Synthesis of propionamide pyridine and pyridine N-oxide ligands

Article abstract of DOI:10.1002/jhet.5570440117

(Chemical Equation Presented) A new set of pyridine and pyridine N-oxides functionalized with N,N-dimethylpropionamide pendant groups in the 2- and 2,6-positions have been prepared from the combination of 2-chloromethylpyridine and 2,6-bis(chloromethyl) pyridine with α-lithio N,N-dimethyl acetamide. The coordination interaction between 2-(N,N-dimethylpropionamide) pyridine N-oxide (10) and Tb(NO₃)₃ has been unambiguously defined via single crystal X-ray diffraction analysis of Tb(10)(NO₃) ₃(H₂O).

Full text of DOI:10.1002/jhet.5570440117

Jan-Feb 2007
99
Synthesis of Propionamide Pyridine and Pyridine N-oxide Ligands
Iris Binyamin,a Sylvie Pailloux,a Benjamin P. Hay,b Brian M. Rapko,b Eileen N. Duesler,a
and Robert T. Painea*
aDepartment of Chemistry, University of New Mexico, Albuquerque, NM 87131, USA
Fax: 505-277-2609 E-mail: rtpaine@unm.edu
bChemical Sciences Division, Pacific Northwest National Laboratory, P. O. Box 999, Richland, WA 99352, USA
Received: March 16, 2006
N
N
O
O
O
CH3
CH3
CH3
CH3
N
N
N
N
O
O O
O O
H3C
H3C
CH3
CH3
H3C
H3C
CH3
CH3
N
N
N
N
A new set of pyridine and pyridine N-oxides functionalized with N,N-dimethylpropionamide pendant
groups in the 2- and 2,6-positions have been prepared from the combination of 2-chloromethylpyridine and
2,6-bis(chloromethyl) pyridine with ꢀ-lithio N,N-dimethyl acetamide. The coordination interaction
between 2-(N,N-dimethylpropionamide) pyridine N-oxide (10) and Tb(NO3)3 has been unambiguously
defined via single crystal X-ray diffraction analysis of Tb(10)(NO3)3(H2O).
J. Heterocyclic Chem., 44, 99 (2007).
also reported that 2-(methylphosphine oxide) and 2,6-bis-
(methylphosphine oxide) substituted pyridines 5, 6 and
pyridine N-oxides 7, 8 can be prepared. The latter two
ligand types act as especially strong chelating ligands
toward lanthanide and actinide ions despite the fact that
the chelate rings contain seven atoms [7-18]. Indeed,
representatives of the ligand 8 have proven to be very
effective liquid-liquid extractants for trivalent lanthanide
and actinide ions [19-21]. Due to the interesting ligation
behavior of these ligands we have continued to seek
synthetic approaches for functionally varied pyridine and
pyridine N-oxide compounds that might serve as useful
INTRODUCTION
Pyridine and pyridine N-oxide rings offer the possibility
to serve as platforms for the assembly of a variety of
useful chelating ligands. Numerous investigators have
described the syntheses of 2-(phosphino)pyridines, 1 and
2,6-bis(phosphino)pyridines, 2 and these generally act as
good ligands toward the softer transition metal cations
[1,2].
Recently, we have described syntheses for
analogous 2-phosphine oxide substituted pyridine, 3, and
pyridine N-oxide, 4, molecules and these are found to
effectively chelate with harder metal ions such as
represented by lanthanide and uranyl ions [3-6]. We have
R2P
N
PR2
N
PR2
N
PR2
N
PR2
OH
4
O
O
1
2
3
N
N
N
N
OH
PR2
PR2
OH
R2P
PR2
PR2
R2P
O
O
O
O
O
O
5
6
7
8

100
I. Binyamin, S. Pailloux, B. P. Hay, B. M. Rapko, E. N. Duesler, and R. T. Paine
Vol 44
are clearly absent in the spectra recorded for compounds 9
and 11.
ligands. In this report, we describe the facile synthesis of
2-(N,N-dimethylpropionamide) pyridine 9, 2-(N,N-
dimethylpropionamide) pyridine N-oxide 10, 2,6-bis(N,N-
dimethylpropionamide) pyridine 11, and 2,6-bis(N,N-
dimethylpropionamide) pyridine N-oxide 12 as well as
crystal structure determinations for free ligand 10 and a
1:1 complex formed with Tb(NO3)3.
