Synthesis, molecular, and crystal structures of 3d transition metal cyanocyclopentadienides [M(MeOH)n(H2O)4-n{C5(CN)4X}2] (M=Mn, Fe, Co, Ni, Cu, Zn; X=H, CN, NH2, NO<s

Article abstract of DOI:10.1515/znb-2018-0175

The reaction of the 3d transition metal dichlorides MCl₂ (M=Mn, Fe, Co, Ni, Cu, Zn) with the silver salts of substituted tetracyanocyclopentadienides Ag⁺ [C₅(CN)₄X]^- (X=CN, H, NH₂ NO_2<

Full text of DOI:10.1515/znb-2018-0175

Z. Naturforsch. 2018; aop
Karlheinz Sünkel*, Dietmar Reimann and Patrick Nimax
Synthesis, molecular, and crystal structures of 3d transition
metal cyanocyclopentadienides [M(MeOH)n(H2O)4–n{C5(CN)4X}2]
(Mꢀ=ꢀMn, Fe, Co, Ni, Cu, Zn; Xꢀ=ꢀH, CN, NH2, NO2)
https://doi.org/10.1515/znb-2018-0175
which still allow for electronic communication between
Received August 18, 2018; accepted October 31, 2018
the metal centers via the polynitrile bridges. In some
cases, however, monomeric complexes of the formula
Abstract: The reaction of the 3d transition metal dichlo-
type “M(CA)2L4” are found [10–14], which still can form
rides MCl2 (Mꢀ=ꢀMn, Fe, Co, Ni, Cu, Zn) with the silver
network structures through hydrogen bonds. The tetra-
+
salts of substituted tetracyanocyclopentadienides Ag
−
and pentacyanocyclopentadienides [C5(CN)4X] (Xꢀ=ꢀH,
−
[C5(CN)4X] (Xꢀ=ꢀCN, H, NH2 NO2) gives the complexes
CN, NH2, …) also belong to the “bigger” polynitrile
[M(MeOH/H2O)4{C5(CN)4)X}2]. Nine of these complexes were
anions. There are some early reports on the synthesis of
characterized by X-ray diffraction and it shows that they all
their (transition) metal salts, e.g. with Mn2+, Fe2+, Al3+, and
are mononuclear with an octahedral M(N)2(O)4 coordina-
Bi3+, included in a patent; however, no characterization
tion sphere. In the structures, extensive hydrogen bonding
data were given [15]. One of these salts, termed “deca-
leads to dense three-dimensional network structures.
cyanoferrocene” and analyzed as “[Fe{C5(CN)5}2]ꢀ·ꢀH2O”
Keywords:
3d
metals;
crystal
structures; was described in two publications and characterized by
infrared (IR), conductivity, and magnetic measurements
[16, 17]. A polymeric structure with the anion acting as a
cyanocyclopentadienides.
triply bridging ligand was suggested, but no crystal struc-
ture determination was performed. Many years later, two
cobalt complexes and one copper (I) complex with the
pentacyanocyclopentadienide anion were described, the
monomeric [Co{C5(CN)5}2(H2O)2(THF)2] and the polymeric
[Co{C5(CN)5}Cl(THF)2]∞ and [Cu{C5(CN)5}(MeCN)2]∞, which
were all characterized by X-ray diffraction [18]. Soon after-
Dedicated to: Professor Wolfgang Bensch on the occasion of his 65th
birthday.
1 Introduction
The coordination chemistry of polynitrile anions with wards, we could show that recrystallization of the penta-
transition metals is studied for quite a while, mainly due cyanocyclopentadienides of Co(II), Ni(II), and Zn(II) from
to their ability to build coordination polymers with inter- dimethylformamide (DMF) yielded the monomeric salts
esting magnetic properties [1–3]. The “small” polynitrile [M(DMF)6][C5(CN)5]2, which contained no coordinated
−
anions like tricyanomethanide [C(CN)3] or dicyanamide nitrile anions [19]. In this paper we report the preparation
−
[N(CN)2] tend to form three-dimensional networks with of the substituted tetra- and pentacyanocyclopentadie-
MN6 coordination polyhedra, even when crystallized from nides [M{C5(CN)4X}2] (Mꢀ=ꢀMn, Fe, Co, Ni, Cu, Zn; Xꢀ=ꢀH, CN,
water [1], although in some special cases ribbon struc- NH2, NO2) and the crystallographic characterization of the
tures of the formula type “M(CA)2(L)2” (CAꢀ=ꢀcyano anion, products of recrystallization from methanol.
Lꢀ=ꢀEtOH [4], NH3 [5]) with MN4O2 or MN4N’2 coordination,
couldalsobeobtained. Increasingthesizeofthepolynitrile
−
anions, as in tetracyanidoborate [B(CN)4] or 2-dicyano-
2 Results and discussion
methylene-1,1,3,3-tetracyanopropanediide [C{C(CN)2}3]2− or
hexacyanotrimethylenecyclopropanediide [C3{C(CN)2}3]2−,
leads predominantly to ribbon structures (Lꢀ=ꢀH2O [6–9]), 2.1 Synthesis
When (m)ethanolic solutions of the metal dichlorides
*Corresponding author: Karlheinz Sünkel, Department of Chemistry,
MCl2 (Mꢀ=ꢀMn, Fe, Co, Ni, Cu, Zn) were treated at room
Ludwig-Maximilians University of Munich, Butenandtstraße 9 81377,
temperature with two equivalents of the silver tetra- and
Munich, Germany, e-mail: suenk@cup.uni-muenchen.de
pentacyanocyclopentadienides Ag[C5(CN)4X] (Xꢀ=ꢀCN, 1a;
Dietmar Reimann and Patrick Nimax: Department of Chemistry,
Ludwig-Maximilians University of Munich, Butenandtstraße 9 81377,
Munich, Germany
H, 1b: NH2, 1c; NO2, 1d), the corresponding bis-tetracya-
nocyclopentadienides [M{C5(CN)4X}2] could be isolated
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ꢀꢀꢀꢁ
2ꢁ ꢁK. Sünkel et al.: Synthesis, molecular, and crystal structures of 3d transition metal cyanocyclopentadienides
N
N
C
C
MeOH
r. t.
