Metal complexes of new scorpionate ligands: 2,2′-Bis(pyrazolyl)ethylamine and its derivatives

Article abstract of DOI:10.1016/j.ica.2009.06.004

The new bis(pyrazolyl)amine ligand NH₂CH₂CH(pz)₂ (1) was prepared from the reaction of N-[2,2-bis(pyrazolyl)ethyl]-1,8-naphthalimide with hydrazine monohydrate. A substituted derivative, C₆H₅CH_2<

Full text of DOI:10.1016/j.ica.2009.06.004

Inorganica Chimica Acta 362 (2009) 4377–4388
Contents lists available at ScienceDirect
Inorganica Chimica Acta
journal homepage: www.elsevier.com/locate/ica
Metal complexes of new scorpionate ligands: 2,20-Bis(pyrazolyl)ethylamine
and its derivatives
a
a
b
Daniel L. Reger a, , Bryn Reinecke , Mark D. Smith , Radu F. Semeniuc
*
a Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208, USA
b Department of Chemistry, Eastern Illinois University, Charleston, IL 61920, USA
a r t i c l e i n f o
a b s t r a c t
Article history:
The new bis(pyrazolyl)amine ligand NH2CH2CH(pz)2 (1) was prepared from the reaction of N-[2,2-
bis(pyrazolyl)ethyl]-1,8-naphthalimide with hydrazine monohydrate. substituted derivative,
Received 1 December 2008
Received in revised form 31 May 2009
Accepted 3 June 2009
A
C6H5CH2NHCH2CH(pz)2 (2), was prepared by the reaction of 1 with benzaldehyde followed by reduction
with NaBH4. Ligand 1 was also converted by two methods to the new bitopic, para-linked bis(pyrazolyl)
amine ligand p-C6H4(CH2NHCH2CH(pz)2)2, (3). The reactions of the ligands 1–3 with [Cu(PPh3)2]NO3
yields {(PPh3)Cu[(pz)2CHCH2NH2]}NO3, {(PPh3)Cu[(pz)2CHCH2NHCH2C6H5]}NO3 and {[(PPh3)Cu]2[p-
((pz)2CHCH2NHCH2)2C6H4]}(NO3)2ꢀsolvate, respectively. Complex {(N3)2Cu[(pz)2CHCH2NHCH2C6H5]}
was obtained from a methanol solution of 2, copper(II) acetate monohydrate and sodium azide. The com-
plex {Cd[(pz)2CHCH2NHCH2C6H5]2}(PF6)2ꢀ3C3H6O was synthesized by reaction of the protonated form of
ligand 2, [(pz)2CHCH2NH2CH2C6H5]PF6, with Cd(acac)2. In all of the structures the ligands are tridentate,
bonding to the metal through the lone pair on the amine group as well as through the pyrazolyl rings –
they act as true scorpionates. The solid state structures all have extensive non-covalent interactions, with
Available online 9 June 2009
Dedicated to the memory of Swiatoslaw
(‘‘Jerry’’) Trofimenko.
Keywords:
Bis(pyrazolyl)amine ligands
Copper(I) triphenylphosphine
Scorpionate ligands
Non-covalent interactions
the N–H functional groups of the amines participating in both N–Hꢀ ꢀ ꢀ and N–Hꢀ ꢀ ꢀO or N–Hꢀ ꢀ ꢀN hydro-
p
gen bonding interactions.
Ó 2009 Elsevier B.V. All rights reserved.
1. Introduction
tion of the poly(pyrazolyl)methane units and varying the poly(pyr-
azolyl)methane unit.
Supramolecular crystal engineering is an area of intense re-
search because of its potential applications in materials design
[1]. Important goals of this research are to understand how specific
functional groups designed into the ligands of transition metal
complexes will organize structure in a predictable fashion. Much
of our research [2] in this area is derived from the poly(pyrazol-
yl)methane family of scorpionate ligands that was first introduced
in 1970 by Trofimenko [3]. Building on his work, we reported ‘‘sec-
ond generation” tris(pyrazolyl)methane ligands, ligands with bulky
groups substituted at the 3-position of the pyrazolyl ring, another
area first developed by Trofimenko with poly(pyrazolyl)borate li-
gands [4]. In order to control the organization of more complex
supramolecular structures, we have prepared a series of ‘‘third
generation” poly(pyrazolyl)methane ligands, ligands specifically
functionalized at the non-coordinating ‘‘back” position as pictured
in Chart 1 [2,5]. Metal complexes of these ligands have shown
interesting molecular and supramolecular structures containing
specific non-covalent interactions that can be controlled to some
degree by altering the flexibility of the ligands, directional orienta-
The ether linkage in ligands I–IX [2] was initially introduced for
synthetic reasons and also to make these ligands semi-rigid so that
metal complexes would have solubility in organic solvents and be
more versatile for the self-assembly process. In addition, the lone
pairs on the ether linkage frequently enter into weak hydrogen
bonding interactions (C–Hꢀ ꢀ ꢀO), interactions not possible with li-
gands X–XIV [5b,c]. Interestingly, in no case have we observed di-
rect coordination of the ether oxygen to a metal.
In order to further manipulate and enhance the coordination
possibilities for these types of poly(pyrazolyl)methane ligands,
we have prepared ligands that incorporate amine functionalities
into the bis(pyrazolyl)methane backbone. We anticipated that
the amine N–H group would be capable of participating in supra-
molecular organization through strong hydrogen bonding interac-
tions, augmenting the organizational features already observed by
the ligands in Chart 1. Described here are the syntheses of the par-
ent bis(pyrazolyl)amine H2NCH2CH(pz)2 (pz=pyrazolyl), the ben-
zyl-substituted bis(pyrazolyl)amine C6H5CH2NHCH2CH(pz)2, and
the bitopic, para-arene linked bis(pyrazolyl)amine p-C6H4(CH2-
NHCH2CH(pz)2)2 and the use of these new ligands for the syntheses
and structural determinations of five metal complexes. While in
certain cases the hydrogen(s) of the amine functionality is involved
in hydrogen bonding, in all of the complexes the lone pair on the
* Corresponding author.
E-mail address: reger@mail.chem.sc.edu (D.L. Reger).
