Cyclopalladation of mono-, di- and tribenzylamine by palladium(II) acetate Influence of bulkiness around the nitrogen atom of benzylamine upon internal metallation

Article abstract of DOI:10.1016/S0022-328X(98)01156-5

Cyclopalladation of mono-, di- and tribenzylamine has been investigated by reacting the corresponding amines with an equimolar amount of palladium(II) acetate (reaction i), or by heating the corresponding bis-amine complexes [Pd(O₂CMe)₂{(PhCH₂)_nNH _3-n}₂] (n = 1, 2) (reaction ii). By the reaction i, all the three amines undergo cyclopalladation. However, in the case of the reaction ii, only the dibenzylamine complex [Pd(O₂CMe)₂ {(PhCH₂)₂NH}₂] has been converted into a cyclopalladated complex. The reactivity of the three benzylamines towards Cyclopalladation has been discussed in terms of the co-ordinating ability influenced by the bulkiness around the nitrogen atom. Temperature-dependent ₁H-NMR spectra are observed for mononuclear cyclopalladated complexes [Pd(O₂CMe){C₆H₄CH₂N(CH ₂Ph)₂-C¹, N} (L = PPh₃, AsPh₃) and are attributed to the dissociation of the nitrogen atom in the cyclopalladated chelate ring. A heteroleptic bis-cyclopalladated complex [Pd[C₆H₄CH₂N(CH₂Ph) ₂-C¹, N](C₆H₄CH₂NMe₂-C¹, N)] has also been prepared. X-ray crystallographic studies on [{Pd(O₂CMe)[C₆H₄CH₂N(CH ₂Ph)₂-C¹, N]}₂] and [Pd[C₆H₄CH₂N(CH₂Ph) ₂-C¹, N](C₆H₄CH₂NMe₂-C¹, N)] have been reported.

Full text of DOI:10.1016/S0022-328X(98)01156-5

Journal of Organometallic Chemistry 580 (1999) 273–281
Cyclopalladation of mono-, di- and tribenzylamine by palladium(II)
acetate
Influence of bulkiness around the nitrogen atom of benzylamine upon
internal metallation
Yoshio Fuchita a,*, Kazuhiko Yoshinaga a, Tomoko Hanaki a, Hiroyuki Kawano b,
Junko Kinoshita-Nagaoka c
a Di6ision of Molecular Chemistry, Graduate School of Science, Kyushu Uni6ersity at Ropponmatsu, Chuo-ku, 810-8560 Fukuoka, Japan
b Graduate School of Marine Science and Engineering, Nagasaki Uni6ersity, Bunkyo-machi, 852-8521 Nagasaki, Japan
c Department of Applied Chemistry, Faculty of Engineering, Nagasaki Uni6ersity, Bunkyo-machi, 852-8521 Nagasaki, Japan
Received 9 October 1998; received in revised form 18 November 1998
Abstract
Cyclopalladation of mono-, di- and tribenzylamine has been investigated by reacting the corresponding amines with an
equimolar amount of palladium(II) acetate (reaction i ), or by heating the corresponding bis-amine complexes
[Pd(O2CMe)2{(PhCH2)nNH3−n}2] (n=1, 2) (reaction ii ). By the reaction i, all the three amines undergo cyclopalladation.
However, in the case of the reaction ii, only the dibenzylamine complex [Pd(O2CMe)2{(PhCH2)2NH}2] has been converted into
a cyclopalladated complex. The reactivity of the three benzylamines towards cyclopalladation has been discussed in terms of the
co-ordinating ability influenced by the bulkiness around the nitrogen atom. Temperature-dependent 1H-NMR spectra are
observed for mononuclear cyclopalladated complexes [Pd(O2CMe){C6H4CH2N(CH2Ph)2–C1, N}L] (L=PPh3, AsPh3) and are
attributed to the dissociation of the nitrogen atom in the cyclopalladated chelate ring. A heteroleptic bis-cyclopalladated complex
[Pd[C6H4CH2N(CH2Ph)2–C1, N](C6H4CH2NMe2–C1, N)] has also been prepared. X-ray crystallographic studies on
[{Pd(O2CMe)[C6H4CH2N(CH2Ph)2–C1, N]}2] and [Pd[C6H4CH2N(CH2Ph)2–C1, N](C6H4CH2NMe2–C1, N)] have been reported.
© 1999 Elsevier Science S.A. All rights reserved.
Keywords: Cyclopalladation; Palladium; Benzylamine
made a step forward in this area, achieving the cyclo-
palladation of primary and secondary benzylamines
1. Introduction
having sterically hindered substituents such as a,a-
For the cyclopalladation of benzylamine derivatives,
a fundamental rule was established in 1968 by Cope
diphenylbenzylamine and N,a-dimethylbenzylamine.
Moreover, Avshu et al. [4] succeeded in obtaining the
and Friedrich: direct activation of C–H bonds by palla-
cyclopalladated complex of non-substituted benzy-
dium(II) species to afford corresponding palladacycles
lamine by treating the adduct [PdI2(NH2CH2Ph)2] with
is the most feasible in the case of tertiary amines,
silver(I) salt. However, the above works did not change
whereas primary and secondary amines are usually
the fundamental rule essentially.
inert toward such activation [1]. Thereafter, in 1973
Lewis et al. [2] and in 1984 Dunina and co-workers [3]
In 1985, studying kinetics concerning the cyclopalla-
dation of N,N-dimethylbenzylamine by palladium(II)
acetate, Ryabov et al. [5] proposed that the cyclopalla-
* Corresponding author. Fax: +8192-726-4753.
dation proceeds mainly via monomeric coordinatively
0022-328X/99/$ - see front matter © 1999 Elsevier Science S.A. All rights reserved.
PII: S0022-328X(98)01156-5

274
Y. Fuchita et al. / Journal of Organometallic Chemistry 580 (1999) 273–281
unsaturated T-shaped intermediate [Pd(O2CMe)2-
(Me2NCH2Ph)]. It is explained in the reviews that the
less sterically demanding primary- and secondary-ben-
zylamines (L) are quite hard to generate the T-shaped
intermediates [Pd(O2CMe)2L] owing to much higher
stability of the corresponding bis-amine adduct
[Pd(O2CMe)2L2] [6,7]. However, Ryabov supposed only
the cases where amines are used in excess, and so it is
only natural to estimate that cyclopalladation should
proceed when one would react the amine with an
equimolar amount of palladium(II) species. As ex-
pected, in 1993 by reacting palladium(II) acetate with
an equimolar amount of PhCH2NH2 or PhCH2NHR
(R=Me, Pri, Ph, CH2But), the authors [8] succeeded in
obtaining the cyclopalladated complexes of both
benzylamines.