2 Ag+
M{C5(CN)4X}2 • x H2O • y MeOH
+ AgCl
MCl2
C
C
N
N
X
Fig. 1:ꢀPreparation of the transition metal bis(tetracyanocyclopentadienides).
−1
after filtering off the precipitated AgCl and evaporation of 3c′ and 6b′ only a single band at ca. 2220 cm could be
the filtrates to dryness in vacuo. The IR and mass spectra observed in this region, which might be indicative of the
were obtained for most compounds. Elemental analyses absence of nitrile coordination. However, this might be
showed that these primary products contained varying misleading, as was shown in the case of the polymeric
amounts of water and methanol (or ethanol, respectively, {Cu[C5(CN)5](MeCN)2}, which contains coordinated and
in case of 2b′ and 3b′). (Fig. 1, Table 1)
uncoordinated nitrile groups, but shows only one ν(CN)
−1
As can be seen from Table 1, in most cases band at ca. 2220 cm [18]. As, neither the IR nor the mass
xꢀ+ꢀyꢀ=ꢀ4 which suggests the metal atoms are octahedrally spectrometric data allowed for a clear distinction of the
coordinated with a MN2O4 chromophor. When the sum is different possibilities, attempts to obtain X-ray quality
greater than 4, either there might be more solvent mole- crystals were undertaken by slow recrystallization of the
cules enclosed as guest molecules, or the solvents have compounds from MeOH or MeCN. Fortunately we were
−
replaced the cyano ligand from the coordination sphere, or successful in the cases of all [C5(CN)4H] salts, except for
both. In the cases where the sum is smaller than 4, either nickel, as well as for the pentacyanocyclopentadienides
an oligomeric/polymeric structure, or a complex with a of Mn(II) and Fe(II), the amino derivative 2c and the nitro
different coordination number might be formed. The IR derivative 4d.
spectra of the pentacyanocyclopentadienides 2a′, 4a′, 5a′
and 6a′ showed two bands in the ν(CN) region, one at ca.
−1
2260–2270 cm , which might be assigned to a coordinated
2.2 Molecular and crystal structures
−1
nitrile group, and another one at ca. 2220 cm , which
would correspond to an uncoordinated nitrile group [17].
2.2.1 The pentacyanocyclopentadienides of Mn(II)
In the IR spectra of the tetracyanocyclopentadienides
and Fe(II)
The two complexes, 2a and 3a, crystallize in the mono-
clinic space groups P21/c and P21/n, respectively, as mono-
nuclear [M(PCC)2(H2O)4] moieties with the metals being
located on an inversion center (Zꢀ=ꢀ2). The iron compound
contains two additional interstitial water molecules in
the crystal structure. Figure 2 shows an Ortep view of the
molecular unit of 2a.
Table 1:ꢀThe prepared penta- and tetracyanocyclopentadienides
and their approximate ( 0.25) analytical composition.
Compound
M
X
x
y
2a′
2b′
2c′
3a′
3b′
3c′
4a′
4b′
4c′
4d′
5a′
5b′
5c′
6a′
6b′
7a′
7b′
7c′
Mn
Mn
Mn
Fe
CN
H
NH2
CN
H
NH2
CN
H
NH2
NO2
CN
H
NH2#
CN
H
CN
H
NH2
4
2
1
2a
0.5
3.5
1.5a
0
0
2
1.5
3
4
2
As a consequence of the inversion center, the
nitrile ligands are in mutual trans positions. Both the
Fe
2
Fe
4
Co
Co
Co
Co
Ni
5
0
2.5
2
1.2
1
2
4
0.5
5
1.25
4
1.8
3
Ni
Ni
Cu
Cu
Zn
Zn
Zn
2
0
2
2
2.25
0.5
Fig. 2:ꢀOrtep view of compound 2a in the crystal with displacement
ellipsoids at the 30% probability level.
aEtOH instead of MeOH.
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ꢁꢀꢀꢀ
K. Sünkel et al.: Synthesis, molecular, and crystal structures of 3d transition metal cyanocyclopentadienidesꢂ ꢂ3
metal-nitrogen and the metal-oxygen bond lengths are acceptors. Each coordinated water molecule forms one
substantially shorter in the Fe(II) compound. While hydrogen bond towards the nitrile nitrogen atoms N4
the M–N–C angle of 2a deviates only slightly from lin- and N5 and one hydrogen bond to the guest water oxygen
earity (ca. 12°), there is a substantial “kink” in 3a. The atom O3, which itself forms two hydrogen bonds toward
ring carbon –CN bond is linear in both compounds (see the remaining nitrogen N atoms N2 and N3. The O...O
Table 2). Platon analysis shows no space that could be distances are in the range 2.76 0.03 Å, while the O...N
accessible by residual solvent in both structures. As the distances range from 2.86 to 2.93 Å. The O–H...N angles
primary products 1a′ and 3a′ both showed methanol deviate more from linearity than in the manganese com-
content, it is surprising that after recrystallization from pound (see Table 3 and Fig. 3).
methanol this solvent appears to be no longer present
in the crystal structure. A possible explanation might
be that the methanol carbon is disordered over the eight 2.2.2 The tetracyanocyclopentadienides [M{C5(CN)4H}2]
hydrogen positions of the “water” molecules, which
makes its position indistinguishable from a “full” hydro-
gen position.
of Mn, Fe, Co, Cu and Zn
The Mn(II), Fe(II), and Zn(II) complexes 2b, 3b. and
In 2a all coordinated water molecules act as hydrogen 7b crystallize in the monoclinic space groups P21/c or
bond donors towards nitrile nitrogen atoms of neighbor- P21/n(all with Zꢀ=ꢀ2) as tetra(aqua)-bis(nitrile) complexes
ing molecules, with N4 acting as acceptor of two hydrogen [M(TCC)2(H2O)4] (“TCC” stands for the [C5(CN)4H] anion),
bonds and N5 accepting no hydrogen bond. The donor- with the iron compound containing two more uncoordi-
acceptor distances vary between 2.80 and 3.00 Å with the nating water molecules. As implied by the space group
O–H...N angles close to linearity (see Table 3). In the iron and Zꢀ=ꢀ2, in all three compounds the metal atom resides
compound 3a all water molecules act as hydrogen bond on an inversion center, and it coordinates to one of the
donors, but the coordinating water molecules act also as nitrile groups next to the CH group of the anion. Figure 4
Table 2:ꢀSelected bond lengths (Å) and bond and dihedral angles (deg).