0020-1693/$ - see front matter Ó 2009 Elsevier B.V. All rights reserved.
doi:10.1016/j.ica.2009.06.004

4378
D.L. Reger et al. / Inorganica Chimica Acta 362 (2009) 4377–4388
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
O
O
O
N
N
N
N
N
N
N
N
N
O
O
O
N
N
N
N
N
N
N
N
N
I
II
III
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
O
N
N
N
N
N
N
O
O
O
O
O
O
N
N
N
N
O
O
O
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
O
N
N
N
N
N
N
N
N
N
N
O
N
O
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
IV
V
VI
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
O
O
O
O
O
N
N
O
N
N
N
N
N
N
VII
VIII
IX
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
(CH2)n
N
N
N
N
N
n=1,2,3
XII,XIII,XIV
XI
X
Chart 1. Third Generation Poly(pyrazolyl)methane Ligands.
amine nitrogen coordinates directly to the metal center, or as put
in the terminology introduced by Trofimenko the scorpionate
‘‘stinger” is striking its prey. Some of these results have previously
been communicated [6].
the presence of triethylamine to give the new para-linked bis(pyr-
azolyl)amine product p-C6H4(CH2NHCH2CH(pz)2)2 (3, Scheme 2).
The initial product isolated from this method was impure, so it
was further recrystallized from ethanol to yield a beige powder,
but this process lowered the yield significantly. Subsequently, it
was discovered that the condensation of 1 with terephthaldehyde
followed by reduction with sodium borohydride in methanol gave
3 in much higher yield.
2. Results
2.1. Synthesis
The complexes {(PPh3)Cu[(pz)2CHCH2NH2]}NO3 (4), {(PPh3)-
Cu[(pz)2CHCH2NHCH2C6H5]}NO3 (5) and {[(PPh3)Cu]2[p-((pz)2-
CHCH2NHCH2)2C6H4]}(NO3)2ꢀsolvate (8), were prepared by the
reaction of the ligands 1, 2 and 3, respectively, and an appropriate
ratio of [Cu(PPh3)2]NO3 in dichloromethane, followed by addition
of hexanes to precipitate the products. Crystals of {(N3)2Cu[(pz)2-
CHCH2NHCH2C6H5]} (6) were obtained by dissolving 2 in dichloro-
N-[2,2-bis(pyrazolyl)ethyl]-1,8-naphthalimide [2a], prepared
earlier by us, was found to react with hydrazine monohydrate to
release the parent bis(pyrazolyl)amine, NH2CH2CH(pz)2, (1)
(Scheme 1). The benzyl derivative of this compound was made
by reaction of 1 with benzaldehyde followed by reduction with
NaBH4 to give C6H5CH2NHCH2CH(pz)2, (2). The parent amine 1 also
reacts with half an equivalent of dibromo-para-xylene in THF in
methane and layering with
a solution of copper(II) acetate

D.L. Reger et al. / Inorganica Chimica Acta 362 (2009) 4377–4388
4379
.
The main distortion is caused by the restricted ‘‘bite” of the 6-
membered chelate rings of the ligand 1 that lowers the N–Cu–N
angles to approximately 90°. The one dimensional supramolecular
N2H4 H2O,
N
N
toluene,
reflux 12 h
N
N
N
O
N
O
N
1
N
H2N
N
structure is organized by concerted N–Hꢀ ꢀ ꢀ
p
and C–Hꢀ ꢀ ꢀ
p interac-
interactions oc-
tions to form cationic chains (Fig. 2). The N–Hꢀ ꢀ ꢀ
p
cur between one of the NH2 hydrogens oriented toward one of the
phenyl rings in the triphenylphosphine moiety on a neighboring
cation. The Hꢀ ꢀ ꢀcentroid and Nꢀ ꢀ ꢀcentroid distances are 2.59 Å
and 3.50 Å, respectively. The nearly linear N–Hꢀ ꢀ ꢀcentroid angle
of 171° shows that the hydrogen atom is almost centered over
the phenyl ring. The phenyl ring that serves as the proton acceptor
PhCHO,
MeOH,
reflux 12 h
NaBH4,
MeOH,
12 h
in the N–Hꢀ ꢀ ꢀ
p
interaction previously described becomes the
interaction. A hydrogen atom from
N
N
hydrogen donor in the C–Hꢀ ꢀ ꢀ
p
N
N
N
this ring is directed toward another triphenylphosphine phenyl
ring from the first molecule in the previous interaction. The
Hꢀ ꢀ ꢀcentroid and Cꢀ ꢀ ꢀcentroid distances are 2.69 Å and 3.47 Å,
respectively, with a C–Hꢀ ꢀ ꢀcentroid angle of 140°, again showing
that the hydrogen is almost centered over the phenyl ring with
which it interacts. These chains are linked together into a cationic
sheet by hydrogen bonding of CH and NH groups through bridging
nitrate counterions (Fig. 3). The NH2 hydrogen that is not used in
N
N
N
N
HN
2
Scheme 1. Synthesis of ligands 1 and 2.
monohydrate and sodium azide in methanol. Crystals of
{Cd[(pz)2CHCH2NHCH2C6H5]2}(PF6)2ꢀ3C3H6O (7) were obtained by
reaction of the protonated form of ligand 2, [(pz)2CHCH2-
NH2CH2C6H5]PF6, with Cd(acac)2 followed by crystallization from
acetone/diethyl ether.
the N–Hꢀ ꢀ ꢀ
p interaction forms a hydrogen bond to a nitrate oxygen
with Hꢀ ꢀ ꢀO and Nꢀ ꢀ ꢀO bond distances of 2.18 Å and 3.08 Å and an
N–Hꢀ ꢀ ꢀO angle of 165°. The CH(pz)2 hydrogen from a different
chain forms a hydrogen bond to a second oxygen atom on the same
nitrate anion with Cꢀ ꢀ ꢀH and Cꢀ ꢀ ꢀO distances of 2.38 Å and 3.29 Å,
respectively and a C–Hꢀ ꢀ ꢀO angle of 151°. The overall structure is
a two dimensional sheet.
2.2. Solid state structure analysis
Crystallographic data are listed in Tables 1 and 2. Selected bond
lengths and angles are shown in Tables 3–5. Hydrogen bonding
parameters are listed in Table 6. The most important result evident
in all of the structures is that the ligands are tridentate, bonding to
the metal through the lone pair on the amine group as well as
through the pyrazolyl rings. There is substantial supramolecular
organization in all of the structures.
In the crystal structure containing the parent bis(pyrazol-
yl)amine, {(PPh3)Cu[(pz)2CHCH2NH2]}NO3 (4, Fig. 1), the copper
is in a pseudotetrahedral environment coordinated to the amine
nitrogen, two pyrazolyl nitrogens, and a triphenyphosphine group.
The analogous complex of the benzyl ligand 2, {(PPh3)Cu[(pz)2-
CHCH2NHCH2C6H5]}NO3 (5), also has the copper in a pseudotetra-
hedral environment with tridentate coordination of the ligand and
the fourth position occupied by triphenylphosphine (Fig. 4). Likely
due to the increased steric hindrance introduced by the benzyl
group, no N–Hꢀ ꢀ ꢀ
p interactions are present in the cationic chains.
