Structure of μ-oxo-bis{{2,2′-[propane-1,3-diylbis (aminomethyl)]diphenolato}oxorhenium(V)}

Article abstract of DOI:10.1023/A:1021192725915

In the title compound, C₃₄H₄₀N₄₀7Re ₂, each of the two Re(V) atoms is hexacoordinated by two amine nitrogens, two phenol oxygens, and two axial oxygens. The compound is a binuclear complex with an O=Re-O-Re=O backbone and nearly octahedral coordination geometry at each Re atom. The Re=O bond distance is 1.720(14) A and the Re-O bridge bond distance is 1.938(12) A. The equatorial plane Re-O bond distances are 1.992(14) and 2.012(13) A, whereas the Re-N bond distances are 2.129(15) and 2.187(16) A.

Full text of DOI:10.1023/A:1021192725915

C
Journal of Chemical Crystallography, Vol. 32, No. 11, November 2002 ( 2002)
Structure of -oxo-bis{{2,20-[propane-1,3-diylbis
(aminomethyl)]diphenolato}oxorhenium(V)}
Wen-Tao Huang,(1) Hsueh-Hua Yao,(1) Bor-Hann Chen,(2)
Fen-Ling Liao,(3) and Jem-Mau Lo(4)
Received May 20, 2002
In the title compound, C34H40N4O7Re2, each of the two Re(V) atoms is hexacoordinated
by two amine nitrogens, two phenol oxygens, and two axial oxygens. The compound is a
==
==
binuclear complex with an O Re O Re O backbone and nearly octahedral coordination
˚
==
bond distance is 1.938(12) A. The equatorial plane Re O bond distances are 1.992(14) and
geometry at each Re atom. The Re O bond distance is 1.720(14) A and the Re O bridge
˚
˚
˚
2.012(13) A, whereas the Re N bond distances are 2.129(15) and 2.187(16) A.
KEY WORDS: Oxorhenium(V); hexacoordinate; binuclear; octahedral coordination.
coordinated with rhenium atoms8–11 to attain clin-
ical trials. We describe here the synthesis and
characterization of a rhenium(V) complex with
Introduction
Both rhenium (Re) and technetium (Tc),
with similar valence electron configurations in
the group VIIa, might be expected to form com-
plexes that have structural and biological similar-
ities. Numerous 99mTc-labeled radiopharmaceu-
ticals are now widely used for gamma images
in diagnostic nuclear medicine.1–3 Among rhe-
nium radioisotopes, both 186Re and 188Re are
beta emitters with therapeutically useful ener-
gies which warrant the potential utility of Re-
labeled radiopharmaceuticals. Recent studies in
radiopharmacology involve the exploitation of
the coordination chemistry of rhenium to de-
velop new radiopharmaceuticals.4–7 Hence, inter-
est is aroused in synthesizing polydentate ligands
an amine-phenol ligand, 1.
Experimental
N,N0-Bis(2-hydroxybenzyl)-1,3-diamino-
propane was synthesized according to the proce-
dure reported in Pillai et al.11 The mixture of sal-
icylaldehyde (40 mmol) and 1,3-diaminopropane
(20 mmol) in 100 mL ethanol was refluxed for
6 h and then placed in a freezer for 24 h. Crystals
were harvested by filtration and purified by
recrystallization from hot ethanol. N,N0-Bis(2-
hydroxybenzyl)-1,3-diiminopropane, in 100 mL
ethanol, was reduced by adding 80 mmol NaBH4
and was stirred overnight at room temperature.
Addition of 100 mL of water gave a white solid of
N,N0-bis(2-hydroxybenzyl)-1,3-diaminopropane.
Bu4NReOCl4 was synthesized according to the
procedure described by Cotton et al.12 The white
precipitate of Bu4NReO4 was collected and dried
(1) Department of Radiological Technology, Yuanpei Institute of
Science and Technology, Hsinchu, Taiwan, Republic of China.
(2) Taiwan Salt Corporation, Tainan, Taiwan, Republic of China.
(3) Department of Chemistry, National Tsing Hua University,
Hsinchu, Taiwan, Republic of China.
(4) Department of Nuclear Science, National Tsing Hua University,
Hsinchu, Taiwan, Republic of China.
To whom correspondence should be addressed.
465
C
1074-1542/02/1100-0465/0 2002 Plenum Publishing Corporation