Compound
M–N
M–O
M–N–C
N–C–Cring
ꢀ∠(Cp1/Cp2)
2a
2b
2c
3a
3b
4d
4b
2.2447(12)
2.1929(15)
2.1487(10)/2.1527(11)
2.2158(14)/2.1790(15)
167.96(12)
168.69(15)
179.29(15)
176.36(18)
0.0
0.0
1.2(3)
0.0
0.0
2.186(4), 2.195(4)
2.1774(12)
2.176(4), 2.148(3), 2.177(4), 2.260(3)
2.0991(11), 2.0620(11)
168.9(6), 168.8(4)
152.45(12)
177.9(4), 178.0(4)
175.79(16)
2.160(2)
2.098(2), 2.127(2)
162.8(2)
179.3(3)
2.118(2), 2.118(2)
2.097(3), 2.110(3)
2.088(3), 2.090(3)
2.3751(15)
2.068(2), 2.073(2), 2.062(2), 2.047(2)
2.098(2), 2.087(2), 2.100(2)
2.062(2), 2.086(2), 2.078(2), 2.070(3)
1.9509(13), 1.9925(13)
171.7(2), 167.9(2)
173.1(3), 168.9(3)
169.3(3), 170.4(3)
163.38(14)
177.7(3), 175.8(3)
175.6(4), 176.7(4)
178.0(4), 178.2(4)
178.63(18)
88.22(9)
3.40(8)
3.50(5)
0.0
36b
7b
2.098(3)
2.100(3), 2.133(2)
169.7(3)
176.5(3)
0.0
Table 3:ꢀHydrogen bond parameters (Å, deg) of 2a and 3a.
Compound
D–H
H...A
D...A
ꢀ<(DHA)
D–H...A
Symm. op. (A)
2a
0.87(3)
0.88(2)
0.83(3)
0.80(3)
0.76(2)
0.85(2)
0.80(2)
0.79(2)
0.74(2)
0.83(3)
1.95(3)
1.99(2)
2.18(3)
2.14(3)
2.20(2)
1.90(2)
1.99(2)
2.15(2)
2.16(2)
2.12(3)
2.7996(17)
2.8384(17)
2.9949(17)
2.9419(17)
2.9359(18)
2.7353(16)
2.7898(17)
2.9309(18)
2.8766(18)
2.862(2)
166(3)
163(2)
165(2)
177(3)
166(2)
168(2)
175(2)
173(2)
164(2)
149(2)
O1–H12...N2
–xꢁ+ꢁ2, –yꢁ+ꢁ1, –zꢁ+ꢁ1
x–1, –yꢁ+ꢁ3/2, zꢁ+ꢁ1/2
x, –yꢁ+ꢁ3/2, zꢁ+ꢁ1/2
–xꢁ+ꢁ1, yꢁ–ꢁ1/2, –zꢁ+ꢁ3/2
x, yꢁ+ꢁ1, z
O2–H22...N3
O1–H11...N4
O2–H21...N4
O3–H31...N2
O2–H21...O3
O1–H11...O3
O1–H12...N5
O2–H22...N4
O3–H32...N3
3a
xꢁ+, 1, y, z
xꢁ+ꢁ1, yꢁ–ꢁ1, z
x, yꢁ–ꢁ1, z
–xꢁ+ꢁ3/2, yꢁ–ꢁ1/2, –zꢁ+ꢁ1/2
–xꢁ+ꢁ1/2, yꢁ+ꢁ1/2, –zꢁ+ꢁ1/2
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ꢀꢀꢀꢁ
4ꢁ ꢁK. Sünkel et al.: Synthesis, molecular, and crystal structures of 3d transition metal cyanocyclopentadienides
The copper complex 6b differs from the complexes
described above by the fact that it contains two coor-
dinated MeOH and two coordinated water molecules
together with two unidentate TCC ligands. It still crystal-
lizes in the monoclinic space group P21/c with the Cu atom
residing on an inversion center (Zꢀ=ꢀ2). Complex 6b shows
substantial Jahn-Teller distortion with the Cu–N bonds
being approximately 0.40 Å longer than the Cu–O bonds,
a situation different from the compounds described so
far, where the two bond lengths were withinꢀ ꢀ0.10 Å. The
Cu–N–C bond is slightly “kinked” (Table 2). Each coordi-
nated water molecule donates two hydrogen bonds to the
nitrile nitrogen atoms N103 and N104, while the methanol
donates one hydrogen bond to the remaining uncoordi-
nated nitrile N 102. The O...N distances are within 2.81
0.01 Å with OHN angles at 162 2° (Table 4, Fig. 6).
Fig. 3:ꢀThe hydrogen bond system in the crystal structure of 3a.
The cobalt complex 4b′, which apparently contained
no water and only two MeOH molecules, was recrystal-
lized from (moist) acetonitrile. The resulting structure of
4b contains two different complexes (together with two
interstitial water molecules) in the noncentrosymmetric-
monoclinic space group P21. One of them is the “usual”
[Co(TCC)2(H2O)4] complex, and the other one has the
Fig. 4:ꢀOrtep view of compound 7b in the crystal with displacement
ellipsoids at the 30% probability level.
shows an Ortep view of the molecular unit of the zinc formula [Co(TCC)2(H2O)3(MeCN)] (Fig. 7). This rather unex-
complex 7b. pected result hints at a polymeric structure of the primary
The metal-nitrogen bond lengths decrease from Mn to product, most likely of the “ribbon” type mentioned in the
Zn, while the metal-oxygen bond lengths for Fe and Zn are introduction, which was then broken up into monomeric
approximately the same and both shorter than the Mn–O units by the water present in the solvent.