Nevertheless, the cations are still arranged in chains by C–Hꢀ ꢀ ꢀ
p
interactions identical to those in 4. A hydrogen atom from a tri-
phenylphosphine phenyl group interacts with a phenyl group from
a neighboring triphenylphosphine (Fig. 5). The Hꢀ ꢀ ꢀcentroid and
Cꢀ ꢀ ꢀcentroid distances are 2.97 Å and 3.86 Å, respectively, with a
Br
NEt3, THF,
reflux 12 h
N
N
+
2
H2N
N
N
N
N
Br
N
1
N
N
HN
NH
N
3
N
N
O
N
N
N
1
+
2
H2N
N
1) EtOH, reflux 12 h;
2) NaBH4, 0o C, EtOH, 5 h;
3) reflux 3 days.
O
Scheme 2. Syntheses of ligand 3.

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D.L. Reger et al. / Inorganica Chimica Acta 362 (2009) 4377–4388
Table 1
Crystallographic information for {(PPh3)Cu[(pz)2CHCH2NH2]}NO3 (4) and {(PPh3)Cu[(pz)2CHCH2NHCH2C6H5]}NO3ꢀ1.5C2H2Cl2 (5ꢀ1.5CH2Cl2).
4
(5ꢀ1.5CH2Cl2)
Empirical formula
Formula weight
Temperature
C26H26CuN6O3P
565.04
150(1) K
C34.50H35Cl3CuN6O3P
782.54
150(1) K
Wavelength
Crystal system
Space group
0.71073 Å
monoclinic
P21/c
0.71073 Å
triclinic
P1
ꢀ
Unit cell dimensions
Unit cell angles
a = 14.4251(7) Å
b = 14.9688(8) Å
c = 13.4458(7) Å
a = 8.3448(5) Å
b = 11.0671(6) Å
c = 19.4718(11) Å
a
= 90°
a
= 83.351(1)°
b = 116.130(1)°
b = 86.171(1)°
c
= 90°
c = 83.428(1)°
Volume
2606.6(2) Å3
1771.83(17) Å3
Z
4
2
Density (calculated)
Absorption coefficient
F (0 0 0)
1.440 Mg/m3
1.467 Mg/m3
0.939 mmꢁ1
0.932 mmꢁ1
1168
806
Crystal size
0.48 ꢂ 0.10 ꢂ 0.08 mm3
0.52 ꢂ 0.30 ꢂ 0.18 mm3
Reflections collected
Independent reflections
Absorption correction
Refinement method
Goodness-of-fit (GoF) on F2
21088
19189
4613 [R(int) = 0.0692]
none
7256 [R(int) = 0.0241]
Semi-empirical from equivalents
full-matrix least-squares on F2
1.041
full-matrix least-squares on F2
0.960
Final R indices [I > 2
R indices (all data)
r(I)]
R1 = 0.0436, wR2 = 0.0868
R1 = 0.0597, wR2 = 0.0921
R1 = 0.0371, wR2 = 0.0987
R1 = 0.0397, wR2 = 0.1007
Table 2
Crystallographic information for {(N3)2Cu[(pz)2CHCH2NHCH2C6H5]} (6), {Cd[(pz)2CHCH2NHCH2C6H5]2}(PF6)2ꢀ3C3H6O (7), and {[(PPh3)Cu]2[p-((pz)2CHCH2NHCH2)2-
C6H4]}(NO3)2ꢀsolvate (8).
6
7
8
Empirical formula
Formula weight
Temperature
Wavelength
Crystal system
Space group
C15H17CuN11
414.94
C39H52CdF12N10O3P2
1111.25
150(1) K
C60H58Cu2N12O6P2
1232.20
150(1) K
150(1) K
0.71073 Å
triclinic
0.71073 Å
triclinic
0.71073 Å
triclinic
ꢀ
ꢀ
ꢀ
P1
P1
P1
Unit cell dimensions
Unit cell angles
a = 7.6788(3) Å
b = 13.3868(6) Å
c = 19.2509(8) Å
a = 10.8757(7) Å
b = 11.1856(7) Å
c = 12.1212(8) Å
a = 10.1775(9) Å
b = 11.9295(10) Å
c = 15.5942(13) Å
a
= 71.920(1)°
a
= 91.616(1)°
a
= 110.561(2)°
b = 86.317(1)°
b = 113.326(1)°
b = 92.662(2)°
c
= 73.553(1)°
c
= 114.490(1)°
c = 93.415(2)°
Volume
Z
1803.60(13) Å3
4
1199.14(13) Å3
1
1765.0(3) Å3
1
Density (calculated)
Absorption coefficient
F (0 0 0)
1.528 Mg/m3
1.539 Mg/m3
1.159 Mg/m3
1.237 mmꢁ1
0.616 mmꢁ1
0.699 mmꢁ1
852
566
638
Crystal size
0.40 ꢂ 0.18 ꢂ 0.04 mm3
0.42 ꢂ 0.32 ꢂ 0.24 mm3
0.30 ꢂ 0.20 ꢂ 0.14 mm3
Reflections collected
Independent reflections
Refinement method
Goodness-of-fit (GoF) on F2
18369
13579
11707
6358 [R(int) = 0.0634]
full-matrix least-squares on F2
0.968
4908 [R(int) = 0.0351]
full-matrix least-squares on F2
1.037
4078 [R(int) = 0.0468]
full-matrix least-squares on F2
0.981
Final R indices [I > 2
R indices (all data)
r(I)]
R1 = 0.0354, wR2 = 0.0797
R1 = 0.0440, wR2 = 0.0826
R1 = 0.0255, wR2 = 0.0657
R1 = 0.0261, wR2 = 0.0660
R1 = 0.0444, wR2 = 0.1118
R1 = 0.0518, wR2 = 0.1144
C–Hꢀ ꢀ ꢀcentroid angle of 159°, again showing that the hydrogen
atom is almost centered over the phenyl ring. The nitrate counte-
rions link the chains together into sheets with N–Hꢀ ꢀ ꢀO and C–
Hꢀ ꢀ ꢀO hydrogen bonds in the same manner as compound 4. One
hydrogen bond is made by the N–H and has Hꢀ ꢀ ꢀO and Nꢀ ꢀ ꢀO dis-
tances of 2.21 Å and 2.97 Å with a N–Hꢀ ꢀ ꢀO angle of 157°. The other
hydrogen bond is through a methine hydrogen from CH(pz)2 to the
same nitrate anion with Hꢀ ꢀ ꢀO and Cꢀ ꢀ ꢀO distances of 2.36 Å and
3.31 Å and a C–Hꢀ ꢀ ꢀO angle of 156°. The benzyl functionality re-
sults in additional interactions that organize compound 5 into a
three dimensional structure. The para-hydrogen from the benzyl
Hꢀ ꢀ ꢀcentroid and Cꢀ ꢀ ꢀcentroid distances of 2.99 Å and 3.73 Å,
respectively and a C–Hꢀ ꢀ ꢀcentroid angle of 137° (Fig. 6).