466
Huang, Yao, Chen, Liao, and Lo
by mixing Bu4NCl (2 M, 20 mL) and NH4ReO4
(20 mmol) in distilled water. Bu4NReO4 was
bubbled with dry HCl in 100 mL of dry ethanol.
The brown precipitate was collected and dried
in vacuo without purification. N,N0-Bis(2-
hydoxybenzyl)-1,3-diaminopropane (0.84 mmol)
was added to solid Bu4NReOCl4 (0.42 mmol) in
dry ethanol. The reaction mixture was refluxed for
3 h and then stirred for 24 h at room temperature.
The blue solution was concentrated until dark
blue crystals of Re(V)-complex were formed.
The crystals were then dissolved in 95% ethanol
at 75 C and the obtained solution was allowed
to stand at room temperature for a few days
whereupon crystals suitable for X-ray structure
analysis were formed.
Fig. 1. ORTEP16 diagramwiththeatomic-numberingscheme
for 1. Ellipsoids are drawn at the 50% probability level. The
hydrogen atoms have been omitted for clarity.
oxygen atom. The characteristic feature is the
Crystal data for 1 were collected with
a Siemens Smart-CCD13 diffractometer with
graphite monochromated Mo K radiation ( =
==
==
presence of the O Re O Re O backbone
which shows a considerable deviation from
linearity in the Re O Re angle (164.5(7) ). The
˚
0.71073 A, ω-scans with a 0.3 step in ω and
Table 1. Crystal Data and Structure Refinement
10 s/frame exposure) at 293(2) K. The struc-
ture was solved by direct method and refined by
a full-matrix least squares again |F2| using the
program SHELXTL-97.14 Absorption correction
was based on symmetry-equivalent reflections us-
ing the SHELXTL-PC program. Non-hydrogen
atoms were refined with anisotropic displace-
ment parameters; hydrogen atoms bound to car-
bon were placed in the calculated positions and
refined using a riding model with isotropic dis-
placement parameters 1.2 times those of the par-
ent carbon atom. The absolute structure of 1 with
noncentrosymmetric structure was determined by
Flack parameter.15 The structures are presented
as ORTEP16 plots at the 50% probability level in
Fig. 1. Crystal data and data collection are sum-
marized in Table 1. Atomic coordinates and equiv-
alent isotropic displacement parameters are given
in Table 2, and the selected bond lengths and an-
gles are listed in Table 3.
Compound
CCDC deposit no.
Color/shape
(C17H20N2O2ReO)2O
CCDC-1003/6182
Blue/columnar
Chemical formula
Formula weight
Temperature, K
Crystal system
Space group
C34H40N4O7Re2
989.10
293(2)
Monoclinic
Cc
˚
Unit cell dimensions
a = 13.8462(2) A
˚
b = 27.00130(10) A
˚
c = 9.68870(10) A
= 92.2470(10)
3
˚
Volume, A
3619.48(7)
Z
4
Density(calculated), Mg/m3
Sample dimension, mm
Absorption coefficient, mm
F(000)
1.815
0.35 0.08 0.06
6.733
1
1912
Diffractometer
Siemens SMART/CCD area
detector
range for data collection, deg
Index ranges
1.51–25.71
16
h
12, 29
k
32,
11
8073
l
11
Reflections measured
Independent/observed reflections 4412/4182
Data/restrains/parameters
Goodness of fit on F2
Final R indices [I > 2 (I)]
R indices (all data)
4412/2/424
1.142
R1 = 0.0473, wR2 = 0.1221
R1 = 0.0515, wR2 = 0.1273
1.521 and 1.565
Results and discussion
The title compound consists of two indepen-
dent {2,20-[propane-1,3-diylbis(aminomethyl)]
diphenolato}oxorhenium(V) units bridged by an
Largest diff. peak and hole,
3
˚
e/A

