule. The crystal structure analysis for 3 4PF6h reveals
3
the Pd4 bowl-shaped macrocyclic structure with two
(μ-pyrazolato-N,N0)2 doubly bridged [(bpy)Pd]2 dimetal
corners. The two anthracene rings each form a dihedral
angle of about 80ꢀ with pz planes in the dipyrazole bridged
ligand, showing a syn-syn orientation according to the
Figure 4a of the three adjacent aromatic planes are 3.067,
˚
3.052, and 2.672 A with the C-H X angles 140.90,
3 3 3
153.35, and 132.54ꢀ, respectively. Similarly short intermo-
lecular C-H π distances were previously found between
3 3 3
CH3 and an aromatic ring (2.75, 2.89 A).23a,c The inclusion
˚
planes of (bpy)Pd1A and (bpy)Pd1B. The Pd1A Pd2A
3 3 3
˚
separation of 3.232 A suggests the presence of weak
(23) (a) Nishio, M.; Umezawa, Y.; Honda, K.; Tsuboyama, S.; Suezawa,
H. CrystEngComm 2009, 11, 1757. (b) Nishio, M. CrystEngComm 2004, 6,
130. (c) Nishio, N.; Hirota, M.; Umezawa, Y. The CH/π Interaction. Evidence,
Nature, and Consequences. Wiley-VCH, New York, 1998. (d) Kishikawa, K.;
Yoshizaki, K.; Kohmoto, S.; Yamamoto, M.; Yamaguchi, K.; Yamada, K. J.
Chem. Soc., Perkin Trans. 1 1997, 1233.
metal-metal interactions. The remarkable structure fea-
ture is that the (bpy)Pd1A and (bpy)Pd2A planes (with a
dihedral angle of 82.4ꢀ) form a cleft with a cavity size of
˚
approximately 7.09 A (center-to-center distance). As shown

Article
Inorganic Chemistry, Vol. 49, No. 17, 2010 7787
Figure 2. ESI-MS spectra of 9 8PF6h in acetonitrile. The inset shows the isotopic distribution of the species [9 PF6h]7þ and [9]8þ
.
3
3
Figure 4. ORTEP diagram of the molecular structure of 3 4PF6h 8CH3-
3
3
CN H2O (a) top and (b) side views. Thermal ellipsoids are shown at 30%
probability level. The counterions, hydrogen atoms (expect hydrogen of
acetonitrile), and free solvent molecules are omitted for clarity.
3
tropism is opposite to the case of CH3CN entrapped within
the (V12O324-) inorganic bowl,24 whereas the cyanogen was
inward. The cavity of the Pd4 bowl-shaped macrocycle is
Figure 3. ORTEP diagram of the molecular structure of 1 4PF6h (a) top
and (b) side views. Thermal ellipsoids are shown at 30% probability level. The
counterions, hydrogen atoms, and solvent molecules are omitted for clarity.
3

7788 Inorganic Chemistry, Vol. 49, No. 17, 2010
Ning et al.
Table 1. Summary of the Association Constants of the New Metallomacrocycle-
Aromatic Guest Complexes Determined by UV-vis Titration Method
complex
Ka (M-1
)
1 Dmb
3
1.42 ꢀ 106
1.11 ꢀ 105
2.7 ꢀ 105
1 Dhb
3
1 An
3
1 Ben-CO2-Naþ
1 Py
1 Hfb
3.48 ꢀ 105
3
a
3
a
3
a Cannot be determined because the change of absorbance does not
linearly relate to [G].
emission intensity of H2L1 in fluorescent spectra was
quenched sharply, and the absorbance of H2L1 in UV-vis
spectra was decreased notably (Supporting Information,
Figure 1S), due to the coordination between the N atom
of pyrazole and the Pd atom and the distortion effects on
the emission quantum yield (Φem) of the anthracenyl
rings.
Upon addition of aromatic guests to the solution of the
receptors in DMSO, the absorbance of the receptors in
the UV-vis spectrum was shifted significantly. Figure 7a
presented the UV-vis spectra of 1 in DMSO in the pre-
sence of an incremental amount of Dmb. (Dhb, An, and
Ben-CO2-Naþ are shown in Supporting Information,
Figures 6S-8S, respectively.) Job’s plot analysis based on
the UV-vis experiments, as shown in Supporting Informa-
tion, Figures 2S-5S, supported a 1:1 stoichiometry for com-
plexes 1:Dmb, 1:Dhb, 1:An, and 1: Ben-CO2-Naþ, which
exhibited the largest change of absorbance at the 1:1 ratio of
the receptor and the aromatic guests when the total concen-
tration of the two samples was kept constant.25,26
Figure 5. ORTEPdiagramofthe molecularstructureof7 4PF6h 6H2O
3
3
(a) top and (b) side views. Thermal ellipsoids are shown at 30% prob-
ability level. The counterions, hydrogen atoms, and solvent molecules are
omitted for clarity.
small. The distance between the two central anthracene
˚
rings is 8.1 A, and the distances of Pd1A-Pd1B and
˚
Pd2A-Pd2B are 8.59 and 12.85 A, respectively.