bond lengths. The M–N–C bond angles in 2b and 7b show
In the Co1-centered molecule, the Co–N bond lengths
only minor deviations from linearity, while similar to are slightly longer than in the Co2-centered molecule;
3a the iron compound 3b is significantly “kinked” (see the same is true for the Co–O bond lengths. All Co–N–C
Table 2). In 2b and in 7b, both coordinated water mole- angles deviate only slightly from linearity, and the devia-
cules act as hydrogen bond donors, O1 towards the nitrile tion is even less for the ring carbon-CN bonds. The cyclo-
atoms N2 and N3 and O2 to the nitrile atom N4, and the pentadienyl ring planes are only slightly twisted against
water oxygen O1 of a neighboring molecule. In the iron each other (Table 2). All water molecules and all nitrile
compound 3b both the uncoordinated and guest water nitrogen atoms except of N112 are involved in a compli-
molecules each donates one hydrogen bond towards one cated hydrogen bond system (Fig. 8).
nitrile nitrogen atom and one towards a water oxygen
Some water molecules donate two (O21 and O23) or
atom. Thus, the guest water molecule accepts two hydro- even three (O12) hydrogen bonds to nitrile N atoms, others
gen bonds and the coordinated water molecules each (O11, O13, O22, O24, and O1) donate one hydrogen bond
accept one hydrogen bond. The O...N distances vary from to another water molecule and a nitrile N atom, and one
2.82 to 2.90 Å in 2b and 7b and from 2.78 to 2.89 Å in 3b, guest water molecule (O2) two hydrogen bonds to nitrile
while the O...O distances are rather long in 2b and 7b (2.97 nitrogen atoms and one to a coordinated water molecule.
and 3.02 Å, respectively). In 3b these distances involving Five water oxygen atoms accept one (O1, O11, O13, O23),
the guest water molecule acting as acceptor are rather or two (O2) hydrogen bonds, and there are three nitrile N
short (2.74 Å), whereas for cases where it is acting as donor atoms which accept two hydrogen bonds (N104, N114, and
they are long (3.09 and 3.21 Å). The O–H...N and O–H...O N204). The O...O distances range from 2.62 to 2.93 Å, while
angles range from 142° to 176° (Table 4). In all cases, a the O...N distances span the range from 2.81 to 3.18 Å, with
three-dimensional network is built. Figure 5 shows a view the O–H...N and O–H...O angles ranging from 117° to 175°
of the molecular packing in 2b.
(Table 4).
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ꢁꢀꢀꢀ
K. Sünkel et al.: Synthesis, molecular, and crystal structures of 3d transition metal cyanocyclopentadienidesꢂ ꢂ5
Table 4:ꢀHydrogen bond parameters (Å, deg) of 2b–7b.
Compound
D–H
H...A
D...A
ꢀ<(DHA)
D–H...A
Symm. op. (A)
2b
0.91(3)
0.97(4)
0.78(4)
0.77(4)
0.84(5)
0.85(4)
0.90(5)
0.78(4)
0.84(4)
0.76(5)
0.76(5)
0.83(3)
0.86(3)
0.86(3)
0.91(3)
0.82(3)
0.93(3)
0.86(3)
0.87(3)
0.93(3)
0.83(3)
0.91(3)
0.96(5)
0.85(5)
0.85(3)
0.90(3)
0.94(3)
0.96(5)
0.96(5)
0.92(3)
0.90(3)
0.76(3)
0.78(3)
0.72(3)
0.86(4)
0.81(5)
0.78(5)
0.82(5)
2.07(3)
1.89(4)
2.08(4)
2.15(4)
2.08(5)
1.89(4)
1.99(5)
1.96(4)
1.94(4)
2.55(5)
2.45(5)
1.99(3)
2.29(3)
2.58(5)
2.11(3)
1.82(3)
2.09(3)
1.79(3)
1.98(3)
1.95(3)
2.11(3)
1.95(3)
2.03(5)
2.01(5)
2.09(3)
1.93(3)
2.00(3)
2.58(5)
2.25(5)
2.23(4)
1.93(3)
2.10(3)
2.04(3)
2.10(3)
2.04(4)
2.07(5)
2.25(5)
2.09(5)
2.967(2)
2.823(2)
2.833(2)
2.902(2)
2.888(3)
2.737(3)
2.843(3)
2.736(3)
2.783(3)
3.205(3)
3.088(4)
2.811(4)
3.063(5)
3.062(4)
2.972(4)
2.621(4)
2.946(4)
2.649(4)
2.828(4)
2.880(4)
2.930(3)
2.853(4)
2.891(4)
2.854(4)
2.890(3)
2.818(4)
2.895(4)
3.184(4)
3.113(4)
3.007(5)
2.832(4)
2.818(2)
2.799(2)
2.793(2)
2.837(4)
2.829(4)
3.022(4)
2.895(4)
172(3)
159(4)
160(3)
167(3)
159(4)
173(4)
159(4)
170(4)
174(4)
145(4)
143(4)
170(5)
149(4)
117(4)
159(4)
163(5)
151(4)
174(5)
165(5)
176(5)
170(5)
171(5)
149(4)
173(5)
155(4)
169(4)
159(4)
121(3)
149(4)
142(4)
175(4)
160(3)
164(3)
161(3)
154(4)
158(4)
170(5)
167(5)
O2–H21...O1
–xꢁ+ꢁ1, –yꢁ+ꢁ1, –zꢁ+ꢁ1
x, –yꢁ+ꢁ1/2, z–1/2
xꢁ+ꢁ1, yꢁ+ꢁ1/2, –zꢁ+ꢁ1/2
–xꢁ+ꢁ1, –yꢁ+ꢁ1, –zꢁ+ꢁ1
–xꢁ+ꢁ1/2, yꢁ–ꢁ1/2, –zꢁ+ꢁ1/2
O1–H11...N4
O1–H12...N3
O2–H22...N2
3b
4b
O1–H11...N3
O1–H12...O3
O2–H21...N2
–x, –yꢁ+ꢁ1, –z
x–1, y, z–1
xꢁ+ꢁ1/2, –yꢁ+ꢁ3/2, zꢁ+ꢁ1/2
xꢁ+ꢁ1, –yꢁ+ꢁ1, –zꢁ+ꢁ1
–xꢁ+ꢁ1, –yꢁ+ꢁ1, –zꢁ+ꢁ1
O2–H22...O3
O3–H31...N4
O3–H32...O1
O3–H32...O2
O1–H1A...O2
O2–H2A...N112