In the copper azide complex {(N3)2Cu[(pz)2CHCH2NHCH2C6H5]}
(6), the copper is in a pseudo-square pyramidal environment with
three coordination sites occupied by ligand 2 in the usual triden-
tate arrangement with the remaining two bonds being to the azide
groups (Fig. 7). One of the pyrazolyl ring donor atoms, N21, occu-
pies the axial site. Supramolecular interactions include two con-
certed N–Hꢀ ꢀ ꢀN hydrogen bonds between the amine hydrogen on
one molecule to an azide nitrogen bonded to the copper atom on
a neighboring molecule of the complex and a reciprocal N–Hꢀ ꢀ ꢀN
bond from the amine hydrogen on the second molecule to an azide
group interacts with a pyrazolyl ring in a C–Hꢀ ꢀ ꢀ
p interaction with

D.L. Reger et al. / Inorganica Chimica Acta 362 (2009) 4377–4388
4381
Table 3
Selected bond lengths (Å) and angles (°) for 4 and 5ꢀ1.5CH2Cl2.
Table 6
Hydrogen bonding parameters for 4–8, lengths (Å) and angles (°).
4
5ꢀ1.5CH2Cl2
Atoms
Dꢀ ꢀ ꢀA
Hꢀ ꢀ ꢀA
D–Hꢀ ꢀ ꢀA
Cu(1)–N(21)
Cu(1)–N(11)
Cu(1)–N(1)
Cu(1)–P(1)
N(21)–Cu(1)–N(11)
N(21)–Cu(1)–N(1)
N(11)–Cu(1)–N(1)
N(21)–Cu(1)–P(1)
N(11)–Cu(1)–P(1)
N(1)–Cu(1)–P(1)
2.053(3)
2.116(2)
2.145(2)
2.1631(9)
89.26(10)
89.72(10)
85.95(9)
132.33(7)
124.11(7)
122.18(7)
Cu(1)–N(11)
Cu(1)–N(21)
Cu(1)–N(1)
Cu(1)–P(1)
N(11)–Cu(1)–N(21)
N(11)–Cu(1)–N(1)
N(21)–Cu(1)–N(1)
N(11)–Cu(1)–P(1)
N(21)–Cu(1)–P(1)
N(1)–Cu(1)–P(1)
2.0645(17)
2.0700(17)
2.1296(17)
2.1542(5)
90.06(7)
89.12(7)
88.75(7)
132.97(5)
121.37(5)
122.34(5)
4
N(1)–H(1B)ꢀ ꢀ ꢀO(1)
3.077(3)
3.297(4)
2.18
2.38
165
151
C(1)–H(1)ꢀ ꢀ ꢀO(3)
5ꢀ1.5CH2Cl2
N(1)–H(1A)ꢀ ꢀ ꢀO(1)
C(1)–H(1)ꢀ ꢀ ꢀO(3)
2.974(2)
3.301(3)
2.21(3)
2.36
157(2)
156
6
N(1)–H(1N)ꢀ ꢀ ꢀN(51)#1
3.094(3)
3.156(3)
2.348(18)
2.430(16)
150(2)
149(2)
N(2)–H(H2N)ꢀ ꢀ ꢀN(61)#2
7
N(1A)–H(1NA)ꢀ ꢀ ꢀO(1)
3.344(3)
2.51(3)
178(3)
8
Table 4
N(1)–H(1N)ꢀ ꢀ ꢀO(1)
C(1)–H(1)ꢀ ꢀ ꢀO(1)#2
C(1)–H(1)ꢀ ꢀ ꢀO(2)#2
2.958(5)
3.250(5)
3.446(5)
2.10(4)
2.32
2.52
147(3)
155
154
Selected bond lengths (Å) and angles (°) for 6 and 7.
6
7
Symmetry codes: 6, #1 = 1 ꢁ x, 1 ꢁ y, z, #2 = 1 ꢁ x, 1 ꢁ y, 1 ꢁ z; 8, #2 = ꢁx, 1 ꢁ y,
1 ꢁ z.
Cu(1)–N(54)
Cu(1)–N(51)
Cu(1)–N(11)
Cu(1)–N(1)
Cu(1)–N(21)
Cu(2)–N(64)
Cu(2)–N(61)
Cu(2)–N(31)
1.969(2)
1.985(2)
2.021(2)
2.059(2)
2.250(2)
1.967(2)
2.000(2)
2.030(2)
2.058(2)
2.249(2)
93.58(9)
92.92(8)
170.53(8)
164.83(9)
87.58(9)
84.36(8)
104.33(8)
99.23(8)
85.81(8)
90.38(8)
93.44(9)
93.84(9)
168.66(9)
167.36(9)
86.91(9)
84.09(8)
102.42(9)
100.43(8)
86.47(8)
89.93(8)
Cd(1)–N(11)
2.3039(14)
2.3424(13)
2.377(2)
180
81.77(5)
86.43(7)
74.24(7)
98.23(5)
93.57(7)
105.76(7)
Cd(1)–N(21)
Cd(1)–N(1Aa)
N(11)–Cd(1)–N(11a)
N(11)–Cd(1)–N(21)
N(11)–Cd(1)–N(1A)
N(21)–Cd(1)–N(1A)
N(11)–Cd(1)–N(21a)
N(11)–Cd(1)–N(1Aa)
N(21)–Cd(1)–N(1Aa)
Cu(2)–N(2)
Cu(2)–N(41)
N(54)–Cu(1)–N(51)
N(54)–Cu(1)–N(11)
N(51)–Cu(1)–N(11)
N(54)–Cu(1)–N(1)
N(51)–Cu(1)–N(1)
N(11)–Cu(1)–N(1)
N(54)–Cu(1)–N(21)
N(51)–Cu(1)–N(21)
N(11)–Cu(1)–N(21)
N(1)–Cu(1)–N(21)
N(64)–Cu(2)–N(61)
N(64)–Cu(2)–N(31)
N(61)–Cu(2)–N(31)
N(64)–Cu(2)–N(2)
N(61)–Cu(2)–N(2)
N(31)–Cu(2)–N(2)
N(64)–Cu(2)–N(41)
N(61)–Cu(2)–N(41)
N(31)–Cu(2)–N(41)
N(2)–Cu(2)–N(41)
a
A = dominant disorder orientation.