2.1. Reactions of mono-, di- and tribenzylamine with
palladium(II) acetate resulting in the formation of the
adducts and the cyclopalladated complexes, and the
molecular structure of [{Pd(v-O2CMe)[C6H4CH2N-
(CH2Ph)2–C1, N]}2] 2c
At room temperature dibenzylamine [(PhCH2)2NH]
as well as monobenzylamine (PhCH2NH2) reacted in
benzene with a half molar equivalent of palladium(II)
acetate to give the corresponding bis-amine adducts
[Pd(O2CMe)2(PhCH2NHR)2] (1a: R=H, yield 84%; 1b:
R=CH2Ph, yield 82%). On the contrary, tribenzyl-
amine [(PhCH2)3N] did not produce a similar bis-amine
complex under the same reaction conditions, recovering
only the starting materials. When the bis-amine com-
plex 1b was heated in benzene at 50°C, the cyclopalla-
dated complex, [{Pd(m-O2CMe)(C6H4CH2-NHCH2Ph–
C1, N)}2] 2b, was precipitated as milky microcrystals
(21% yield). However, similar treatment of 1a, the
bis-amine adduct of monobenzylamine, did not afford
In order to clarify the influence of bulkiness around
the nitrogen atom of benzylamine upon formation of
the bis-amine complexes and cyclopalladated com-
plexes, we have chosen benzyl-substituted benzylamine
derivatives, i.e. mono-, di- and tribenzylamine, and
studied the reactions with palladium(II) acetate. In
addition to the above results, we wish to report here a
dynamic behaviour of the cyclopalladated complex of
corresponding
cyclopalladated
complex
[{Pd(m-
O2CMe)(C6H4CH2NH2–C1, N)}2] 2a. As reported pre-
viously [8], cyclopalladation of monobenzylamine
proceeds in benzene at 50°C when the amine is heated
with an equimolar amount of palladium(II) acetate. By
using this 1:1 molar ratio of Pd(O2CMe)2/amine, diben-
zylamine cyclopalladated much more smoothly (around
20°C) giving 2b in 52% yield and moreover even triben-
zylamine did cyclopalladate in refluxing benzene to give
[{Pd(m-O2CMe)[C6H4CH2N(CH2Ph)2–C1, N]}2] 2c in
50% yield. It has already been confirmed that at room
temperature monobenzylamine produces the dinuclear
amine adduct [{Pd(O2CMe)(m-O2CMe)(PhCH2NH2)}2]
under the 1:1 molar ratio of Pd(O2CMe)2/amine and
the adduct can be converted into the cyclopalladated
complex 2a [9].
1
tribenzylamine observed by its H-NMR spectroscopy.
2. Results and discussion
The reactions of palladium(II) acetate with the three
benzylamines, mono-, di- and tribenzylamine, are sum-
marized in Scheme 1. The 1H-NMR spectral assignment
of the new complexes has been performed with the aid
of 1H–1H correlation spectroscopy (COSY) and the
data are listed in Table 1.
Scheme 1. (i ) 1/2 [Pd(O2CMe)2] in benzene. Reaction did not proceed for tribenzylamine; (ii ) Benzene at 80°C. Reaction did not proceed for 1a;
(iii ) [Pd(O2CMe)2] in benzene at 50°C for mono-benzylamine, at 20°C for dibenzylamine and at 80°C for tribenzylamine; (i6) PPh3 in CH2Cl2;
(6) AsPh3 in CH2Cl2; (6i ) LiCl in an acetone–water mixed solvent; (6ii ) Lithiated N,N-dimethylbezylamine.

Y. Fuchita et al. / Journal of Organometallic Chemistry 580 (1999) 273–281
275
Table 1
Proton NMR spectra of the new complexesa
Complex Cyclopalladated benzylamine moiety
NR2
Ph
C6H4
–
CH2
CH2
NH
Others
1b
2c
–
7.3–7.5
(20H, c)
3.17 (4H, dd)b
8.0–8.1 (2H, m) 1.83 (6H, s, MeCO2)
3.77 (4H, dd)c
6.54 (4H, d)g
7.2–7.5
6.77 (2H, dt)d
7.00 (2H, t)e
6.90 (2H, d)e
7.01 (2H, d)e
3.12 (2H, d)f
4.35 (2H, d)f
3.49 (2H, d)f
3.84 (4H, d)f
–
1.88 (6H, s, MeCO2)
(12H, c)
8.24 (4H, d)e
–
4.07 (2H, d)e
–
3a
3b
3cj
6.4 (2H, c)
6.83 (1H, t)e
4.34 (2H, dt)g
4.6–4.7 (2H, br) 1.40 (3H, s, MeCO2)
7.3–7.5 (9H, c, PPh3)
6.98 (1H, d)e
7.7–7.8 (6H, c, PPh3)
6.3–6.5 (2H, c) 6.83 (1H, t)e
6.97 (1H, d)e
3.74 (1H, ddd)h 7.3–7.5 (5H, c) 3.86 (1H, dd)i
4.4–4.5 (1H, c)
7.1 (1H, br)
–
1.47 (3H, s, MeCO2)
7.3-7.5 (9H, c, PPh3)
7.7–7.8 (6H, c, PPh3)
1.71 (3H, s, MeCO2)
6.95–7.1 (9H, c, PPh3)
4.4–4.5 (1H, c)
6.4–6.5 (1H, m) 6.64 (1H, t)e
6.75–6.85
(2H, c)
3.85 (2H, s)
7.1–7.2 (6H, m) 3.91 (2H, dd)k
7.55–7.65
(4H, m)
4.80 (2H, d)l
7.95–8.1 (6H, c, PPh3)
1.67 (3H, s, MeCO2)
4cm
6c
6.37 (1H, dt)d
6.65–6.75
(3H, c)
3.88 (2H, s)
4.02 (2H, s)
6.95–7.2
(6H, c)n
3.76 (2H, d)o
4.77 (2H, d)o
–
6.95–7.2 (9H, c, AsPh3)n
7.7–7.95 (6H, m, AsPh3)
7.73 (4H, d)f
7.54 (1H, d)e
7.07 (2H, t)e
7.63 (1H, d)e
7.35–7.5
(6H, m)
7.9–8.0 (4H, m)
3.89 (2H, d)p
3.99 (2H, d)p
1.82 (6H, s, NMe2)
3.52 (2H, s, CH2)
6.9–7.0 (4H, c, C6H4)
a Recorded in CDCl3 solution at 270 MHz and at 23 °C except for 3c and 4c (toluene-d8); d in ppm with respect to SIMe4; s=singlet,
d=doublet, t=triplet, dt=doublet of triplets, ddd=doublet of doublets of doublets, br=broad, m=multiplet, c=complex.