O2–H2A...O23
O11–H11A...N203
O11–H11B...O1
O12–H12E...N104
O13–H13A...O2
O21–H21A...N204
O13–H13B...N113
O22–H22A...O11
O22–H22B...N213
O23–H23B...N104
O24–H24A...N103
O24–H24B...O13
O21–H21B...N214
O2–H2B...N204
O12–H12D...N114
O12–H12D...N202
O1–H1B...N102
O23–H23A...N114
O1W–H1W...N104
O1W–H2W...N103
O1M–H1M...N102
O2–H22...N3
x, y, zꢁ+ꢁ1
–xꢁ+ꢁ1, yꢁ+ꢁ1/2, –zꢁ–ꢁ1
x, y, zꢁ–ꢁ1
–xꢁ+ꢁ1, yꢁ+ꢁ1/2, –z
–xꢁ+ꢁ2, yꢁ+ꢁ1/2, –zꢁ–ꢁ1
xꢁ+ꢁ1, yꢁ–ꢁ1/2, –zꢁ+ꢁ1
xꢁ+ꢁ1, y, z
xꢁ+ꢁ2, yꢁ–ꢁ1/2, –z
–xꢁ+ꢁ1, yꢁ+ꢁ1/2, –z
–xꢁ+ꢁ1, yꢁ+ꢁ1/2, –zꢁ–ꢁ1
x, y, zꢁ–ꢁ1
–xꢁ+ꢁ2, yꢁ–ꢁ1/2, –zꢁ–ꢁ1
–xꢁ+ꢁ1, yꢁ+ꢁ1/2, –z
–xꢁ+ꢁ1, yꢁ–ꢁ1/2, –z
x, y, zꢁ+ꢁ1
x, y, zꢁ+ꢁ1
–xꢁ+ꢁ1, yꢁ–ꢁ1/2, –z
–xꢁ+ꢁ1, yꢁ–ꢁ1/2, –zꢁ+ꢁ3/2
X–1, –yꢁ+ꢁ1/2, zꢁ+ꢁ1/2
x–1, y, z
6b
7b
x–1, –yꢁ+ꢁ1/2, zꢁ+ꢁ1/2
xꢁ+ꢁ1, yꢁ+ꢁ1/2, –zꢁ+ꢁ3/2
xꢁ+ꢁ1, y, z
O2–H21...N4
O1–H11...O2
O1–H12...N2
xꢁ+ꢁ2, –yꢁ+ꢁ1, –zꢁ+ꢁ1
Fig. 5:ꢀPacking diagram of 2b in the crystal.
Fig. 6:ꢀThe hydrogen bond system in the crystal structure of 6b.
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ꢀꢀꢀꢁ
6ꢁ ꢁK. Sünkel et al.: Synthesis, molecular, and crystal structures of 3d transition metal cyanocyclopentadienides
Fig. 9:ꢀView of the molecular unit of 2c in the crystal (displacement
ellipsoids at the 30% probability level).
shorter (by 0.11 Å, corresponding to 36σ) than the Mn–O4
bond. The Mn–N–C bonds deviate only slightly from
linearity, as was observed in nearly all other structures
described here, and both cyclopentadienyl rings are close
to coplanar (Table 2). All water molecules act as hydrogen
bond donors: atom O1 donates one hydrogen bond each
to another water molecule (O4) of a neighboring complex
and to a nitrile nitrogen atom (N2); all the other water
molecules donate two hydrogen bonds to nitrile N atoms.
The amino nitrogen atoms donate one (N5) or two (N15)
hydrogen bonds to nitrile N atoms. All nitrile N atoms act
as acceptors, with some of them (N2, N12, and N13) accept-
ing even two hydrogen bonds. Only one oxygen atom (O4)
acts as an acceptor, which might be the reason for the
longer Mn–O4 bond length (Table 5). All these hydrogen
bonds lead to a complicated three-dimensional network,
which is shown in Figs. 10 and 11.
Fig. 7:ꢀThe two different cobalt complexes in the crystal structure of
4b (displacement ellipsoids at the 30% probability level).
Besides extensive hydrogen bonding, the cyclopenta-
dienyl rings show also π stacking along a with a stacking
distance of 3.79 Å, which corresponds to a rather weak
interaction.
Fig. 8:ꢀThe hydrogen bond system in the crystal structure of 4b.
2.2.4 The nitrotetracyanocyclopentadienyl complex 4d
2.2.3 The aminotetracyanocyclopentadienyl complex 2c
4d is the only compound in this study that crystallizes
The compound 2c crystallizes as a twin in the monoclinic with methanol only as an auxiliary ligand [Co{C5(CN)4NO2}2
̅
space group P21/n with Zꢀ=ꢀ2 as a monomeric octahedral (MeOH)4] (triclinic, space group P1). There is no coordina-
complex of formula [Mn{C5(CN)4NH2}2(H2O)4]. Quite unex- tion of the nitro groups, which are positionally disordered
pected, the anion coordinates via the nitrile group next to (approximately 3:1) with cyano groups, one with that in
the amino substituent, with no interaction of the amino the α’-position relative to the Co-coordinated nitrile func-
group with the metal atom (Fig. 9).
tion, and the other with that in the ß-position. 4d is also
The manganese atom resides on a general position the only compound where the cyclopentadienyl planes
and the asymmetric unit consists of the complete mole- are nearly perpendicular to each other (Table 2, Fig. 12).
cule. The metal atoms thus reside on noncrystallographic
Both Co–N–C bonds deviate only slightly from linear-
inversion centers. The Mn–N bond lengths are identi- ity, and so do the ring-carbon-CN bonds. If one looks at the
cal within 2σ, and this is also true for the O1/O3 water hydrogen bonds (Table 5), all methanol O atoms donate
molecules. Surprisingly, the Mn–O2 bond is significantly one hydrogen bond each to four nitrile N atoms (N13, N14,
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ꢁꢀꢀꢀ
K. Sünkel et al.: Synthesis, molecular, and crystal structures of 3d transition metal cyanocyclopentadienidesꢂ ꢂ7
Table 5:ꢀHydrogen bond parameters (Å, deg) of 2c and 4d.