The ORTEP diagram of 7 4PF6h 6H2O is shown in
The association constants (Ka) of complexes 1 Dmb,
3
3
3
1 Dhb, 1 An, and 1 Ben-CO2-Naþ in DMSO were then
Figure 5. Complex 7 4PF6h crystallizes in the monoclinic
3
3
3
3
space group P21/c. The crystal structure analysis for
evaluated by the UV-vis titration method. On the basis
of the change values of absorbance with (aromatic guests),
we estimated the Ka of the four complexes to be 1.42 ꢀ 106,
1.11 ꢀ 105, 2.7 ꢀ 105, and 3.48 ꢀ 105 M-1, respectively
(Table 1). Fluorescence studies (Figure 7b) revealed that
the emission intensity of the anthracene ring units of the
receptors could be significantly increased by the aromatic
guest (Dhb, An, and Ben-CO2-Naþ are shown in Support-
ing Information, Figures 9S-11S, respectively). These
results are consistent with the above UV-vis investigation,
reflecting the remarkably complexing affinity between the
two anthracene rings of 1 and the aromatic guest due to the
π-π stacking interactions (Figure 6).
7 4PF6h reveals the Pd4 bowl-shaped macrocyclic struc-
3
ture with two (μ-pyrazolato-N,N0)2 doubly bridged
[(bpy)Pd]2 dimetal corners. The two benzene rings form
a dihedral angle of 56.18ꢀ and form dihedral angles of
about 85.09, 85.43ꢀ and 83.95, 87.24ꢀ with pz planes in the
bipyrazole bridged ligand, showing a syn-syn orienta-
tion according to the planes of (bpy)Pd1 and (bpy)Pd3.
˚
The Pd1 Pd2 separation of 3.232 A suggests the pre-
3 3 3
sence of weak metal-metal interactions. The dihedral
angles between the two pz (N7-N8 and N5-N6; N13-
N14 and N15-N16) planes at each corner are 58.34 and
87.31ꢀ , which are smaller than the dihedral angles bet-
ween the Pd1-N7-N8-Pd2 and Pd3-N13-N14-
Pd4 planes (117.77 and 118.76ꢀ). The cavity of the Pd4
bowl-shaped macrocycle is small because the four pyrazole
methyl groups fill in the cavity. The distances of Pd1-Pd4
Such similar spectroscopic changes were not observed
when an incremental amount of Hfb and Py were added
to the solution of 1 in DMSO as well as An, Hfb, and
Ben-CO2-Naþ were added to the solution of 3 in
DMSO, which may be rationalized by considering steric
hindrance and electrostatic repulsion. The cavity of host
1 is too small to include the Py, and Hfb is an electron-
defect compound which is unfavorable for binding with
the positively charged metallomacrocycle 1. There are
˚
and Pd2-Pd3 are 12.685 and 7.823 A, respectively.
UV-vis Titrations and Fluorescent Spectra. The H2L1
has been synthesized in high yields (Scheme 1). In dimethyl
sulfoxide (DMSO), it exhibited characteristic anthracene
emission and fluorescence maxima at 421, 440, and 465 nm
and UV-vis spectrum peaks at 405, 382, 364, and 346 nm,
respectively (Supporting Information, Figure 1S). When
the [(bpy)2Pd2(NO3)2](NO3)2 was added into H2L1, the
(25) (a) Schneider, H. J.; Yatasimirsky, A. Principle and Methods in Supra-
molecular Chemistry, Wiley: New York, 2000. (b) Conners, K. A. Binding
Constants: The Measurement of Molecular Complex Stability, Wiley: New York,
1987.
(24) Day, V. W.; Klemperer, W. G.; Yaghi, O. M. J. Am. Chem. Soc. 1989,
111, 5959–5961.
(26) Li, W. S.; Jiang, D. L.; Suna, Y.; Aida, T. J. Am. Chem. Soc. 2005,
127, 7700–7702.

Article
Inorganic Chemistry, Vol. 49, No. 17, 2010 7789
Figure 6. Possible mechanism for host-guest interaction. Left, crystal structure of 1 and right, 1:1 complex Dmb 1 calculated with CAChe 6.1.1
3
program30 (yellow: Pd; gray: C; white: H; and blue: N).
Figure 7. (a) Absorption spectral changes of 1 (1 ꢀ 10-5 M) upon addition of Dmb in DMSO at 25 ꢀC (black is the UV-vis absorbance of 1, and inset is the
plot of the absorbance change vs [Dmb], at peak of 406 nm). (b) Changes in emission spectra of 1 (1 ꢀ 10-5 M) upon addition of Dmb in DMSO (the inset shows
the color difference for visual observation of the emission intensities, at λex = 365 nm, of H2L1 (2 ꢀ 10-5 M), 1 (1 ꢀ 10-5 M), and Dmb 1 = 1:1 in DMSO).