b 2J(HH)=12.9, 3J(HH)=7.1 Hz.
c 2J(HH)=12.9, 3J(HH)=6.1 Hz.
d 3J(HH)=7.3, 4J(HH)=1.5 Hz.
e 3J(HH)=7.3 Hz.
f 2J(HH)=13.7 Hz.
g 3J(HH)=6.1, 4J(HP)=2.5 Hz.
h 2J(HH)=14.7, 3J(HH)=3.9, 4J(HP)=2.0 Hz.
i 2J(HH)=13.7, 3J(HH)=11.2 Hz.
j Measured at −10 °C.
k 2J(HH)=12.7, 3J(HH)=3.9 Hz.
l 2J(HH)=12.7 Hz.
m Measured at 0 °C.
n Overlapping signals.
o 2J(HH)=12.5 Hz.
p 2J(HH)=13.5 Hz.
The above results clearly showed that the strength
of palladium–amine bonds decreases in the following
order, monobenzylamine\dibenzylamine\tribenzyl-
amine: tribenzylamine did not form isolable bis-amine
complex owing to the three bulky benzyl groups on
the nitrogen atom, whereas less sterically demanding
monobenzylamine coordinated palladium much more
tightly, preventing the conversion of the bis-amine ad-
duct 1a to the cyclopalladated complex 2a, making
sharp contrast to the case of the moderate ligand
dibenzylamine which produced the cyclopalladated
complex 2b from the bis-amine complex 1b. In the
reactions by using the 1:1 molar ratio of
Pd(O2CMe)2/the amine, cyclopalladation proceeded
fairy smoothly irrespective of the coordination ability
of the benzylamine ligands. Under these reaction con-
ditions it seems reasonable that dinuclear amine ad-
ducts [{Pd(O2CMe)(m-O2CMe)L}2] are initially formed
[9]. Accordingly it may be concluded that the dinu-
clear amine adducts are the key precursor for follow-
ing the formation of the reactive co-ordinatively
unsaturated species [Pd(O2CMe)2L] which affords the
cyclopalladated complexes (Scheme 2).
The structure of the acetato-bridged dinuclear
cyclopalladated complex [{Pd(m-O2CMe)[C6H4CH2N-
(CH2Ph)2–C1, N]}2] 2c was established by X-ray
diffraction and as ORTEP [10] view of the molecule
is shown in Fig. 1. Selected bond distances

276
Y. Fuchita et al. / Journal of Organometallic Chemistry 580 (1999) 273–281
Table 2
˚
Selected bond distances (A) and angles (°) with estimated S.D. in
parentheses for complex 2c·0.5CH2Cl2
˚
Bond lengths (A)
Pd(1)ꢀC(12)
Pd(1)ꢀO(1)
Pd(2)ꢀC(42)
Pd(2)ꢀO(2)
O(1)ꢀC(1)
1.957(4)
2.142(3)
1.958(4)
2.047(3)
1.247(5)
1.245(4)
1.499(4)
1.503(5)
1.391(5)
Pd(1)ꢀN(1)
Pd(1)ꢀO(4)
Pd(2)ꢀN(2)
Pd(2)ꢀO(3)
O(2)ꢀC(1)
2.099(3)
2.047(3)
2.097(3)
2.127(3)
1.266(5)
1.263(4)
1.510(5)
1.497(5)
1.392(5)
O(3)ꢀC(3)
O(4)ꢀC(3)
Scheme 2. Reaction pathways for cyclopalladation of benzylamine
derivatives. (i ) 1/2 [Pd(O2CMe)2]; (ii ) [Pd(O2CMe2)].
N(1)ꢀC(10)
C(10)ꢀC(11)
C(11)ꢀC(12)
N(2)ꢀC(40)
C(40)ꢀC(41)
C(41)ꢀC(42)
and angles are summarized in Table 2. The molecule
possesses approximate (noncrystallographic) C2 symme-
try with the nitrogen atoms mutually trans with respect
to the di-m-acetato bridges. The coordinations around
each palladium atoms are essentially square planar and
the maximum deviations from the mean planes com-
posed of Pd(1)–O(1)–O(4)–C(12)–N(1) [plane 1] and
Bond angles (°)
O(1)ꢀPd(1)ꢀO(4)
N(1)ꢀPd(1)ꢀC(12)
O(1)ꢀPd(1)ꢀC(12)
Pd(1)ꢀO(1)ꢀC(1)
O(2)ꢀPd(2)ꢀO(3)
N(2)ꢀPd(2)ꢀC(42)
O(3)ꢀPd(2)ꢀC(42)
Pd(2)ꢀO(3)ꢀC(3)
O(3)ꢀC(3)ꢀO(4)
90.1(1)
82.0(1)
174.9(1)
129.2(3)
90.5(1)
82.3(1)
173.7(1)
132.7(3)
116.3(4)
O(1)ꢀPd(1)ꢀN(1)
O(4)ꢀPd(1)ꢀC(12)
O(4)ꢀPd(1)ꢀN(1)
Pd(1)ꢀO(4)ꢀC(3)
O(3)ꢀPd(2)ꢀN(2)
O(2)ꢀPd(2)ꢀC(42)
O(2)ꢀPd(2)ꢀN(2)
Pd(2)ꢀO(2)ꢀC(1)
O(1)ꢀC(1)ꢀO(2)
95.3(1)
92.2(1)
172.6(1)
121.5(3)
94.6(1)
92.1(1)
172.2(1)
123.8(3)
127.0(4)
˚
Pd(2)–O(2)–O(3)–C(42)–N(2) [plane 2] are 0.066 A at
˚
Pd(1) and 0.081 A at Pd(2), respectively. Complex 2a
has a folded structure typical for acetato-bridged
dimers with the dihedral angle of 41.8° between plane 1
and plane 2. This angle is much larger than those
reported for other dinuclear acetato-bridged cyclopalla-
dated complexes of 2-(4-methylphenyl)benzothiazole
(A, 24.5°) [11], 2-(4-methylphenyl)benzoxazole (B,
24.0°) [11], 2-(3-nitrophenyl)pyridine (C, 25.7°) [12] and
2,4-bis(4-chlorophenyl)pyridine (D, 25.9°) [12], which is
caused by the steric repulsion of the bulky benzyl
groups facing each other. Accordingly, the nonbonding
˚
palladium…palladium distance [3.0621(4) A] becomes
˚
longer than those in A–D cited above (2.871–2.906 A).