Compound
D–H
H...A
D...A
ꢀ<(DHA)
D–H...A
Symm. op. (A)
2c
0.82(3)
0.82(3)
0.84(3)
0.84(3)
0.84(3)
0.84(3)
0.84(3)
0.84(3)
0.85(3)
0.84(3)
0.83(3)
0.88(4)
0.72(3)
0.70(4)
0.76(4)
2.49(3)
2.64(3)
2.12(3)
2.05(3)
2.14(3)
2.07(3)
2.23(3)
2.07(3)
2.01(3)
2.04(3)
2.28(3)
1.94(4)
2.11(4)
2.15(4)
2.02(4)
3.206(5)
3.425(5)
2.947(5)
2.857(5)
2.956(5)
2.885(5)
3.051(5)
2.886(5)
2.828(5)
2.868(5)
3.038(6)
2.786(3)
2.806(3)
2.833(3)
2.788(3)
146(4)
159(4)
173(7)
161(7)
164(7)
166(7)
163(6)
163(7)
162(6)
168(7)
153(4)
163(4)
165(4)
166(4)
177(4)
N15–H11...N12
N15–H12...N13
O1–H101...O4
O1–H102...N2
O2–H111...N4
O2–H112...N3
O3–H121...N4
O3–H122...N12
O4–H131...N14
O4–H132...N13
N5–H1...N2
xꢁ+ꢁ1/2, –yꢁ+ꢁ3/2, zꢁ–ꢁ1/2
xꢁ+ꢁ1/2, –yꢁ+ꢁ3/2, zꢁ–ꢁ1/2
–xꢁ+ꢁ1, –yꢁ+ꢁ1, –zꢁ+ꢁ1
–xꢁ+ꢁ1, –yꢁ+ꢁ1, –zꢁ+ꢁ1
–xꢁ+ꢁ1/2, yꢁ+ꢁ1/2, –zꢁ+ꢁ3/2
x–1/2, –yꢁ+ꢁ1/2, zꢁ+ꢁ1/2
–xꢁ+ꢁ3/2, yꢁ+ꢁ1/2, –zꢁ+ꢁ3/2
–xꢁ+ꢁ1, –yꢁ+ꢁ1, –zꢁ+ꢁ2
–xꢁ+ꢁ3/2, yꢁ–ꢁ1/2, –zꢁ+ꢁ3/2
xꢁ+ꢁ1/2, –yꢁ+ꢁ3/2, zꢁ–ꢁ1/2
x–1/2, –yꢁ+ꢁ1/2, zꢁ+ꢁ1/2
–xꢁ+ꢁ1, –y, –z
4d
O1M–H1M...N23
O2M–H2M...N14
O3M–H3M...N22
O4M–H4M...N13
–xꢁ+ꢁ2, –yꢁ+ꢁ2, –zꢁ+ꢁ1
–xꢁ+ꢁ1, –yꢁ+ꢁ1, –z
–xꢁ+ꢁ1, –yꢁ+ꢁ2, –zꢁ+ꢁ1
Fig. 12:ꢀView of the molecular unit of compound 4d. Only the
major occupied of the disordered positions is shown. Displacement
ellipsoids at the 30% probability level.
Fig. 10:ꢀPacking diagram of 2c, looking down the a axis.
3 Experimental part
3.1 General remarks
All reactions were performed under nitrogen, using stand-
ard Schlenk techniques; work-up procedures including
chromatography were performed in air. The solvents used
were of analytical grade and used as supplied. The start-
ing materials 1a–d were obtained as described by us earlier
[20]. The metal chlorides were obtained as hydrates from
Sigma-Aldrich Chemie, Munich, Germany, in “analytical
Fig. 11:ꢀPacking diagram of 2c, looking down the c axis.
N22, and N23). All O...N distances are within a narrow grade.” Anhydrous metal chlorides were prepared from
range from 2.79 to 2.83 Å, and all O–H...N angles are close the corresponding hydrates by heating in the presence of
to linearity. Due to the disorder problem, no comment can SOCl2. Mass spectra were recorded with a Jeol Mstation
be offered about the involvement in hydrogen bonds of the JMS 700 (Jeol, Tokyo, Japan). Microanalyses (C, H, N) were
nitro and the remaining cyano groups. The fact that there performed by the Microanalytical Laboratory of the Depart-
is positional disorder makes this participation in hydro- ment of Chemistry, LMU Munich, using a Heraeus Elemen-
gen bonds rather improbable.
tar Vario EL instrument (Bitterfeld-Wolfen, Germany).
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ꢀꢀꢀꢁ
8ꢁ ꢁK. Sünkel et al.: Synthesis, molecular, and crystal structures of 3d transition metal cyanocyclopentadienides
4a′: From 51 mg CoCl2ꢀ·ꢀ6H2O a yield of 65 mg (49%)
3.2 Syntheses
−1
was obtained (yellow-green powder). –IR (KBr, cm ):
+
3.2.1 General procedure for the synthesis of 2–7
ν(CN)ꢀ=ꢀ2269s, 2220s. –MS(FAB ): m/zꢀ=ꢀ285.3 [Co(PCC)
+
(H2O)2] . –C20H10N10CoO5 (529.3) calcd. C 45.38, H 1.90, N
A solution of the metal dichloride (0.25 mmol) in metha- 26.46; found C 45.37, H 1.87, N 26.19.
nol (20 mL) was treated with a solution of Ag{C5(CN)4X}
4b′: From 32 mg CoCl2 a yield of 378 mg (82%) was
(0.50 mmol) in methanol (20 mL) at room temperature. obtained (red powder). –C20H10N8CoO2 (453.3) calcd. C
Stirring was continued for 16 h. After filtering off the pre- 52.99, H 2.22, N 24.72; found C 52.06, H 2.27, N 24.22. Recrys-
cipitated AgCl, the product was precipitated by addition tallization from MeCN gave single crystals of 4b.
of dichloromethane, isolated by filtration, and dried in
vacuo.