3
Table 2. Crystallographic Data for Complexes 1, 3, and 7
1 4PF6h
3 4PF6h 8CH3CN H2O
7 4PF6h 6H2O
3 3
3
3
3
3
formula
FW
C132H96N16F24P4Pd4
2911.73
0.20 ꢀ 0.22 ꢀ 0.24
orthorhombic
Fddd
44.0262(10)
22.4503(5)
71.5704(16)
90
90
90
70 740(3)
16
1.094
C108H106F24N24OP4Pd4
2761.65
0.22 ꢀ 0.24 ꢀ 0.28
monoclinic
C2/c
38.8468(8)
12.6578(2)
25.2201(4)
90
103.034(1)
90
12 081.6(4)
4
1.518
C82H96F24N16O6P4Pd4
2407.23
0.20 ꢀ 0.22 ꢀ 0.26
monoclinic
P21/c
21.483(10)
18.296(8)
30.191(14)
90
100.777(6)
90
11 657(9)
4
1.372
crystal size [mm]
crystal system
space group
˚
a [A]
˚
b [A]
˚
c [A]
R [ꢀ]
β [ꢀ]
γ [ꢀ]
3
˚
V [A ]
Z
F
calcd, [g/cm-3
]
μ [mm-1
F(000)
]
0.502
23 360
0.733
5560
0.749
4832
2θmax [ꢀ]
50.00
15 599
811
1.02
0.0488, 0.0934
-0.32, 0.64
52.00
11 874
752
1.05
0.0495, 0.1338
-0.58, 0.35
52.00
22 867
1320
1.09
0.0514, 0.1379
-0.65, 0.33
no. unique data
parameters
GOF [F2]a
R [F2 > 2σ(F2)], wR[F2]b
-3
˚
ΔFmax, ΔFmin [e A
]
a GOF = [w(Fo2 - Fc2)2]/(n - p)1/2, where n and p denote the number of data points and parameters, respectively. b R1 = (||Fo| - |Fc||)/|Fo|; wR2 =
[w(Fo2 - Fc2)2]/[w(Fo2)2]1/2, where w = 1/[σ2(Fo2) þ (aP)2 þ bP] and P = [max(0,Fo2) þ 2Fc2]/3.
four methyl groups filling the small cavity of 3, which
keeps the aromatic guests outside the cavity.
quantitative yield from [(bpy)2Pd2(NO3)2](NO3)2 or [(phen)2-
Pd2(NO3)2](NO3)2 and 1H-bipyrazolyl ligands in a 2:1 molar
ratio via a directed self-assembly process that occurs along
with spontaneous deprotonation of the ligands. Ring size and
shape of cyclic assemblies {[M4L2](NO3)4 and [M8L4](NO3)8}
have been controlled by fine-tuning different dimetallic clips
Conclusions
Fluorescent dipyrazolate-bridged metallomacrocycles
with dipalladium(II, II) centers can be obtained in nearly

7790 Inorganic Chemistry, Vol. 49, No. 17, 2010
Ning et al.
and flexible dipyrazole ligands. The assemblies have been char-
acterized by elemental analysis, 1H and 13C NMR, electrospray
ionization mass spectrometry (ESI-MS), and single crystal
X-ray diffraction methods for 1, 3, and 7. In addition, the 1:1
host-guest complexation for the anthracene-based dipyrazo-
late-bridged macrocycle (1 and 3) with aromatic guests was
investigated via UV-vis and fluorescence spectra.
solvent and excess acetylacetone was distilled. Further puri-
fication was achieved by recrystallization or column chromato-
graphy, as noted below.
General Procedure for Bis(1,3-diphenylpropane-1,3-dione)
Preparation. Bis(bromomethyl) (2 mmol), sodium 1,3-diphenyl-
prop-1-en-1-olate (DBMNa) (4.4 mmol), and KI (10% of
quality of bis(bromomethyl)) were mixed in a 250 mL round
flask. Then 150 mL dry acetone was added under N2 protection,
the resulting solution was stirred and refluxed for 16 h. After
cooling to room temperature, most of solvent was distilled. Then
the residue was washed with water and extracted with CH2Cl2,
the organic phase was dried over anhydrous MgSO4 and filtered,
and the solvent was distilled. Further purification was achieved
by recrystallization or column chromatography, as noted below.
General Pyrazole Preparation. Hydrazine hydrate (1 mL,
80%) was added during a 10 min period to a stirred and refluxed
solution of dione (1 mmol) in 30 mL of ethanol. After 12 h, most
of the solvent was distilled and filtered, and the resulting solid
was washed twice with water and vacuum dried.
2,20-(Anthracene-9,10-diylbis(methylene))bis(1,3-diphenylpro-
pane-1,3-dione) (a). The above general bis(1,3-diphenylpropane-
1,3-dione) preparation procedure was followed with 9,10-bis-
(chloromethyl)anthracene (550 mg, 2 mmol) to give a as a light-
yellow powder. The rough product was washed twice with hot
50 mL ethanol and vacuum dried. (1.17 g, 90%). 1H NMR (400
MHz, CDCl3, 25 ꢀC, ppm): δ = 8.08-8.06 (m, 4H), 7.47-7.45
(m, 8H), 7.36-7.34 (m, 4H), 7.31-7.28 (m, 4H), 7.09-7.05 (m,
8H), 5.61-5.57 (t, J = 2.84 Hz, 2H), 4.41-4.40 (s, J = 2.84 Hz,
4H). 13C NMR (100 MHz, CDCl3, 25 ꢀC, ppm): δ = 196.2,
135.8, 133.2, 130.6, 129.6, 128.3, 128.2, 125.5, 124.8, 57.5, 27.3.
MS (EI) m/z: Anal. calcd for [C46H34O4 þ Na]þ, 673.2349;
found: 673.2344.