Fig. 1. ORTEP diagram of {(PPh3)Cu[(pz)2CHCH2NH2]}NO3 (4).
C–H bond pointed directly toward a pyrazolyl ring oriented per-
Table 5
Selected bond lengths (Å) and angles (°) for 8.
pendicularly to the stack which results in a C–Hꢀ ꢀ ꢀ
p interaction.
The Hꢀ ꢀ ꢀcentroid distances are 2.73 Å and 2.74 Å and the Cꢀ ꢀ ꢀcen-
troid distances are 3.52 Å and 3.36 Å with C–Hꢀ ꢀ ꢀcentroid angles
Cu(1)–N(21)
Cu(1)–N(11)
Cu(1)–P(1)
Cu(1)–N(1)
N(21)–Cu(1)–N(11)
N(21)–Cu(1)–P(1)
N(11)–Cu(1)–P(1)
N(21)–Cu(1)–N(1)
N(11)–Cu(1)–N(1)
P(1)–Cu(1)–N(1)
2.041(3)
2.068(3)
2.1450(11)
2.155(3)
90.93(12)
130.82(9)
124.93(10)
88.79(11)
87.63(12)
121.31(8)
of 142° and 144°. This interaction containing one
p p stack and
ꢁ
two C–Hꢀ ꢀ ꢀ
p interactions is known as the pyrazolyl embrace [2e],
and it serves to link the hydrogen-bound asymmetric units into
chains. Other C–Hꢀ ꢀ ꢀN hydrogen bonds occur between hydrogens
on the pyrazolyl rings and terminal azide nitrogens on neighboring
chains to give 2D sheets with Cꢀ ꢀ ꢀN and Nꢀ ꢀ ꢀH lengths of 3.44 Å and
2.53 Å, respectively with a C–Hꢀ ꢀ ꢀN angle of 161° (Fig. 9). These
sheets are then linked into a 3D structure by C–Hꢀ ꢀ ꢀN hydrogen
bonds between the CH(pz)2 methine hydrogen and an azide nitro-
gen. The Cꢀ ꢀ ꢀN and Nꢀ ꢀ ꢀH distances are 3.31 Å and 2.35 Å, respec-
tively with a C–Hꢀ ꢀ ꢀN angle of 160°.
nitrogen on the first (Fig. 8). The Nꢀ ꢀ ꢀH and Nꢀ ꢀ ꢀN lengths are 2.35 Å
and 3.09 Å, respectively, and the N–Hꢀ ꢀ ꢀN angle is 150° for one
bond. The lengths for the second bond are similar at 2.43 Å and
3.16 Å with an N–Hꢀ ꢀ ꢀN angle of 149°. Two pyrazolyl rings on
neighboring ‘‘dimers” formed by the two N–Hꢀ ꢀ ꢀN hydrogen bonds
Two tridentate ligands of
2
bond to cadmium(II) in
{Cd[(pz)2CHCH2NHCH2C6H5]2}(PF6)2ꢀ3C3H6O (7) to yield a pseudo-
octahedral environment around the metal (Fig. 10). There is disor-
der in the benzyl region of the molecule over two closely spaced
orientations in the refined ratio A/B = 0.701(4)/0.299(4). Only the
participate in a
p
ꢁp
stack with a centroidꢀ ꢀ ꢀcentroid distance of
3.527 Å and a slip angle of 13°. These stacked rings each have a

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D.L. Reger et al. / Inorganica Chimica Acta 362 (2009) 4377–4388
Fig. 4. ORTEP diagram of the {(PPh3)Cu[(pz)2CHCH2NHCH2C6H5]}+ building block of
5ꢀ1.5CH2Cl2. Displacement ellipsoids drawn at the 50% probability level.
bond from the CH(pz)2 methine hydrogen to two oxygen atoms on
the same nitrate anion, thus linking the individual bimetallic units
into one dimensional ribbons (Fig. 13). The N–Hꢀ ꢀ ꢀO hydrogen
bonds form with Hꢀ ꢀ ꢀO and Nꢀ ꢀ ꢀO lengths of 2.10 Å and 2.96 Å,
respectively and an N–Hꢀ ꢀ ꢀO angle of 147°. The bifurcated C–
Hꢀ ꢀ ꢀO bonds form from the CH(pz)2 methine hydrogen to the ni-
trate anion with Hꢀ ꢀ ꢀO and Cꢀ ꢀ ꢀO bond lengths of 2.33 Å and
2.52 Å, and 3.25 Å and 3.45 Å, respectively, with C–Hꢀ ꢀ ꢀO angles
of 154° and 155°. These ribbons are further linked into two dimen-
Fig. 2. Self-assembly of {(PPh3)Cu[(pz)2CHCH2NH2]}+ in 4 into chains through N–
Hꢀ ꢀ ꢀp and C–Hꢀ ꢀ ꢀp interactions.
A orientation is examined here. In the crystal, the only supramolec-
ular interaction observed is a C–Hꢀ ꢀ ꢀ interaction between a
hydrogen from the backbone carbon nearest the benzyl ring to a
benzyl ring from neighboring molecule of the complex
p
a
sional sheets by
p p stacks between two phenyl rings on neigh-
ꢁ
(Fig. 11). The Hꢀ ꢀ ꢀcentroid and Cꢀ ꢀ ꢀcentroid distances are 2.99 Å
and 3.88 Å, respectively, with a C–Hꢀ ꢀ ꢀcentroid angle of 150°.
Although this appears to be a strong interaction, there is a great
deal of disorder in this region of the structure so the non-covalent
interactions cannot be analyzed definitively.
boring units with a centroid-centroid distance of 4.09 Å and slip
angle of 25° (Fig. 14).
3. Discussion
The bitopic bridging ligand 3, analogous to the ether linked li-
gand IX in Chart 1, was prepared in order to build a more highly
organized covalent architecture. Fig. 12 shows the structure of its
dinuclear copper(I) triphenylphosphine adduct, {[(PPh3)Cu]2[p-
((pz)2CHCH2NHCH2)2C6H4]}(NO3)2ꢀsolvate (8). Each end of the
para-linked bis(pyrazolyl)amine ligand coordinates in the same tri-
dentate manner as bis(pyrazolyl)amine ligands 1 and 2. The supra-
molecular interactions include one hydrogen bond between the
amine hydrogen and the nitrate counterion, as well as a bifurcated
The most important result of this investigation is that the new
amine substituted bis(pyrazolyl)methane ligands coordinate to
the metal atom in a tridentate manner with fairly similar M–N
bond distances in all five complexes studied – they act as true scor-
pionates. This result was unexpected because in the ether ana-
logues, the ligands only coordinated in
a bidentate fashion
through the pyrazolyl ring donor atoms; the oxygen atoms of the
ether link only participate in the non-covalent structure.