In addition, whereas the Pd–C distances [1.957(4),
˚
˚
1.958(4) A] are similar to those in A–D [1.94–1.975 A],
˚
the Pd–N distances [2.099(3), 2.097(3) A] are longer
than those found in A–D [2.02–2.053 A] and in
˚
[{Pd(O2 CMe)(m-O2CMe)(H2NCH2 C6H4 NO2-p)}2]
˚
[2.021(6), 2.008(7) A] [12]. These data suggested that
sterically demanding benzyl groups at nitrogen atom
lengthens the Pd–N bond. Concerning the two five-
membered palladacycles, they are not planar but have
typical envelope type structures [13] with the nitrogen
˚
atom 0.678 [N(1)] and 0.671 A [N(2)] out of the planes
defined by the remaining four atoms.
2.2. Synthesis of the mononuclear cyclopalladated
complexes and the dynamic beha6iour ascribed to
dissociation of nitrogen donor in the cyclopalladated
chelate ring deri6ed from tribenzylamine
The acetato-bridged cyclopalladated complexes of
mono- (2a), di- (2b) and tribenzylamine (2c) reacted
with triphenylphosphine to afford the corresponding
mononuclear cyclopalladated complexes [Pd(O2CMe)-
(C6H4CH2NRR%–C1, N)(PPh3)] (3a: R=R%=H, 74%;
3b: R=CH2Ph, R%=H, 89%; 3c: R=R%=CH2Ph,
39%). In the 1H-NMR spectra of these complexes,
only four aromatic protons due to one of the benzyl
groups were observed in the range l 6.3–7.0, confirm-
ing the cyclopalladated structures of the three
Fig.
1.
An
ORTEP
view
of
complex
[{Pd(m-
O2CMe)[C6H4CH2N(CH2Ph)2–C1,N]}2] 2c.

Y. Fuchita et al. / Journal of Organometallic Chemistry 580 (1999) 273–281
277
mol−1, DGc (300 K)=63.3 kJ mol−1, DHc =79.6 kJ
benzylamines. Concerning the methylene protons of the
cyclopalladated benzylamine moiety, they appeared at
l 4.34 (2H) as a doublet of triplets [3J(HH)=6.1,
4J(HP)=2.5 Hz] in 3a, whereas those in 3b resonated
at l 3.74 (1H) as a doublet of doublets of doublets
[2J(HH)=14.7, 3J(HH)=3.9, 4J(HP)=2.0 Hz] and
near l 4.45 (1H) as complexed signals owing to over-
lapping with one methylene proton of benzyl–
methylene group. In the case of 3c, temperature-
mol−1 and DSc =54.5 J mol−1
K
−1. A relatively
larger positive value for DSc strongly suggested the
dissociation of the N-donor atom. However, a reaction
of 2c with a two-fold excess of triphenylphosphine did
not
afford
[Pd(O2CMe)[C6H4CH2N(CH2Ph)2–
C1](PPh3)2] where metallated tribenzylamine coordi-
nates to palladium through the C atom. In the case of
the
triphenylarsine
complex
[Pd(O2CMe)-
[C6H4CH2N(CH2Ph)2–C1, N](AsPh3)] 4c, similar tem-
perature-dependent 1H-NMR spectra were observed
with higher coalescence temperature of 70°C. This fact
showed that the AsPh3 ligand has a smaller trans effect
than the PPh3 ligand which is the same order found in
the trans influence [15].
1
dependent H-NMR spectra were observed in toluene-
d8. In the low-temperature limiting spectrum at
−10°C, the methylene protons of the cyclopalladated
moiety appeared at l 3.85 as a singlet [14], while the
diastereotopic methylene protons of the chemically
equivalent two benzyl groups resonated at l 3.91 [dd,
2J(HH)=12.7, 4J(HP)=3.9 Hz] and 4.80 [d,
2J(HH)=12.7 Hz] as an AB pattern. These
diastereotopic methylene protons began to broaden at
20°C, reached coalescence point at 45°C and changed
to a fairly sharp singlet (l 4.33) at 95°C. Disappearance
of the diastereotopic character of the methylene pro-
tons suggested the dissociation of the N-donor atom in
the chelate moiety. Assuming that the lower field signal
of the AB pattern, though it is splitting into a doublet
of doublets due to the coupling with a phosphorous
nucleus, would have same shape to the higher field
signals, the rate to dissociation of the N-donor atom
was measured by line shape analysis of the AB quartet
from the geminal protons. Fig. 2 shows the experimen-
tal and simulated spectra together with the dissociation
rates kobs. Activation parameters for the dissociation of
the N-donor atom in the chelate moiety calculated from
Arrhenius and Eyring equations were Ea=82.2 kJ
2.3. Synthesis and molecular structure of the
heteroleptic bis-cyclopalladated complex of
[Pd[C6H4CH2N(CH2Ph)2–C%,N](C6H4CH2NMe2–C%N]
6c
Bis-cyclometallated complexes of platinum(II) and
palladium(II) have received interest in connection with
the chiral inorganic compounds [16]. However, all the
complexes prepared so far had cis configurations. To
see whether the bulky [2-(N,N-dibenzylaminomethyl)-
phenyl–C1, N]palladium(II) could form a trans-bis-cy-
clopalladated complex or not, a reaction between
lithiated N,N-dimethylbenzylamine and [{PdCl[C6H4-
CH2N(CH2Ph)2–C1, N]}2] 5c was investigated. A het-
eroleptic bis-cyclopalladated complex of [Pd[C6H4-
CH2N(CH2Ph)2–C1, N](C6H4CH2NMe2–C1, N)]
6c
was obtained in 67% yield and its structure was estab-
lished by X-ray diffraction. Fig. 3 shows the numbering
scheme for 6c, whereas Table 3 contains some selected
bond distances and angles. The X-ray structural analy-
sis revealed that unfortunately 6c has a cis configured
complex and that the coordination around the palla-
dium atom is essentially square planar, the maximum
deviations from the mean planes composed of
˚
Pd(1)ꢀN(1)ꢀN(2)ꢀC(16)ꢀC(26) [plane 3] being 0.088 A
at C(16). This fact excluded the formation of a het-
eroleptic chiral D- or L-configured bis-cyclopalladated
complex like a L-cis-bis-cycloplatinated complex of
2,6-diphenylpyridine [16]. Although two five-membered
palladacycles in 6c, Pd(1)ꢀN(1)ꢀC(2)ꢀC(21)ꢀC(26) and
Pd(1)ꢀN(2)ꢀC(1)ꢀC(11)ꢀC(16), again have envelope
type structures with the nitrogen atoms 0.817 [N(1)]
˚
and 0.772 A [N(2)] out of the planes defined by the
remaining four atoms, a side-view of the structure
drawn in Fig. 2(b) showed that C(1) and C(2) are
˚
˚
located 0.834 A above and 0.938 A below the least
square plane 3 to avoid collision between dibenzyl-
Fig. 2. Methylene region of the 1H-NMR spectra of complex
[Pd(O2CMe)[C6H4CH2N(CH2Ph)2–C1,N](PPh3)] 3c. (a) Observed
spectra, (b) simulated curves.