Experimental Section
Materials. All chemicals and solvents were of reagent grade
and were purified according to conventional methods.27 The
dimetal clips [(bpy)2Pd2(NO3)2](NO3)2 and [(phen)2Pd2(NO3)2]-
(NO3)2 were prepared according to literature procedures.28,29
X-ray Structural Determinations. X-ray diffraction measure-
ments were carried out at 291 K on a Bruker Smart Apex CCD
area detector equipped with a graphite monochromated Mo KR
˚
radiation (λ = 0.71073 A). The absorption correction for all
complexes was performed using SADABS. All the structures
were solved by direct methods and refined employing full-matrix
least-squares on F2 by using the SHELXTL (Bruker, 2000)
program and were expanded using Fourier techniques. All
nonhydrogen atoms of the complexes were refined with aniso-
tropic thermal parameters. The hydrogen atoms were included
in idealized positions. Final residuals along with unit cell, space
group, data collection, and refinement parameters are presented
in Table 2.
Typical Procedures for the UV-vis Titration and Evaluation
Constants Ka. Aliquots of a fixed solution of the aromatic guests
in DMSO were added to a DMSO solution of the receptors
(1 and 3), and the mixture was heated at 60 ꢀC then cooled to
25 ꢀC and subjected to the UV-vis spectroscopy. The spectrum
was corrected with a dilution factor and background subtrac-
tion. The difference in absorbance (ΔAbs) of the receptors in the
presence of the guest and the absence of the guest was recorded,
and the data were plotted against [G]. The association constant
Ka for the 1:1 complexes was derived by using the nonlinear
curve fitting based on the equation:25,26
9,10-bis((3,5-Diphenyl-1H-pyrazol-4-yl)methyl)anthracene
(H2L1). The above general pyrazole preparation procedure
was followed with a (715 mg, 1.1 mmol) and a yellow solid
H2L1 was obtained. (672 mg, 95%).1H NMR (400 MHz,
DMSO-d6, 25 ꢀC, ppm): δ = 12.7 (s, 2H), 7.85-7.83 (m,
4H), 7.38 (2, 4H), 7.18-7.10 (m, 10H), 6.91-6.65 (m, 10H),
4.80(s, 4H). 13C NMR (100 MHz, DMSO-d6, 25 ꢀC, ppm):
δ = 130.9, 129.4, 128.1, 127.3, 127.0, 125.0, 124.0, 114.7,
23.3. Mass spectrometry (MS) Mtrix-assisted laser-desorp-
tion ionization (MALDI-TOF) coupled cluster approxima-
tion (CCA) (þ) m/z: Anal. calcd for [C46H34N4 þ H]þ,
643.2856; found: 643.2859.
3,30-(Anthracene-9,10-diylbis(methylene))dipentane-2,4-dione)
(b). 9,10-Bis(chloromethyl)anthracene (2.75 g, 10 mmol) scat-
tered in DMF was slowly added to sodium 2,4-pentanedionat
(3.66 g, 30 mmol) in 120 mL dry DMF, then the reaction was
stirred and heated at 80 ꢀC overnight. The resulting solution was
cooled and poured into 500 mL of ice water. The solution was
extracted twice with CH2Cl2 (500 mL), washed with saturated
NaCl, organic phase dried over anhydrous Na2SO4, filtered, and
the solvent was distilled. Chromatography on silica gel elution
with CH2Cl2 afforded the intermediate as a light-yellow powder
b (829 mg, 20.4%). 1H NMR (400 MHz, CDCl3, 25 ꢀC, ppm):
δ = 8.20-8.18 (m, 4H), 7.56-7.54 (m, 4H), 4.23-4.17 (m, 6H),
1.95 (s, 12H). 13C NMR (100 MHz, CDCl3, 25 ꢀC, ppm): δ =
203.8, 130.4, 129.4, 125.9, 124.8, 68.25, 30.5, 26.28. MS (EI) m/z:
Anal. calcd for [C26H26O4 þ Na]þ, 425.1723; found: 425.1706.
9,10-Bis((3,5-dimethyl-1H-pyrazol-4-yl)methyl)anthracene
(H2L2). The above general pyrazole preparation procedure
was followed except for the substitution of hydrazine hydrate
(2 mL, 80%) and the b (680 mg, 1.7 mmol) in 50 mL of ethanol.
Then the yellow solid H2L2 was obtained. (635 mg, 95%).1H
NMR (400 MHz, DMSO-d6, 25 ꢀC, ppm): δ = 8.27-8.25 (m,
4H), 7.50-7.47 (m, 4H), 4.68 (s, 4H), 1.62 (s,12H). 13C NMR
(100 MHz, DMSO-d6, 25 ꢀC, ppm): δ = 131.3, 129.7, 125.5,
125.2, 112.9, 22.62, 10.8. MS (MALDI-TOF) m/z: Anal. calcd for
[C26H26N4 þ H]þ, 395.2230; found: 395.2233.
2
ΔA ¼ ΔA¥ðð1 þ Ka½Gꢁ þ Ka½Hꢁ0Þ - ðð1þKa½GꢁþKa½Hꢁ0Þ
0:5
2
- 4Ka ½Hꢁ0½GꢁÞ ÞÞ=ð2Ka½Hꢁ0Þ
where ΔA = A - ΔA0, ΔA¥ = A¥ - A0, [G] is concentration of
aromatic guests, [H]0 is [1 4NO3h].
3
CAChe Program 6.1.1. A visual molecular model was com-
puted using the CAChe program 6.1.130 to evaluate shape of
macrocycle 9 (Scheme 3) and the host-guest complex Dmb 1
3
(Figure 6).