Fig. 3. 2D organization of 4 via D–Hꢀ ꢀ ꢀ
p interactions (D@ C, N); (blue dotted lines) and D–Hꢀ ꢀ ꢀO hydrogen bonds (red dotted lines). (For interpretation of the references to
colour in this figure legend, the reader is referred to the web version of this article.)

D.L. Reger et al. / Inorganica Chimica Acta 362 (2009) 4377–4388
4383
Fig. 7. ORTEP diagram of one molecule of {(N3)2Cu[(pz)2CHCH2NHCH2C6H5]} (6).
For example, in the sheet structure of 4 the NH2 group forms both
a N–Hꢀ ꢀ ꢀ and N–Hꢀ ꢀ ꢀO hydrogen bonding interaction. The struc-
ture of 5 is similar, but the addition of the benzyl group blocks
interaction, with this new functionality adding addi-
tional organizing features that lead to a three dimensional supra-
molecular structure. In addition to these non-covalent
interactions, the bimetallic structure of 8 is also organized by the
bitopic linking arrangement of the two bis(pyrazolyl)amine units
in each ligand.
p
Fig. 5. 2D supramolecular organization of 5ꢀ1.5CH2Cl2 via C–Hꢀ ꢀ ꢀ
p interactions
(dotted blue lines) and N–Hꢀ ꢀ ꢀO and C–Hꢀ ꢀ ꢀO hydrogen bonds (dotted red lines).
(For interpretation of the references to colour in this figure legend, the reader is
referred to the web version of this article.)
the N–Hꢀ ꢀ ꢀ
p
In the neutral, diazide structure of 6 hydrogen bonding from the
ligand is still an important non-covalent force, with the nitrogens
of the azide ligands coordinated to the copper(II) acting as the do-
nor group in the hydrogen bonding. In addition to this interaction,
we observe the cooperative
p
ꢁ
p
stack/two C–Hꢀ ꢀ ꢀ
p interactions
known as the pyrazolyl embrace, a feature that we have character-
ized previously as an important non-covalent interaction present
in the structures of many metal complexes of poly(pyrazolyl)meth-
ane and poly(pyrazolyl)borate ligands [2e]. Compound 7 is a typi-
cal six-coordinate complex of Cd(II).
4. Experimental
4.1. General considerations
Starting materials were purchased from Aldrich. 1H NMR spec-
tra were recorded on a Varian AM300 spectrometer using a broad-
band probe. Proton chemical shifts are reported in ppm versus
internal (CH3)4Si. Mass spectral data were recorded on either a
MicroMass QTOF spectrometer or a VG70S instrument. Elemental
analyses were performed by Robinson Microlit, Madison, NJ. N-
[2,2-bis(pyrazolyl)ethyl]-1,8-naphthalimide was prepared as re-
ported previously [2a].
4.2. Synthesis of H2NCH2CH(pz)2 (1)
Fig. 6. 3D architecture of 5ꢀ1.5CH2Cl2, based on a C–Hꢀ ꢀ ꢀ
p interaction between the
benzyl group and a pyrazolyl ring. The phenyls marked with a star are those that act
N-[2,2-bis(pyrazolyl)ethyl]-1,8-naphthalimide (40.00 g, 0.11
mol) was dissolved completely in warm toluene (250 mL). Hydra-
zine monohydrate (40 mL, 98%, 0.83 mol) was added and the mix-
ture was heated at reflux overnight. After cooling to room
temperature, the toluene and excess hydrazine were removed by
rotary evaporation and the product, 2,2-dipyrazol-1-yl-ethyla-
mine, 1, dried under vacuum. The solid was dissolved in two
100 mL portions of H2O and these solutions filtered. The water
was removed via rotary evaporation to yield the product as an oily
as hydrogen receptors in the chain formation shown in Fig. 5.
The goal of using the N–H functional groups of the amines to
build extensive non-covalent interactions was successful. In the
three structures with nitrate counterions, 4, 5 and 8, N–Hꢀ ꢀ ꢀO
hydrogen bonding with this ion is an important organizational fea-
ture. Interestingly, N–Hꢀ ꢀ ꢀp interactions also are very important.

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D.L. Reger et al. / Inorganica Chimica Acta 362 (2009) 4377–4388
Fig. 8. N–Hꢀ ꢀ ꢀN hydrogen bonding (red lines) between two molecules of 6 creates centrosymmetric dimers,
pꢁp and C–Hꢀ ꢀ ꢀp interactions between dimers (blue lines)
organizes them into chains. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)
Fig. 9. C–Hꢀ ꢀ ꢀN hydrogen bonding in the plane perpendicular to the plane in Fig. 8 (orange and green lines) organizes chains of 6 into a 3D supramolecular network. (For
interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)
7.60, 7.58 (d, d; J = 1, 2 Hz; 2H, 2H; H3,H5-pz), 6.37 (t, J = 7 Hz,
1H, CH), 6.30 (d, d, J = 2, 1 Hz, 2H, H4-pz), 3.78 (d, J = 7 Hz, 2H,
CH2), 1.68 (br s, 2H, NH2).
4.3. Synthesis of C6H5CH2NHCH2CH(pz)2 (2)
Compound 1 (3.54 g, 0.020 mol) was dissolved in methanol
(75 mL). Once completely dissolved, benzaldehyde (2.0 mL,
0.020 mol) was added and the mixture was heated at reflux over-
night. After cooling to room temperature, excess of NaBH4
(1.50 g, 0.040 mol) was added in portions and the mixture stirred
for 6 h. The solvent was removed via rotary evaporation and the
residue was dissolved in ethyl acetate (75 mL). The organic layer
was washed with three 100 mL aliquots of water, dried over anhy-
drous sodium sulfate, filtered, and then the solvent removed via ro-
tary evaporation to yield the product as a sticky yellow solid
(4.92 g, 92%). HRMS (direct probe): calcd. for C15H17N5: 267.1484,
Fig. 10. ORTEP diagram of cationic {Cd[(pz)2CHCH2NHCH2C6H5]2}2+ building block of
7.
found 267.1483. 1H NMR (300 MHz, CDCl3) dH 7.58, 7.56 (d, d;
J = 1, 2 Hz; 2H, 2H; H3,H5-pz), 7.25 (m, 5H, C6H5), 6.52 (t, J = 7 Hz,
1H, CH), 6.28 (dd, J = 2, 1 Hz, 2H, H4-pz), 3.82 (s, 2H, C6H5–CH2)
3.69 (d, J = 7 Hz, 2H, N–CH2).
brown solid (12.0 g, 60.5%). HRMS (direct probe): calcd. for
C8H11N5 178.1093, found 178.1088. 1H NMR (300 MHz, CDCl3) dH

D.L. Reger et al. / Inorganica Chimica Acta 362 (2009) 4377–4388
4385
Fig. 11. 1D supramolecular organization of 7 into chains via C–Hꢀ ꢀ ꢀ
p interactions between backbone hydrogens and benzyl rings (dotted red lines). (For interpretation of the
references to colour in this figure legend, the reader is referred to the web version of this article.)