1
The H and 13C{1H} NMR spectra for 9 – 12 confirm
1
the purity of the compounds. The H NMR line widths
for the N-oxide compounds are slightly broadened relative
to the line widths observed for the pyridine progenitors,
consequently several long range JHH interactions less than
2 Hz are not resolved for 10 and 12. Assignments were
made with the use of COSY and HMQC methods. The
amido groups have inequivalent methyl group
environments resulting from hindered rotation within the
– C(O)–NMe2 units. Hence, two methyl resonances
appear in the 1H and 13C{1H} spectra. The exo C2H4 arms
RESULTS AND DISCUSSION
The synthetic methodology involves combinations of
ꢀ-lithio N,N-dimethylacetamide [22] with 2-chloromethyl
pyridine (1:1) and 2,6-bis(chloromethyl) pyridine (2:1) in
THF. These combinations produce, in moderate yields, 2-
(N,N-dimethylpropionamide) pyridine, 9, and 2,6-
bis(N,N-dimethylpropionamide) pyridine, 11, as a light
yellow oil and a white powder, respectively (Schemes 1
and 2). Subsequent oxidations with OXONE give, in high
yields, 2-(N,N-dimethylpropionamide) pyridine N- oxide,
1
in each molecule produce two triplets in the H NMR
spectra: one upfield of the NMe2 resonance that is
assigned to C8H2 in 9 and 10 or C6H2 in 11 and 12, and
one downfield of the NMe2 resonance due to C7H2 in 9
and 10 or C5H2 in 11 and 12. Upfield shifts of the
Scheme 1
4
O
THF
-LiCl
OXONE
5
6
3
2
+
LiCH2C
N
N(CH3)2
7
N
O
N
Cl
8
O
O
C1H3
CH3
CH3
N
N
C1H3
9
10
Scheme 2
4
O
3
THF
OXONE
LiCH2C
+
2
-2 LiCl
N(CH3)2
N
N
5
N
O
Cl
Cl
O
N
6
O
O
O
H3C
H3C
C1H3
CH3
CH3
H3C
H3C
N
N
N
C1H3
11
12
10, and 2,6-bis(N,N-dimethylpropionamide) pyridine N-
oxide, 12, as a colorless oil and white solid, respectively.
Compounds 9 – 11 are obtained in analytically pure
form while 12 is isolated as a hydrate (12)2•H2O. The
compounds have been fully characterized by
spectroscopic methods and the data are consistent with the
proposed formulations. FAB-MS spectra show (M + H+)
and (M+) ions at appropriate m/z values. Infrared spectra
of the oil, 9, and powder, 11, dispersed in KBr pellets
show an adsorption at 1647 cm-1 and 1643 cm-1,
respectively, that are assigned to ꢁCO of the amide group.
The N-oxidized molecules 10 and 12 show adsorptions at
1644 and 1243 cm-1 and 1644 and 1257 cm-1, respectively.
These bands are assigned to ꢁCO and ꢁNO. The ꢁNO bands
13C{1H} resonances assigned to C2 and C7 in 10 and C2
and C5 in 12 relative to the corresponding resonances in 9
and 11 are diagnostic of the N-oxidation of the pyridine
ring.
The molecular structure of 10 was unambiguously
determined by single crystal X-ray diffraction methods
and a view of the molecule is shown in Figure 1 [23].
The pyridine N-oxide and amide groups have normal
bond lengths and angles: N1-O1 1.3091(9)Å, C8-O2
1.2286(15)Å, C8-N2 1.3547(13)Å, C9-N2-C10
116.61(13)°, C8-N2-C9 119.27(14)°, C8-N2-C10
123.96(13)°, C7-C8-N2 116.36(11)°, O2-C8-N2
121.89(11)°, O2-C8-C7 121.75(9)°. Interestingly and
somewhat surprisingly, the N1-O1 and C8-O2 bond

Jan-Feb 2007
Synthesis of Propionamide Pyridine and Pyridine N-oxide Ligands
101
expected for a molecule with such large bond dipoles.
The fifth structure, 1.53 kcal/mole in energy above the
computed lowest energy structure, corresponds to the
structure found in the solid state. Given this result, it is
not unreasonable to expect that 10 might further rearrange
to a structure suitable for chelate formation.