C34H40N4O7Re2
467
Table 2. Atomic Coordinates and Equivalent Isotropic Displacement
Parameters (A ) for Non-Hydrogen Atoms in (C17H20N2O2ReO)2O
˚
Table 3. Selected Bond Lengths (A) and Bond Angles (deg)
2
˚
Bond length
----
Atom
x
y
Z
U(eq)
----
Re1 O5
Re1 O6
1.720(14)
1.992(14)
2.129(15)
1.665(13)
1.50(3)
1.938(12)
2.012(13)
2.187(16)
1.924(12)
1.52(3)
----
----
Re1 O1
Re1 O2
----
----
Re1 N2
Re1 N1
----
Re1
Re2
O1
O2
O3
O4
O5
O6
O7
N1
N2
N3
N4
C1
C2
C3
C4
0.0000(1)
0.0143(1)
0.1005(11) 0.0548(5)
0.0949(12) 0.0525(5)
0.0974(1)
0.1689(1)
0.0001(1)
0.3396(1)
0.037(1)
0.034(1)
----
Re2 O7
Re2 O5
----
----
N2 C4
N1 C17
0.0812(15) 0.051(3)
0.1004(14) 0.052(4)
0.2833(12) 0.037(3)
0.2680(13) 0.044(3)
0.1584(13) 0.039(3)
0.1644(16) 0.055(4)
0.5094(13) 0.044(3)
0.0766(15) 0.044(4)
0.0512(15) 0.044(4)
0.3811(15) 0.039(4)
0.3664(15) 0.039(4)
0.1670(20) 0.055(6)
0.1220(20) 0.055(6)
0.1580(20) 0.047(5)
0.0860(20) 0.057(6)
0.0290(20) 0.043(5)
0.0490(30) 0.070(7)
0.1590(40) 0.082(9)
0.2380(30) 0.080(8)
0.2170(30) 0.079(9)
0.1100(20) 0.041(5)
0.0470(20) 0.051(5)
0.1170(30) 0.064(6)
0.0810(30) 0.081(8)
0.0220(40) 0.107(12)
0.0930(30) 0.069(7)
0.0570(20) 0.054(6)
0.1420(20) 0.067(7)
0.4830(20) 0.044(5)
0.4510(20) 0.062(6)
0.4710(20) 0.051(6)
0.3970(20) 0.052(5)
0.2780(20) 0.047(6)
0.2280(20) 0.056(6)
0.1260(30) 0.066(6)
0.0710(30) 0.065(7)
0.1210(20) 0.050(5)
0.2240(20) 0.047(5)
0.2391(18) 0.039(4)
0.1280(20) 0.045(5)
0.0740(30) 0.059(6)
0.1240(30) 0.067(7)
0.2360(30) 0.060(7)
0.2970(20) 0.047(5)
0.4130(20) 0.049(6)
Bond angle
0.0685(9)
0.2269(4)
---- ----
----
----
----
Re1 O5 Re2 164.5(7)
O1 Re1 O6 101.1(6)
0.1230(10) 0.2119(4)
0.0006(10) 0.1412(4)
0.0031(12) 0.0736(5)
0.0155(11) 0.1783(4)
0.1116(13) 0.1455(6)
0.1214(13) 0.1449(5)
0.1175(12) 0.1237(5)
0.1092(12) 0.1075(5)
0.0853(18) 0.1880(8)
0.0072(18) 0.2124(7)
0.0955(17) 0.1847(8)
0.2097(17) 0.1147(8)
0.2494(15) 0.0857(8)
0.3450(20) 0.0827(10)
0.3900(20) 0.0539(11)
0.3380(20) 0.0265(11)
0.2380(30) 0.0259(9)
0.1924(15) 0.0550(6)
0.1976(16) 0.0524(7)
0.2480(20) 0.0170(8)
0.3420(20) 0.0072(12)
0.3840(20) 0.0317(14)
0.3354(18) 0.0681(10)
0.2398(19) 0.0787(9)
0.1932(17) 0.1166(10)
0.1079(16) 0.0846(7)
0.0280(20) 0.0508(7)
0.0748(17) 0.0698(7)
0.2067(16) 0.1230(8)
0.2534(18) 0.1508(8)
0.3433(16) 0.1386(9)
0.3924(19) 0.1672(9)
0.3484(17) 0.2063(8)
0.2586(15) 0.2219(8)
0.2122(16) 0.1945(7)
0.1581(15) 0.2236(6)
0.1867(16) 0.2519(8)
0.2746(18) 0.2466(9)
0.3420(20) 0.2149(9)
0.3183(19) 0.1856(8)
0.2261(16) 0.1888(7)
0.2045(17) 0.1570(10)
----
----
----
O2 Re1 O6
100.5(7)
87.9(6)
171.0(6)
110.3(16)
N1 Re1 O6
---- ----
87.2(7)
----
----
N2 Re1 O6
---- ----
O1 Re1 N2 169.6(5)
---- ----
O2 Re1 N1
---- ----
O5 Re1 O6 164.4(6)
---- ----
113.4(16)
C1 N1 C17
C3 N2 C4
the Re O bridge bond distances (1.938(12),
1.924(12) A), and the Re N distances (2.129(15),
2.187(16) A) are consistent with the correspond-
˚
˚
ing values reported in the literature.11,17,18
Of particular note is the Re O Re angle of
164.5(7) which is considerably smaller than that
reported in Pillai et al.11 (169.2(9)–169.4(4) ).
The octahedron is appreciably distorted, with the
four equatorial donor atoms being displaced away
C5
C6
C7
C8
C9
C10
C11
C12
C13
C14
C15
C16
C17
C18
C19
C20
C21
C22
C23
C24
C25
C26
C27
C28
C29
C30
C31
C32
C33
C34
==
from the Re O bond. The effect is small for
==
the N1 and N2 atoms (N1 Re1 O6 87.2(7) ,
N2 Re1 O6 87.9(6) ), but is more important
for the atoms O1 and O2 (O1 Re1 O6
101.1(6) , O2 Re1 O6 100.5(7) ). Besides,
the trans O1 Re1 N2 and trans O2 Re1 N1
angles are 169.6(5) and 171.0(6) , respectively.
The least-square planes show that the Re atom
is 0.1392(4) and 0.1523(5) A out of the plane
defined by the coordinated atoms of tetradentate
ligand toward the terminal oxygen atoms (Fig. 1).
==
==
19
==
˚
Acknowledgment
We thank the National Science Council for finan-
cial support under Grant NSC89-2113-M-264-001.
References
1. Nerinckx, R.D.; Canning, L.R.; Piper, I.M.; Nowotnik, D.P.;
Pickett, R.D.; Holmes, R.A.; Volkert, W.A.; Forster, A.M.;
Weisner, P.S.; Marriott, J.A.; Chaplin, S.B. J. Nucl. Med. 1987,
28, 191–202.
2. Kelly, J.D.; Forster, A.M.; Highly, B.; Archer, C.M.; Booker,
F.S.; Canning, L.R.; Chiu, K.W.; Edwards, B.; Gill, H.K.;
dinuclear structure is comparable to those found
for similar ( -oxo)bis(oxo)rhenium(V)9 and the
( -oxo)bis(oxo)technetium(V) complexes.12 The
˚
==
Re O bond distances (1.720(14), 1.665(13) A),