1
amino and dimethylamino groups. The H-NMR spec-
trum of 6c exhibited sharp singlets at l 3.52 and 4.02

278
Y. Fuchita et al. / Journal of Organometallic Chemistry 580 (1999) 273–281
2a was prepared according to the previously reported
method [8]. o-Lithio-N,N-dimethylbenzylamine was
prepared according to the literature method [18]. Other
reagents were obtained commercially and used without
purification. Reactions involving lithium reagents were
carried out under an argon atmosphere.
3.1. Syntheses
3.1.1. [Pd(O2CMe)2(PhCH2NH2)2] (1a)
A benzene (5 cm3) solution of benzylamine (0.305 g,
2.85 mmol) was added to a solution of palladium(II)
acetate (0.300 g, 1.34 mmol) in the same solvent (30
cm3) and the resulting solution was stirred at room
temperature for 30 min. After filtration the yellow
filtrate was concentrated and diluted with hexane to
yield yellow microcrystals, which was filtered off and
washed with hexane to give 1a (0.482 g, 84%). Complex
1a has already prepared in acetone by Vicente et al. [9].
3.1.2. [Pd(O2CMe)2(PhCH2NHCH2Ph)2] (1b)
This complex was obtained as yellow microcrystals
by the reaction of palladium(II) acetate with dibenzy-
lamine in a similar way as described for 1a. Yield 82%,
m.p. (dec.) 159°C (Found: C, 62.05; H, 5.9; N, 4.6.
C32H36N2O4Pd requires C, 62.1; H, 5.85; N, 4.55; wmax
(cm−1) (KBr) 1591, 1378 (CO)).
Fig. 3. An ORTEP view of complex [Pd[C6H4CH2N(CH2Ph)2–
C1,N](C6H4CH2NMe2–C1,N)] 6c.
due to CH2 groups in the two chelated moieties, indi-
cating that in solution inversion of the two five-mem-
bered chelate rings occurs rapidly.
3.1.3. [{Pd(v-O2CMe)(C6H4CH2NHCH2Ph–C1, N)}2]
(2b)
Method (a). A benzene (5 cm3) solution of dibenzy-
lamine (0.264 g, 1.34 mmol) was added to a solution of
palladium(II) acetate (0.300 g, 1.34 mmol) in the same
solvent (30 cm3) and the resulting solution was stirred
at room temperature. After 6 h the white precipitate
was filtered off and washed with hexane to give 2b
(0.251 g, 52%), m.p. (dec.) 244°C (Found: C, 53.15; H,
4.8; N, 3.8. C32H34N2O4Pd2 requires C, 53.15; H, 4.75;
N, 3.85; wmax (cm−1) (KBr) 1566, 1411 (CO). The NMR
spectrum could not be obtained because of its low
solubility in common organic solvents.
3. Experimental
The IR spectra were measured on a JASCO FT/IR-
420 spectrophotometer, 1H-NMR spectra were
recorded on a JEOL JNM-GX-270 spectrometer using
tetramethylsilane as an internal standard. Melting
points were determined on a Yanaco MP-500D micro
melting-point apparatus and are uncorrected.
Palladium(II) acetate was prepared according to the
procedures of Wilkinson and co-workers [17]. Complex
Method (b). A benzene (10 cm3) solution of 1b (0.100
g, 0.162 mmol) was heated at 50°C for 3 days. Precipi-
tated white microcrystals were collected and washed
with diethyl ether to give 2b (0.012 g, 21%).
Table 3
˚
Selected bond distances (A) and angles (°) with estimated S.D. in
parentheses for complex 6c
3.1.4. [{Pd(v-O2CMe)[C6H4CH2N(CH2Ph)2–C1, N]}2]
(2c)
˚
Bond lengths (A)
PdꢀC(16)
PdꢀN(1)
N(1)ꢀC(2)
C(2)ꢀC(21)
C(21)ꢀC(26)
Bond angles (°)
C(26)ꢀPdꢀN(1)
C(16)ꢀPdꢀC(26)
N(1)ꢀPdꢀC(16)
1.995(6)
2.257(5)
1.498(7)
1.518(8)
1.371(8)
PdꢀC(26)
PdꢀN(2)
N(2)ꢀC(1)
C(1)ꢀC(11)
C(11)ꢀC(16)
2.010(6)
2.237(5)
1.465(7)
1.500(9)
1.392(8)
Tribenzylamine (0.403 g, 1.40 mmol) was added to a
benzene (30 cm3) solution of palladium(II) acetate
(0.300 g, 1.34 mmol) and the resulting solution was
heated under reflux. After 1 day the resulting mixture
was filtered and the filtrate was evaporated to dryness.
The residue was recrystallized from diethyl ether and
hexane to give 2c (0.303 g, 50%), m.p. (dec.) 156°C
(Found: C, 61.3; H, 5.45; N, 3.0. C46H46N2O4Pd2 re-
80.0(2)
96.0(2)
172.6(2)
C(16)ꢀPdꢀN(2)
N(1)ꢀPdꢀN(2)
N(2)ꢀPdꢀC(26)
80.1(2)
104.1(2)
175.6(2)

Y. Fuchita et al. / Journal of Organometallic Chemistry 580 (1999) 273–281
279
quires C, 61.15; H, 5.15; N, 3.1; wmax (cm−1) (KBr)
1571, 1415 (CO)).
extract was concentrated and diluted with hexane to
give pale yellow microcrystals of 5c, (0.154 g, 81%),
m.p. (dec.) 179°C (Found: C, 58.6; H, 4.75; N, 3.3.