Since we are interested in the extraction performance of
ligand types represented by 10 and 12, we have begun to
explore the coordination chemistry of the ligands with
lanthanide ions. Initially, we examined 1:1 and 2:1
combination of 10 with Tb(NO3)3•5H2O in MeOH/CH2Cl2
solutions. In both cases, following standard work-up,
white powders were obtained. Infrared spectra recorded
from KBr pellets showed evidence for ligand binding, e.g.
ꢀꢀCO = 30-40 cm-1 and ꢀꢀNO = 15-30 cm-1; however, CHN
analyses gave consistently low results suggesting that
solvent of crystallization in the lattice was unaccounted
for. All attempts to obtain suitable crystallographic
quality crystals for X-ray analysis failed. At this point, a
ligand deficient mixture, 1:2 (10:Tb), was employed from
which an oily complex was obtained. Single crystals
slowly deposited in the oil and they were recovered by
washing with isopropyl alcohol. Subsequent single crystal
X-ray diffraction analysis showed that a 1:1 complex
formed and a view of the structure is shown in Figure 3
[25]. The Tb(III) is nine-coordinate with the inner sphere
coordination polyhedron generated by six oxygen atoms
from three bidentate nitrate anions, one oxygen atom from
a coordinated water molecule and two oxygen atoms from
one bidentate chelating ligand 10. The key metrical
parameters include Tb-O1 2.272(2) Å, Tb-O2 2.290(2) Å,
N1-O1 1.326(4) Å, C8-O2 1.253(3) Å and these are
consistent with the bidentate chelation. The resulting
Figure 1. Crystal structure of 10 with atom labeling scheme (50%
thermal ellipsoids).
vectors reside on the same side of the molecule: the
atoms C1O1N1C5C6C7C8O2N2 nearly lie in a single
plane (mean deviation, 0.065Å) and planes defined by
N1O1C5C6 and C6C7C8O2 are twisted by 5.6° relative
to each other. This conformation is likely stabilized by
crystal packing forces. Conformational analysis of the
free ligand [24] reveals several low energy forms in the
gas phase. The five most stable conformers are shown in
Figure 2. The global minimum energy structure and the
next three higher energy structures have the N-O and C=O
bond vectors rotated away from each other as would be
Figure 3. Crystal structure of Tb(10)(NO3)3(H2O) with atom
labeling scheme (50% thermal ellipsoids).
Figure 2. The five lowest energy gas-phase conformers for 10.

102
I. Binyamin, S. Pailloux, B. P. Hay, B. M. Rapko, E. N. Duesler, and R. T. Paine
Vol 44
IR(KBr): 1647 cm-1 (ꢀCO); H NMR (CDCl3, 500 MHz): ꢂ =
2.71 (t, 2H, C8H2 J = 7.3 Hz), 2.82 (s, 3H, CH3), 2.87 (s, 3H,
CH3), 3.02 (t, 2H, C7H2 J = 7.3 Hz), 6.99 (ddd, 1H, C5H J = 7.5,
4.8, 1.0 Hz), 7.13 (d, 1H, C3H J = 7.8 Hz), 7.45 (dt, 1H, C4H J =
7.6, 1.9 Hz), 8.39 (dd, 1H, C6H J = 4.0, 1.5 Hz); 13C{1H} NMR
(CDCl3, 125 MHz): ꢂ = 32.9 (C8), 33.6 (C7), 35.7 (C1), 37.4
(C1), 121.5 (C5), 123.7 (C3), 136.6 (C4), 149.4 (C6), 161.3 (C2),
172.4 (C9); MS(FAB): m/z = 179(M + H)+; Anal. Calcd. for
C10H14N2O(178.23): C, 67.39; H, 7.92; N, 15.72. Found: C,
66.86; H, 8.07; N, 15.83.
1
eight-membered chelate ring is somewhat unusual as such
large rings are usually found supported by a smaller five-
or six-member chelate ring formed by other donor groups
present in a multifunctional ligand. It is worth noting that
a
molecular mechanics calculation for the ligand
conformation adopted in the complex (metal removed) is
3.035 kcal/mole higher in energy than the energy of the
global minimum energy structure and 1.50 kcal/mole
higher in energy than the structure of the free ligand
found in the solid state. The modest reorganization
energy clearly favors the formation of the metal chelate
structure.