4c′: From 32 mg CoCl2 a yield of 80 mg (77%) was
obtained (yellow powder). –C19.5H15N10CoO4 (512.2) calcd. C
45.70, H 2.95, N 27.33; found C 45.11, H 3.03, N 26.79.
4d′: From 32 mg CoCl2 a yield of 44.5 mg (81%) was
obtained (brown powder). –MS((–)–FAB): m/zꢀ=ꢀ689.5
3.2.2 Yields and characterization
−
[Co(NTCC)3] . –C21H16N10CoO9 (611.35) calcd. C 41.26, H 2.64,
2a′: From 49 mg MnCl2ꢀ·ꢀ4H2O a yield of 411 mg (81%) was N 22.91; found C 40.94, H 2.52, N 23.15. Recrystallization
obtained (light brown powder). –MS((–)–FAB): m/zꢀ=ꢀ625.6 from MeOH gave single crystals of 4d suitable for X-ray
−
−
−1
[Mn(PCC)3] ; 696.6 [Mn(PCC)3(H2O)4] . –IR (KBr, cm ): diffraction (see below).
ν(CN)ꢀ=ꢀ2245m, 2222s. –C21H12MnN10O5 (539.3): calcd. C
46.77, H 2.24, N25.97; found C 47.02, H 2.25, N25.81. Recrys- obtained (blue powder). –IR (ATR, cm ): ν(CN)ꢀ=ꢀ2269s,
5a′: From 32.4 mg NiCl2 a yield of 53 mg (24%) was
−1
−
tallization from MeOH gave single crystals of 2a suitable 2214s.
for X-ray diffraction (see below).
–MS((–)–FAB):
–C21.8H9.6N10NiO3 (518.20) calcd. C 50.52, H 1.87, N 27.01;
m/zꢀ=ꢀ627.9
[Ni(PCC)3] .
2b′: From 49 mg MnCl2ꢀ·ꢀ4H2O, using a mixed MeOH/ found C 50.47, H 1.62, N 26.94.
EtOH solvent, a yield of 388 mg (85%) was obtained (light
5b′: From 32.4 mg NiCl2 a yield of 30 mg (31%) was
−
brown powder). –MS((–)–FAB): m/zꢀ=ꢀ549.7 [Mn(TCC)3] . obtained (white powder). –C21H16N8NiO4 (503.10) calcd. C
–C22H18MnN8O4 (513.38): calcd. C 51.47, H 3.53, N 21.83; 50.13, H 3.21, N 22.27; found C 50.40, H 3.04, N 23.05.
found C 51.56, H 2.90, N 21.54. Recrystallization from
5c′: From 32.4 mg NiCl2 a yield of 27 mg (26%) was
MeOH gave single crystals of 2b suitable for X-ray diffrac- obtained (yellow powder). –C20H16N10NiO4 (519.10) calcd. C
tion (see below).
46.85, H 2.48, N 28.76; found C 46.99, H 2.45, N 29.26.
2c′: From 49 mg MnCl2ꢀ·ꢀ4H2O, a yield of 405 mg (83%)
6a′: From 43 mg CuCl2ꢀ·ꢀ2H2O a yield of 90 mg (70%)
−1
was obtained (red powder). –C18.5H14MnN10O4.5 (503.24): was obtained (yellow-green powder). –IR (KBr, cm ):
calcd. C 44.15, H 2.80, N 27.83; found C 44.52, H 2.70, N ν(CN)ꢀ=ꢀ2261m, 2246m, 2222s. –MS((–)–FAB): m/zꢀ=ꢀ443.1
−
27.78. Recrystallization from MeOH gave single crystals of [Cu(PCC)2] . –C20H8N10CuO4 (515.9): calcd. C 46.56, H 1.56,
2c suitable for X-ray diffraction (see below).
N 27.13; found C 46.88, H 1.87, N 27.03.
3a′: From 31 mg FeCl2 a yield of 213 mg (42%) was
6b′: From 33 mg CuCl2 a yield of 68 mg (69%) was
−1
obtained (yellow powder). –MS((–)–FAB): m/zꢀ=ꢀ626.6 obtained (yellow powder). –IR (ATR, cm ): ν(CN)ꢀ=ꢀ2221s.
−
−
−
[Fe(PCC)3] . –C23.5H18FeN10O5.5(584.2): calcd. C 48.31, H 3.11, –MS((–)–FAB): m/zꢀ=ꢀ393.1 [Cu(TCC)2] , 620.7 [Cu(TCC)3] .
N 22.96; found C 48.72, H 3.19, N 24.04. Recrystallization –C20H11N8CuO2.5(466.9): calcd. C 51.44, H 2.37, N 23.99;
from MeOH gave single crystals of 3a suitable for X-ray dif- found C 51.23, H 2.26, N 23.72. Recrystallization from MeOH
fraction (see below).
gave single crystals of 6b suitable for X-ray diffraction (see
3b′: From 31 mg FeCl2 in mixed MeOH/EtOH solvent below).
a yield of 179 mg (39%) was obtained (yellow powder).
7a′: From 34 mg ZnCl2 a yield of 97 mg (88%) was
−
–MS((–)–FAB): m/zꢀ=ꢀ550.5 [Fe(TCC)3] . –C21H15FeN8O3.5 obtained (white powder). –MS((–)–FAB): m/zꢀ=ꢀ634.5
−
(491.2): calcd. C 51.35, H 3.08, N 22.80; found C 51.46, H [Zn(PCC)3] . –C22H18N10ZnO7 (599.8): calcd. C 44.04, H 3.02,
2.60, N 22.48. Recrystallization from MeOH gave single N 23.33; found C 44.05, H 2.26, N 23.42.
crystals of 3a suitable for X-ray diffraction (see below).
7b′: From 34 mg ZnCl2 a yield of 100 mg (86%) was
3c′: From 31 mg FeCl2 a yield of 70 mg (69%) was obtained (white powder). –C20.25H13.5N8ZnO3.5 (490.2): calcd.
−1
obtained (red powder). –IR (ATR, cm ): ν(CN)ꢀ=ꢀ2212m. C 49.61, H 2.78, N 22.85; found C 49.45, H 2.41, N 22.76.