Fig. 12. ORTEP diagram of cationic {[(PPh3)Cu]2[p-((pz)2CHCH2NHCH2)2C6H4]}2+ building block of 8. Displacement ellipsoids drawn at the 30% probability level.
Fig. 13. 1D supramolecular organization of 8 via N–Hꢀ ꢀ ꢀO and C–Hꢀ ꢀ ꢀO hydrogen bonds (dotted blue lines). (For interpretation of the references to colour in this figure legend,
the reader is referred to the web version of this article.)

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D.L. Reger et al. / Inorganica Chimica Acta 362 (2009) 4377–4388
Fig. 14. 2D supramolecular organization of 8. Red stars show
p
–p
stacking sites. (For interpretation of the references to colour in this figure legend, the reader is referred to
the web version of this article.)
4.4. Synthesis of p-C6H4(CH2NHCH2CH(pz)2)2 (3)
tion was stirred for 15 min and hexanes (100 mL) were added
yielding a pale yellow powder (0.127 g, 95%). Anal. Calc. for
Compound 3 was synthesized by two different methods. In the
first synthesis, (1.76 g, 9.93 mmol) was dissolved in THF
C26H26CuN6O3P: C, 55.27; H, 4.64; N, 14.87. Found: C, 54.97; H,
1
4.61; N, 15.11%. Layering a dichloromethane solution of the prod-
uct with hexanes yielded single crystals suitable for X-ray diffrac-
tion studies.
(100 mL), placed under a nitrogen atmosphere and triethylamine
(0.50 g, 4.9 mmol) added via syringe. Dibromo-para-xylene
(1.30 g, 4.92 mmol) was dissolved in THF (50 mL) and slowly added
via syringe. The solution was stirred for 1 h, then heated at reflux
overnight. After cooling, the solution was filtered, the solvent re-
moved via rotary evaporation, the resulting yellow oil extracted
with water and ethyl acetate, the organic layer dried over anhy-
drous sodium sulfate, filtered, and the solvent removed by rotary
evaporation to yield 0.75 g of product. As this product was impure,
it was dissolved in boiling ethanol and chilled overnight. The pure
product formed as 0.21 g of a beige powder (0.46 mmol, 15.9%). In
the second synthesis, compound 1 (3.54 g, 0.020 mol) was dissolved
in ethanol (100 mL) with terephthalaldehyde (1.34 g, 0.010 mol)
and heated at reflux overnight. After cooling with an ice bath,
NaBH4 (1.13 g, 0.030 mol) was added in small portions and the solu-
tion was heated at reflux for 72 h. The solution was filtered, the sol-
vent was removed via rotary evaporation, the residue redissolved in
chloroform (75 mL), filtered, and dried. This chloroform-soluble
fraction was dissolved in hot methanol (50 mL), filtered, and dried
to give 3 as a light yellow powder of high purity (0.32 g, 38%). HRMS
(direct probe): calcd. for C24H28N10 457.2576, found 457.2578. Anal.
Calc. for C24H28N10: C, 63.14; H, 6.18; N, 30.68. Found: C, 63.35; H,
5.85; N, 30.33%. 1H NMR (300 MHz, CDCl3) dH 7.60, 7.58 (d, d;
J = 1, 2 Hz; 4H, 4H; H3,H5-pz), 7.20 (s, 4H, C6H4), 6.55 (t, J = 7 Hz,
2H, CH), 6.25 (dd, J = 1, 2 Hz, 4H, H4-pz), 3.80 (d, J = 7 Hz, 4H, N–
CH2), 3.67 (br s, 4H, C6H4–CH2), 2.18 (br s, 2H, NH).
4.6. Synthesis of {(PPh3)Cu[(pz)2CHCH2NHCH2C6H5]}NO3 (5)
Compound 2 (0.044 g (0.16 mmol) and [Cu(PPh3)2]NO3 (0.108 g,
0.16 mmol) were dissolved in dichloromethane (20 mL). The solu-
tion was stirred for 15 min and hexanes (100 mL) were added
yielding a pale yellow powder (0.123 g, 89%). Anal. Calc. for
C33H32CuN6O3P: C, 60.50; H, 4.92; N, 12.83. Found: C, 60.72; H,
5.32; N, 12.41%. Layering a dichloromethane solution of the prod-
uct with hexanes yielded single crystals suitable for X-ray diffrac-
tion studies.
4.7. Synthesis of {(N3)2Cu[(pz)2CHCH2NHCH2C6H5]} (6)
Compound 2 (0.028 g, 0.10 mmol) was dissolved in dichloro-
methane (20 mL). Copper(II) acetate monohydrate (0.020 g,
0.10 mmol) and sodium azide (0.010 g, 0.10 mmol) were dissolved
in methanol (20 mL). The two solutions were layered in a test tube
and a small quantity of X-ray quality crystals were obtained in sev-
eral days.
4.8. Synthesis of {Cd[(pz)2CHCH2NHCH2C6H5]2}(PF6)2ꢀ3C3H6O (7)
To a methanolic solution of (pz)2CHCH2NHCH2C6H5 (0.267 g,
1.00 mmol) was added dropwise concentrated HCl until pH 2.
The solvents were removed by rotary evaporation and the residue
was redissolved in water (50 mL). To this solution an excess of a
saturated aqueous solution of NH4PF6 (ca. 1.0 g in 75 mL water)
was added dropwise, resulting in the precipitation of
4.5. Synthesis of {(PPh3)Cu[(pz)2CHCH2NH2]}NO3 (4)
Compound 1 (0.029 g, 0.16 mmol) and [Cu(PPh3)2]NO3 (0.108 g,
0.16 mmol) were dissolved in dichloromethane (20 mL). The solu-

D.L. Reger et al. / Inorganica Chimica Acta 362 (2009) 4377–4388
4387
[(pz)2CHCH2NH2CH2C6H5]PF6 (0.37 g, 89%). [(pz)2CHCH2NH2CH2-
C6H5]PF6 (0.103 g (25 mmol) was dissolved in acetone and added
to a solution of Cd(acac)2 (0.038 g, 12.5 mmol) in acetone under
stirring yielding {Cd[(pz)2CHCH2NHCH2C6H5]2}(PF6)2 (0.100 g, 86
%) as an off-white powder. A portion of this solid was then dis-
solved in acetone in a small vial, sealed in a larger tube containing
diethyl ether, and X-ray quality crystals of (7) formed after several
days.