The infrared spectroscopic data collected for the
complex dispersed in a KBr pellet show small down-
frequency coordination shifts relative to the free ligand,
ꢀꢀCO = -28cm-1 and ꢀꢀNO = -29 cm-1, consistent with the
formation of the chelate structure. Analytical data (CHN)
for the complex are low in carbon which historically has
also been observed by us in lanthanide complexes of 7
and 8 and this may result from incomplete combustion/
competing formation of lanthanide carbides.
Attempts were made to isolate 1:1 or 2:1 complex of 12
with lanthanide nitrates and characterization data for one
2:1 complex proposed as La(12)2(NO3)3(H2O)2 are
provided. The IR data are consistent with the formation
of a bis-tridentate chelate complex: coordination shifts
ꢀꢀCO = -33 cm-1 and ꢀꢀNO = -48 cm-1. However, suitable
single crystals of this complex have not yet been obtained
and a crystal structure determination that would confirm
this proposal remains to be completed.
2-(N,N-dimethylpropionamide)pyridine N-oxide (10). A
suspension of 9 (500 mg, 2.8 mmol), NaHCO3 (0.5 g, 6.0 mmol)
and OXONE (1.25 g, 2.9 mmol) in water (4 mL) and MeOH (12
mL) was stirred under a nitrogen atmosphere at 45-50°C (24 h).
The resulting mixture was filtered and the filtrate was vacuum
evaporated. The residue was treated with fresh MeOH (20 mL),
filtered, and solvent evaporated leaving a colorless oil (550 mg).
Column chromatography (silica gel, 70-230 mesh,
CH2Cl2:MeOH 100:4 ꢃ 100:8 eluant) led to recovery of a
colorless oil 10 (500 mg, 92%). Soluble in CH2Cl2, CHCl3 and
MeOH. IR(KBr): 1243 cm-1 (ꢀNO), 1644 cm-1 (ꢀCO); H NMR
1
(CDCl3, 500 MHz): ꢂ = 2.83 (t, 2H, C8H2 J = 6.8 Hz), 2.86 (s,
3H, CH3), 2.91 (s, 3H, CH3), 3.17 (t, 2H, C7H2 J = 7.1 Hz), 7.12
(m, 2H, C3H, C5H), 7.39 (d, 1H, C4H J = 7.2 Hz), 8.16 (d, 1H,
C6H J = 5.8 Hz); 13C{1H}NMR(CDCl3, 125 MHz):ꢂ = 28.0 (C8),
29.9 (C7), 36.0 (C1), 37.8 (C1), 124.5 (C5), 126.3 (C3), 128.3
(C4), 140.1 (C6), 152.0 (C2), 172.4 (C9). MS(FAB): m/z =
195(M + H)+; Anal. Calcd. for C10H14N2O2 (194.23): C, 61.84;
H, 7.26; N, 14.42. Found: C, 60.95; H, 7.43; N, 14.17.
2,6-Bis(N,N-dimethylpropionamide)pyridine (11). Under a
dry nitrogen atmosphere, a sample of ꢁ-lithio N,N-dimethyl-
acetamide (10 mmol) in dry THF (20 mL) was cooled to 0°C. A
solution of 2,6-bis(chloromethyl)pyridine (0.88 g, 5 mmol) in
THF (20 mL) was injected all at once. After stirring at 23°C (30
min), the solvent was vacuum evaporated and CH2Cl2 (500 mL)
and water (100 mL) were added. The phases were separated and
the organic phase dried over MgSO4. The solvent was then
vacuum evaporated leaving a yellow oil (1.4 g) that was purified
by column chromatography (silica gel 70-230 mesh,
CH2Cl2:MeOH 8:1) from which a white powder (11) was
recovered (650 mg, 46%); mp 87-88°C; soluble in CH2Cl2,
CHCl3, and MeOH. IR(KBr): 1643 cm-1 (ꢀCO); 1H NMR
(CDCl3, 500 MHz): ꢂ = 2.73 (t, 4H, C6H2, J = 7.5 Hz), 2.90 (s,
C1H3, 6H), 2.95 (s, 6H, C1H3), 3.05 (t, 4H, C5H, J = 7.5 Hz),
6.98 (d, 2H, C3H2, J = 7.6 Hz), 7.43 (t, 1H, C4H, J = 7.7 Hz);
13C{1H} NMR (CDCl3, 125 MHz): ꢂ = 33.4 (C6), 34.1 (C5), 36.1
(C1), 37.8 (C1), 121.2 (C3), 137.2 (C4), 160.9 (C2), 173.1 (C7);
MS(FAB): m/z = 278(M + H)+; Anal. Calcd. for C15H23N3O2
(277.36): C, 64.96; H, 8.36; N, 15.15. Found: C, 65.02; H,
8.42; N, 15.08.