General Procedure for Bis(methylene)dipentane-2,4-dione
Preparation20. Acetylacetone (1.81 g, 18.1 mmol) was added
during a 30 min period to a stirred, refluxing solution prepared
from potassium (706 mg, 18.1 mmol) and 60 mL of t-butyl
alcohol. After 50 min, the solution of bis(bromomethyl) com-
pound (8.23 mmol) in 30 mL of THF was added during a 30 min
period, and 1 h after the addition, KI (10% quality of bis-
(bromomethyl) compounds) was added. The resultant solution
was stirred and heated at reflux temperature until acidic to moist
litmus (ca. 16 h). After three-fourths of the solvent was distilled,
the residue was washed with water and extracted with CH2Cl2.
The organic phase was dried over anhydrous MgSO4, and the
(27) Armarego, W. L. F.; Perrin, D. D. Purification of Laboratory
Chemicals, 4th ed.; Butterworth Heinemann; Oxford, U.K., 1997.
(28) (a) Huang, H. P.; Li, S. H.; Yu, S.-Y.; Li, Y.-Z.; Jiao, Q.; Pan, Y.-J.
Inorg. Chem. Commun. 2005, 8, 656–660. (b) Yu, S.-Y.; Fujita, M.; Yamaguchi,
K. J. Chem. Soc., Dalton. Trans. 2001, 3145–3416.
(29) Conrad, R. C.; Rund, J. V. Inorg. Chem. 1972, 11, 129–134.
(30) CAChe 6.1.1 for Windows; Fujitsu Ltd.: Chiba, Japan, 2003.

Article
2,7-Bis((3,5-dimethyl-1H-pyrazol-4-yl)methyl)naphthalene
Inorganic Chemistry, Vol. 49, No. 17, 2010 7791
with f (200 mg, 0.36 mmol), and a white solid H2L6 was obtained.
(H2L3). The above general pyrazole preparation procedure
was followed with c31 (250 mg, 0.71 mmol), and a white solid
H2L3 was obtained. (232 mg, 95%).1H NMR (400 MHz,
DMSO-d6, 25 ꢀC, ppm): δ = 12.02 (s, 2H) 7.72-7.704 (d, J = 8.2
Hz, 2H), 7.47 (s, 2H), 7.18-7.17 (d, J = 1.2 Hz, 2H), 3.78 (s, 4H),
2.06 (s,12H). 13C NMR (100 MHz, DMSO-d6, 25 ꢀC, ppm): δ =
139.1, 133.2, 129.9, 127.4, 126.4, 125.2, 113.1, 28.7, 10.7. MS
(MALDI-TOF) m/z: Anal. calcd for [C22H24N4 þ H]þ, 345.2074;
found: 345.2072.
(187 mg, 95%). H NMR (400 MHz, DMSO-d6, 25 ꢀC, ppm):
1
δ = 13.33 (s, 2H) 7.46-7.32 (m, 20H), 6.98 (m, 4H), 4.00 (s, 4H).
13C NMR (100 MHz, DMSO-d6, 25 ꢀC, ppm): δ = 138.4, 128.4,
127.8, 127.1, 111.8, 28.6. MS (MALDI-TOF) m/z: Anal. calcd for
[C38H30N4 þ Na]þ, 565.2363; found: 565.2361.
Self-Assembly of Metalomacrocycles. General Procedures.
{[(phen)Pd]8L1 }(NO3)8 (9 8NO3h). [(phen)2Pd2(NO3)2](NO3)2
4
3
(41 mg, 0.1 mmol) was added to a suspension of H2L1 (32.2 mg,
0.05 mmol) in H2O (10 mL), and the mixture was stirred for 2 h
at room temperature. Then acetone (5 mL) was added, and the
reaction was heated at 60 ꢀC for 12 h at least. The resulting clear
yellow solution was evaporated to dryness to give a yellow solid
3,30-(2,4,6-Trimethyl-1,3-phenylene)bis(methylene)dipentane-
2,4-dione (d). The above general bis(methylene)dipentane-2,4-
dione preparation procedure was followed with 2,4-bis(bromo-
methyl)-1,3,5-trimethylbenzene (2.5 g, 8.23 mmol) to give e as a
white powder. Then the rough product was recrystallized from
95% EtOH, and the colorless needle crystal was obtained. (2.49
g, 90%). 1H NMR (400 MHz, CDCl3, 25 ꢀC, ppm): δ = 6.78 (s,
1H), 3.86-3.83 (t, J = 7.32 Hz, 2H), 3.15-3.13 (d, J = 7.32 Hz,
4H), 2.16 (s, 6H) 2.14 (s, 3H), 2.01 (s, 12H). 13C NMR (100 MHz,
CDCl3, 25 ꢀC, ppm): δ = 203.9, 134.7, 134.6, 133.3, 130.9, 66.7,
30.1, 28.5, 20.1, 16.1. MS (EI) m/z: Anal. calcd for [C21H28O4 þ
Na]þ, 367.1880; found: 367.1881.