C42H40N2Cl2Pd2 requires C, 58.9; H, 4.7; N, 3.25).
3.1.5. [Pd(O2CMe)(C6H4CH2NH2–C1, N)(PPh3)] (3a)
Addition of triphenylphosphine (0.106 g, 0.404
mmol) to a suspension of 2a (0.100 g, 0.184 mmol) in
dichloromethane (10 cm3) gave a clear solution immedi-
ately. Stirring was continued for 5 h at room tempera-
ture, during which a pale yellow precipitate appeared.
Pale yellow microcrystals were filtered off and washed
with hexane to yield 3a (0.145 g, 74%), m.p. (dec.)
173°C (Found: C, 60.7; H, 5.0; N, 2.6. C27H26NO2PPd
requires C, 60.75; H, 4.9; N, 2.6; wmax (cm−1) (KBr)
1572, 1387 (CO)).
3.1.10. [Pd[C6H4CH2N(CH2Ph)2–C1, N]-
(C6H4CH2NMe2–C1, N)] (6c)
A THF (2 cm3) solution of o-lithio-N,N-dimethyl-
benzylamine, prepared from the reaction of N,N-
dimethylbenzylamine (0.203 g, 1.50 mmol) and 1.1 cm3
(1.80 mmol) of butyllithium (15% in hexane), was
added to a THF (10 cm3) solution of 5c (0.300 g, 0.350
mmol) at 0°C. Stirring was continued at 0°C for 15 min
and then the resulting orange solution was allowed to
warm to 30°C. After 2 h the reaction mixture was
evaporated to dryness and the residue was extracted
with dichloromethane. Addition of hexane yielded 6c,
(0.246 g, 67%), m.p. (dec.) 177°C (Found: C, 67.5; H,
6.15; N, 5.25. C30H32N2Pd requires C, 68.35; H, 6.1; N,
5.3).
3.1.6. [Pd(O2CMe)(C6H4CH2NHCH2Ph–C1, N)(PPh3)]
(3b)
Addition of triphenylphosphine (0.064 g, 0.244
mmol) to a suspension of 2b (0.080 g, 0.111 mmol) in
dichloromethane (10 cm3) gave a clear solution immedi-
ately. After stirring at room temperature for 3 h the
reaction mixture was concentrated. Addition of hexane
afforded white microcrystals of 3b (0.123 g, 89%), m.p.
(dec.) 182°C (Found: C, 65.1; H, 5.65; N, 2.15.
C34H32NO2PPd requires C, 65.45; H, 5.15; N, 2.25; wmax
(cm−1) (KBr) 1581, 1395 (CO)).
3.2. Line shape analysis of [Pd(O2CMe)[C6H4CH2N-
(CH2Ph)2–C1, N](PPh3)] (3c)
Experimental line shapes for the diastereotopic
methylene proton signals of the benzyl groups were
measured in the temperature range 273–368 K, and
matched against those calculated for different exchange
rate constants kobs, using the modified Bloch equation
[19] and Binsch’s [20] computer program QUABEX.
The Arrhenius and Eyring equations were used to
3.1.7. [Pd(O2CMe)[C6H4CH2N(CH2Ph)2–C1, N](PPh3)]
(3c)
This complex was obtained as white microcrystals by
the reaction of 2c and triphenylphosphine in a similar
way as described for 3b. Yield 39%, m.p. (dec.) 166°C
(Found: C, 68.75; H, 5.45; N, 2.05. C41H38NO2PPd
requires C, 68.95; H, 5.35; N, 1.95; wmax (cm−1) (KBr)
1606, 1378 (CO)).
evaluate Ea, DHc and DSc from kobs
.
3.3. X-ray crystallography
Suitable crystals of [{Pd(m-O2CMe)[C6H4CH2N-
(CH2Ph)2–C1, N]}2] 2c and [Pd[C6H4CH2N(CH2Ph)2–
C1, N](C6H4CH2NMe2–C1, N)] 6c were grown from
dichloromethane and hexane. Details of the crystal
data, data collection and refinement are summarized in
Table 4. All measurements were made on a Rigaku
AFC7S diffractometer with graphite-monochromated
3.1.8. [Pd(O2CMe)[C6H4CH2N(CH2Ph)2C1, N](As-
Ph3)] (4c)
Triphenylarsine (0.068 g, 0.222 mmol) was added to a
solution of 2c (0.100 g, 0.111 mmol) in
dichloromethane (10 cm3) and the resulting mixture was
stirred at room temperature for 5 h. The resulting
mixture was filtered and the filtrate was concentrated
under reduced pressure. Addition of hexane gave a pale
yellow precipitate which was collected and washed with
hexane to yield 4c, (0.154 g, 89%), m.p. (dec.) 168°C
(Found: C, 64.85; H, 5.1; N, 1.95. C41H38NO2AsPd
requires C, 64.95; H, 5.05; N, 1.85; wmax (cm−1) (KBr)
1576, 1395 (CO)).
˚
Mo–Ka radiation (u=0.71069 A) at 23°C. Cell con-
stants were obtained from a least-squares refinement of
the setting angles of 25 reflections in the range 26.08B
2qB29.28° for 2c·0.5CH2Cl2 and 26.41B2qB29.42°
for 6c. During the data collection the intensities of
three representative reflections were measured after ev-
ery 150 and an absorption correction based on az-
imuthal scans of several reflections was applied for 2c
(transmission range 0.92–1.00) and 6c (transmission
range 0.81–1.00). The observed data were corrected for
Lorentz-polarization effects. All the calculations were
performed on a Rigaku RASA-7 automatic structure
analysis system using the TEXSAN software package
[21].