EXPERIMENTAL
Chemicals were purchased from Aldrich and VWR. The
starting material ꢁ-lithio N,N-dimethyl acetamide was prepared
as described in the literature [22].
Melting points are
uncorrected and elemental analysis data were obtained from
Galbraith Laboratories. FAB-MS data were obtained from the
Midwest Center for Mass Spectrometry, University of Nebraska.
Infrared spectra were recorded on
a Bruker Tensor 27
spectrometer and H and 13C NMR spectra were obtained on
Bruker 250 and 500 MHz spectrometers. Chemical shifts are
reported in ppm units with +ꢂ values downfield of the reference
Me4Si.
1
2-(N,N-Dimethylpropionamide)pyridine (9). Under a dry
nitrogen atmosphere, a sample of ꢁ-lithio N,N-dimethylaceta-
mide (10 mmol) in dry THF (20 mL) was cooled to 0°C.
A
2,6-Bis(N,N-dimethylpropionamide)pyridine N-oxide (12).
A suspension of 11 (500 mg, 1.8 mmol), NaHCO3 (0.31 g, 3.75
mmol) and OXONE (800 mg, 1.29 mmol) in water (2.7 mL) and
MeOH (8.5 mL) was stirred under nitrogen at 45-50°C (24 h).
The MeOH was then vacuum evaporated and additional water
was added to dissolve the salts. The product was extracted with
CH2Cl2 (3 x 50 mL) and dried (MgSO4). Vacuum evaporation
left a white solid (12)2•H2O that was recrystallized from
CH2Cl2/hexane (500 mg, 92%); mp 79-80°C; soluble in CH2Cl2,
CHCl3, and MeOH. IR(KBr): 1257 cm-1 (ꢀNO), 1645 cm-1 (ꢀCO);
1H NMR (CDCl3, 500 MHz): ꢂ = 1.88 (bs, H2O), 2.80 (t, 4H,
C6H2, J = 6.9 Hz), 2.88(s, 6H, C1H3), 2.96(s, 6H, C1H3), 3.18(t,
solution of freshly distilled 2-chloromethylpyridine (1.27 g, 10
mmol) in dry THF (20 mL) was injected via a septum capped
side-arm and the resulting mixture stirred with a stir bar and
warmed to 23°C (30 min.). The THF was vacuum evaporated
and the residue was treated with CH2Cl2, (250 mL) and H2O (50
mL). The organic phase was collected, dried over MgSO4 and
solvent vacuum evaporated leaving a yellow oil (1.4 g). The oil
was dissolved in CH2Cl2, combined with silica gel (70-230
mesh) and purified by column chromatography (CH2Cl2:MeOH
100:1 ꢃ 100:4 eluant). The product 9 is a light yellow oil (825
mg, 46%); soluble in CH2Cl2 and CHCl3; insoluble in hexane.

Jan-Feb 2007
Synthesis of Propionamide Pyridine and Pyridine N-oxide Ligands
103
[13]
X. Gan, S. Parveen, W. L. Smith, E. N. Duesler and R. T.
4H, C5H2, J = 6.7 Hz), 7.06 (t, 1H, C4H J = 7.0 Hz), 7.25 (d, 2H,
(C3H), J = 7.6 Hz); 13C{1H} NMR (CDCl3, 125 MHz): ꢀ =
28.39 (C6), 30.25 (C5), 36.07 (C1), 37.82 (C1), 125.63 (C3),
125.83 (C4), 151.78 (C2), 172.57 (C7); MS(FAB): m/z = 294(M
+ H)+; Anal. Calcd. for C30H48N6O7 (604.74): C, 59.58; H, 8.00;
N, 13.89. Found: C, 59.32; H, 8.08; N, 13.77.