4,40-(2,4,6-Trimethyl-1,3-phenylene)bis(methylene)bis(3,5-di-
methyl-1H-pyrazole) (H2L4). The above general pyrazole pre-
paration procedure was followed with d (500 mg, 1.45 mmol),
and the yellow solid H2L4 was obtained. (463 mg, 95%).1H
NMR (400 MHz, DMSO-d6, 25 ꢀC, ppm): δ = 12.80 (s, 2H),
7.31-6.96 (m, 20H), 6.24 (s, 1H), 3.71 (s, 4H), 1.73 (s, 6H), 1.36
(s, 3H). 13C NMR (100 MHz, DMSO-d6, 25 ꢀC, ppm): δ =
135.1, 134.4, 133.4, 129.2, 128.4, 127.6, 127.1, 113.2, 25.0, 19.9,
1 8NO3h. Yield: 69 mg (95%). The PF6h salt of 9 was obtained
as yellow microcrystals. ESI-MS (acetonitrile) m/z: 1058.1
3
[9 3PF6 ] ] ] .
- 5þ, 857.8 [9 2PF6- 6þ, 714.4 [9 PF6- 7þ, 607.1 [9]8þ
Found: C, 54.50; H, 3.48; N, 7.19. Calcd for C280H192N32-
3
3
3
F48P8Pd8 8H2O (%): C, 54.59; H, 3.40; N, 7.28.
{[(bpy)Pd]4L1 }(NO3)4 (1 4NO3h). The same procedure as
3
2
3
employed for 9 8NO3h was followed except that [(bpy)2Pd2-
3
(NO3)2](NO3)2 (39 mg, 0.1 mmol) was used as the starting
material. Yield: 58 mg (95%). The PF6h salt of 1 was obtained
as yellow microcrystals in quantitative yield. 13C NMR (100
MHz, CD3CN, 25 ꢀC, ppm): δ = 207.8, 152.6, 152.4, 149.5,
149.2, 142.6, 142.1, 132.4, 129.3, 128.3, 127.6, 122.7, 83.2, 31.2,
25.9, 15.1. ESI-MS (acetonitrile) m/z: 1310.2 [1 2PF6
3
]
- 2þ, 825.5
-
[1 PF6
]
3þ, 583.1 [1]4þ. Found: C, 54.08; H, 3.40; N, 7.69.
Calcd for C132H96N16F24P4Pd4 H2O (%): C, 54.11; H, 3.37; N,
3
3
7.65. The single crystals suitable for X-ray determination were
grown by the vapor diffusion of diethyl ether into a solution of
16.1. MS (MALDI-TOF) m/z: Anal. calcd for [C21H28N4
þ
1 4PF6h in acetonitrile at room temperature.
3
Na]þ, 359.2206; found: 359.2198.
{[(phen)Pd]4L2 }(NO3)4 (2 4NO3h). The same procedure as
2
3
2,20-(2,4,6-Trimethyl-1,3-phenylene)bis(methylene)bis(1,3-di-
phenylpropane-1,3-dione) (e). The above general bis(1,3-diphenyl-
propane-1,3-dione) preparationprocedurewas followedwith1,4-
bis(bromomethyl)benzene (1 g, 4.11 mmol) to give e as a white
solid. (2.31 g, 95%). 1H NMR (400 MHz, CDCl3, 25 ꢀC, ppm):
δ = 7.70-7.68 (m, 8H), 7.46-7.44 (m, 4H), 7.31-7.27 (m, 8H),
6.58 (s, 1H), 5.21-5.18 (t, J = 6.48 Hz, 2H), 3.46-3.44 (d, J =
6.48 Hz, 4H), 2.03 (s, 6H), 2.01 (s, 3H). 13C NMR (100 MHz,
CDCl3, 25 ꢀC, ppm): δ = 196.2, 136.0, 134.88, 134.82, 134.0,
133.3, 130.0, 128.5, 128.4, 57.3, 29.7, 20.2, 16.4. MS (EI) m/z:
Anal. calcd for [C41H36O4 þ Na]þ, 615.2506; found: 615.2500.
4,40-(2,4,6-Trimethyl-1,3-phenylene)bis(methylene)bis(3,5-di-
phenyl-1H-pyrazole) (H2L5). The above general pyrazole pre-
paration procedure was followed with f (500 mg, 0.60 mmol),
and a white solid H2L5 was obtained. (468 mg, 95%).1H NMR
(400 MHz, DMSO-d6, 25 ꢀC, ppm): δ = 12.80 (s, 2H) 7.31-
7.15 (m, 16H), 6.96 (s, 4H), 6.24 (s, 1H), 3.71 (s, 4H), 1.73 (s,
6H), 1.36 (s, 3H). 13C NMR (100 MHz, DMSO-d6, 25 ꢀC, ppm):
δ = 135.1, 134.4, 133.4, 129.2, 128.4, 127.6, 127.1, 113.2, 25.0,
19.9, 16.1. MS (MALDI-TOF) m/z: Anal. calcd for [C41H36-
N4 þ Na]þ, 607.2832; found: 607.2831.