3.1.9. [{PdCl[C6H4CH2N(CH2Ph)2–C1, N]}2] (5c)
An acetone–water suspension (10:1, 22 cm3) contain-
ing 2c (0.200 g, 0.221 mmol) and lithium chloride (0.048
g, 1.13 mmol) was stirred at room temperature for 1
day. The resulting mixture was evaporated to dryness
and the residue extracted with dichloromethane. The

280
Y. Fuchita et al. / Journal of Organometallic Chemistry 580 (1999) 273–281
Table 4
Table 5
Crystallographic data for complexes 2c·0.5CH2Cl2 and 6ca
Atomic coordinates for complex 2c
2c·0.5CH2Cl2
6c
Atom
x
y
z
Formula
M
C46.5H47N2O4Pd2Cl C30H32N2Pd
Pd(1)
Pd(2)
O(1)
O(2)
O(3)
O(4)
N(1)
N(2)
C(1)
0.14331(2)
0.24252(2)
0.0204(2)
0.1081(2)
0.1517(2)
0.1061(2)
0.1831(2)
0.3892(2)
0.0270(3)
0.27024(2)
0.09889(2)
0.1472(2)
0.0340(2)
0.0899(2)
0.2302(2)
0.3298(2)
0.1513(2)
0.0660(3)
−0.0009(4)
0.1485(3)
0.1195(3)
0.3844(3)
0.4365(3)
0.3899(3)
0.4329(3)
0.5217(4)
0.5686(3)
0.5255(3)
0.4019(3)
0.3676(3)
0.3785(5)
0.3518(7)
0.3158(8)
0.302(1)
0.3304(7)
0.2494(3)
0.2785(3)
0.3093(3)
0.3321(4)
0.3254(4)
0.2938(4)
0.2699(3)
0.2088(3)
0.1540(3)
0.0971(3)
0.0431(3)
0.0482(4)
0.1057(4)
0.1581(3)
0.0668(3)
−0.0086(3)
−0.0803(4)
−0.1461(5)
−0.1406(6)
−0.0737(6)
−0.0082(4)
0.2158(3)
0.2788(3)
0.2471(3)
0.3094(4)
0.4040(4)
0.4382(3)
0.3760(3)
0.30123(2)
0.27659(3)
0.3103(2)
0.3283(2)
0.1136(2)
0.1267(2)
0.4778(2)
0.2320(3)
0.3256(3)
0.3471(4)
0.0731(3)
−0.0526(4)
0.5000(3)
0.4052(3)
0.2996(3)
0.2074(3)
0.2219(4)
0.3274(4)
0.4191(4)
0.5120(3)
0.4630(4)
0.3569(5)
0.3117(7)
0.369(1)
946.15
527.00
Crystal system
Space group
Triclinic
P1
Orthorhombic
Pbca
˚
a (A)
13.234(1)
14.500(2)
12.155(1)
100.570(9)
98.359(8)
103.731(8)
2183.4(4)
2
21.811(4)
22.379(4)
10.325(3)
˚
b (A)
˚
c (A)
a (°)
b (°)
g (°)
U (A )
Z
C(2)
C(3)
C(4)
−0.0710(3)
0.1109(3)
0.0650(4)
0.2981(3)
0.3142(3)
0.2487(3)
0.2605(3)
0.3358(4)
0.3991(4)
0.3876(3)
0.1221(3)
0.0053(4)
−0.0326(5)
−0.1399(7)
−0.2075(6)
−0.1743(7)
−0.0660(5)
0.1670(3)
0.2173(3)
0.1646(4)
0.2122(4)
0.3125(5)
0.3661(4)
0.3185(4)
0.4621(3)
0.4375(3)
0.3335(3)
0.3074(4)
0.3824(4)
0.4851(4)
0.5128(4)
0.4305(3)
0.3505(3)
0.2762(4)
0.1963(5)
0.1919(6)
0.2669(7)
0.3465(5)
0.3811(3)
0.4845(3)
0.5429(4)
0.6326(4)
0.6646(4)
0.6087(4)
0.5196(3)
3
˚
5039(1)
8
F(000)
962
2176
C(10)
C(11)
C(12)
C(13)
C(14)
C(15)
C(16)
C(20)
C(21)
C(22)
C(23)
C(24)
C(25)
C(26)
C(30)
C(31)
C(32)
C(33)
C(34)
C(35)
C(36)
C(40)
C(41)
C(42)
C(43)
C(44)
C(45)
C(46)
C(50)
C(51)
C(52)
C(53)
C(54)
C(55)
C(56)
C(60)
C(61)
C(62)
C(63)
C(64)
C(65)
C(66)
Dc (g cm−3
)
1.439
1.389
Crystal dimensions (mm) 0.15×0.15×0.20
0.50×0.20×0.03
7.57
m(Mo–Ka) (cm−1
)
9.28
Scan range (°)
No. measured reflections 10480
No. unique observed
reflections [I=3|(I)]
R, R%
0.79+0.30 tan q
0.94+0.30 tan q
6432
6846
2366
0.034, 0.038
0.037, 0.032
a Details in common: scan speed 16° min−1; 2qmax 55°; R=S
ꢀFoꢁ−ꢁFcꢀ/S ꢁFoꢁ, R%=(S wꢀFoꢁ−ꢁFcꢀ /S wꢁFoꢁ2)1/2, w=1/|2(Fo).
2
0.473(1)
0.5216(7)
0.5427(3)
0.6680(3)
0.7521(4)
0.8659(4)
0.8988(4)
0.8174(4)
0.7033(4)
0.3434(3)
0.4336(3)
0.4180(3)
0.4982(4)
0.5920(4)
0.6082(4)
0.5279(4)
0.1850(4)
0.0916(4)
0.1199(5)
0.0355(8)
−0.0763(9)
−0.1065(6)
−0.0230(5)
0.1491(3)
0.1338(3)
0.0560(4)
0.0379(4)
0.0967(5)
0.1743(4)
0.1934(4)
The structure of 2c was solved by heavy-atom Patter-
son methods [22] and expanded using Fourier tech-
niques [23]. All non-hydrogen atoms except for Cl, Cl
and C of the CH2Cl2 molecule were refined anisotropi-
cally. Hydrogen atoms were included but not refined.
The anisotropic parameters of Cl, Cl and C were not
converged because the solvent molecule was slightly
disordered and overlapped with the disordered
molecule. Therefore, those parameters were approxi-
mated by the partly refined values and fixed in the final
cycle of the refinement. This treatment of the parame-
ters of Cl, Cl and C gave no significant change in the
molecular structure of 2c; final R and R% values and a
goodness of fit indicator were almost the same as those
before the parameters were fixed.
The structure of 6c were solved by direct methods,
expanded using Fourier techniques and refined by full-
matrix least squares on F2. The non-hydrogen atoms
were refined anisotropically. Hydrogen atoms were in-
cluded but not refined.
Tables 5 and 6 give the final atomic coordinates of 2c
and 6c, respectively.