468
Huang, Yao, Chen, Liao, and Lo
McPartlin, M.; Nagle, K.R.; Latham, I.A.; Pickett, R.D.; Storey,
10. Pillai, M.R.A.; Barnes, C.L.; Schlemper, E.O. Polyhedron 1994,
13, 701–708.
11. Pillai, M.R.A.; John, C.S.; Lo, J.M.; Schlemper, E.O.; Troutner,
D.E. Inorg. Chem. 1990, 29, 1850–1856.
12. Cotton F.A.; Lippard S.J. Inorg. Chem. 1966, 5, 9–16.
13. Siemens. SMART and SAINT, Data Collection and Processing
Software for the SMART System; Siemens Analytical X-ray In-
struments Inc.: Madison, WI, 1995.
14. Sheldrick, G.M. SHELXL97;UniversityofGo¨ttingen:Germany.
1997.
A.E.; Webbon, P.M. J. Nucl. Med. 1993, 34, 222–227.
3. Wackers, F.J.T.; Berman, D.S.; Maddahi, J.; Watson, D.D.;
Beller, G.A.; Strauss H.W.; Boucher, C.A.; Picard, M.; Holman,
B.L.; Fridrich, R; Inglese, E.; Delaloye, B.; Bischof-Delaloye,
A.; Camin, L.; McKusick, K. J. Nucl. Med. 1989, 30, 301–
311.
4. Alyafei, S.; Tomiyoshi, K.; Sarwar, M.; Ahmed, K.; Zhang, H.;
Oriuchi, N.; Inoue, T.; Endo, K. Nucl. Med. Biol. 1999, 20,
551–557.
5. Ha¨feli, U.; Tiefenauer, L.X.; Schubiger, P.A.; Weder, H.G. Nucl.
Med. Biol. 1991, 18, 449–454.
6. Zhen, W.; Han, H.; Anguiano, M.; Lemere, C.A.; Cho, C.G.;
Lansbury, P.T. J. Med. Chem. 1999, 42, 2805–2815.
7. Bandoli, G.; Nicolini, M.; Mazzi, U.; Refosco, F. J. Chem. Soc.,
Dalton Trans. 1984, 2505–2511.
15. Flack. H.D. Acta Crystallogr. Sect. A 1983, 39, 876–881.
16. Johnson, C.K. ORTEP-II;reportedORNL-5138;OakRidgeNa-
tional Laboratory: Oak Ridge, TN, 1976.
17. Stavropoulos, P.; Edwards, P.G.; Wilkinson, G.; Motevalli, M;
Malik, K.M.A.; Hursthouse, M.B. J. Chem. Soc., Dalton Trans.
1985, 2167–2175.
8. Mazzi, U.; Refosco, F.; Tisato, F.; Bandoli, G.; Nicolini, M. J.
Chem. Soc., Dalton Trans. 1986, 1623–1628.
18. Shandles, R.; Schlemper, E.O.; Murmann, R.K. Inorg. Chem.
1971, 10, 2785–2789.
9. Tisato, F.; Refosco, F.; Moresco, A.; Bandoli, G.; Mazzi, U.;
Nicolini, M. J. Chem. Soc., Dalton Trans. 1990, 2225–2232.
19. Pietzsch, H.J.;Spies, H.;Leibnitz, P.;Reck, G. Polyhedron1995,
14, 1849–1853.