employed for 9 8NO3h was followed except that H2L2 (19.7 mg,
3
0.05 mmol) was used as the starting material. Yield: 49 mg
(80%). The PF6h salt of 2 was obtained by adding a 10-fold
excess of KPF6 to its aqueous solution at 60 ꢀC, which resulted in
the immediate deposition of 2 4PF6h as yellow microcrystals in
3
quantitative yield. The crystals were filtered, washed with a
minimum amount of cold water, and dried. 1H NMR (400 MHz,
CD3CN, 25 ꢀC, ppm) δ = 8.31-8.30 (m, 8H, phen-H2,9), 8.13-
8.11 (m, 8H, phen-H4,7), 8.09 (s, 8H, phen-H5,6), 7.93-7.90 (m,
8H, phen-H3,8), 7.59-7.57 (m, 8H), 7.44-7.42 (m, 8H), 3.98 (s,
8H, L2-CH2), 2.44 (s, 24H, L2-CH3). 13C NMR (100 MHz,
CD3CN, 25 ꢀC, ppm): δ = 207.9, 153.1, 152.8, 152.5, 150.4,
148.7, 148.5, 142.7, 142.3, 132.2, 129.1, 128.7, 127.5, 123.2,
114.3, 82.2, 31.2, 26.2, 15.5. ESI-MS (acetonitrile) m/z: 1111.6
[2 2PF6h]2þ, 693.2 [2 PF6h]3þ, 483.3 [2]4þ. Found: C, 46.85; H,
3
3
3.33; N, 8.67. Calcd for C100H80N16F24P4Pd4 3H2O (%): C,
3
46.82; H, 3.38; N, 8.74. Unfortunately the crystals were too
small to collect the X-ray data.
{[(bpy)Pd]4L2 }(NO3)4 (3 4NO3h). The same procedure as
2
3
employed for 9 8NO3h was followed except that [(bpy)2Pd2-
3
(NO3)2](NO3)2 (39 mg, 0.1 mmol) and H2L2 (19.7 mg, 0.05
mmol) were used as the starting material. Yield: 55.7 mg (95%).
The PF6h salt of 3 was obtained by adding a 10-fold excess of
KPF6 to its aqueous solution at 60 ꢀC, which resulted in the
2,20-(1,4-Phenylenebis(methylene))bis(1,3-diphenylpropane-
1,3-dione) (f). The above general bis(1,3-diphenylpropane-1,3-
dione) preparation procedure was followed with 1,4-bis(bromo-
methyl)benzene (500 mg, 1.89 mmol) to give f as a light-yellow
powder. (1.00 g, 95%). 1H NMR (400 MHz, CDCl3, 25 ꢀC, ppm):
δ = 7.86-7.84 (m, 8H), 7.51-7.47 (m, 4H), 7.39-7.35 (m, 8H),
7.12 (s, 4H), 5.43-5.40 (t, J = 6.68 Hz, 2H), 3.37-3.35 (d, J =
6.64 Hz, 4H). 13C NMR (100 MHz, CDCl3, 25 ꢀC, ppm):
δ = 195.3, 137.4, 135.9, 133.4, 129.2, 128.8, 128.5, 58.9, 34.6.
MS (EI) m/z: Anal. calcd for [C38H30O4 þ Na]þ, 573.2036;
found: 573.2032.
immediate deposition of 3 4PF6h as yellow microcrystals in
3
quantitative yield. The crystals were filtered, washed with a
minimum amount of cold water, and dried. ESI-MS (aceto-
nitrile) m/z: 1062.1 [3 2PF6h]2þ, 660.1 [3 PF6h]3þ, 458.8 [3]4þ
Found: C, 44.38; H, 3.60; N, 9.09. Calcd for C92H80F24N16-
.
3
3
P4Pd4 4H2O (%): C, 44.42; H, 3.57; N, 9.01. The single crystals
3
suitable for X-ray determination were grown by the vapor
diffusion of diethyl ether into a 1.0 mM solution of 3 4PF6h in
acetonitrile at room temperature.
3
1,4-Bis((3,5-diphenyl-1H-pyrazol-4-yl)methyl)benzene (H2L6).
The above general pyrazole preparation procedure was followed
{[(phen)Pd]4L3 }(NO3)4 (4 4NO3h). The same procedure as
2
3
employed for 9 8NO3h was followed except that H2L3 (17.2 mg,
0.05 mmol) was used as the starting material. Yield: 55 mg
3
(31) Maverick, A. W.; Buckingham, S. C.; Yao, Q.; Bradbury, J. R.;
Stanley, G. G. J. Am. Chem. Soc. 1986, 108, 7430–7431.
(95%). The PF6h salt of 4 was obtained as yellow microcrystals

7792 Inorganic Chemistry, Vol. 49, No. 17, 2010
Ning et al.
in quantitative yield. 1H NMR (400 MHz, CD3CN, 25 ꢀC, ppm)
δ = 8.96-8.94 (d, J = 6.48 Hz, 8H, phen-H2,9), 8.56-8.54 (d,
J= 6.48 Hz, 8H, phen-H4,7), 8.19 (s, 8H, phen-H5,6),7.94-7.91 (dd,
J = 6.48 Hz, 8H, phen-H3,8), 4.15 (s, 8H, L4-CH2), 2.40 (s, 24H,
immediate deposition of 7 4PF6h as yellow microcrystals in
3
1
quantitative yield. H NMR (500 MHz, CD3CN, 25 ꢀC, ppm)
0
0
δ = 8.36-8.24 (m, 16H, bpy-H6,6 ; bpy-H3,3 ), 8.10-8..01 (m,
0
0
8H,; bpy-H5,5 ), 7.70-7.63 (m, 8H, bpy-H4,4 ), 7.00 (s, 2H;
L4-CH3); ESI-MS (acetonitrile) m/z: 1062.0 [4 2PF6h]2þ, 657.8
L5-Ph-H), 3.83 (s, 8H; L5-CH2), 2.27 (s, 6H), 2.12 (s, 9H), 2.06 (s,
3
[4 PF6h]3þ, 457.1 [4]4þ. Found: C, 45.20; H, 3.23; N, 9.09. Calcd
24H); ESI-MS (acetonitrile) m/z: 1255.1 [7 4PF6h]2þ, 788.1
3
3
for C92H76F24N16P4Pd4 2H2O (%): C, 45.15; H, 3.29; N, 9.16.