4. Supplementary material available
Additional material available from the Cambridge
Crystallographic Data Centre comprises hydrogen
atom coordinates, thermal parameters and the remain-
ing bond lengths and angles.

Y. Fuchita et al. / Journal of Organometallic Chemistry 580 (1999) 273–281
281
Table 6
[3] V.V. Dunina, O.A. Zalevskaya, V.M. Potatov, Zh. Obsch.
Khim. 54 (1984) 389.
Atomic coordinates for complex 6c
[4] A. Avshu, R.D. O’Sullivan, A.W. Parkins, N.W. Alcock, R.M.
Countryman, J. Chem. Soc. Dalton Trans. (1983) 1619.
[5] A.D. Ryabov, I.K. Sakodinskaya, A.K. Yatsimirsky, J. Chem.
Soc. Dalton Trans. (1985) 2629.
[6] A.D. Ryabov, Chem. Rev. 90 (1990) 403.
[7] I. Omae, Chem. Rev. 79 (1979) 287.
[8] Y. Fuchita, H. Tsuchiya, Inorg. Chim. Acta 209 (1993) 229; Y.
Fuchita, H. Tsuchiya, Polyhedron 12 (1993) 2079; Y. Fuchita,
H. Tsuchiya, A. Miyafuji, Inorg. Chim. Acta 233 (1995) 91.
[9] J. Vicente, I. Saura-Llamas, M.G. Palin, P.G. Jones, M.C.
Ramirez de Arellano, Organometallics 16 (1997) 826.
[10] C.K. Johnson, ORTEP, Report ORNL-5138, Oak Ridge Na-
tional Laboratory, Oak Ridge, TN (1976).
[11] M.R. Churchill, H.J. Wasserman, G.J. Young, Inorg. Chem. 19
(1980) 762.
[12] J. Selbin, K. Abboud, S.F. Watkins, M.A. Gutierrez, F.R.
Fronczek, J. Organomet. Chem. 241 (1983) 259.
[13] A. Crisini, M. Ghedini, J. Chem. Soc. Dalton Trans. (1997) 75.
[14] At 20°C, these proton resonated as a doublet due to the coupling
with phosphorus nuclei at l 3.96 (4JHP=2.0 Hz).
[15] A. Yamamoto, Organotransition Metal Chemistry, Wiley, New
York, 1986, p. 181.
[16] P. Jolliet, M. Gianini, A. von Zelewsky, G. Bernardinelli, H.
Stoeckli-Evans, Inorg. Chem. 35 (1996) 4883; M. Gianini, A.
Forster, P. Haag, A. von Zelewsky, H. Stoeckli-Evans, Inorg.
Chem. 35 (1997) 4889; M. Gianini, A. von Zelewsky, H.
Stoeckli-Evans, Inorg. Chem. 36 (1997) 6094.
[17] T.A. Stephenson, S.M. Morehouse, A.P. Powell, J.P. Heffer, G.
Wilkinson, J. Chem. Soc. (1965) 3632.
[18] A.C. Cope, R.N. Gourley, J. Organomet. Chem. 8 (1967) 527.
[19] F.A. Bovey, Nuclear Magnetic Resonance Spectroscopy, Aca-
demic Press, (London), 1969, ch. 7.
[20] G. Binsch, Top. Stereochem. 3 (1968) 97.
[21] TEXTAN, Crystal Structure Analysis Package, Molecular Struc-
ture Corporation, Houston TX, (1985 and 1992).
Atom
x
y
z
Pd(1)
N(1)
N(2)
C(1)
C(2)
0.50281(3)
0.4149(2)
0.5384(2)
0.5712(3)
0.4173(3)
0.5816(4)
0.4960(4)
0.6087(3)
0.6660(3)
0.7003(3)
0.6780(3)
0.6209(3)
0.5839(3)
0.4332(3)
0.4077(3)
0.4241(4)
0.4635(3)
0.4891(3)
0.4748(3)
0.3579(3)
0.3556(3)
0.3884(3)
0.3857(3)
0.3506(3)
0.3166(3)
0.3190(3)
0.4155(3)
0.3679(3)
0.3775(3)
0.3350(4)
0.2824(5)
0.2727(4)
0.3150(4)
0.13418(2)
0.0929(2)
0.1852(2)
0.2335(3)
0.0348(3)
0.1478(3)
0.2121(3)
0.2089(3)
0.2319(3)
0.2058(3)
0.1565(3)
0.1340(3)
0.1600(3)
0.0477(3)
0.0143(3)
0.0275(3)
0.0732(3)
0.1061(3)
0.0924(3)
0.1251(3)
0.1899(3)
0.2318(3)
0.2917(3)
0.3114(3)
0.2708(3)
0.2101(3)
0.0805(3)
0.0381(3)
0.59491(4)
0.6673(4)
0.7654(5)
0.6996(6)
0.5952(7)
0.8379(7)
0.8590(6)
0.5902(7)
0.5610(7)
0.4648(7)
0.3995(7)
0.4304(6)
0.5252(6)
0.4548(6)
0.3549(7)
0.2281(7)
0.2019(6)
0.3034(6)
0.4330(6)
0.6274(6)
0.6662(6)
0.5971(7)
0.6282(7)
0.7297(7)
0.7979(6)
0.7663(7)
0.8099(6)
0.8648(6)
0.8621(7)
0.9115(8)
0.966(1)
C(3)
C(4)
C(11)
C(12)
C(13)
C(14)
C(15)
C(16)
C(21)
C(22)
C(23)
C(24)
C(25)
C(26)
C(30)
C(31)
C(32)
C(33)
C(34)
C(35)
C(36)
C(40)
C(41)
C(42)
C(43)
C(44)
C(45)
C(46)
−0.0232(3)
−0.0624(3)
−0.0408(5)
0.0193(5)
0.975(1)
0.9245(8)
0.0583(4)
[22] P.T. Beurskens, G. Admiraal, G. Beurskens, W.P. Bosman, S.
Garcia-Granda, R.O. Gould, J.M.M. Smits, C. Smykalla,
PATTY, The DIRDIF program system, Technical Report of the
Crystallography Laboratory; University of Nijmegen (The
Netherlands), (1992).
References
[23] P.T Beurskens, G. Admiraal, G. Beurskens, W.P. Bosman, R. de
Gelder, R. Israel, J.M.M. Smits, DIRDIF94, The DIRDIF-94
program system, Technical Report of the Crystallography Labo-
ratory; University of Nijmegen, (The Netherlands) (1994).
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