Paine, Inorg. Chem., 39, 4591 (2000).
[14]
Polyhedron, 24, 2135 (2000).
[15]
Paine, Inorg. Chem., 41, 444 (1992).
[16]
E. M. Bond, E. N. Duesler, R. T. Paine and H. Nöth,
E. M. Bond, N. Donhart, E. N. Duesler, H. Nöth and R. T.
J. H. Matonic, M. P. Neu, R. T. Paine and B. L. Scott, J.
Formation of Complexes: Tb(10)(NO3)3(H2O). A sample of
Tb(NO3)3•5H2O (2.24 g, 5.1 mmol) was dissolved in MeOH ( 5
mL) and combined with 10 (0.5 g, 2.6 mmol) in CH2Cl2. The
mixture was stirred at 23 °C (1 h) and solvent evaporated. The
residue was treated with a 1:1 mixture of MeOH/acetone and the
solution allowed to slowly evaporate. X-ray quality crystals
were obtained. IR(KBr, cm-1): 1228 (ꢁNO), 1616 (ꢁCO). Anal.
Calcd. for C10H16N5O12Tb(557.20): C, 21.56; H, 2.89; N, 12.57.
Found: C, 18.97; H, 2.94; N, 12.57.
La(12)2(NO3)3(H2O)2. A sample of La(NO3)3•6H2O (40 mg,
0.09 mmol) was dissolved in MeOH ( 3 mL) and combined with
5 (60 mg, 0.2 mmol) in CH2Cl2 (3 mL). The solution was stirred
at 23 °C (30 min) and the solvent evaporated. IR(KBr): 1209.0
cm-1 (ꢂNO), 1611.2 cm-1 (ꢂCO); MS(FAB): m/z = 849(M – NO3)+;
Anal. Calcd. For C30H50N9O17La(947.63): C, 38.02; H, 5.32; N,
13.30. Found: C, 34.27; H, 4.67; N, 13.07.
Chem. Soc. Dalton, 2328 (2002).
[17]
X. Gan, R. T. Paine, E. N. Duesler and H. Nöth, J. Chem.
Soc. Dalton, 153 (2003).
[18]
X. Gan, B. M. Rapko, E. N. Duesler and R. T. Paine,
Polyhedron, 24, 469 (2005).
[19] E. M. Bond, U. Engelhardt, T. P. Deere, B. M. Rapko, R. T.
Paine and J. R. FitzPatrick, Solv. Extr. Ion Exch., 15, 381 (1997).
[20]
Paine and J. R. FitzPatrick, Solv. Extr. Ion Exch., 16, 967 (1998).
[21] K. L. Nash, C. Lavallette, M. Borkowski, R. T. Paine and X.
Gan, Inorg. Chem., 41, 5849 (2002).
E. M. Bond, U. Engelhardt, T. P. Deere, B. M. Rapko, R. T.
[22]
(1977).
[23]
R. P. Woodbury and R. W. Rathke, J. Org. Chem., 42, 1688
Crystal structure analysis for 10: C10H14N2O2, Mr = 194.23 g
9.5942(2)Å, b =
mol-1, monoclinic, space group P2(1)/c,
a
=
6.96430(10)Å, c = 15.2146(3)Å, ꢀ = 90°; ꢁ = 97.2160(10)°; ꢂ = 90; V =
1008.54(3)Å3, Z = 4, ꢃ = 1.279 g cm-3, μ = 0.090 mm-1, F(000) = 416,
crystal size = 0.40 x 0.38 x 0.10 mm3. Crystal data collected on a Bruker
X8 Apex2 CCD-based diffractometer with Oxford Cryostream 700 low
temperature device (T = 223(2)K), MoKꢄ radiation (ꢅ = 0.71073Å). A
full sphere of data was collected, 2282 frames, scan width of 0.5° in
omega and phi at 15s/frame. A total of 20,918 reflections (2ꢆ max =
67.80°) gave 4072 independent reflections with 3170(I > 2ꢇ(I)). Data
were processed with SADABS [26] and corrected for absorption (semi-
empirical). The structure was refined with the Bruker SHELXTL
(Version 6.12) [26] software package. All non-hydrogen atoms were
refined anisotropically and all H-atoms were included in idealized
positions with fixed isotropic U’s set to xU(equiv) of the parent atom (x
= 1.3 for aromatic H, x = 1.4 for CH2 and x = 1.5 for CH3).