–C18H12FeN10O4 (488.2): calcd. C 44.28, H 2.48, N 28.69; Recrystallization from MeOH gave single crystals of 7b
found C 44.49, H 2.64, N 28.15.
suitable for X-ray diffraction (see below).
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K. Sünkel et al.: Synthesis, molecular, and crystal structures of 3d transition metal cyanocyclopentadienidesꢂ ꢂ9
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ꢀꢀꢀꢁ
10ꢁ
ꢁK. Sünkel et al.: Synthesis, molecular, and crystal structures of 3d transition metal cyanocyclopentadienides
[2] S. Benmansour, C. Atmani, F. Setifi, S. Triki, M. Marchivie,
7c′: From 34 mg ZnCl2 a yield of 90 mg (85%) was
C. J. Gómez-García, Coord. Chem. Rev. 2010, 254, 1468.
[3] S. R. Batten, K. S. Murray. Coord. Chem. Rev. 2003, 246, 103.
[4] S. R. Batten, B. F. Hoskins, B. Moubaraki, K. S. Murray,
R. Robson, J. Chem. Soc. Dalton Trans. 1999, 2977.
[5] O. Reckeweg, A. Schulz, F. J. DiSalvo, Z. Naturforsch. 2015, 70b,
177.
obtained (yellow powder). –C18.5H14N10ZnO4.5(513.7): calcd.
C 43.25, H 2.75, N 27.25; found C 43.73, H 2.72, N 27.42.
3.3 Crystal structure determination
[6] C. Nitschke, M. Köckerling, Z. Anorg. Allg. Chem. 2009, 635,
503.
Most details of the crystallographic studies are collected
and shown in Table 6. All crystals except for 3a (Bruker D8
Quest) were measured using a Bruker D8 Venture instru-
ment (Bruker AXS, Karlsruhe, Germany). Cell determina-
tion and refinement, data processing, and absorption
correction were performed with the respective diffractom-
eter software. The program package Wingx was used for
structure solution and refinement as well as for structure
evaluation, production of the CIFs, and crystallographic
tables [21–25]. Nearly all structures were solved using
Shelxt; the structures of 3a (Sir97) and 6b (Sir2014) were
solved by different programs. All structures were refined
with Shelxl (version2014/7). The crystals of 2c turned out
to be twinned and were, therefore, refined with the HKLF5
dataset (BASFꢀ=ꢀ0.458; twin matrix: –1.001 –0.001 –0.005;
0.012 –1.000 0.008; 0.361 –0.002 1.001).
[7] C. Nitschke, M. Köckerling, Inorg. Chem. 2011, 50, 4313.
[8] S. Triki, J. S. Pala, M. Decoster, P. Molinié, L. Toupet, Angew.
Chem. Int. Ed. 1999, 38, 113.
[9] A. M. Kutasi, D. R. Turner, P. Jensen, B. Moubaraki, S. R. Batten,
K. S. Murray, Inorg. Chem. 2011, 50, 6673.
[10] J. A. Schlueter, U. Geiser, J. L. Manson, Acta Crystallogr. 2003,
C59, m1.
[11] E. Lefebvre, F. Conan, N. Cosquer, J.-M. Kerbaol, M. Marchivie,
J. Sala-Pala, M. M. Kubicki, E. Vigier, C. J. Gómez-García, New J.
Chem. 2006, 30, 1197.
[12] Q. Li, Y. Wang, P. Yan, G. Hou, G. Li, Inorg. Chim. Acta 2014, 413,
32.
[13] S. I. Gurskiy, V. A. Tafeenko, CrystEngComm 2012, 14, 2721.
[14] J. C. Bullinger, D. M. Eichhorn, Inorg. Chim. Acta 2009, 362,
4510.
[15] O. W. Webster, United States Patent 3,835,943, 1974.
[16] O. W. Webster, J. Am. Chem. Soc. 1966, 88, 4055.
[17] R. E. Christopher, L. M. Venanzi, Inorg. Chim. Acta 1973, 7, 489.
[18] R. J. Less, T. C. Wilson, M. McPartlin, P. T. Wood, D. S. Wright,
Chem. Commun. 2011, 47, 10007.
[19] K. Sünkel, D. Reimann, Z. Naturforsch. 2013, 68b, 546.
[20] P. R. Nimax, K. Sünkel, ChemistrySelect 2018, 3, 3330.
[21] L. J. Farrugia, J. Appl. Crystallogr. 1999, 32, 837.
[22] C. F. Macrae, P. R. Edgington, P. McCabe, E. Pidcock,
G. P. Shields, R. Taylor, M. Towler, J. van derStreek,
J. Appl. Crystallogr. 2006, 39, 453.
The Cambridge Crystallographic Data Center (CCDC)
1862594–1862602 (see Table 6) contains the supplemen-
tary crystallographic data for this paper. These data can
be obtained free of charge from the CCDC via www.ccdc.
cam.ac.uk/data_request/cif.
[23] A. L. Spek, J. Appl. Crystallogr. 2003, 36, 7.
[24] G. M. Sheldrick, ActaCrystallogr. 2008, A64, 112.
[25] A. Altomare, M. C. Burla, M. Camalli, G. L. Cascarano,
C. Giacovazzo, A. Guagliardi, A. G. G. Moliterni, G. Polidori,
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References
[1] D. R. Turner, A. S. R. Chesman, K. S. Murray, G. B. Deacon, S. R.
Batten, Chem. Commun. 2011, 47, 10189.
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Z. Naturforsch.ꢂ
ꢂ2018 | Volume x | Issue x(b)
Graphical synopsis
Karlheinz Sünkel, Dietmar Reimann and
Patrick Nimax
Synthesis, molecular, and crystal
structures of 3d transition metal
cyanocyclopentadienides [M(MeOH)n
(H2O)4–n{C5(CN)4X}2] (Mꢀ=ꢀMn, Fe, Co, Ni,
Cu, Zn; Xꢀ=ꢀH, CN, NH2, NO2)
https://doi.org/10.1515/znb-2018-0175
Z. Naturforsch. 2018; x(x)b: xxx–xxx
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