{[(bpy)Pd]4L3 }(NO3)4 (5 4NO3h). The same procedure as
[7 3PF6h]3þ. Found: C, 38.88; H, 4.46; N, 8.86. Calcd for C82-
3
3
H84N16F24P4Pd4 13H2O (%): C, 38.88; H, 4.38; N, 8.85. The
single crystals suitable for X-ray determination were grown by
the vapor diffusion of diethyl ether into a 1.0 mM solution of
2
3
3
employed for 9 8NO3h was followed except that [(bpy)2Pd2-
3
(NO3)2](NO3)2 (39 mg, 0.1 mmol) and H2L3 (17.2 mg, 0.05
mmol) were used as the starting material. Yield: 54 mg (95%).
The PF6h salt of 5 was obtained as yellow microcrystals in
quantitative yield. 1H NMR (400 MHz, DMSO-d6, 25 ꢀC, ppm)
7 4PF6h in acetonitrile at room temperature.
3
{[(bpy)Pd]4L6 }(NO3)4 (8 4NO3h). The same procedure as
2
3
employed for 9 8NO3h was followed except that [(bpy)2Pd2-
3
δ = 8.68-8.66 (d, J = 8.22 Hz, 8H, bpy-H6,6 ), 8.52-8.42 (m,
(NO3)2](NO3)2 (39 mg, 0.1 mmol) and H2L6 (27.1 mg, 0.05
mmol) were used as the starting material. Yield: 53 mg (95%).
The PF6h salt of 8 was obtained as yellow microcrystals in
quantitative yield. 1H NMR (400 MHz, CD3CN, 25 ꢀC, ppm) δ
= 8.08-8.06 (m, 16 H, DBM-PhH), 7.78 (d, J = 5.6 Hz, 8 H,
0
4
0
0
0
16H, bpy-H3,3 ; bpy-H4,4 ), 7.86-7.82 (m, 8H, bpy-H5,5 ; L ),
7.33-7.25 (m, 4H), 7.22 (s, 4H), 4.18 (s, 8H, L4-CH2), 2.43 (s,
24H, L4-CH3); ESI-MS (acetonitrile) m/z: 1013.6 [5 2PF6h]2þ
,
3
626.4 [5 PF6h]3þ, 433.3 [5]4þ. Found: C, 41.91; H, 3.63; N, 9.39.
3
0
0
0
0
Calcd for C84H76F24N16P4Pd4 5H2O (%): C, 41.95; H, 3.60; N,
9.32.
bpy-H6,6 ), 7.31-7.35 (m, 24 H, bpy-H3,3 4,4 5,5 ), 7.15-7.11 (m,
8H, DBM-PhH), 6.97-6.93 (m, 16H, DBM-PhH), 6.28 (s, 8H,
PhH), 3.86 (s, 8H, CH2); ESI-MS (acetonitrile) m/z: 759.1
3
{[(bpy)Pd]4L4 }(NO3)4 (6 4NO3h). The same procedure as
2
3
[8 PF6h]3þ, 532.6 [8]4þ. Found: C, 50.65; H, 3.40; N, 8.08; Calcd
employed for 9 8NO3h was followed except that [(bpy)2Pd2-
3
3
(NO3)2](NO3)2 (39 mg, 0.1 mmol) and H2L4 (20.18 mg, 0.05 mmol)
were used as the starting material. Yield: 63.6 mg (95%). The PF6h
salt of 6 was obtained as yellow microcrystals in quantitative yield.
for C116H88N16 F24 P4Pd4 2H2O (%): C, 50.71; H, 3.37; N, 8.16.
3
Acknowledgment. This project was supported by National
Natural Science Foundation of China (no. 20772152).
ESI-MS (acetonitrile) m/z: 1004.4 [6 2PF6h]2þ, 621.5 [6 PF6h]3þ
,
-
3
3
429.8 [6]4þ. Found: C, 50.73; H, 3.89; N, 7.82. Calcd for C122H100
F24N16P4Pd4 5H2O (%): C, 50.78; H, 3.84; N, 7.77.
Supporting Information Available: 1H NMR and 13C NMR-
spectra of a-f and H2Ln (n labeled by 1, 2, 3, 4, 5, 6). Tables of
selected bond lengths and angles for 1, 3, and 7; Packing
diagrams of 1, 3, and 7; X-ray crystallographic files in CIF
format for complexes 1, 3, and 7; and UV-vis and fluorescence
spectra. This material is available free of charge via the Internet
at http://pubs.acs.org.
3
{[(bpy)Pd]4L5 }(NO3)4 (7 4NO3h). The same procedure as
2
3
employed for 9 8NO3h was followed except that [(bpy)2Pd2-
3
(NO3)2](NO3)2 (39 mg, 0.1 mmol) and H2L5 (35.05 mg, 0.05
mmol) were used as the starting material. Yield: 50 mg (75%).
The PF6h salt of 7 was obtained by adding a 10-fold excess of
KPF6 to its aqueous solution at 60 ꢀC, which resulted in the