Crystallographic data deposited at Cambridge Crystallographic Data
Centre as supplementary material.
Acknowledgment. This work was supported by the U. S.
Department of Energy (DOE) with
a grant (DE-FG02-
03ER15419) to UNM from Chemical Sciences, Geosciences and
Biosciences Office, Office of Basic Energy Sciences, Office of
Science and a grant (73759) to PNNL (operated for DOE by
Battelle) from the Environmental Management Science
Program, Office of Science.
REFERENCES AND NOTES
[1]
[2]
G. R. Newkome, Chem. Rev., 93, 2067 (1993).
Z. -Z. Zhang and H. Cheng, Coord. Chem. Rev., 147, 1
[24]
B. P. Hay and T. K. Firman, Inorg. Chem., 41, 5502 (2002).
Conformational analysis of 10 was conducted with the MM3 force field
using the GMMX search engine in PCModel, v. 9.1, Serena Software,
Box 3076, Bloomington, IN 47402.
(1996).
[3]
A. A. Russell, R. L. Meline, E. N. Duesler and R. T. Paine,
Inorg. Chim. Acta, 231, 1 (1995).
[4] D. J. McCabe, A. A. Russell, S. Karthikeyan, R. T. Paine, R.
R. Ryan and B. F. Smith, Inorg. Chem., 26, 1230 (1987).
[25]
Crystal
structure
analysis
for
Tb(10)(NO3)3•H2O:
C10H16N5O12Tb, Mr = 557.20 g mole-1, monoclinic, space group, C2/c, a
= 16.2497(11) Å, b = 9.2283(5) Å, c = 25.1818(13) Å, ꢀ = ꢂ = 90 °, ꢁ =
102.056(4)°; V = 3692.9(4) Å3, Z = 8, ꢃcalc = 2.004 g cm-3, μ = 3.902
mm-1, F(000) = 2176, crystal size = 0.24 x 0.20 x 0.10 mm. Crystal data
collected on a Bruker X8 Apex2 CCD-based diffractometer with Oxford
Cryostream 700 low temperature device (T = 223(2) K), MoKꢄ radiation
(ꢅ = 0.71073 Å). A full sphere of data was collected, 2112 frames, scan
width of 0.5 ° in omega and phi at 20s/frame. A total of 32,007
reflections (2ꢆ max = 76.26 °) gave 9499 independent reflections with
8603(I>2ꢇ(I)). Data were processed with SADABS [26] and corrected
for absorption. The structure was refined with Bruker SHELXTL
(Version 6.12) software [26]. All non-hydrogen atoms were refined
anisotropically.
[5]
G. S. Conary, A. A. Russell, R. T. Paine and R. R. Ryan,
Inorg. Chem., 27, 3242 (1988).
[6]
S. L. Blaha, D. J. McCabe and R. T. Paine, Radiochimica
Acta, 46, 123 (1989).
[7]
B. M. Rapko, E. N. Duesler, P. H. Smith, R. T. Paine and R.
R. Ryan, Inorg. Chem., 32, 2164 (1993).
[8]
U. Engelhardt, B. M. Rapko, E. N. Duesler, D. Frutos and R.
T. Paine, Polyhedron, 14, 2361(1995).
[9]
E. M. Bond, X. Gan, J. R FitzPatrick and R. T. Paine, J.
Alloys Comps., 271-273, 172 (1998).
[10] E. M. Bond, E. N. Duesler, R. T. Paine, M. P. Neu, J. H.
Matonic and B. L. Scott, Inorg. Chem., 39, 4152 (2000).
[26]
G. M. Sheldrick, SADABS, v.2.10; Program for empirical
[11]
X. Gan, E. N. Duesler and R. T. Paine, Inorg. Chem., 40,
absorption correction of area detector data, University of Goettingen:
Goettingen, Germany, 2003; G. M. Sheldrick, SHELXTL, v.6.12;
Bruker Analytical X-ray Madison, WI, 2001.
4420 (2001).
[12]
X. Gan, E. N. Duesler, E. M. Bond, P. H. Smith and R. T.
Paine, Inorg. Chim. Acta, 247, 29 (1996).