For compound 7, final unit cell parameters were determined by
least-squares refinement of 5645 reflections with I > 5 (I) from the
r
data set. The compound crystallizes in the triclinic crystal system.
ꢀ
The space group P1 was confirmed by the successful solution and
refinement of the data. The asymmetric unit consists of half of
the {Cd[(pz)2CHCH2NHCH2C6H5]2}2+ complex located on an inver-
ꢁ
sion center, one PF6 anion, and 1.5 independent acetone mole-
cules of crystallization. The half-acetone is disordered about an
inversion center. The ligand is disordered over two closely spaced
orientations in the refined ratio A/B = 0.701(4)/0.299(4). The disor-
der affects only the -CH2NHCH2C6H5 part of the ligand; the CH(pz)2
part is normal. The total population of the two disorder compo-
nents was constrained to sum to unity. The geometry of the minor
component was restrained to be similar to that of the major with a
SHELX SAME instruction (21 restraints). Counterpart atoms in each
component were refined with common displacement parameters
(e.g., Uij(N1A) = Uij(N1B), etc.). All non-hydrogen atoms were re-
fined with anisotropic displacement parameters. Hydrogen atoms
were placed in geometrically idealized positions and included as
riding atoms, with the exception of the nitrogen proton H1NA of
the major disorder component, which was located and refined
freely.
4.9. Synthesis of {[(PPh3)Cu]2[p-
((pz)2CHCH2NHCH2)2C6H4]}(NO3)2ꢀsolvate (8)
Cu(PPh3)2NO3 (0.130 g, 0.32 mmol) and half an equivalent of 3
(0.045 g, 0.16 mmol) were each dissolved in dichloromethane
(10 mL). The two solutions were combined and stirred. The result-
ing solution was layered with hexanes in capped vials, from which
X-ray quality crystals were obtained overnight. HRMS ESI(+) m/z:
calcd. for [(C60H58Cu2N10P2)NO3]+ 1168.2792, found 1168.2762.
4.10. Crystallographic studies
Crystal information, data collection, and refinement parameters
are given in Tables 1 and 2. For all five complexes X-ray intensity
data were measured at 150(1) K on a Bruker SMART APEX CCD-based
For compound 8, final unit cell parameters were determined by
least-squares refinement of 6455 reflections with I > 5r(I) from the
diffractometer system (Mo K
a
radiation, k = 0.71073 Å) [7]. Raw
data set. The compound crystallizes in the triclinic system. The
space group P1 was confirmed by the successful solution and
ꢀ
data frame integration and Lorentz-polarization corrections were
performed with SAINT+ [7]. Direct methods structure solution, dif-
ference Fourier calculations, and full-matrix least-squares refine-
ment against F2 were performed with SHELXTL [8].
refinement of the data. The asymmetric unit contains half a
{[(PPh3)Cu]2[p-((pz)2CHCH2NHCH2)2C6H4]}2+ complex located on
ꢁ
an inversion center, one NO3 anion and a region of severely disor-
For compound 4, final unit cell parameters were determined by
least-squares refinement of 7990 reflections from the data set with
I > 5r(I). No absorption correction was applied. The compound
crystallizes in the space group P21/c. There is one complete formula
unit in the asymmetric unit. Non-hydrogen atoms were refined
with anisotropic displacement parameters; hydrogen atoms were
placed in idealized positions and included as riding atoms.
For compound 5ꢀ1.5CH2Cl2, final unit cell parameters were
determined by least-squares refinement of 7074 reflections with
dered solvent centered at (½, 0, ½). The disordered solvent could
not be modeled reasonably and was therefore accounted for with
the SQUEEZE program in PLATON [9]. The solvent occupies a volume
of 448.0 Å3 per unit cell, corresponding to 148 eꢁ/cell. The contri-
bution of these species was removed from subsequent structure
factor calculations. Note that the reported FW, dcalc and F (0 0 0)
refer to known unit cell contents only. Based on unsuccessful dis-
order models, the included solvent is most likely CH2Cl2. All non-
hydrogen atoms were refined with anisotropic displacement
parameters. Hydrogen atoms were placed in geometrically ideal-
ized positions and included as riding atoms except for H1N, which
was located and refined freely.
I > 5r(I) from the data set. The data were corrected for absorption
effects with SADABS [7]. The compound crystallizes in the triclinic
ꢀ
system. The space group P1 was confirmed by the successful solu-
tion and refinement of the data. The asymmetric unit contains a
{(PPh3)Cu[(pz)2CHCH2NHCH2C6H5]}NO3 cation-anion pair, and 1.5
independent CH2Cl2 molecules of crystallization. The CH2Cl2 mole-
cules are disordered. C61/Cl1/Cl2 is disordered about a general po-
sition; C71–Cl6 is disordered about an inversion center and was
modeled as two independent partial molecules with occupancies
fixed at 0.35 and 0.15. A total of 31 restraints were used to main-
tain chemically reasonable geometries for these species. Eventually
all non-hydrogen atoms were refined with anisotropic displace-
ment parameters except those disordered atoms with occupancies
<0.5. Hydrogen atoms were placed in geometrically idealized posi-
tions and included as riding atoms with the exception of the nitro-
gen-bound H1A, which was located and refined freely.
Acknowledgment
The authors thank the National Science Foundation (CHE-
0715559) for support.
Appendix A. Supplementary material
CCDC 613951, 613952; 706338, 706339, 706340 contain the
supplementary crystallographic data for this paper. These data
can be obtained free of charge from The Cambridge Crystallo-
graphic Data Centre via www.ccdc.cam.ac.uk/data_request/cif.
Supplementary data associated with this article can be found, in
the online version, at doi:10.1016/j.ica.2009.06.004.
For compound 6, final unit cell parameters were determined by
least-squares refinement of 7008 reflections with I > 5r(I) from the
data set. The compound crystallizes in the triclinic system. The
space group P1 was assumed and confirmed by the successful solu-
References
ꢀ
tion and refinement of the data. The asymmetric unit consists of
two crystallographically independent molecules. All non-hydrogen
atoms were refined with anisotropic displacement parameters.
Hydrogen atoms bonded to carbon were placed in geometrically
idealized positions and included as riding atoms with refined iso-
tropic displacement parameters. The nitrogen-bound hydrogens
H1N and H2N were refined isotropically subject to an N–
H = 0.84(2) Å distance restraint.
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